[TenTec] Omni VI and power supply occilation???

[denton]

The power supply is a linear one...with over 200,000 microfarads of 
filtering, with tight regulation. The Omni was in cw mode when it failed, 
and the amp meter on the power supply indicated about 14 amps of current 
when the Omni failed....with it being on for about an hour this morning.
I am not sure of the ripple voltage or fequency, but will hook up an 
ocilloscope on the power supply output this morning and see what it 
indicates.
Regulator for the power supply is a LM 317 with a pair of transistors 
wrapped around it, feeding  6 2N-3055's. Crowbar is set to 15 vdc.
My digitial vom indicates 14.37 vdc no load to 22 amps full load, with 
ripple of 0.005 vac no load to full load.
At battery output, I have13.4 vdc no load to 12.88 full load output and 
ripple is 0.001 vac no load to full load.
----- Original Message ----- 
From: "J. Reed" <jhreed at chilitech.net>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Tuesday, April 19, 2005 8:32 AM
Subject: Re: [TenTec] Omni VI and power supply occilation???


> Hey, 'D',  tell us the type of power supply, eg: linear, switching, etc...
> also, what is the ripple voltage and frequency at this 35 amp load...
>    Also, is the Omni on SSB or CW or AM while failing.   You
> also weren't very clear on yesterdays operation, did it fail overnight
> or during the morning cold start...  help us help you...  Jim R.
>  ----- Original Message ----- 
>  From: denton
>  To: Discussion of Ten-Tec Equipment
>  Sent: Saturday, April 09, 2005 11:14
>  Subject: [TenTec] Omni VI and power supply occilation???
>
>
>  I recently purchased a used Omni VI that quit transmitting, sent it in to 
> TT
>  for repair and alingment. TT replaced the finals and some other work...
>  I recieved the repaired Omni yesterday and wasted no time getting back on
>  the air.
>  This morning....no rf out AGAIN!!! Exact same sympthons as before.
>  I made a call to the TT repair department, and they said since I run a
>  homebrew power supply, I may have an ocillation from the power supply 
> that
>  is destroying the finals in the Omni.
>  What ocillation??
>  I have used this power supply for years. It is currently feeding an FT 
> 990
>  and uhf/vhf radio without problems. The power supply has fed various TT 
> hf
>  rigs thru the years without problem. Is there something unique about an 
> Omni
>  that will not allow it to be used in my station on the existing power
>  supply??
>  The power supply is currently hooked up to a pair of absorption mat deep
>  cycle batteries with a blocking diode between the B+ and the batteries. 
> It
>  has been used this way for quite some time without problem, and the power
>  supply alone is capable of 35 amps continous all day long.
>  TT also tried to tell me this morning that I may have to run the Omni, 
> when
>  it gets back from being repaired a second time, on a separate power 
> supply
>  that will shut down when it detects ocillation.
>  Anyone run across this before...thanks....
>
>
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