RICHARD ANDREN wrote:
> Hi Bernie,
>
> On my VI, the jump is also transmitted, but only on 10M for me. If you
> find the fix, could you please forward any info to me? I've spent hundreds
> of dollars trying to get TT to repair my VI since I bought it new six years
> ago. They simply cannot repair it, but sure know how to charge me for a
> bad repair job like you.
>
> 73, Rick AE9D
Pin 11 on the phase-lock-loop chip on the logic bd. needs to be adjusted for
the narrowest possible pulse width (50mhz or better o'scope). The variable
"L" for each xtal osc is your adjustment (tweak).
Caveat: The 20mhz oven ref osc must, must, I repeat must be stable (some of
them aren't) and right on frequency (+ or - < 5hz) (and how accurate is your
freq counter?)!!!
I have found when you put the cover back over the xtal oscillator section the
pulse width at pin 11 shifts ever so slightly. I drilled
holes in the cover, one per adjustment, dabbed on a little water cure RTV to
keep the coil from moving and used a stiff non-metallic tweaking tool.
Of course you can ignore the above and just turn each coil 1/4 to 1/2 turn
either way and evaluate....If your symptom goes away,
great!
There are 10 coils to adjust for the 12 bands. 80 and 20; 17 and 10b each
share an xtal.
If your oven ref and BFO xtals are good, you can change the sprague goodman
variable caps (ie cheap but ok if you don't turn them much) to Johansan(sp?)
highly stable over temp piston trimmers available from Newark at around $15
ea. I don't have the Newark # handy, but will look it up if necessary.
73 Bill N4WC
PS TenTec advertise the Omni VI to + or - 50hz. I would like to believe mine
is + or - 10hz(it's close).
--
FAQ on WWW: http://www.contesting.com/tentecfaq.htm
Submissions: tentec@contesting.com
Administrative requests: tentec-REQUEST@contesting.com
Problems: owner-tentec@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|