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RE: [FT897] Re: TX frequency off by 50 Hz - TXCO-9 the solution?

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  • Ralph A. Schmid, DK5RAS
    ... I do not know the 60m situation, but is this because there are only some channels assigned, not a whole frequency range?
    Message 1 of 22 , Aug 1, 2003
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      > do that at the better the accuracy. Just using another receiver to
      > check your radio is not advisable. If you want to work 60 meters you
      > need to really be on frequency, and that takes skill and equipment.
      > I have heard several folks that are not with-in tolerance and will
      > not talk to them. Most folks are on frequency.

      I do not know the 60m situation, but is this because there are only some
      channels assigned, not a whole frequency range?

      > Good Luck
      > Steve W4CNG
    • Ralph A. Schmid, DK5RAS
      ... This sounds good. I guess it has no oven, no heat-up time, so it should work with good accuracy even immediately after the power-up?!
      Message 2 of 22 , Aug 1, 2003
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        >
        > I would consider myself very picky when it comes to freq stability as
        > I get to play with military radios that have ovenized oscillators
        > that cost more than my 817 and 897 combined. The TCXO that I put in
        > my FT-817 and later swapped to an FT-897 has been more than adequate
        > for my purposes and I can recommend it for VHF/UHF SSB work. I

        This sounds good. I guess it has no oven, no heat-up time, so it should work
        with good accuracy even immediately after the power-up?!

        > adjusted it when first installed and touched it up once after the
        > first year. I don't remember it needing adjustment, the radio was
        > opened up for another reason
        > Mike
      • w4cng
        You need to put some in between the lines information here. Yes no oven, short start up, but it does have a long term aging issue. The TCXO-9 needs to be
        Message 3 of 22 , Aug 1, 2003
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          You need to put some in between the lines information here. Yes no
          oven, short start up, but it does have a long term aging issue. The
          TCXO-9 needs to be checked every 90 days for the first couple of
          years to insure it stays put (+/-20hz at 5Mhz). Some will, some will
          not. If you look at frequency tolerances of Commercially available
          radio's that operate in the NTIA frequency spectrum (2-20mhz), their
          yearly aging is 1PPM. That is tight, but can be achieved with most
          modern (last 5 years comercial radio designs). Most that are older
          than 7-10 years use an Oven Controlled Oscillator to achieve the
          same. An oven is the cheapest most reliable way to control a Crystal
          unit used in an oscillator. That is the primary reason the
          commercially licensed GROL folks get the $$$ to certify radio's
          as "On Frequency and Zero Beat". I have a GROL, formerly 1st Class
          Radio Telephone License from 1969 when you had to draw diagrams and
          write answers, not like the multiple chance exams given now. I can
          still pass the old exam.
          Good Luck
          Steve W4CNG

          > This sounds good. I guess it has no oven, no heat-up time, so it
          should work
          > with good accuracy even immediately after the power-up?!
        • Ralph A. Schmid, DK5RAS
          ... This is absolutely right. Of yourse it is aging, and I guess at this price it cannot be pre-aged in a way that you can put it in and forget it. I maintain
          Message 4 of 22 , Aug 2, 2003
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            > You need to put some in between the lines information here. Yes no
            > oven, short start up, but it does have a long term aging issue. The

            This is absolutely right. Of yourse it is aging, and I guess at this price
            it cannot be pre-aged in a way that you can put it in and forget it. I
            maintain some repeater systems with different sites operating on one
            frequency, and I know what frequency accuracy can mean; it can be a oain in
            the a** :)

            > as "On Frequency and Zero Beat". I have a GROL, formerly 1st Class
            > Radio Telephone License from 1969 when you had to draw diagrams and
            > write answers, not like the multiple chance exams given now. I can
            > still pass the old exam.

