[ARC5] 10 meter BC-454 - instability possibly found

[Mike Everette]

Another trick that really works well is to use McDonalds Pancake Syrup to lock the slugs.

No kidding!

Some years back, the agency I work for was cursed with Aerotron low-band VHF mobile radios (political payoff?  Hmmmm).  The slugs in those &@#^ things were loose-as-a-goose.  If the car went down a "washboard" dirt road or over a rough railroad crossing, the radio would quit receiving, transmitting or both.

The cure was to realign the receiver and/or transmitter exciter (usually the exciter was the biggest problem).  We tried a lot of things to lock the slugs, but what worked best was a drop or two of the syrup, dribbled into the coil form using a toothpick.  The syrup would dry, harden, and keep things in place.

If there was a need to realign the circuit (which often happened because of silver migration in the crapacitors Aerotron aka ERRORtron, used) , all we had to do was stick an Allen key of the proper size into the slug and heat it gently with a soldering iron to make the syrup melt -- then swizzle happily away.  

Yes, it does work.

By the way, the first Aerotrons we had were called the MPAC.  We never found out what MPAC was supposed to be an acronym for.... however, the radio made an MPAC when it hit the floor!!!!

73

Mike
W4DSE

--- On Tue, 2/12/13, Robert  Eleazer <releazer at earthlink.net> wrote:

> From: Robert  Eleazer <releazer at earthlink.net>
> Subject: Re: [ARC5] 10 meter BC-454 - instability possibly found
> To: arc5 at mailman.qth.net
> Date: Tuesday, February 12, 2013, 10:30 PM
> I saw in a GE Voice Commander where
> they took rubber bands, cut them and stretched them
> lengthwise through the coil form, screwing the slug in with
> the rubber band running from top to bottom.  It did not
> follow the screw threads but rather ran across them at right
> angles.
> 
> I used this technique in a Ten Tec kit in which the slugs
> fit so loosely in the coil forms that it was only good for
> about two trips up and down the length of the coil before
> the threads wore out and you could no longer adjust the
> slug.
> 
> I would try the rubber band trick, perhaps reinforced with a
> little dab of RTV silicone once you get it in the proper
> position.
> 
> Wayne     
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