Greetings,
I recently performed the following mods on my Omni VI/Option 1:
- replaced the original crystal oven on the Logic Board with a Ten-Tec
supplied TXCO
- replaced the BFO crystals on the TX Audio Board with ICM high tolerance
crystals
I'm trying to check alignment on my Omni VI to make sure everything is where
it should be.
The Ten-Tec owner's manual sez that I should adjust the various trimmer
capacitors on the TX Audio Board to ensure proper alignment of the BFO freq
with respect to the IF filter response. Well... I was able to adjust the
first trimmer, C10/LSB to exactly 9.000000 Mhz. C12/USB would not adjust
down to 9.003000, so I set it to as low as it would go (9.003089). C13/FSK
Space, C18/FSK Mark, and C16/CW read right at 9.000000 Mhz on the freq
counter and do not vary as I adjust the respective trimmer capacitors. What
does lack of adjustability indicate here? Am I doing this the right way?
(After thinking about this a little... I can understand why changing out Y1
and Y2 might affect LSB/USB, but what effect will they have on CW that a
trimmer capacitor can 'fix' or adjust? IOW, do these trimmer caps have any
function in these modes? I would think so, otherwise why would they be
there?)
Also, I want to zero the new TXCO so that what is on the display is what I'm
showing. Currently, going to WWV at 10 Mhz and then alternating between
USB/LSB until the tones match shows that I'm 50 Hz off (high). My owner's
manual has no info on how to adjust the master freq... so if anyone knows
what to do please tell me.
TIA,
- jgc
John Clifford KD7KGX
Heathkit HW-9 WARC/HFT-9/HM-9
Elecraft K2 #1678 /KSB2/KIO2/KBT2/KAT2/KNB2/KAF2/KPA100
Ten-Tec Omni VI/Opt1
email: kd7kgx@arrl.net
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