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#8581 From: "tom_iphi" <iphi@...>
Date: Wed Jan 31, 2007 8:27 am
Subject: Re: TX/RX 6.1
tom_iphi
Send Email Send Email
 
Hi Keith and all,

I have posted high resolution pictores of my SoftRockV6.1RxTx on my
webpage:
http://www.mydarc.de/dg8saq/SoftRockV61RxTx/index.shtml

These should be helpful to place the parts on the bottom.

73, Tom DG8SAQ

--- In softrock40@yahoogroups.com, "Tony Parks" <raparks@...> wrote:
>
> Hi Keith,
>
> I will work on getting a bottom of the circuit map put together
soon. However, the ICs locations on the bottom of the circuit board
have a little "1" mark in the copper to show their pin 1 corner.
Each IC in the kit will be the right IC for a given location if the
pin count is right for that location.  Pin one of an SOIC size IC is
in the lower left corner when the print on the top of the IC reads
upright and  from left to right.  The SMT caps that are on the bottom
of the board are all the same, a 0.1uF size 1206 part.  The board map
for the top of the board indicates where capacitors are omitted on
the bottom of the board.
>
> Hope this helps and I hope your build of the kit goes well.
>
> 73,
> Tony KB9YIG
>
>
>   ----- Original Message -----
>   From: gu6efb
>   To: softrock40@yahoogroups.com
>   Sent: Tuesday, January 30, 2007 3:36 PM
>   Subject: [softrock40] TX/RX 6.1
>
>
>
>
>
>
>
>   Hi Tony and the group
>
>
>
>   I am having great fun building the softrock TX/RX and have a
question
>
>
>
>
>
>   Is their a component layout for the bottom of the board for the
surface mount parts?
>
>   as some of the capacitors are left out depending on the bands to
be used
>
>   I also need to know the origination of the surface mount I/C's
>
>
>
>   I have looked in the file section and did not see any info but I
may have missed it
>
>
>
>   73 Keith GU6EFB
>
>
>
>   This message was checked by MailScan for WorkgroupMail.
>

#8582 From: "Tony Parks" <raparks@...>
Date: Wed Jan 31, 2007 9:06 am
Subject: Re: Re: TX/RX 6.1
kb9yig
Send Email Send Email
 
Hi Tom,
 
I need to mention to people that your pictures are of the pre-production RXTXv6.1 and are a little different than the production version of the circuit board.  Also I note that you have mounted the brass heat sink arrangement with the nut below the board.  My intent was that the brass screw head should be on the bottom of the board.  The head of the brass screw needs to be filed down so that its height is less than 1/8 inch so that the board mounting hardware supplied in the kit will hold the board above a flat surface without the screw head making contact.  Another thing is that you still have the source bypass capacitors mounted on the board which should be omitted in the production kit build.
 
Thanks and 73,
Tony KB9YIG
 
 
----- Original Message -----
From: tom_iphi
Sent: Wednesday, January 31, 2007 3:27 AM
Subject: [softrock40] Re: TX/RX 6.1

Hi Keith and all,

I have posted high resolution pictores of my SoftRockV6.1RxTx on my
webpage:
http://www.mydarc.de/dg8saq/SoftRockV61RxTx/index.shtml

These should be helpful to place the parts on the bottom.

73, Tom DG8SAQ

--- In softrock40@yahoogroups.com, "Tony Parks" <raparks@...> wrote:
>
> Hi Keith,
>
> I will work on getting a bottom of the circuit map put together
soon. However, the ICs locations on the bottom of the circuit board
have a little "1" mark in the copper to show their pin 1 corner.
Each IC in the kit will be the right IC for a given location if the
pin count is right for that location. Pin one of an SOIC size IC is
in the lower left corner when the print on the top of the IC reads
upright and from left to right. The SMT caps that are on the bottom
of the board are all the same, a 0.1uF size 1206 part. The board map
for the top of the board indicates where capacitors are omitted on
the bottom of the board.
>
> Hope this helps and I hope your build of the kit goes well.
>
> 73,
> Tony KB9YIG
>
>
> ----- Original Message -----
> From: gu6efb
> To: softrock40@yahoogroups.com
> Sent: Tuesday, January 30, 2007 3:36 PM
> Subject: [softrock40] TX/RX 6.1
>
>
>
>
>
>
>
> Hi Tony and the group
>
>
>
> I am having great fun building the softrock TX/RX and have a
question
>
>
>
>
>
> Is their a component layout for the bottom of the board for the
surface mount parts?
>
> as some of the capacitors are left out depending on the bands to
be used
>
> I also need to know the origination of the surface mount I/C's
>
>
>
> I have looked in the file section and did not see any info but I
may have missed it
>
>
>
> 73 Keith GU6EFB
>
>
>
> This message was checked by MailScan for WorkgroupMail.
>


#8583 From: N Munro <norman@...>
Date: Wed Jan 31, 2007 9:22 am
Subject: Re: Re: MiniBoots Amp
gm4kgk
Send Email Send Email
 
jabauzit wrote:
>
>
> The bias adjustment is common - may be 2 would be better.
> One things I do not understand regarding the biasing: the bias voltage
> is adjusted with a variable resistor but there is also a 3.3V zener
> between the gates and ground. How does it work?
>
> Jean-Claude PJ2BVU
>

