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Re: Troubleshooting Softrock lite RX

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  • norman.billingham
    Thanks Tony. It all checks out visually so I ll take out the capacitors tomorrow and see what happens. I ll probably order up a new U5 just in case. Our local
    Message 1 of 20 , Dec 1, 2008
    • 0 Attachment
      Thanks Tony.

      It all checks out visually so I'll take out the capacitors tomorrow
      and see what happens.

      I'll probably order up a new U5 just in case. Our local stockist
      lists 3 versions of the LTC6241, with numbers LTC6241CS8,
      LTC6241HVCS8 and LTC6241HVIS8. The first two seem to be identical
      except for a wider temperature range for the second - both are
      described as type "low noise". The third is decribed as
      type "CMOS". Does it matter which I get?

      Norman






      --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@...> wrote:
      >
      > Hi Norman,
      >
      > With DC gain of each op-amp about right, it seems that R9 has a
      larger resistance than 10 ohms, or C14 has more capacitance than 220
      pF, or there is an AC load on the pin 1 output of U5. (Also still
      the possibility there is a problem with U5.) I would suggest
      removing C16 first to see if the AC voltage at pin 1 of U5 increases
      with the RF test signal input you are using. Next, remove C14.
      >
      > 73,
      > Tony KB9YIG
      >
      > ----- Original Message -----
      > From: norman.billingham
      > To: softrock40@yahoogroups.com
      > Sent: Monday, December 01, 2008 1:27 PM
      > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
      >
      >
      >
      >
      > Hi Tony
      >
      > There is a fine strong signal on pin 7 and on the output side of
      the
      > capacitor. There is no signal at all on pin 1 or on the output
      lead.
      >
      > All measured wrt ground at the screen connection for I and Q
      lines.
      >
      > Only load is the scope probe - at the moment I just have bits of
      wire
      > soldered into the I and Q outputs to provide test points before I
      > mount the board properly in a box and put in the audio cable.
      >
      > Thanks for all the help
      >
      > 73 Norman
      >
      > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@> wrote:
      > >
      > > Hi Norman,
      > >
      > > The DC gain of each of op-amp is about right.
      > >
      > > When you checked for the AC I and Q outputs was it at pins 1
      and 7
      > of the dual op-amp each with reference to circuit ground or at
      the
      > tip and ring connections beyond SMT caps C16 and C17? Also, what
      > load did you have on the I and Q output lines?
      > >
      > > 73,
      > > Tony KB9YIG
      > > ----- Original Message -----
      > > From: norman.billingham
      > > To: softrock40@yahoogroups.com
      > > Sent: Monday, December 01, 2008 11:44 AM
      > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
      > >
      > >
      > >
      > > Hi Tony
      > >
      > > pin 1 goes from 2.49 to 3.73V with 10K at pin 2
      > >
      > > pin 7 goes from 2.49 to 3.89 with 10K at pin 6
      > >
      > > Norman
      > >
      > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@> wrote:
      > > >
      > > > Hi Norman,
      > > >
      > > > Please repeat the DC gain test for the dual op-amp. A 10k
      > resistor
      > > to ground at pin 2 or pin 6 should result in a voltage change
      of
      > 1.25
      > > volts at pin 1 or pin 7 respectively.
      > > >
      > > > 73,
      > > > Tony KB9YIG
      > > > ----- Original Message -----
      > > > From: norman.billingham
      > > > To: softrock40@yahoogroups.com
      > > > Sent: Monday, December 01, 2008 10:20 AM
      > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
      > > >
      > > >
      > > > Hi Tony
      > > >
      > > > Thanks for coming back so fast
      > > >
      > > > This is a 6.0 board so I assume you mean C12 and C13, the two
      > > 0.047
      > > > uF decouplers? With my scope AC coupled and on its best
      > > sensitvity,
      > > > and 50mV of RF on the input all I can see there (or at pins 7
      > and
      > > 9
      > > > of U4) is about 20 mV of local oscillator frequency. Likewise
      > at
      > > > pins 2 and 6 of U5.
      > > >
      > > > Pin 1 of U5 is producing nothing and pin 7 has a nice strong
      Q
      > > signal
      > > > at just the right audio frequency.
      > > >
      > > > 73
      > > >
      > > > Norman
      > > >
      > > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@>
      wrote:
      > > > >
      > > > > Hi Norman,
      > > > >
      > > > > How do the signals look on C11 and C13 with reference to
      > > circuit
      > > > ground when you have an RF input to the antenna terminals?
      > > > >
      > > > > 73,
      > > > > Tony KB9YIG
      > > > > ----- Original Message -----
      > > > > From: norman.billingham
      > > > > To: softrock40@yahoogroups.com
      > > > > Sent: Monday, December 01, 2008 7:32 AM
      > > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
      > > > >
      > > > >
      > > > > Dear Tony
      > > > >
      > > > > OK I'm really lost now.
      > > > >
      > > > > Carefully checked all component values and soldering of T1
      > > leads -
      > > >
      > > > > all seems OK. Checked all leads and for solder bridges with
      > > high
      > > > > magnification and all seems OK.
      > > > >
      > > > > With no power and no signal there is continuity between the
      > two
      > > > ends
      > > > > of T1. There is 20 ohms between pins 11 and 12 of U4 and
      also
      > > > > between pins 3 and 6.
      > > > >
      > > > > There is 774 ohms between CT of T1 and pin 8 of U5, and
      > > > essentially
      > > > > zero ohms between CT of T1 and pins 3 and 5 of U5.
      > > > >
      > > > > With no power and 1V p/p at 7.1MHz on the antenna there are
      > > > > symmetrical 450mV signals 180 out of phase at 11/2 and at
      3/6
      > > on
      > > > U4 -
      > > > > all suggests T1 is OK.
      > > > >
      > > > > With power on the board and no signal, there is 5.4V p/p at
      > > 7.15
      > > > MHZ
      > > > > on the two test points on the board - square wave and 90
      > phase
      > > > > shifted and these signals are also on pins 2 and 14 of U4.
      > > > >
      > > > > With power on and around 50 mV ont he antenna at 7.15 Mhz
      > there
      > > > is
      > > > > about 1V of AF on the Q line and essentially nothing on the
      I
      > > > line.
      > > > >
      > > > > When I measured the voltahes around U%, all were OK but
      > > > the "normal"
      > > > > values (both 2.47V) both went to 4.93 when a 2.6K resistor
      > was
      > > > used
      > > > > to bridge the inputs - Robbie's program predicts 3.41V.
      > > > >
      > > > > Is it possible that one channel of U5 just isn't working?
      or
      > is
      > > > > there some other possible fault?
      > > > >
      > > > > Any ides gratefully received
      > > > >
      > > > > TIA
      > > > >
      > > > > Norman
      > > > >
      > > > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@>
      > wrote:
      > > > > >
      > > > > > Hi Norman,
      > > > > >
      > > > > > Please check the soldering around T1 and make sure the
      > > resistor
      > > > > values are according to the schematic.
      > > > > >
      > > > > > 73,
      > > > > > Tony KB9YIG
      > > > > > ----- Original Message -----
      > > > > > From: norman.billingham
      > > > > > To: softrock40@yahoogroups.com
      > > > > > Sent: Sunday, November 30, 2008 12:53 PM
      > > > > > Subject: [softrock40] Troubleshooting Softrock lite RX
      > > > > >
      > > > > >
      > > > > > Dear all
      > > > > >
      > > > > > Hopefully someone can offer words of help to a non-expert.
      > > > > >
      > > > > > I just finished my second softrock, using a V6.0 kit I've
      > had
      > > > for
      > > > > a
      > > > > > while.
      > > > > >
      > > > > > When I inject about 50mV of signal into the antenna at
      > about
      > > > > 16kHz
      > > > > > off centre, I get a beautiful sine wave at both I and Q
      and
      > > 90o
      > > > > phase
      > > > > > shift but the p/p voltage on Q is about 3.5 V and on I is
      > > only
      > > > > around
      > > > > > 50mV.
      > > > > >
      > > > > > I followed the detailed instructions and tests on
      WB5RVZ's
      > > > great
      > > > > > pages and all checked out OK except for:
      > > > > >
      > > > > > The op-amps. All voltages were OK but the "normal" values
      > > (both
      > > > > > 2.47V) both went to 4.93 when a 2.6K resistor was used to
      > > > bridge
      > > > > the
      > > > > > inputs - Robbie's program predicts 3.41V
      > > > > >
      > > > > > I measure 500mV at pins 1 and 15 on the mixer where
      > Robbie's
      > > > > values
      > > > > > are 45 mV - looking at the circuit, these pins are both
      on
      > an
      > > > > 1/11K
      > > > > > potential divider from the 5V rail and 500mV is the
      > > calculated
      > > > > value.
      > > > > >
      > > > > > I've checked all the component values and soldering
      around
      > > the
      > > > op
      > > > > > amps and can't find a problem.
      > > > > >
      > > > > > Anyone any good ideas please?
      > > > > >
      > > > > > Thanks in advance
      > > > > >
      > > > > > Norman (M0EBI)
      > > > > >
      > > > >
      > > >
      > >
      >
    • Tony Parks
      Hi Norman, The TLC6241CS8 should do the job if the op-amp is needing to be replaced. 73, Tony KB9YIG ... From: norman.billingham To: softrock40@yahoogroups.com
      Message 2 of 20 , Dec 1, 2008
      • 0 Attachment
        Hi Norman,
         