            Here in Germany everyone until 2002 had to write down the answers and draw
            schematics and such, just the new beginners class a few years ago had MC.
            Unfortunately they switched everything to MC this year :( The technical part
            I still would pass, but all the abbreviations and band plans...I do not know
            if I wuld remember them all :)

            > Good Luck
            > Steve W4CNG
          • ae6gt
            When I bench tested the radio I meant literally, not in the technical sense with use of calibration standards. Unfortunately, I do not have a high frequency
            Message 5 of 22 , Aug 2, 2003
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              When I "bench" tested the radio I meant literally, not in the
              technical sense with use of calibration standards. Unfortunately, I
              do not have a high frequency standard to use. I am able to determine
              in a less technical manner its "off-centeredness" because the second
              radio that I use sounds centered when listening to general QSO's, e.g.
              a QSO may be going on at frequencies on whole numbers or half, i.e.
              14178.0, 14340.0, etc., and my "bench" test results at 14150.05
              indicate an off-centeredness, otherwise by my example the second radio
              receive would need to be corrected to listen to the same listed
              frequencies to 14178.05 and 14,340.05.

              A 50 Hz offset is enough to detect a "twang" in a person's voice even
              without hearing them in person. Because I can hear the "twang" in the
              transmission, it sounds un-natural, from my FT-897 on the second
              receiver, and because I can adjust for it to "normalize" it, this
              indicates to me there is an off-centeredness somewhere. Being
              equipped with only my ears and general senses, tells me enough without
              the calibration standard available to me.

              My question remains, will buying and installing the TCXO-9 oscillator
              improve the situation or do you think the radio must be realigned
              first before receiving any benefit from the TCXO-9?

              And.... Is this a normal deviation for this type of amateur equipment
              with out a TCXO, as some else suggesed?

              Jon - Thanks
            • ae6gt
              So the TCXO will give the radio stability, but not necessarily accuracy. Would you know whether the TCXO replaces the oscillator in the base unit in operation?
              Message 6 of 22 , Aug 2, 2003
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                So the TCXO will give the radio stability, but not necessarily
                accuracy.

                Would you know whether the TCXO replaces the oscillator in the base
                unit in operation?

                Otherwise, if it does not, an error in the base FT-897 frequency
                oscilitor will only gain frequency stability not accuracy?

                Jon
              • prcradio
                The TCXO replaces the original osc on the radio, pull old one out and stick new one in. You may have to make an adjustment to the new TCXO to get it right on,
                Message 7 of 22 , Aug 2, 2003
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                  The TCXO replaces the original osc on the radio, pull old one out and
                  stick new one in. You may have to make an adjustment to the new TCXO
                  to get it right on, which can be done with test equipment, or WWV in a
                  pinch. If you tune in WWV at 20 or 15mHz, switch between LSB and USB
                  while listening to the tone of the clock pulses. One sideband will
                  probably sound like "bing, bing, bing" and the other like "bong, bong
                  bong". Tweek the osc for the exact same pitch on both sidebands and
                  you should be fine for most hams. You could try this with your stock
                  osc to get it on freq also.
                  Mike

                  --- In FT897@yahoogroups.com, "ae6gt" <ae6gt@e...> wrote:
                  > So the TCXO will give the radio stability, but not necessarily
                  > accuracy.
                  >
                  > Would you know whether the TCXO replaces the oscillator in the base
                  > unit in operation?
                  >
                  > Otherwise, if it does not, an error in the base FT-897 frequency
                  > oscilitor will only gain frequency stability not accuracy?
                  >
                  > Jon
                • Cortland
                  Stability rating (from the manual) is: ±4 ppm from 1 min. to 60 min after power on. @25 °C: 1 ppm/hour afterwards. The TCXO-9 is ±0.5 ppm/1 hour @25 °C,
                  Message 8 of 22 , Aug 2, 2003
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                    Stability rating (from the manual) is:
                    ±4 ppm from 1 min. to 60 min after power on. @25 °C: 1 ppm/hour
                    afterwards. The TCXO-9 is ±0.5 ppm/1 hour @25 °C, after warmup.

