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[Amps] Fw: Vacuum relay adjustment?

To: <>
Subject: [Amps] Fw: Vacuum relay adjustment?
From: <>
Date: Thu, 11 Sep 2008 11:45:26 +1200
List-post: <">>

Hi Tim

You need to try employing a "contact wetting circuit"

Install a .01 Capacitor in series with the transceiver antenna in to the

Put a 470 ohm 2 watt resistor from the relay side to +12-24 volts DC.

Then install a 1k 2 watt resistor between the antenna and ground via a spare
 relay contact on the antenna change over relay or another relay in parallel
to the RF one.

It will keep a small flow of current during receive to ensure the contacts

I have in the past also turned a vacuum relay upside down and increased the
current through the contacts and pulsing the relay.

This has also fixed the problem.

Good luck

Cheers Gary
> ----- Original Message ----- 
> From: "N3XX" <>
> To: <>
> Sent: Thursday, September 11, 2008 11:23 AM
> Subject: [Amps] Vacuum relay adjustment?
>> Hope someone on the list can help with information about a vacuum relay I
>> have.  I'm working on getting an LK-800 amp back in good working 
>> condition,
>> and one of the problems it has is a T/R vacuum relay that won't go back 
>> to
>> receive after transmitting.  If I tap on the relay, it does go back to
>> receive.  The relay is a Jennings RJ1A-26S.  On this relay is a screw 
>> that
>> looks as if it is for adjustment, but I don't know what it adjusts.  I'm
>> guessing it has to be either contact spacing or spring tension.  I hope 
>> it's
>> for spring tension, and by adjusting this screw I can put a little more
>> tension on the spring, and it will return to receive when finished
>> transmitting.
>> Just thought I would check here and see if someone knows what the screw 
>> is
>> for before I start turning it, not knowing what it is supposed to do.
>> Thanks for any info.
>> 73,
>> Tim - N3XX
>> _______________________________________________
>> Amps mailing list
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