I think the zener is there to limit the input drive level (i.e to
prevent it exceeding 3.3.v). Apparently the IRF510 is susceptible to
damage if over-driven, but then I suppose that applies to most solid
state devices.
73

Norman - GM4KGK

#8584 From: "tom_iphi" <iphi@...>
Date: Wed Jan 31, 2007 10:34 am
Subject: Re: Feedback components on RXTX PA Daughter Board (again)
tom_iphi
Send Email Send Email
 
Salut Jean-Claude,

in theory, yes. There should be enough gain reserve. You might have
to reduce the QSE output resistors from 100Ohms to 50Ohms, though,
and increase the audio gain auf the input OpAmps.

But I have not tested this!

73, Tom DG8SAQ

--- In softrock40@yahoogroups.com, "jabauzit" <jabauzit@...> wrote:
>
> --- In softrock40@yahoogroups.com, "tom_iphi" <iphi@> wrote:
> >
> > Hi Dave,
> >
> > what you state below is exactly correct.
> > You can improve your carrier suppression by removing these parts.
> >
> > 73, Tom DG8SAQ
>
> Is this also true for the Beta RXTX with the 2N3866?
>
> Jean-Claude PJ2BVU
>

#8586 From: "ut1wpr" <vgol@...>
Date: Wed Jan 31, 2007 1:25 pm
Subject: Shared MIC/LINE inputs at Audigy SE ? How to use with SoftRock ?
ut1wpr
Send Email Send Email
 
My soundcard Audigy SE has a shared (selected by soundcard control
program) MIC / LINE input. Seems this card useless for SoftRock RxTx v6.1.
Am I wrong?
73!
Vic

#8587 From: "kb9yig" <raparks@...>
Date: Wed Jan 31, 2007 3:01 pm
Subject: RXTX setup drawings with external USB soundcard
kb9yig
Send Email Send Email
 
Good Morning All,

Hidehiko, JA9MAT, has sent some good drawings showing how he has
connected his RXTX beta unit to his laptop computer where an external
USB soundcard is used as well as the internal soundcard.  He running
with the KGKSDR software and one of the drawings shows the program and
ASIO4ALL setups.  The two files may be downloaded by following the
path:

Files > SoftRock v6.0 docs > v6 RXTX transceiver info > RXTXv6.1

Hidehiko has been very active with actual on the air experience with
his stack and RXTX beta version of the transceiver so his setup
information should be quite useful.

Thanks Hidehiko.

73,
Tony KB9YIG

#8588 From: "Phil Covington" <p.covington@...>
Date: Wed Jan 31, 2007 4:10 pm
Subject: IDT Femtoclocks
phil_at_vhmi
Send Email Send Email
 
Anyone looked at these?

<http://www.idt.com/?id=3409>

Jitter specs under 0.3 - 0.8 pS.  Might be a good clock generator for
a higher frequency SoftRock ( > 15 MHz )...

Phil N8VB

#8589 From: "DOUG PHILLIPS" <w7rdp@...>
Date: Wed Jan 31, 2007 5:01 pm
Subject: Re:MiniBoots Amp
w7rdp
Send Email Send Email
 
Guys the amp is class C as original designed, but Wayne, NB6M modified it to
class AB or A (not sure which) for SSB and Digital mode operation.  The
details are in the AMQRP HOMEBREWER magazine available on CD from AMQRP.

73, Doug W7RDP

#8590 From: "jabauzit" <jabauzit@...>
Date: Wed Jan 31, 2007 5:08 pm
Subject: Re: MiniBoots Amp
jabauzit
Send Email Send Email
 
--- In softrock40@yahoogroups.com, N Munro <norman@...> wrote:
>
> jabauzit wrote:
> >
> >
> > The bias adjustment is common - may be 2 would be better.
> > One things I do not understand regarding the biasing: the bias voltage
> > is adjusted with a variable resistor but there is also a 3.3V zener
> > between the gates and ground. How does it work?
> >
> > Jean-Claude PJ2BVU
> >
>
> I think the zener is there to limit the input drive level (i.e to
> prevent it exceeding 3.3.v). Apparently the IRF510 is susceptible to
> damage if over-driven, but then I suppose that applies to most solid
> state devices.

Hi Norman,

Yes the Zener is here to protect the IRF510 and is soldered directly
to the gate to also provide thermal protection.
What I don't understand is that in order to adjust the bias you have
to vary the voltage applied to the gate and in this case it would not
be able to go above 3.3v, the problem is that there is a lot of
variation between IRF-510: "the exact gate voltage that cause drain
current to start to conduct varies from about 3.5 to 4.2v".
That is why this zener value is a mystery for me. The bias current is
also a mystery, depending on various sources the bias for linear
operation varies between 10mA and 150mA.
Any help would be greatly appreciated.