                    4 ppm at 14.178 MHz is almost 57 Hz. However, as has been noted, you
                    may simply be _off frequency_ -- which adjusting the master
                    oscillator trimmer cap can fix.

                    How's it sound on WWV? A 100 Hz difference between USB and LSB should
                    be VERY noticeable.

                    Cortland

                    --- In FT897@yahoogroups.com, "ae6gt" <ae6gt@e...> wrote:
                    > 14178.0, 14340.0, etc., and my "bench" test results at 14150.05
                    > indicate an off-centeredness, otherwise by my example the second
                    radio
                    > receive would need to be corrected to listen to the same listed
                    > frequencies to 14178.05 and 14,340.05.
                  • Keith Nishihara
                    It sounds to me like ae6gt s question here has to do with alignment between receive and transmit frequency on SSB. I.E. if I tune to another station so that
                    Message 9 of 22 , Aug 3, 2003
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                      It sounds to me like ae6gt's question here has to do with alignment
                      between receive and transmit frequency on SSB. I.E. if I tune to
                      another station so that his audio pitch is correct (i.e. his carrier
                      would be zero-beated if I could hear it) and then transmit back to
                      him, would a third party hear my signal properly on the same
                      frequency? If its not, what does one adjust on the 897 to correct
                      that alignment error?

                      While were at it, is switching between LSB and USB actually moving the
                      receiver reference osc to one side or the other of the IF pass-band?
                      If so that offset is another calibration point that could be off.

                      Anyone have ideas on how to tease apart these different possible
                      calibration errors using whats arount the typical shack?

                      regards

                      -- Keith KH6FQR

                      >
                      > --- In FT897@yahoogroups.com, "ae6gt" <ae6gt@e...> wrote:
                      > > 14178.0, 14340.0, etc., and my "bench" test results at 14150.05
                      > > indicate an off-centeredness, otherwise by my example the second
                      > radio
                      > > receive would need to be corrected to listen to the same listed
                      > > frequencies to 14178.05 and 14,340.05.
                    • ae6gt
                      I have concluded that there is likely nothing wrong with the radio, but is most probably a phenomenon of having the receive and transmit radios too close
                      Message 10 of 22 , Aug 19, 2003
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                        I have concluded that there is likely nothing wrong with the radio,
                        but is most probably a phenomenon of having the receive and transmit
                        radios too close together. Probably some kind of phase shifting or
                        distorting because the close proximity and actual wave length between
                        receive and transmit radios.

                        I used a third radio to do comparisons and this 50 hz- 90 hz off-tune
                        is present between all three. They all can't be off-tune?

                        Thanks all for your responses.





                        --- In FT897@yahoogroups.com, "ae6gt" <ae6gt@e...> wrote:
                        > Hi All,
                        >
                        > I bench tested my radio to see how the audio is on the FT897 and
                        > discovered that while listening on a second receiver, the TX frequency
                        > on the FT-897 was TXing about 50Hz too high.
                        >
                        > Can anyone tell me whether installing the TXCO-9 high stability
                        > oscillator will take care of this or is my radio just not aligned
                        > properly?
                        >
                        > Serial Number 2M08xxxxx
                        >
                        > Thanks, Jon
                      • w4cng
                        What are the frequency tolerances for the Receivers you used? There are only a few ways to know exactly where you are transmiting. Calibrated Commercial Radio
                        Message 11 of 22 , Aug 19, 2003
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                          What are the frequency tolerances for the Receivers you used? There
                          are only a few ways to know exactly where you are transmiting.
                          Calibrated Commercial Radio Service Monitors (lots of brands), and
                          references against known rubidium standards. Anything else is just a
                          guess and when operating on 60 meters, you really do have to know
                          where you are. I have more than 50 contacts with On-Frequency
                          stations there, and have chosen not to talk to more than 100 stations
                          I measured as out of tolerance. The world get's tougher, but the
                          requirements can be met, with calibrated test equipment, and periodic
                          testing of your equipment against those standards.
                          Good Luck
                          Steve W4CNG, on frequency and Zero beat.



