Great suggestions from Ken N6KB.
In case you have an intermittent BFO cable connection, you might
make/break both connector ends several times on the BFO cable (46)
between the TX Audio board and the IF/AF board.
73, Barry N1EU
On Sun, Aug 14, 2011 at 9:27 PM, Ken Brown <ken.d.brown@hawaiiantel.net> wrote:
> My first guess is that the crystal oscillator on the XTAL OSC.-L.O.
> MIXER BOARD is not properly locking to the reference oscillator on the
> LOGIC BOARD. If that is the case, then the problem may go away, or at
> least change a bit on different bands.
>
> Instability of any of the oscillators would cause a warbling sound.
> Oscillators that are part of a phase locked loop are probably more
> likely to have that sort of problem than ones which operate independently.
>
> To test whether it is the BFO, try listening to CW using USB. A
> different crystal and trimmer capacitor are used, so if the warbling
> goes away suspect the BFO parts used for CW and LSB receive.
>
> If you have another receiver you could try tuning in to the various
> oscillator frequencies used inside the Omni VI to see which ones are
> stable and which ones warble. You might hear some of them with an
> antenna in the shack, but more likely will need to use some sort of
> pickup loop or probe inside the Omni VI to receive them.
>
> Listen to the 20 MHz reference oscillator, or the 10 MHz product from
> it. Is it rock solid or warbling? Listen to the BFO at 9 to 9.003 MHz.
> Listen to the XTAl OSC which operates at different frequencies depending
> on what band the radio is on.
>
> Eventually you should be able to determine where the instability
> originates.
>
> DE N6KB
>
> DENNIS BRICKEY wrote:
>>
>> Good evening,
>>
>>
>>
>> I have an Omni VI Option 1. I had the radio checked and aligned
>>
>> just a little over a year ago. When I got it home, I made a hand full
>>
>> of contacts and put it in its box. I got it out this weekend, and is
>>
>> an issue with CW receive. The CW audio sounds like it is
>>
>> warbling, like the cw note is unstable. I left it on all weekend, but
>>
>> there has been no change. Just wondering, short of another trip to
>>
>> the mothership, if anyone has a suggestion for where to look and
>>
>> what to look for. I have no instruments for troubleshooting, but I
>>
>> could possible check some simple items.
>>
>>
>>
>> If anyone can offer advice, please respond direct, and off line. I do
>>
>> not want to tie up the reflector.
>>
>>
>>
>> Thanks in advance for any help.
>>
>>
>>
>> 73,,
>> Dennis
>> _______________________________________________
>> 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
>
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|