Jean-Claude PJ2BVU

#8591 From: "jabauzit" <jabauzit@...>
Date: Wed Jan 31, 2007 5:15 pm
Subject: Re: Feedback components on RXTX PA Daughter Board (again)
jabauzit
Send Email Send Email
 
--- In softrock40@yahoogroups.com, "tom_iphi" <iphi@...> wrote:
>
> Salut Jean-Claude,
>
> in theory, yes. There should be enough gain reserve. You might have
> to reduce the QSE output resistors from 100Ohms to 50Ohms, though,
> and increase the audio gain auf the input OpAmps.
>
> But I have not tested this!
>
Danke schön herr Tom,

I will put this in my notes and may be implement it later.

Jean-Claude PJ2BVU

#8592 From: "jabauzit" <jabauzit@...>
Date: Wed Jan 31, 2007 5:16 pm
Subject: Re: Shared MIC/LINE inputs at Audigy SE ? How to use with SoftRock ?
jabauzit
Send Email Send Email
 
--- In softrock40@yahoogroups.com, "ut1wpr" <vgol@...> wrote:
>
> My soundcard Audigy SE has a shared (selected by soundcard control
> program) MIC / LINE input. Seems this card useless for SoftRock RxTx
v6.1.
> Am I wrong?
> 73!
> Vic
>

PowerSDR supports that and Duncan is looking into it for KGKSDR.

Jean-Claude PJ2BVU

#8593 From: "jeanphanson" <hansongr@...>
Date: Wed Jan 31, 2007 6:02 pm
Subject: Linear Amp by KD1JV
jeanphanson
Send Email Send Email
 
I thought some you might be interested in the linear amp designed by
KD1JV, in case it hasn't been mentioned in previous posts.  Sorry, I
don't keep up with the threads on a daily basis so I apologize if this
is a redundant posting.

For those who want a little more punch than typical qrp levels, Steve
designed a pair of push-pull IRF510's that generate 25 watts  on 75
meters using a 12 volt power source.  I assume it is a class AB as it
was designed for SSB, but I'm not enough of an engineer to tell by
looking at the schematic.  Better minds than mine can explain. :-)

You can see the schematic as this website:
http://kd1jv.qrpradio.com/ssbrig2/SSB2.HTM

With a little bad weather this weekend, I should be able to finish the
exciter board and then start on the amp.  I'll add a post if/when I
get the amp working.

Cheers,

Gary, KJ5VW

#8594 From: "ut1wpr" <vgol@...>
Date: Wed Jan 31, 2007 8:07 pm
Subject: Re: Shared MIC/LINE inputs at Audigy SE ? How to use with SoftRock ?
ut1wpr
Send Email Send Email
 
--- In softrock40@yahoogroups.com, "jabauzit" <jabauzit@...> wrote:

> PowerSDR supports that and Duncan is looking into it for KGKSDR.
>
Didn't understood.. In which way this card switching his MIC/LINE-IN
mixer? Does it make by PowerSDR or KGKSDR soft? Not sure...
Please explaine it with more details..

Anyway thank you,

73!
Vic/ut1wpr

#8595 From: "jabauzit" <jabauzit@...>
Date: Wed Jan 31, 2007 8:19 pm
Subject: Re: Shared MIC/LINE inputs at Audigy SE ? How to use with SoftRock ?
jabauzit
Send Email Send Email
 
--- In softrock40@yahoogroups.com, "ut1wpr" <vgol@...> wrote:
>
> --- In softrock40@yahoogroups.com, "jabauzit" <jabauzit@> wrote:
>
> > PowerSDR supports that and Duncan is looking into it for KGKSDR.
> >
> Didn't understood.. In which way this card switching his MIC/LINE-IN
> mixer? Does it make by PowerSDR or KGKSDR soft? Not sure...
> Please explaine it with more details..
>
PowerSDR switches the recording source from line in to microphone when
switching from RX to TX. And vice versa. I did not test it personally,
this is the information I was given by people using it.

The current version of KGKSDR does not do it and you must use 2 sound
cards. This is the software I am using for now. Duncan, KGKSDR
developer, is looking into the problem to have the software work with
the same sound card.

Jean-Claude PJ2BVU

#8596 From: "kb9yig" <raparks@...>
Date: Wed Jan 31, 2007 8:42 pm
Subject: RXTXv6.1 builder"s notes January 31 update
kb9yig
Send Email Send Email
 
Good Afternoon All,

The RXTXv6.1 builder's notes have been updated to include not mounting
Q2 until T2 and other components near Q2 have first been mounted.  Q2
will need to be raised above the circuit board for its heat sink to
clear nearby components such as T2.

73,
Tony KB9YIG

#8597 From: Art <KY1K@...>
Date: Wed Jan 31, 2007 11:30 pm
Subject: old generation DDS + PLL?
KY1K@...
Send Email Send Email
 
Greetings,

Many who have the DDS-60 don't use them much, and even fewer than
that feed them into a transmitter due to the multitude of close in
spurs. Even those that use them for receivers note that the spur
content is high enough so that the MDS is impacted on receive. I have
never built my DDS-60 in fact, it's still in the sealed bag!

We can clean up the spur ridden old technology DDS units such as the
DDS-60 by using it to feed a PLL (as the reference frequency) and
using the output of the PLL to feed into our radios. While PLL's are
known for having phase noise, it can be minimized if the PLL doesn't
have to lock on a new frequency quickly-because we can use a lower
loop gain. The point being that we can make a PLL that is more
suitable for this purpose by careful design rather than using a
general purpose design.