        The TLC6241CS8 should do the job if the op-amp is needing to be replaced.
         
        73,
        Tony KB9YIG
        ----- Original Message -----
        Sent: Monday, December 01, 2008 3:05 PM
        Subject: [softrock40] Re: Troubleshooting Softrock lite RX

        Thanks Tony.

        It all checks out visually so I'll take out the capacitors tomorrow
        and see what happens.

        I'll probably order up a new U5 just in case. Our local stockist
        lists 3 versions of the LTC6241, with numbers LTC6241CS8,
        LTC6241HVCS8 and LTC6241HVIS8. The first two seem to be identical
        except for a wider temperature range for the second - both are
        described as type "low noise". The third is decribed as
        type "CMOS". Does it matter which I get?

        Norman

        --- In softrock40@yahoogro ups.com, "Tony Parks" <kb9yig@...> wrote:
        >
        > Hi Norman,
        >
        > With DC gain of each op-amp about right, it seems that R9 has a
        larger resistance than 10 ohms, or C14 has more capacitance than 220
        pF, or there is an AC load on the pin 1 output of U5. (Also still
        the possibility there is a problem with U5.) I would suggest
        removing C16 first to see if the AC voltage at pin 1 of U5 increases
        with the RF test signal input you are using. Next, remove C14.
        >
        > 73,
        > Tony KB9YIG
        >
        > ----- Original Message -----
        > From: norman.billingham
        > To: softrock40@yahoogro ups.com
        > Sent: Monday, December 01, 2008 1:27 PM
        > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
        >
        >
        >
        >
        > Hi Tony
        >
        > There is a fine strong signal on pin 7 and on the output side of
        the
        > capacitor. There is no signal at all on pin 1 or on the output
        lead.
        >
        > All measured wrt ground at the screen connection for I and Q
        lines.
        >
        > Only load is the scope probe - at the moment I just have bits of
        wire
        > soldered into the I and Q outputs to provide test points before I
        > mount the board properly in a box and put in the audio cable.
        >
        > Thanks for all the help
        >
        > 73 Norman
        >
        > --- In softrock40@yahoogro ups.com, "Tony Parks" <kb9yig@> wrote:
        > >
        > > Hi Norman,
        > >
        > > The DC gain of each of op-amp is about right.
        > >
        > > When you checked for the AC I and Q outputs was it at pins 1
        and 7
        > of the dual op-amp each with reference to circuit ground or at
        the
        > tip and ring connections beyond SMT caps C16 and C17? Also, what
        > load did you have on the I and Q output lines?
        > >
        > > 73,
        > > Tony KB9YIG
        > > ----- Original Message -----
        > > From: norman.billingham
        > > To: softrock40@yahoogro ups.com
        > > Sent: Monday, December 01, 2008 11:44 AM
        > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
        > >
        > >
        > >
        > > Hi Tony
        > >
        > > pin 1 goes from 2.49 to 3.73V with 10K at pin 2
        > >
        > > pin 7 goes from 2.49 to 3.89 with 10K at pin 6
        > >
        > > Norman
        > >
        > > --- In softrock40@yahoogro ups.com, "Tony Parks" <kb9yig@> wrote:
        > > >
        > > > Hi Norman,
        > > >
        > > > Please repeat the DC gain test for the dual op-amp. A 10k
        > resistor
        > > to ground at pin 2 or pin 6 should result in a voltage change
        of
        > 1.25
        > > volts at pin 1 or pin 7 respectively.
        > > >
        > > > 73,
        > > > Tony KB9YIG
        > > > ----- Original Message -----
        > > > From: norman.billingham
        > > > To: softrock40@yahoogro ups.com
        > > > Sent: Monday, December 01, 2008 10:20 AM
        > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
        > > >
        > > >
        > > > Hi Tony
        > > >
        > > > Thanks for coming back so fast
        > > >
        > > > This is a 6.0 board so I assume you mean C12 and C13, the two
        > > 0.047
        > > > uF decouplers? With my scope AC coupled and on its best
        > > sensitvity,
        > > > and 50mV of RF on the input all I can see there (or at pins 7
        > and
        > > 9
        > > > of U4) is about 20 mV of local oscillator frequency. Likewise
        > at
        > > > pins 2 and 6 of U5.
        > > >
        > > > Pin 1 of U5 is producing nothing and pin 7 has a nice strong
        Q
        > > signal
        > > > at just the right audio frequency.
        > > >
        > > > 73
        > > >
        > > > Norman
        > > >
        > > > --- In softrock40@yahoogro ups.com, "Tony Parks" <kb9yig@>
        wrote:
        > > > >
        > > > > Hi Norman,
        > > > >
        > > > > How do the signals look on C11 and C13 with reference to
        > > circuit
        > > > ground when you have an RF input to the antenna terminals?
        > > > >
        > > > > 73,
        > > > > Tony KB9YIG
        > > > > ----- Original Message -----
        > > > > From: norman.billingham
        > > > > To: softrock40@yahoogro ups.com
        > > > > Sent: Monday, December 01, 2008 7:32 AM
        > > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
        > > > >
        > > > >
        > > > > Dear Tony
        > > > >
        > > > > OK I'm really lost now.
        > > > >
        > > > > Carefully checked all component values and soldering of T1
        > > leads -
