It occurred to me while restoring the gear to operational use that I
neglected to set the sidetone in the Omni VI+ back to 700 Hz before I did
the test with it. I had lowered the frequency of the sidetone on the VI+
to 400 Hz while testing the Omni VI. Those readings I reported for the
Omni VI+ are likely off by 300 Hz. I beg your pardon.
73 de W6OGC Jim Allen
On Wed, Jul 30, 2014 at 3:07 PM, Jim Allen <jim.allen@longhornband.net>
wrote:
> Fascinating!
>
> I am here out in the shack with the radios, and have performed the test
> you outlined.
>
> I tuned the 706 with a pick up lead to 9.000.040 to hear the Omni BFO, It
> was not heard with the 706 in USB but was heard in CW mode. I then tuned
> in a 400 hz note. I verified this by using the VI+ sidetone, matching the
> tones exactly. Omni is in LSB with dummy load. When I put it in tune, the
> tone raised, to 460 hz, again measured using the sidetone in the Omni VI+
> (not the VI). The sidetone varies in 10 Hz steps.
>
> I also have a tuner in my iPhone for tuning up band instruments which
> shows the pitch of tones in notes and in Hz. The tone was 401 in LSB and
> in tune 466 Hz. I tried repeatedly to set the 706 to exactly 400 Hz tone,
> before realizing that the 706 tunes in 10 Hz steps, so it was either 402 Hz
> or 392 Hz!
>
> The sidetone setting on the VI is 700 Hz.
>
> This was so much fun I put the top back on the VI and took the top off the
> VI+, same set up other wise. The tone beat to 400Hz was much lower in
> frequency, 8999.700 on the 706 to get a 400 Hz tone. When I went to tune,
> the tone jumped to 768 Hz on the instrument tuner.
>
> The sidetone setting on the VI+ is 700 Hz also.
>
> So on the VI, the tone increased ~60 Hz. On the VI+ the tone increased
> 368 Hz.
>
> This seems to confirm your "guess," Steve.
>
> What do we do next?
>
> Many thanks BTW.
>
> 73 de W6OGC Jim Allen
>
>
> On Wed, Jul 30, 2014 at 1:01 PM, Steve Hunt <steve@karinya.net> wrote:
>
>> Jim,
>>
>> Try this simple experiment if you have a receiver that will cover 9MHz:
>>
>> 1) Take the top cover off the Omni (4 screws)
>> 2) Place a piece of hook-up wire into the receiver's antenna socket and
>> drape the other end near the Omni BFO board (at rear left on the omni).
>> Don't short anything!!!
>> 3) Set the Omni to LSB
>> 4) Tune in the BFO signal at 9MHz on the receiver. Use USB on the
>> receiver and tune for a fairly low audio note - say 400Hz.
>> 5) Switch the Omni to USB temporarily to check that you are listening to
>> its BFO and not some extraneous signal. The audio should disappear or move
>> to a very high pitch (about 3kHz)
>> 6) Switch the Omni back to LSB and hear the 400Hz note again
>> 5) Now hit Tune on the Omni
>>
>> If all is well, the audio pitch should increase to about 1kHz. I'm
>> guessing with your fault it will hardly change pitch at all.
>>
>> Steve G3TXQ
>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec@contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>
>
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|