Many of us want higher frequencies to run quadrature based detectors
as well, so the PLL becomes a spectrally clean means to double or
quadruple or multiply the output frequency by a very large margin.

It seems the DDS-60 and similar DDS units can be operated in
conjunction with PLL technology to make them useful again rather than
shunned as a little too dirty for prime time use::>

There are thousands of DDS-60 units out there, and I wonder if a
companion PLL can be built to accommodate them and the many other DDS
units that have less than stellar performance?

Additionally, I can't see any practical reason to upgrade to newer
DDS units that use much more power due to higher clocking rates
(plus, they need multipliers on their clock inputs just to have the
clock operate at 500 MHz).  Does anyone else here see the
practicality of the old technology DDS + PLL combination, or is it just me??

Regards,

Art

#8598 From: "Terry" <wb4jfi@...>
Date: Thu Feb 1, 2007 12:05 am
Subject: Re: old generation DDS + PLL?
wb4jfi
Send Email Send Email
 
Art:

The PLL approach may be a good alternative, some have done it in the
past (such as a QEX article, I think).  It will also help if the
output freq needs to be very high.

I'm not sure I agree with the comment about the newer DDS chips,
however.  The middle-generation (98532, 9854, etc) may draw a lot of
power.  But the AD9951, 9952, 9954 all draw less power than the
9851.  The 9851 can draw over 600mW at 5V, which is required for
180MHz.  The 9952 draws only 170mW, granted at 1.8V

Plus, the AD9951-4 use 14-bit DACs, unlike the 10-bit DAC of the 9851
in the DDS-60.  They create far fewer spurs.

The DDS-60 uses an AD9851, which has a PLL, just like the newer DDS
chips.  In fact, the DDS-60 comes with only a 30MHz oscillator, I
believe, which requires a x6 multiplier to reach 180MHz.  The AD9951
family can use a multiplier of only 4x, if a higher input oscillator
frequency is used, I think that may lead to lower jitter given the
same DDS output frequency.

Phil's comment earlier today about femtoclocks may be what is needed
to reduce jitter from the DDS.  Plus, these chips seem to create a
higher clock freq (approx 125-250MHz on one).  It will not fix spurs,
but the better, 14-bit DACs go a long way to fix that.  I have been
pretty impressed with the new AD9951 series DDS devices.  I can't
wait to see when Analog Devices comes up with 16-bit DAC DDS units.

Adding a PLL may be counter-productive, since unless the loop
filtering is very carefully designed, more short and long-
term "jitter" may result.  Nevertheless, it should be interesting to
experiment with, especially with all the 9850 and 9851 DDS chips out
there.  I agree 100% with you that if you plan to use a 9850 or 9851
DDS, the PLL idea could be cleaner if properly designed.
Terry


--- In softrock40@yahoogroups.com, Art <KY1K@...> wrote:
>
> Greetings,
>
> Many who have the DDS-60 don't use them much, and even fewer than
> that feed them into a transmitter due to the multitude of close in
> spurs. Even those that use them for receivers note that the spur
> content is high enough so that the MDS is impacted on receive. I
have
> never built my DDS-60 in fact, it's still in the sealed bag!
>
> We can clean up the spur ridden old technology DDS units such as
the
> DDS-60 by using it to feed a PLL (as the reference frequency) and
> using the output of the PLL to feed into our radios. While PLL's
are
> known for having phase noise, it can be minimized if the PLL
doesn't
> have to lock on a new frequency quickly-because we can use a lower
> loop gain. The point being that we can make a PLL that is more
> suitable for this purpose by careful design rather than using a
> general purpose design.
>
> Many of us want higher frequencies to run quadrature based
detectors
> as well, so the PLL becomes a spectrally clean means to double or
> quadruple or multiply the output frequency by a very large margin.
>
> It seems the DDS-60 and similar DDS units can be operated in
> conjunction with PLL technology to make them useful again rather
than
> shunned as a little too dirty for prime time use::>
>
> There are thousands of DDS-60 units out there, and I wonder if a
> companion PLL can be built to accommodate them and the many other
DDS
> units that have less than stellar performance?
>
> Additionally, I can't see any practical reason to upgrade to newer
> DDS units that use much more power due to higher clocking rates
> (plus, they need multipliers on their clock inputs just to have the
> clock operate at 500 MHz).  Does anyone else here see the
> practicality of the old technology DDS + PLL combination, or is it
just me??
>
> Regards,
>
> Art
>

#8599 From: Dan Andersson <dan@...>
Date: Thu Feb 1, 2007 12:07 am
Subject: Re: old generation DDS + PLL?
dlea5098
Send Email Send Email
 