        > > >
        > > > > all seems OK. Checked all leads and for solder bridges with
        > > high
        > > > > magnification and all seems OK.
        > > > >
        > > > > With no power and no signal there is continuity between the
        > two
        > > > ends
        > > > > of T1. There is 20 ohms between pins 11 and 12 of U4 and
        also
        > > > > between pins 3 and 6.
        > > > >
        > > > > There is 774 ohms between CT of T1 and pin 8 of U5, and
        > > > essentially
        > > > > zero ohms between CT of T1 and pins 3 and 5 of U5.
        > > > >
        > > > > With no power and 1V p/p at 7.1MHz on the antenna there are
        > > > > symmetrical 450mV signals 180 out of phase at 11/2 and at
        3/6
        > > on
        > > > U4 -
        > > > > all suggests T1 is OK.
        > > > >
        > > > > With power on the board and no signal, there is 5.4V p/p at
        > > 7.15
        > > > MHZ
        > > > > on the two test points on the board - square wave and 90
        > phase
        > > > > shifted and these signals are also on pins 2 and 14 of U4.
        > > > >
        > > > > With power on and around 50 mV ont he antenna at 7.15 Mhz
        > there
        > > > is
        > > > > about 1V of AF on the Q line and essentially nothing on the
        I
        > > > line.
        > > > >
        > > > > When I measured the voltahes around U%, all were OK but
        > > > the "normal"
        > > > > values (both 2.47V) both went to 4.93 when a 2.6K resistor
        > was
        > > > used
        > > > > to bridge the inputs - Robbie's program predicts 3.41V.
        > > > >
        > > > > Is it possible that one channel of U5 just isn't working?
        or
        > is
        > > > > there some other possible fault?
        > > > >
        > > > > Any ides gratefully received
        > > > >
        > > > > TIA
        > > > >
        > > > > Norman
        > > > >
        > > > > --- In softrock40@yahoogro ups.com, "Tony Parks" <kb9yig@>
        > wrote:
        > > > > >
        > > > > > Hi Norman,
        > > > > >
        > > > > > Please check the soldering around T1 and make sure the
        > > resistor
        > > > > values are according to the schematic.
        > > > > >
        > > > > > 73,
        > > > > > Tony KB9YIG
        > > > > > ----- Original Message -----
        > > > > > From: norman.billingham
        > > > > > To: softrock40@yahoogro ups.com
        > > > > > Sent: Sunday, November 30, 2008 12:53 PM
        > > > > > Subject: [softrock40] Troubleshooting Softrock lite RX
        > > > > >
        > > > > >
        > > > > > Dear all
        > > > > >
        > > > > > Hopefully someone can offer words of help to a non-expert.
        > > > > >
        > > > > > I just finished my second softrock, using a V6.0 kit I've
        > had
        > > > for
        > > > > a
        > > > > > while.
        > > > > >
        > > > > > When I inject about 50mV of signal into the antenna at
        > about
        > > > > 16kHz
        > > > > > off centre, I get a beautiful sine wave at both I and Q
        and
        > > 90o
        > > > > phase
        > > > > > shift but the p/p voltage on Q is about 3.5 V and on I is
        > > only
        > > > > around
        > > > > > 50mV.
        > > > > >
        > > > > > I followed the detailed instructions and tests on
        WB5RVZ's
        > > > great
        > > > > > pages and all checked out OK except for:
        > > > > >
        > > > > > The op-amps. All voltages were OK but the "normal" values
        > > (both
        > > > > > 2.47V) both went to 4.93 when a 2.6K resistor was used to
        > > > bridge
        > > > > the
        > > > > > inputs - Robbie's program predicts 3.41V
        > > > > >
        > > > > > I measure 500mV at pins 1 and 15 on the mixer where
        > Robbie's
        > > > > values
        > > > > > are 45 mV - looking at the circuit, these pins are both
        on
        > an
        > > > > 1/11K
        > > > > > potential divider from the 5V rail and 500mV is the
        > > calculated
        > > > > value.
        > > > > >
        > > > > > I've checked all the component values and soldering
        around
        > > the
        > > > op
        > > > > > amps and can't find a problem.
        > > > > >
        > > > > > Anyone any good ideas please?
        > > > > >
        > > > > > Thanks in advance
        > > > > >
        > > > > > Norman (M0EBI)
        > > > > >
        > > > >
        > > >
        > >
        >

      • Jose Bonanca
        Norman please check out what chip you need if it is the audio chip should be LTC 6231 and not 6241. LTC6231 is dual and 6241 is one only audio amp. 73 On Mon,
        Message 3 of 20 , Dec 1, 2008
        • 0 Attachment
          Norman please check out what chip you need if it is the audio chip should be LTC 6231 and not 6241.
          LTC6231 is dual and 6241 is one only audio amp.
          73

          On Mon, Dec 1, 2008 at 8:05 PM, norman.billingham <norman.billingham@...> wrote:

          Thanks Tony.

          It all checks out visually so I'll take out the capacitors tomorrow
          and see what happens.

          I'll probably order up a new U5 just in case. Our local stockist
          lists 3 versions of the LTC6241, with numbers LTC6241CS8,
          LTC6241HVCS8 and LTC6241HVIS8. The first two seem to be identical
          except for a wider temperature range for the second - both are
          described as type "low noise". The third is decribed as
          type "CMOS". Does it matter which I get?

