[TenTec] Omni 6 plus chirp on 30 meters

[alexander jack]

Ken,
Thanks for the email.I may need your notes.I will be intouch again soon.
Again thanks.Veryhelpful.
Sandy

--- On Tue, 23/2/10, Ken Brown <ken.d.brown at hawaiiantel.net> wrote:


From: Ken Brown <ken.d.brown at hawaiiantel.net>
Subject: Re: [TenTec] Omni 6 plus chirp on 30 meters
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Date: Tuesday, 23 February, 2010, 4:41


Hi Sandy,
>  30 meters only.At regular intervals the rig appears to jump or chirp.This is common to both TX and RX.
> Perhaps it is some kind of instability??
>
>   
The Omni VI uses a bunch of crystals in an oscillator as part of the 
local oscillator system. There would be one crystal for each band, were 
it not for the fact that a few of them are used on two bands. This 
oscillator system is locked to a reference oscillator. There are slug 
tuned variable inductors, one for each crystal. If the inductor is 
adjusted properly, the oscillator will stay properly locked to the 
reference. If not it may occasionally drift out of lock, and then need 
to get pulled back into lock. My guess is this is what you are experiencing.

I have had this problem with my Omni VI, and it is a bit tricky to fix. 
The adjustable ferrite slugs in the inductors are sort of delicate, as 
are the threads in the inductor forms. I don't know if the adjustment 
can be properly done without the aid of an oscilloscope. I used an 
oscilloscope to monitor a waveform on the LOGIC BOARD, while adjusting 
the slug on the XTAL OSC - LO MIXER BOARD. Just getting to that board to 
make the adjustments is somewhat involved.

I can probably find my notes explaining what to look for in the waveform 
while adjusting the slug. Let me know if you want that information.

DE N6KB

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