                          --- In FT897@yahoogroups.com, "ae6gt" <ae6gt@e...> wrote:
                          >
                          > I have concluded that there is likely nothing wrong with the radio,
                          > but is most probably a phenomenon of having the receive and transmit
                          > radios too close together. Probably some kind of phase shifting or
                          > distorting because the close proximity and actual wave length
                          between
                          > receive and transmit radios.
                          >
                          > I used a third radio to do comparisons and this 50 hz- 90 hz off-
                          tune
                          > is present between all three. They all can't be off-tune?
                          >
                          > Thanks all for your responses.
                          >
                          >
                          >
                          >
                          >
                          > --- In FT897@yahoogroups.com, "ae6gt" <ae6gt@e...> wrote:
                          > > Hi All,
                          > >
                          > > I bench tested my radio to see how the audio is on the FT897 and
                          > > discovered that while listening on a second receiver, the TX
                          frequency
                          > > on the FT-897 was TXing about 50Hz too high.
                          > >
                          > > Can anyone tell me whether installing the TXCO-9 high stability
                          > > oscillator will take care of this or is my radio just not aligned
                          > > properly?
                          > >
                          > > Serial Number 2M08xxxxx
                          > >
                          > > Thanks, Jon
                        • ae6gt
                          Steve, Perhaps you can comment on this then.... Calibration and accuracy aside, when two radios are too close together, that is, within one wave length of each
                          Message 12 of 22 , Aug 20, 2003
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                            Steve,

                            Perhaps you can comment on this then....

                            Calibration and accuracy aside, when two radios are too close
                            together, that is, within one wave length of each other, is there an
                            apparent "distortion" generated?

                            Thanks,

                            Jon


                            --- In FT897@yahoogroups.com, "w4cng" <w4cng@b...> wrote:
                            > What are the frequency tolerances for the Receivers you used? There
                            > are only a few ways to know exactly where you are transmiting.
                            > Calibrated Commercial Radio Service Monitors (lots of brands), and
                            > references against known rubidium standards. Anything else is just a
                            > guess and when operating on 60 meters, you really do have to know
                            > where you are. I have more than 50 contacts with On-Frequency
                            > stations there, and have chosen not to talk to more than 100 stations
                            > I measured as out of tolerance. The world get's tougher, but the
                            > requirements can be met, with calibrated test equipment, and periodic
                            > testing of your equipment against those standards.
                            > Good Luck
                            > Steve W4CNG, on frequency and Zero beat.
                            >
                            >
                            >
                            > --- In FT897@yahoogroups.com, "ae6gt" <ae6gt@e...> wrote:
                            > >
                            > > I have concluded that there is likely nothing wrong with the radio,
                            > > but is most probably a phenomenon of having the receive and transmit
                            > > radios too close together. Probably some kind of phase shifting or
                            > > distorting because the close proximity and actual wave length
                            > between
                            > > receive and transmit radios.
                            > >
                            > > I used a third radio to do comparisons and this 50 hz- 90 hz off-
                            > tune
                            > > is present between all three. They all can't be off-tune?
                            > >
                            > > Thanks all for your responses.
                            > >
                            > >
                            > >
                            > >
                            > >
                            > > --- In FT897@yahoogroups.com, "ae6gt" <ae6gt@e...> wrote:
                            > > > Hi All,
                            > > >
                            > > > I bench tested my radio to see how the audio is on the FT897 and
                            > > > discovered that while listening on a second receiver, the TX
                            > frequency
                            > > > on the FT-897 was TXing about 50Hz too high.
                            > > >
                            > > > Can anyone tell me whether installing the TXCO-9 high stability
                            > > > oscillator will take care of this or is my radio just not aligned
                            > > > properly?
                            > > >
                            > > > Serial Number 2M08xxxxx
                            > > >
                            > > > Thanks, Jon
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