On Wednesday 31 January 2007 23:30:17 Art wrote:
> Greetings,
>
> Many who have the DDS-60 don't use them much, and even fewer than
> that feed them into a transmitter due to the multitude of close in
> spurs. Even those that use them for receivers note that the spur
> content is high enough so that the MDS is impacted on receive. I have
> never built my DDS-60 in fact, it's still in the sealed bag!
>
> We can clean up the spur ridden old technology DDS units such as the
> DDS-60 by using it to feed a PLL (as the reference frequency) and
> using the output of the PLL to feed into our radios. While PLL's are
> known for having phase noise, it can be minimized if the PLL doesn't
> have to lock on a new frequency quickly-because we can use a lower
> loop gain. The point being that we can make a PLL that is more
> suitable for this purpose by careful design rather than using a
> general purpose design.
>
> Many of us want higher frequencies to run quadrature based detectors
> as well, so the PLL becomes a spectrally clean means to double or
> quadruple or multiply the output frequency by a very large margin.
>
> It seems the DDS-60 and similar DDS units can be operated in
> conjunction with PLL technology to make them useful again rather than
> shunned as a little too dirty for prime time use::>
>
> There are thousands of DDS-60 units out there, and I wonder if a
> companion PLL can be built to accommodate them and the many other DDS
> units that have less than stellar performance?
>
> Additionally, I can't see any practical reason to upgrade to newer
> DDS units that use much more power due to higher clocking rates
> (plus, they need multipliers on their clock inputs just to have the
> clock operate at 500 MHz).  Does anyone else here see the
> practicality of the old technology DDS + PLL combination, or is it just
> me??
>
> Regards,
>
> Art


Art,

You are partly correct. There are no reason to dump the older generation DDS
designs a they can be re-vitalised as PLL references. This works OK as long
as you don't expect to sweep over the frequency range or change frequency to
often.

However, When using these DDS chips with PLL's with a high N rate, you benefit
from the 14 bit resolution but one of the more important reasons is the
increased frequency agility of the new breed of DDS chips.

I use the older AD9850 and the AD9851 in combination with the PLL chip
ADF4007. I'm using an extra external divider to be able to run the vco well
up in the microwave bands. And as you say, "slow" frequency changes are not a
problem.

OK - so your DDS don't reach 440MHz because it's an AD9850? Wrong! it does.

Look in the DDS information from Analog about aliased images.

If you intend to use your DDS as a reference to drive a spur insensitive
application like a PLL, you can use the DDS aliased images even if you might
add 6 or 12 dB (or so... ) gain after the DDS output. Also, the DDS output
filter needs changes as well. There area number of blind spots in the
frequency range but that can be controlled by using a suitable system clock
for the DDS. And if you intend to run low frequencies like 440MHz or so,
there are cheap PLLs available like the ADF4007 from Analog Devices.

So don't bin your old DDS-60 yet!

//Dan


--
Dan Andersson, M0DFI
dan@...

#8600 From: "Kees & Sandy" <windy10605@...>
Date: Thu Feb 1, 2007 12:18 am
Subject: Re: old generation DDS + PLL?
keestheham
Send Email Send Email
 

Using the AD9851 .....is there anything to be gained by better grounding schemes ? analog and digital ground isolation (seems like that was key according to AD), etc to improve (but not eliminate) the spur situation ? Just because the DDS-60 has a certain magnitude of certain spurs, doesn't mean all designs using the AD98xx do.

73 Kees K5BCQ

  

-- Dan Andersson <dan@...> wrote:
On Wednesday 31 January 2007 23:30:17 Art wrote:
> Greetings,
>
> Many who have the DDS-60 don't use them much, and even fewer than
> that feed them into a transmitter due to the multitude of close in
> spurs. Even those that use them for receivers note that the spur
> content is high enough so that the MDS is impacted on receive. I have
> never built my DDS-60 in fact, it's still in the sealed bag!
>
> We can clean up the spur ridden old technology DDS units such as the
> DDS-60 by using it to feed a PLL (as the reference frequency) and
> using the output of the PLL to feed into our radios. While PLL's are
> known for having phase noise, it can be minimized if the PLL doesn't
> have to lock on a new frequency quickly-because we can use a lower
> loop gain. The point being that we can make a PLL that is more
> suitable for this purpose by careful design rather than using a
> general purpose design.
>
> Many of us want higher frequencies to run quadrature based detectors
> as well, so the PLL becomes a spectrally clean means to double or
> quadruple or multiply the output frequency by a very large margin.
>
> It seems the DDS-60 and similar DDS units can be operated in
> conjunction with PLL technology to make them useful again rather than
> shunned as a little too dirty for prime time use::>
>
> There are thousands of DDS-60 units out there, and I wonder if a
> companion PLL can be built to accommodate them and the many other DDS
> units that have less than stellar performance?
>
> Additionally, I can't see any practical reason to upgrade to newer
> DDS units that use much more power due to higher clocking rates
> (plus, they need multipliers on their clock inputs just to have the
> clock operate at 500 MHz).  Does anyone else here see the
> practicality of the old technology DDS + PLL combination, or is it just
> me??
>
> Regards,
>
> Art


Art,

You are partly correct. There are no reason to dump the older generation DDS 
designs a they can be re-vitalised as PLL references. This works OK as long 
as you don't expect to sweep over the frequency range or change frequency to 
often. 

However, When using these DDS chips with PLL's with a high N rate, you benefit 
from the 14 bit resolution but one of the more important reasons is the 
increased frequency agility of the new breed of DDS chips.

I use the older AD9850 and the AD9851 in combination with the PLL chip 
ADF4007. I'm using an extra external divider to be able to run the vco well 
up in the microwave bands. And as you say, "slow" frequency changes are not a 
problem.

OK - so your DDS don't reach 440MHz because it's an AD9850? Wrong! it does.

Look in the DDS information from Analog about aliased images.

If you intend to use your DDS as a reference to drive a spur insensitive 
application like a PLL, you can use the DDS aliased images even if you might 
add 6 or 12 dB (or so... ) gain after the DDS output. Also, the DDS output 
filter needs changes as well. There area number of blind spots in the 
frequency range but that can be controlled by using a suitable system clock 
for the DDS. And if you intend to run low frequencies like 440MHz or so, 
there are cheap PLLs available like the ADF4007 from Analog Devices.   

So don't bin your old DDS-60 yet!

//Dan


-- 
Dan Andersson, M0DFI
dan@... 




 
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#8601 From: Graham Haddock <GrahamH@...>
Date: Thu Feb 1, 2007 12:47 am
Subject: Re: old generation DDS + PLL?
baron55434
Send Email Send Email
 
Art:

The DDS-60 was intended to be an educational tool, not
a universal high performance VFO.  I think it does that beautifully.
Learn about how to program, control and manage a DDS, with a simple
PIC controller.  It's performance is good enough to be a useful
signal generator, sweeper, drive an antenna analyzer, etc.

I think your time looking for a higher performance universal
VFO will lead you in the direction of the higher performance
DDS, like the 9951 series, rather than coming up with the
ultimate PLL.  Single band or limited bands, yes you can
come up with a PLL, but all band HF coverage will take
multiple PLLs.  If you start with a 9851, it might take more
than one stage of PLL filtering to get to world class receiver
LO performance.

The 9951 series has a lot more capability, but needs more
control lines to manage it.  I have one running from a 125 MHz
chip oscillator. No multiplier needed.  I don't perceive any
jitter or spur problems that will limit my attaching it to a
transmitter.  It is not quite as good as the Drake R8, so
still not in high performance receiver territory, but still
some 20+ dB better than the 9850/9851.

--- Graham

Art wrote:
>
> Greetings,
>
> Many who have the DDS-60 don't use them much, and even fewer than
> that feed them into a transmitter due to the multitude of close in
> spurs. Even those that use them for receivers note that the spur
> content is high enough so that the MDS is impacted on receive. I have
> never built my DDS-60 in fact, it's still in the sealed bag!
>
> We can clean up the spur ridden old technology DDS units such as the
> DDS-60 by using it to feed a PLL (as the reference frequency) and
> using the output of the PLL to feed into our radios. While PLL's are
> known for having phase noise, it can be minimized if the PLL doesn't
> have to lock on a new frequency quickly-because we can use a lower
> loop gain. The point being that we can make a PLL that is more
> suitable for this purpose by careful design rather than using a
> general purpose design.
>
> Many of us want higher frequencies to run quadrature based detectors
> as well, so the PLL becomes a spectrally clean means to double or
> quadruple or multiply the output frequency by a very large margin.
>
> It seems the DDS-60 and similar DDS units can be operated in
> conjunction with PLL technology to make them useful again rather than
> shunned as a little too dirty for prime time use::>
>
> There are thousands of DDS-60 units out there, and I wonder if a
> companion PLL can be built to accommodate them and the many other DDS
> units that have less than stellar performance?
>
> Additionally, I can't see any practical reason to upgrade to newer
> DDS units that use much more power due to higher clocking rates
> (plus, they need multipliers on their clock inputs just to have the
> clock operate at 500 MHz). Does anyone else here see the
> practicality of the old technology DDS + PLL combination, or is it
> just me??
>
> Regards,
>
> Art
>
>

#8602 From: Len Warner <novost@...>
Date: Thu Feb 1, 2007 2:06 am
Subject: Re: MiniBoots Amp
hejsek2005
Send Email Send Email
 
At 8:20 pm ((PST)) Tue Jan 30, 2007, Terry wrote:
>5e. Re: MiniBoots Amp
>     Posted by: "Terry" wb4jfi@... wb4jfi
>     Date: Tue Jan 30, 2007 8:20 pm ((PST))
>
>For the last several years, there has been a push-pull IRF510 amp
>design int he ARRL handbook as well.  The boards are available from
>Far Circuits.  Each 510 has its own bias pot.  I am in the process of
>building it right now.  Chapter 14 I think

ARRL HANDBOOK 2001
Chapter 17 - Receivers, Transmitters, Transceivers and Projects

http://info.awmn.net/users/images/stories/Library/RadioTheory/ARRL%20HANDBOOK%20\
2001/17.pdf

[17.136] A Broadband HF Amplifier Using Low-Cost Power MOSFETs


Regards, LenW

#8603 From: FRANCIS CARCIA <carcia@...>
Date: Thu Feb 1, 2007 2:38 am
Subject: Re: Re: MiniBoots Amp
wa1gfz
Send Email Send Email
 
I know of a guy who built a big 6 meter linear amplifier using IRF510s. I think it was 2 modules of 8 fets push pull parallel. I think it was running on 24 VDC.
I run IRF840s class e on 160 meters. Legal limit 14 in push pull parallel. The 840 has a lot more gate C so harder to drive.
the Fairchild FNQ11N90 makes a great RF FET and has been used in linear mode.
Only usable to 40 meters though. 2700 pf input C. fc

Len Warner <novost@...> wrote:
At 8:20 pm ((PST)) Tue Jan 30, 2007, Terry wrote:
>5e. Re: MiniBoots Amp
> Posted by: "Terry" wb4jfi@knology.net wb4jfi
> Date: Tue Jan 30, 2007 8:20 pm ((PST))
>
>For the last several years, there has been a push-pull IRF510 amp
>design int he ARRL handbook as well. The boards are available from
>Far Circuits. Each 510 has its own bias pot. I am in the process of
>building it right now. Chapter 14 I think

ARRL HANDBOOK 2001
Chapter 17 - Receivers, Transmitters, Transceivers and Projects

http://info.awmn.net/users/images/stories/Library/RadioTheory/ARRL%20HANDBOOK%202001/17.pdf

[17.136] A Broadband HF Amplifier Using Low-Cost Power MOSFETs

Regards, LenW



#8604 From: "jabauzit" <jabauzit@...>
Date: Thu Feb 1, 2007 2:53 am
Subject: Re: MiniBoots Amp
jabauzit
Send Email Send Email
 
--- In softrock40@yahoogroups.com, FRANCIS CARCIA <carcia@...> wrote:
>
> I know of a guy who built a big 6 meter linear amplifier using
> IRF510s. I think it was 2 modules of 8 fets push pull parallel.
> I think it was running on 24 VDC.

500W out, 40V PS. I have been looking into it but wondered how the
IRF-510 can be used on 6m.

http://home24.inet.tele.dk/oz1pif/50MHz_IRF510.htm


Does anyone has an idea on how to bias the IRF-510 for SSB?

What I found varies from 10mA to 150mA per FET, quite a range!

Jean-Claude PJ2BVU

#8605 From: FRANCIS CARCIA <carcia@...>
Date: Thu Feb 1, 2007 3:07 am
Subject: Re: Re: MiniBoots Amp
wa1gfz
Send Email Send Email
 
I would think a push pull stage would not need a lot of bias. The closer to class A the lower your third order crud. 150 ma at 40 volts would be 6 watts of heat. That would require a good sized heat sink with multiple devices. I think the typical 12 V pp 100 watt final runs around 100 ma. gfz  

jabauzit <jabauzit@...> wrote:
--- In softrock40@yahoogroups.com, FRANCIS CARCIA <carcia@...> wrote:
>
> I know of a guy who built a big 6 meter linear amplifier using
> IRF510s. I think it was 2 modules of 8 fets push pull parallel.
> I think it was running on 24 VDC.

500W out, 40V PS. I have been looking into it but wondered how the
IRF-510 can be used on 6m.

http://home24.inet.tele.dk/oz1pif/50MHz_IRF510.htm

Does anyone has an idea on how to bias the IRF-510 for SSB?

What I found varies from 10mA to 150mA per FET, quite a range!

Jean-Claude PJ2BVU



#8606 From: "Kees & Sandy" <windy10605@...>
Date: Thu Feb 1, 2007 3:40 am
Subject: T1 characteristics
keestheham
Send Email Send Email
 

Does someone have an idea at what signal levels a 40m SoftRock T1 (lets assume 1:1 windings) with 10 turns each on a T-25-2 core might go into saturation ? ....just a ballpark estimate is fine. Just curious. Also, as we solder these things, getting the cores too hot is probably not a good idea. 

73 Kees K5BCQ


#8607 From: "Leon Heller" <leon.heller@...>
Date: Thu Feb 1, 2007 4:38 am
Subject: Re: old generation DDS + PLL?
leon_heller
Send Email Send Email
 
----- Original Message -----
From: "Art" <KY1K@...>
To: <softrock40@yahoogroups.com>
Sent: Wednesday, January 31, 2007 11:30 PM
Subject: [softrock40] old generation DDS + PLL?


> Greetings,
>
> Many who have the DDS-60 don't use them much, and even fewer than
> that feed them into a transmitter due to the multitude of close in
> spurs. Even those that use them for receivers note that the spur
> content is high enough so that the MDS is impacted on receive. I have
> never built my DDS-60 in fact, it's still in the sealed bag!
>
> We can clean up the spur ridden old technology DDS units such as the
> DDS-60 by using it to feed a PLL (as the reference frequency) and
> using the output of the PLL to feed into our radios. While PLL's are
> known for having phase noise, it can be minimized if the PLL doesn't
> have to lock on a new frequency quickly-because we can use a lower
> loop gain. The point being that we can make a PLL that is more
> suitable for this purpose by careful design rather than using a
> general purpose design.
>
> Many of us want higher frequencies to run quadrature based detectors
> as well, so the PLL becomes a spectrally clean means to double or
> quadruple or multiply the output frequency by a very large margin.
>
> It seems the DDS-60 and similar DDS units can be operated in
> conjunction with PLL technology to make them useful again rather than
> shunned as a little too dirty for prime time use::>
>
> There are thousands of DDS-60 units out there, and I wonder if a
> companion PLL can be built to accommodate them and the many other DDS
> units that have less than stellar performance?
>
> Additionally, I can't see any practical reason to upgrade to newer
> DDS units that use much more power due to higher clocking rates
> (plus, they need multipliers on their clock inputs just to have the
> clock operate at 500 MHz).  Does anyone else here see the
> practicality of the old technology DDS + PLL combination, or is it just
> me??