          Norman

          --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@...> wrote:
          >
          > Hi Norman,
          >
          > With DC gain of each op-amp about right, it seems that R9 has a
          larger resistance than 10 ohms, or C14 has more capacitance than 220
          pF, or there is an AC load on the pin 1 output of U5. (Also still
          the possibility there is a problem with U5.) I would suggest
          removing C16 first to see if the AC voltage at pin 1 of U5 increases
          with the RF test signal input you are using. Next, remove C14.
          >
          > 73,
          > Tony KB9YIG
          >
          > ----- Original Message -----
          > From: norman.billingham
          > To: softrock40@yahoogroups.com
          > Sent: Monday, December 01, 2008 1:27 PM
          > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
          >
          >
          >
          >
          > Hi Tony
          >
          > There is a fine strong signal on pin 7 and on the output side of
          the
          > capacitor. There is no signal at all on pin 1 or on the output
          lead.
          >
          > All measured wrt ground at the screen connection for I and Q
          lines.
          >
          > Only load is the scope probe - at the moment I just have bits of
          wire
          > soldered into the I and Q outputs to provide test points before I
          > mount the board properly in a box and put in the audio cable.
          >
          > Thanks for all the help
          >
          > 73 Norman
          >
          > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@> wrote:
          > >
          > > Hi Norman,
          > >
          > > The DC gain of each of op-amp is about right.
          > >
          > > When you checked for the AC I and Q outputs was it at pins 1
          and 7
          > of the dual op-amp each with reference to circuit ground or at
          the
          > tip and ring connections beyond SMT caps C16 and C17? Also, what
          > load did you have on the I and Q output lines?
          > >
          > > 73,
          > > Tony KB9YIG
          > > ----- Original Message -----
          > > From: norman.billingham
          > > To: softrock40@yahoogroups.com
          > > Sent: Monday, December 01, 2008 11:44 AM
          > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
          > >
          > >
          > >
          > > Hi Tony
          > >
          > > pin 1 goes from 2.49 to 3.73V with 10K at pin 2
          > >
          > > pin 7 goes from 2.49 to 3.89 with 10K at pin 6
          > >
          > > Norman
          > >
          > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@> wrote:
          > > >
          > > > Hi Norman,
          > > >
          > > > Please repeat the DC gain test for the dual op-amp. A 10k
          > resistor
          > > to ground at pin 2 or pin 6 should result in a voltage change
          of
          > 1.25
          > > volts at pin 1 or pin 7 respectively.
          > > >
          > > > 73,
          > > > Tony KB9YIG
          > > > ----- Original Message -----
          > > > From: norman.billingham
          > > > To: softrock40@yahoogroups.com
          > > > Sent: Monday, December 01, 2008 10:20 AM
          > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
          > > >
          > > >
          > > > Hi Tony
          > > >
          > > > Thanks for coming back so fast
          > > >
          > > > This is a 6.0 board so I assume you mean C12 and C13, the two
          > > 0.047
          > > > uF decouplers? With my scope AC coupled and on its best
          > > sensitvity,
          > > > and 50mV of RF on the input all I can see there (or at pins 7
          > and
          > > 9
          > > > of U4) is about 20 mV of local oscillator frequency. Likewise
          > at
          > > > pins 2 and 6 of U5.
          > > >
          > > > Pin 1 of U5 is producing nothing and pin 7 has a nice strong
          Q
          > > signal
          > > > at just the right audio frequency.
          > > >
          > > > 73
          > > >
          > > > Norman
          > > >
          > > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@>
          wrote:
          > > > >
          > > > > Hi Norman,
          > > > >
          > > > > How do the signals look on C11 and C13 with reference to
          > > circuit
          > > > ground when you have an RF input to the antenna terminals?
          > > > >
          > > > > 73,
          > > > > Tony KB9YIG
          > > > > ----- Original Message -----
          > > > > From: norman.billingham
          > > > > To: softrock40@yahoogroups.com
          > > > > Sent: Monday, December 01, 2008 7:32 AM
          > > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
          > > > >
          > > > >
          > > > > Dear Tony
          > > > >
          > > > > OK I'm really lost now.
          > > > >
          > > > > Carefully checked all component values and soldering of T1
          > > leads -
          > > >
          > > > > all seems OK. Checked all leads and for solder bridges with
          > > high
          > > > > magnification and all seems OK.
          > > > >
          > > > > With no power and no signal there is continuity between the
          > two
          > > > ends
          > > > > of T1. There is 20 ohms between pins 11 and 12 of U4 and
          also
          > > > > between pins 3 and 6.
          > > > >
          > > > > There is 774 ohms between CT of T1 and pin 8 of U5, and
          > > > essentially
          > > > > zero ohms between CT of T1 and pins 3 and 5 of U5.
          > > > >
          > > > > With no power and 1V p/p at 7.1MHz on the antenna there are
          > > > > symmetrical 450mV signals 180 out of phase at 11/2 and at
          3/6
          > > on
          > > > U4 -
          > > > > all suggests T1 is OK.
          > > > >
          > > > > With power on the board and no signal, there is 5.4V p/p at
          > > 7.15
          > > > MHZ
          > > > > on the two test points on the board - square wave and 90
          > phase
          > > > > shifted and these signals are also on pins 2 and 14 of U4.
          > > > >
          > > > > With power on and around 50 mV ont he antenna at 7.15 Mhz
          > there
          > > > is
          > > > > about 1V of AF on the Q line and essentially nothing on the
          I
          > > > line.
          > > > >
          > > > > When I measured the voltahes around U%, all were OK but
          > > > the "normal"
          > > > > values (both 2.47V) both went to 4.93 when a 2.6K resistor
          > was
          > > > used
          > > > > to bridge the inputs - Robbie's program predicts 3.41V.
          > > > >
          > > > > Is it possible that one channel of U5 just isn't working?
          or
          > is
          > > > > there some other possible fault?
          > > > >
          > > > > Any ides gratefully received
          > > > >
          > > > > TIA
          > > > >
          > > > > Norman
          > > > >
          > > > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@>
          > wrote:
          > > > > >
          > > > > > Hi Norman,
          > > > > >
          > > > > > Please check the soldering around T1 and make sure the
          > > resistor
          > > > > values are according to the schematic.
          > > > > >
          > > > > > 73,
          > > > > > Tony KB9YIG
          > > > > > ----- Original Message -----
          > > > > > From: norman.billingham
          > > > > > To: softrock40@yahoogroups.com
          > > > > > Sent: Sunday, November 30, 2008 12:53 PM
          > > > > > Subject: [softrock40] Troubleshooting Softrock lite RX
          > > > > >
          > > > > >
          > > > > > Dear all
          > > > > >
          > > > > > Hopefully someone can offer words of help to a non-expert.
          > > > > >
          > > > > > I just finished my second softrock, using a V6.0 kit I've
          > had
          > > > for
          > > > > a
          > > > > > while.
          > > > > >
          > > > > > When I inject about 50mV of signal into the antenna at
          > about
          > > > > 16kHz
          > > > > > off centre, I get a beautiful sine wave at both I and Q
          and
          > > 90o
          > > > > phase
          > > > > > shift but the p/p voltage on Q is about 3.5 V and on I is
          > > only
          > > > > around
          > > > > > 50mV.
          > > > > >
          > > > > > I followed the detailed instructions and tests on
          WB5RVZ's
          > > > great
          > > > > > pages and all checked out OK except for:
          > > > > >
          > > > > > The op-amps. All voltages were OK but the "normal" values
          > > (both
          > > > > > 2.47V) both went to 4.93 when a 2.6K resistor was used to
          > > > bridge
          > > > > the
          > > > > > inputs - Robbie's program predicts 3.41V
          > > > > >
          > > > > > I measure 500mV at pins 1 and 15 on the mixer where
          > Robbie's
          > > > > values
          > > > > > are 45 mV - looking at the circuit, these pins are both
          on
          > an
          > > > > 1/11K
          > > > > > potential divider from the 5V rail and 500mV is the
          > > calculated
          > > > > value.
          > > > > >
          > > > > > I've checked all the component values and soldering
          around
          > > the
          > > > op
          > > > > > amps and can't find a problem.
          > > > > >
          > > > > > Anyone any good ideas please?
          > > > > >
          > > > > > Thanks in advance
          > > > > >
          > > > > > Norman (M0EBI)
          > > > > >
          > > > >
          > > >
          > >
          >




          --
          Jose Bonanca  (CT1aos)
        • Jose Bonanca
          Well Tony I have here some LT6241 and they are different from LT6231.. So , now are you sure? Regards. ... -- Jose Bonanca (CT1aos)
          Message 4 of 20 , Dec 1, 2008
          • 0 Attachment
            Well Tony I have here some LT6241 and they are different from LT6231..
            So , now are you sure?
            Regards.


             
            On Mon, Dec 1, 2008 at 8:34 PM, Tony Parks <kb9yig@...> wrote:

            Hi Norman,
             
            The TLC6241CS8 should do the job if the op-amp is needing to be replaced.
             
            73,
            Tony KB9YIG
            ----- Original Message -----
            Sent: Monday, December 01, 2008 3:05 PM
            Subject: [softrock40] Re: Troubleshooting Softrock lite RX

            Thanks Tony.

            It all checks out visually so I'll take out the capacitors tomorrow
            and see what happens.

            I'll probably order up a new U5 just in case. Our local stockist
            lists 3 versions of the LTC6241, with numbers LTC6241CS8,
            LTC6241HVCS8 and LTC6241HVIS8. The first two seem to be identical
            except for a wider temperature range for the second - both are
            described as type "low noise". The third is decribed as
            type "CMOS". Does it matter which I get?

            Norman

            --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@...> wrote:
            >
            > Hi Norman,
            >
            > With DC gain of each op-amp about right, it seems that R9 has a
            larger resistance than 10 ohms, or C14 has more capacitance than 220
            pF, or there is an AC load on the pin 1 output of U5. (Also still
            the possibility there is a problem with U5.) I would suggest
            removing C16 first to see if the AC voltage at pin 1 of U5 increases
            with the RF test signal input you are using. Next, remove C14.
            >
            > 73,
            > Tony KB9YIG
            >
            > ----- Original Message -----
            > From: norman.billingham
            > To: softrock40@yahoogroups.com
            > Sent: Monday, December 01, 2008 1:27 PM
            > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
            >
            >
            >
            >
            > Hi Tony
            >
            > There is a fine strong signal on pin 7 and on the output side of
            the
            > capacitor. There is no signal at all on pin 1 or on the output
            lead.
            >
            > All measured wrt ground at the screen connection for I and Q
            lines.
            >
            > Only load is the scope probe - at the moment I just have bits of
            wire
            > soldered into the I and Q outputs to provide test points before I
            > mount the board properly in a box and put in the audio cable.
            >
            > Thanks for all the help
            >
            > 73 Norman
            >
            > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@> wrote:
            > >
            > > Hi Norman,
            > >
            > > The DC gain of each of op-amp is about right.
            > >
            > > When you checked for the AC I and Q outputs was it at pins 1
            and 7
            > of the dual op-amp each with reference to circuit ground or at
            the
            > tip and ring connections beyond SMT caps C16 and C17? Also, what
            > load did you have on the I and Q output lines?
            > >
            > > 73,
            > > Tony KB9YIG
            > > ----- Original Message -----
            > > From: norman.billingham
            > > To: softrock40@yahoogroups.com
            > > Sent: Monday, December 01, 2008 11:44 AM
            > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
            > >
            > >
            > >
            > > Hi Tony
            > >
            > > pin 1 goes from 2.49 to 3.73V with 10K at pin 2
            > >
            > > pin 7 goes from 2.49 to 3.89 with 10K at pin 6
            > >
            > > Norman
            > >
            > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@> wrote:
            > > >
            > > > Hi Norman,
            > > >
            > > > Please repeat the DC gain test for the dual op-amp. A 10k
            > resistor
            > > to ground at pin 2 or pin 6 should result in a voltage change
            of
            > 1.25
            > > volts at pin 1 or pin 7 respectively.
            > > >
            > > > 73,
            > > > Tony KB9YIG
            > > > ----- Original Message -----
            > > > From: norman.billingham
            > > > To: softrock40@yahoogroups.com
            > > > Sent: Monday, December 01, 2008 10:20 AM
            > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
            > > >
            > > >
            > > > Hi Tony
            > > >
            > > > Thanks for coming back so fast
            > > >
            > > > This is a 6.0 board so I assume you mean C12 and C13, the two
            > > 0.047
            > > > uF decouplers? With my scope AC coupled and on its best
            > > sensitvity,
            > > > and 50mV of RF on the input all I can see there (or at pins 7
            > and
            > > 9
            > > > of U4) is about 20 mV of local oscillator frequency. Likewise
            > at
            > > > pins 2 and 6 of U5.
            > > >
            > > > Pin 1 of U5 is producing nothing and pin 7 has a nice strong
            Q
            > > signal
            > > > at just the right audio frequency.
            > > >
            > > > 73
            > > >
            > > > Norman
            > > >
            > > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@>
            wrote:
            > > > >
            > > > > Hi Norman,
            > > > >
            > > > > How do the signals look on C11 and C13 with reference to
            > > circuit
            > > > ground when you have an RF input to the antenna terminals?
            > > > >
            > > > > 73,
            > > > > Tony KB9YIG
            > > > > ----- Original Message -----
            > > > > From: norman.billingham
            > > > > To: softrock40@yahoogroups.com
            > > > > Sent: Monday, December 01, 2008 7:32 AM
            > > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
            > > > >
            > > > >
            > > > > Dear Tony
            > > > >
            > > > > OK I'm really lost now.
            > > > >
            > > > > Carefully checked all component values and soldering of T1
            > > leads -
            > > >
            > > > > all seems OK. Checked all leads and for solder bridges with
            > > high
            > > > > magnification and all seems OK.
            > > > >
            > > > > With no power and no signal there is continuity between the
            > two
            > > > ends
            > > > > of T1. There is 20 ohms between pins 11 and 12 of U4 and
            also
            > > > > between pins 3 and 6.
            > > > >
            > > > > There is 774 ohms between CT of T1 and pin 8 of U5, and
            > > > essentially
            > > > > zero ohms between CT of T1 and pins 3 and 5 of U5.
            > > > >
            > > > > With no power and 1V p/p at 7.1MHz on the antenna there are
            > > > > symmetrical 450mV signals 180 out of phase at 11/2 and at
            3/6
            > > on
            > > > U4 -
            > > > > all suggests T1 is OK.
            > > > >
            > > > > With power on the board and no signal, there is 5.4V p/p at
            > > 7.15
            > > > MHZ
            > > > > on the two test points on the board - square wave and 90
            > phase
            > > > > shifted and these signals are also on pins 2 and 14 of U4.
            > > > >
            > > > > With power on and around 50 mV ont he antenna at 7.15 Mhz
            > there
            > > > is
            > > > > about 1V of AF on the Q line and essentially nothing on the
            I
            > > > line.
            > > > >
            > > > > When I measured the voltahes around U%, all were OK but
            > > > the "normal"
            > > > > values (both 2.47V) both went to 4.93 when a 2.6K resistor
            > was
            > > > used
            > > > > to bridge the inputs - Robbie's program predicts 3.41V.
            > > > >
            > > > > Is it possible that one channel of U5 just isn't working?
            or
            > is
            > > > > there some other possible fault?
            > > > >
            > > > > Any ides gratefully received
            > > > >
            > > > > TIA
            > > > >
            > > > > Norman
            > > > >
            > > > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@>
            > wrote:
            > > > > >
            > > > > > Hi Norman,
            > > > > >
            > > > > > Please check the soldering around T1 and make sure the
            > > resistor
            > > > > values are according to the schematic.
            > > > > >
            > > > > > 73,
            > > > > > Tony KB9YIG
            > > > > > ----- Original Message -----
            > > > > > From: norman.billingham
            > > > > > To: softrock40@yahoogroups.com
            > > > > > Sent: Sunday, November 30, 2008 12:53 PM
            > > > > > Subject: [softrock40] Troubleshooting Softrock lite RX
            > > > > >
            > > > > >
            > > > > > Dear all
            > > > > >
            > > > > > Hopefully someone can offer words of help to a non-expert.
            > > > > >
            > > > > > I just finished my second softrock, using a V6.0 kit I've
            > had
            > > > for
            > > > > a
            > > > > > while.
            > > > > >
            > > > > > When I inject about 50mV of signal into the antenna at
            > about
            > > > > 16kHz
            > > > > > off centre, I get a beautiful sine wave at both I and Q
            and
            > > 90o
            > > > > phase
            > > > > > shift but the p/p voltage on Q is about 3.5 V and on I is
            > > only
            > > > > around
            > > > > > 50mV.
            > > > > >
            > > > > > I followed the detailed instructions and tests on
            WB5RVZ's
            > > > great
            > > > > > pages and all checked out OK except for:
            > > > > >
            > > > > > The op-amps. All voltages were OK but the "normal" values
            > > (both
            > > > > > 2.47V) both went to 4.93 when a 2.6K resistor was used to
            > > > bridge
            > > > > the
            > > > > > inputs - Robbie's program predicts 3.41V
            > > > > >
            > > > > > I measure 500mV at pins 1 and 15 on the mixer where
            > Robbie's
            > > > > values
            > > > > > are 45 mV - looking at the circuit, these pins are both
            on
            > an
            > > > > 1/11K
            > > > > > potential divider from the 5V rail and 500mV is the
            > > calculated
            > > > > value.
            > > > > >
            > > > > > I've checked all the component values and soldering
            around
            > > the
            > > > op
            > > > > > amps and can't find a problem.
            > > > > >
            > > > > > Anyone any good ideas please?
            > > > > >
            > > > > > Thanks in advance
            > > > > >
            > > > > > Norman (M0EBI)
            > > > > >
            > > > >
            > > >
            > >
            >




            --
            Jose Bonanca  (CT1aos)
          • Jose Bonanca
            OK Sorry Tony I have seen the 6241sc8 and it really should do the job. I am sorry for the mistake. 73 ... -- Jose Bonanca (CT1aos)
            Message 5 of 20 , Dec 1, 2008
            • 0 Attachment
              OK
              Sorry Tony I have seen the 6241sc8 and it really should do the job.
               
              I am sorry for the mistake.
               
              73


               
              On Mon, Dec 1, 2008 at 8:34 PM, Tony Parks <kb9yig@...> wrote:

              Hi Norman,
               
              The TLC6241CS8 should do the job if the op-amp is needing to be replaced.
               
              73,
              Tony KB9YIG
              ----- Original Message -----
              Sent: Monday, December 01, 2008 3:05 PM
              Subject: [softrock40] Re: Troubleshooting Softrock lite RX

              Thanks Tony.

              It all checks out visually so I'll take out the capacitors tomorrow
              and see what happens.

              I'll probably order up a new U5 just in case. Our local stockist
              lists 3 versions of the LTC6241, with numbers LTC6241CS8,
              LTC6241HVCS8 and LTC6241HVIS8. The first two seem to be identical
              except for a wider temperature range for the second - both are
              described as type "low noise". The third is decribed as
              type "CMOS". Does it matter which I get?

              Norman

              --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@...> wrote:
              >
              > Hi Norman,
              >
              > With DC gain of each op-amp about right, it seems that R9 has a
              larger resistance than 10 ohms, or C14 has more capacitance than 220
              pF, or there is an AC load on the pin 1 output of U5. (Also still
              the possibility there is a problem with U5.) I would suggest
              removing C16 first to see if the AC voltage at pin 1 of U5 increases
              with the RF test signal input you are using. Next, remove C14.
              >
              > 73,
              > Tony KB9YIG
              >
              > ----- Original Message -----
              > From: norman.billingham
              > To: softrock40@yahoogroups.com
              > Sent: Monday, December 01, 2008 1:27 PM
              > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
              >
              >
              >
              >
              > Hi Tony
              >
              > There is a fine strong signal on pin 7 and on the output side of
              the
              > capacitor. There is no signal at all on pin 1 or on the output
              lead.
              >
              > All measured wrt ground at the screen connection for I and Q
              lines.
              >
              > Only load is the scope probe - at the moment I just have bits of
              wire
              > soldered into the I and Q outputs to provide test points before I
              > mount the board properly in a box and put in the audio cable.
              >
              > Thanks for all the help
              >
              > 73 Norman
              >
              > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@> wrote:
              > >
              > > Hi Norman,
              > >
              > > The DC gain of each of op-amp is about right.
              > >
              > > When you checked for the AC I and Q outputs was it at pins 1
              and 7
              > of the dual op-amp each with reference to circuit ground or at
              the
              > tip and ring connections beyond SMT caps C16 and C17? Also, what
              > load did you have on the I and Q output lines?
              > >
              > > 73,
              > > Tony KB9YIG
              > > ----- Original Message -----
              > > From: norman.billingham
              > > To: softrock40@yahoogroups.com
              > > Sent: Monday, December 01, 2008 11:44 AM
              > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
              > >
              > >
              > >
              > > Hi Tony
              > >
              > > pin 1 goes from 2.49 to 3.73V with 10K at pin 2
              > >
              > > pin 7 goes from 2.49 to 3.89 with 10K at pin 6
              > >
              > > Norman
              > >
              > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@> wrote:
              > > >
              > > > Hi Norman,
              > > >
              > > > Please repeat the DC gain test for the dual op-amp. A 10k
              > resistor
              > > to ground at pin 2 or pin 6 should result in a voltage change
              of
              > 1.25
              > > volts at pin 1 or pin 7 respectively.
              > > >
              > > > 73,
              > > > Tony KB9YIG
              > > > ----- Original Message -----
              > > > From: norman.billingham
              > > > To: softrock40@yahoogroups.com
              > > > Sent: Monday, December 01, 2008 10:20 AM
              > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
              > > >
              > > >
              > > > Hi Tony
              > > >
              > > > Thanks for coming back so fast
              > > >
              > > > This is a 6.0 board so I assume you mean C12 and C13, the two
              > > 0.047
              > > > uF decouplers? With my scope AC coupled and on its best
              > > sensitvity,
              > > > and 50mV of RF on the input all I can see there (or at pins 7
              > and
              > > 9
              > > > of U4) is about 20 mV of local oscillator frequency. Likewise
              > at
              > > > pins 2 and 6 of U5.
              > > >
              > > > Pin 1 of U5 is producing nothing and pin 7 has a nice strong
              Q
              > > signal
              > > > at just the right audio frequency.
              > > >
              > > > 73
              > > >
              > > > Norman
              > > >
              > > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@>
              wrote:
              > > > >
              > > > > Hi Norman,
              > > > >
              > > > > How do the signals look on C11 and C13 with reference to
              > > circuit
              > > > ground when you have an RF input to the antenna terminals?
              > > > >
              > > > > 73,
              > > > > Tony KB9YIG
              > > > > ----- Original Message -----
              > > > > From: norman.billingham
              > > > > To: softrock40@yahoogroups.com
              > > > > Sent: Monday, December 01, 2008 7:32 AM
              > > > > Subject: [softrock40] Re: Troubleshooting Softrock lite RX
              > > > >
              > > > >
              > > > > Dear Tony
              > > > >
              > > > > OK I'm really lost now.
              > > > >
              > > > > Carefully checked all component values and soldering of T1
              > > leads -
              > > >
              > > > > all seems OK. Checked all leads and for solder bridges with
              > > high
              > > > > magnification and all seems OK.
              > > > >
              > > > > With no power and no signal there is continuity between the
              > two
              > > > ends
              > > > > of T1. There is 20 ohms between pins 11 and 12 of U4 and
              also
              > > > > between pins 3 and 6.
              > > > >
              > > > > There is 774 ohms between CT of T1 and pin 8 of U5, and
              > > > essentially
              > > > > zero ohms between CT of T1 and pins 3 and 5 of U5.
              > > > >
              > > > > With no power and 1V p/p at 7.1MHz on the antenna there are
              > > > > symmetrical 450mV signals 180 out of phase at 11/2 and at
              3/6
              > > on
              > > > U4 -
              > > > > all suggests T1 is OK.
              > > > >
              > > > > With power on the board and no signal, there is 5.4V p/p at
              > > 7.15
              > > > MHZ
              > > > > on the two test points on the board - square wave and 90
              > phase
              > > > > shifted and these signals are also on pins 2 and 14 of U4.
              > > > >
              > > > > With power on and around 50 mV ont he antenna at 7.15 Mhz
              > there
              > > > is
              > > > > about 1V of AF on the Q line and essentially nothing on the
              I
              > > > line.
              > > > >
              > > > > When I measured the voltahes around U%, all were OK but
              > > > the "normal"
              > > > > values (both 2.47V) both went to 4.93 when a 2.6K resistor
              > was
              > > > used
              > > > > to bridge the inputs - Robbie's program predicts 3.41V.
              > > > >
              > > > > Is it possible that one channel of U5 just isn't working?
              or
              > is
              > > > > there some other possible fault?
              > > > >
              > > > > Any ides gratefully received
              > > > >
              > > > > TIA
              > > > >
              > > > > Norman
              > > > >
              > > > > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@>
              > wrote:
              > > > > >
              > > > > > Hi Norman,
              > > > > >
              > > > > > Please check the soldering around T1 and make sure the
              > > resistor
              > > > > values are according to the schematic.
              > > > > >
              > > > > > 73,
              > > > > > Tony KB9YIG
              > > > > > ----- Original Message -----
              > > > > > From: norman.billingham
              > > > > > To: softrock40@yahoogroups.com
              > > > > > Sent: Sunday, November 30, 2008 12:53 PM
              > > > > > Subject: [softrock40] Troubleshooting Softrock lite RX
              > > > > >
              > > > > >
              > > > > > Dear all
              > > > > >
              > > > > > Hopefully someone can offer words of help to a non-expert.
              > > > > >
              > > > > > I just finished my second softrock, using a V6.0 kit I've
              > had
              > > > for
              > > > > a
              > > > > > while.
              > > > > >
              > > > > > When I inject about 50mV of signal into the antenna at
              > about
              > > > > 16kHz
              > > > > > off centre, I get a beautiful sine wave at both I and Q
              and
              > > 90o
              > > > > phase
              > > > > > shift but the p/p voltage on Q is about 3.5 V and on I is
              > > only
              > > > > around
              > > > > > 50mV.
              > > > > >
              > > > > > I followed the detailed instructions and tests on
              WB5RVZ's
              > > > great
              > > > > > pages and all checked out OK except for:
              > > > > >
              > > > > > The op-amps. All voltages were OK but the "normal" values
              > > (both
              > > > > > 2.47V) both went to 4.93 when a 2.6K resistor was used to
              > > > bridge
              > > > > the
              > > > > > inputs - Robbie's program predicts 3.41V
              > > > > >
              > > > > > I measure 500mV at pins 1 and 15 on the mixer where
              > Robbie's
              > > > > values
              > > > > > are 45 mV - looking at the circuit, these pins are both
              on
              > an
              > > > > 1/11K
              > > > > > potential divider from the 5V rail and 500mV is the
              > > calculated
              > > > > value.
              > > > > >
              > > > > > I've checked all the component values and soldering
              around
              > > the
              > > > op
              > > > > > amps and can't find a problem.
              > > > > >
              > > > > > Anyone any good ideas please?
              > > > > >
              > > > > > Thanks in advance
              > > > > >
              > > > > > Norman (M0EBI)
              > > > > >
              > > > >
              > > >
              > >
              >




              --
              Jose Bonanca  (CT1aos)
            • norman.billingham
              Hi Tony Checka all capacitor and rseitance values this afternoon and all seemed OK. Despite having inspected everything under 10X magnifcation and found no
              Message 6 of 20 , Dec 3, 2008
              • 0 Attachment
                Hi Tony

                Checka all capacitor and rseitance values this afternoon and all
                seemed OK. Despite having inspected everything under 10X
                magnifcation and found no problems, I decided before yanking
                components to flux everything around the mixer and op amps and touch
                up every joint with a hot iron and it came to life - must have been a
                joint that was OK for DC but not AC as all voltages were OK.

                It's sitting on the bench putting out about 1.6V of I and Q from
                about 40mV RF in.

                Anyway - thanks again for all the help.

                Any news on when I'm likely to get the Si570 for my V9 kit? Ordered
                on October 8

                73 Norman


                --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@...> wrote:
                >
                > Hi Norman,
                >
                > With DC gain of each op-amp about right, it seems that R9 has a
                larger resistance than 10 ohms, or C14 has more capacitance than 220
                pF, or there is an AC load on the pin 1 output of U5. (Also still
                the possibility there is a problem with U5.) I would suggest
                removing C16 first to see if the AC voltage at pin 1 of U5 increases
                with the RF test signal input you are using. Next, remove C14.
                >
                > 73,
                > Tony KB9YIG
                >
                >
              • Tony Parks
                Hi Norman, I have 100 pices of the CMOS Si570 due in later this week or early next week. Your October 8 order would put you in the group to receive one of the
                Message 7 of 20 , Dec 3, 2008
                • 0 Attachment
                  Hi Norman,
                   
                  I have 100 pices of the CMOS Si570 due in later this week or early next week.  Your October 8 order would put you in the group to receive one of the Si570 devices to be mailed next Monday or Tuesday.
                   
                  Glad to hear the I and Q signals now look right with the AC gain about right from antenna input to audio output.
                   
                  73,
                  Tony KB9YIG
                  ----- Original Message -----
                  Sent: Wednesday, December 03, 2008 1:20 PM
                  Subject: [softrock40] Re: Troubleshooting Softrock lite RX - FIXED!!

                  Hi Tony

                  Checka all capacitor and rseitance values this afternoon and all
                  seemed OK. Despite having inspected everything under 10X
                  magnifcation and found no problems, I decided before yanking
                  components to flux everything around the mixer and op amps and touch
                  up every joint with a hot iron and it came to life - must have been a
                  joint that was OK for DC but not AC as all voltages were OK.

                  It's sitting on the bench putting out about 1.6V of I and Q from
                  about 40mV RF in.

                  Anyway - thanks again for all the help.

                  Any news on when I'm likely to get the Si570 for my V9 kit? Ordered
                  on October 8

                  73 Norman

                  --- In softrock40@yahoogro ups.com, "Tony Parks" <kb9yig@...> wrote:
                  >
                  > Hi Norman,
                  >
                  > With DC gain of each op-amp about right, it seems that R9 has a
                  larger resistance than 10 ohms, or C14 has more capacitance than 220
                  pF, or there is an AC load on the pin 1 output of U5. (Also still
                  the possibility there is a problem with U5.) I would suggest
                  removing C16 first to see if the AC voltage at pin 1 of U5 increases
                  with the RF test signal input you are using. Next, remove C14.
                  >
                  > 73,
                  > Tony KB9YIG
                  >
                  >

                • norman.billingham
                  Hi Tony Thanks - that s Christmas sorted then! All best Norman ... next week. Your October 8 order would put you in the group to receive one of the Si570
                  Message 8 of 20 , Dec 3, 2008
                  • 0 Attachment
                    Hi Tony

                    Thanks - that's Christmas sorted then!

                    All best

                    Norman

                    --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@...> wrote:
                    >
                    > Hi Norman,
                    >
                    > I have 100 pices of the CMOS Si570 due in later this week or early
                    next week. Your October 8 order would put you in the group to
                    receive one of the Si570 devices to be mailed next Monday or Tuesday.
                    >
                    > Glad to hear the I and Q signals now look right with the AC gain
                    about right from antenna input to audio output.
                    >
                    > 73,
                    > Tony KB9YIG
                    > ----- Original Message -----
                    > From: norman.billingham
                    > To: softrock40@yahoogroups.com
                    > Sent: Wednesday, December 03, 2008 1:20 PM
                    > Subject: [softrock40] Re: Troubleshooting Softrock lite RX -
                    FIXED!!
                    >
                    >
                    > Hi Tony
                    >
                    > Checka all capacitor and rseitance values this afternoon and all
                    > seemed OK. Despite having inspected everything under 10X
                    > magnifcation and found no problems, I decided before yanking
                    > components to flux everything around the mixer and op amps and
                    touch
                    > up every joint with a hot iron and it came to life - must have
                    been a
                    > joint that was OK for DC but not AC as all voltages were OK.
                    >
                    > It's sitting on the bench putting out about 1.6V of I and Q from
                    > about 40mV RF in.
                    >
                    > Anyway - thanks again for all the help.
                    >
                    > Any news on when I'm likely to get the Si570 for my V9 kit?
                    Ordered
                    > on October 8
                    >
                    > 73 Norman
                    >
                    > --- In softrock40@yahoogroups.com, "Tony Parks" <kb9yig@> wrote:
                    > >
                    > > Hi Norman,
                    > >
                    > > With DC gain of each op-amp about right, it seems that R9 has a
                    > larger resistance than 10 ohms, or C14 has more capacitance than
                    220
                    > pF, or there is an AC load on the pin 1 output of U5. (Also still
                    > the possibility there is a problem with U5.) I would suggest
                    > removing C16 first to see if the AC voltage at pin 1 of U5
                    increases
                    > with the RF test signal input you are using. Next, remove C14.
                    > >
                    > > 73,
                    > > Tony KB9YIG
                    > >
                    > >
                    >
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