[Collins] 30S-1 Relay hang

[Roy Reed]

Hi Gerald,
           Many thanks for reply.I tried a piece of card between the clapper
and the pole but no change.I will check out the bypass caps and get back to
you.I am working tomorrow so it may be a couple of days or so before I
resolve the problem. I thank all who replied to my problem and will report
back to all .
              73 Roy.

-----Original Message-----
From: Dr. Gerald N. Johnson [mailto:geraldj at weather.net] 
Sent: 01 February 2010 16:48
To: Roy Reed; collins at mailman.qth.net
Subject: Re: [Collins] 30S-1 Relay hang

On Mon, 2010-02-01 at 15:23 +0000, Roy Reed wrote:
> Please can anyone advise regarding relay hang on a 30S-1 when you go from
> transmit back to receive. I have recently acquired this amp and was
advised
> to swap the supply leads to K205 relay. I have done this and there is no
> change .It will hang on transmit for several seconds. Any ideas would be
> greatly appreciated. Thank you.
> 
>                                         73 Roy G3ZIG
> 
Which relay is hanging? They are interconnected. Then the next question
is do the relays hang when you disconnect the cable from J203,(YES IT DOES)
e.g. is
it internal to the 30S-1 or external? If internal,(YES , INTERNAL) I'd
suspect the
bypass capacitors on that line. If a relay was hanging from the core
becoming magnetized, either K205 or K101, reversing the coil connections
ought to be effective at a cure.

Try not to change the connections at the coil, the coil construction is
fragile 
and can easily go open if the connections inside break from the forces
required 
to remove the wrapped lead. 

Otherwise slip a bit of card stock between the clapper and the pole piece to

keep the flux down a bit. QSL card or thinner probably should be enough. It 
will wear so brass shim would be better in the long run if this is a fix.

The coil current switched at J203 is nearly 1 third of an amp, might be
over dissipating a switch transistor. What is driving that circuit?

-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer