[TenTec] OMNI6 PLUS Alignment procedure needed

[Dave Edwards]

On that note, I cringe when I (often) hear the comment "I just got a mint 
condition <radio name here> , so first thing I did was throw it on the bench 
and give it a complete alignment.
IMO....a BAD idea!

....Dave


----- Original Message ----- 
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
To: <tentec at contesting.com>
Sent: Tuesday, January 01, 2008 11:26 AM
Subject: Re: [TenTec] OMNI6 PLUS Alignment procedure needed


> On alignment. In my 50 plus years of trouble shooting and fixing
> experience, never ONCE has alignment fixed an ailing radio.
>
> Sure, alignment has been needed to touch up a radio after a part was
> replaced. Most alignment was designed in because coils were not made to
> the precision needed for proper performance, or the gain of active
> devices wasn't controlled in manufacture, or most often the input and
> output C of a vacuum tube varied a few pf and at RF more than IF the
> differences from one tube to the next (more serious when changing
> brands) changed the resonant frequency significantly. That was much
> worse when the tuned circuit C was under 100 pf.
>
> Yes, tuned circuits do drift, faster with lots of heat and cold
> temperature cycles. But a radio down in performance may have a failing
> part like an IC or a transistor or more likely miniature aluminum
> electrolytics with high series resistance (e.g. dried out). Crystals
> drift too but on a scale hard to measure with the ordinary ham rig.
> Circuits about crystals drift more than the crystals do.
>
> Point is, when a radio's performance is down, find and fix the ailing
> part before you go in a "align" it trying to compensate for the failed
> part and then adding the need for a proper alignment after you do fix
> the failed part.
>
> 73, Jerry, K0CQ
>
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