It's a good solution (I think my FT-817ND uses it), and the same controller
could be used for both the DDS and the PLL. The Nat Semi PLL chips are quite
cheap and easy to get hold of, I started designing a PCB for a PLL using one
but never got round to finishing it. I could resurrect the project if there
is any interest.

73, Leon
--
Leon Heller
Amateur radio call-sign G1HSM
Yaesu FT-817ND transceiver
Suzuki SV1000S motorcycle
leon355@...
http://www.geocities.com/leon_heller

#8608 From: "ut1wpr" <vgol@...>
Date: Thu Feb 1, 2007 4:56 am
Subject: Re: Shared MIC/LINE inputs at Audigy SE ? How to use with SoftRock ?
ut1wpr
Send Email Send Email
 
--- In softrock40@yahoogroups.com, "jabauzit" <jabauzit@...> wrote:
> >
> PowerSDR switches the recording source from line in to microphone when
> switching from RX to TX. And vice versa. I did not test it personally,
> this is the information I was given by people using it.
>
> The current version of KGKSDR does not do it and you must use 2 sound
> cards. This is the software I am using for now. Duncan, KGKSDR
> developer, is looking into the problem to have the software work with
> the same sound card.

Dear Jean-Claude, thanks for info.
As far as I can understood, it's need two soundcards with the same
excellent parametres, one for RX and second for TX. And both of this
cards must be at least D44 ? So expensive solve as for me :-)

Thanks againe,

73!

Vic/ut1wpr

#8609 From: Art <KY1K@...>
Date: Thu Feb 1, 2007 5:28 am
Subject: Re: old generation DDS + PLL?
KY1K@...
Send Email Send Email
 
>
>
>It's a good solution (I think my FT-817ND uses it), and the same controller
>could be used for both the DDS and the PLL. The Nat Semi PLL chips are quite
>cheap and easy to get hold of, I started designing a PCB for a PLL using one
>but never got round to finishing it. I could resurrect the project if there
>is any interest.


I'm not sure there is enough interest Leon, the reception here has
been somewhat (barely) luke warm. But, I know they made a million of
those DDS-60's and few are happy with them. If someone made a
companion board to go with the DDS-60 (same size, maybe stackable),
it would seem  to me that many would buy it.

I've been looking at the PLL's commonly on the market today-many (the
majority) are called clock multiplier PLL's, with a built in rc
oscillator that typically operates over a very very wide frequency
range. These are fairly common among clock multiplier PLL's, and this
type of vco needs to be avoided like the plague::>

Anything with an outboard VCO should perform well, as long as the vco
itself is clean and the loop gain is kept low. The Analog Devices
AD4007 PLL as mentioned by Dan Anderson is very easy to use, with
fixed 8, 16, 32 or 64 divide ratios that can be set with 2 inputs.

I might clock the DDS with a 20 Mhz crystal, set the divide by at 32
and ask the DDS to produce 100 KHz to 5 MHz-giving me a clean 3.2 MHz
to 160 MHz capability. I suspect several vco ranges would be needed,
so some inductors and caps could be switched in/out with dip switches
on the PCB. This would give me a relatively low power DDS with at
least 4 samples for each output cycle, so the output signal would be
fairly pure.

I didn't happen to see the article in QEX about this, anyone know if
it is published on the web?

Regards,

Art

#8610 From: "Warren Butler" <njhamguy@...>
Date: Thu Feb 1, 2007 5:34 am
Subject: Icom R7000/R7100 as front end for 10.7 MHz SoftRock v6.2 lite
njhamguy
Send Email Send Email
 
Is anyone using the Icom R7000 or R7100 receiver as a front end for a
SDR 10.7MHz v6???  If so, what are your experiences?  Thanks

#8611 From: "Loren Moline WA7SKT" <lmoline@...>
Date: Thu Feb 1, 2007 5:39 am
Subject: RE: Icom R7000/R7100 as front end for 10.7 MHz SoftRock v6.2 lite
l_moline
Send Email Send Email
 
Warren,

I will be as soon as I get it built. It may need a gain stage...I will seen.



Loren




----Original Message Follows----
From: "Warren Butler" <njhamguy@...>
Reply-To: softrock40@yahoogroups.com
To: softrock40@yahoogroups.com
Subject: [softrock40] Icom R7000/R7100 as front end for 10.7 MHz SoftRock
v6.2 lite
Date: Thu, 01 Feb 2007 05:34:47 -0000

Is anyone using the Icom R7000 or R7100 receiver as a front end for a
SDR 10.7MHz v6???  If so, what are your experiences?  Thanks

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