[CW] Bug Adjustments

[David J. Ring, Jr.]

I would like to recommend a relay to use.

Radio Shack has for years sold a small relay that has small pins for
mounting on a printed circuit board.  I would estimate the size to be
1/2-inch wide by 1-1/4 inches long by 3/4 inches high.  It comes in a 12 vdc
coil voltage.  I don't know the current part number, but it is a very fast
and light weight relay.  If I remember correctly the contacts are rated at 2
amps carry current.  This is just a standard relay in a small plastic box -
it is NOT a reed relay.  Radio Shack also made a small reed relay, but this
small regular relay was just as fast and much tougher to destroy.  I would
use this relay all the time except I had to key a 160 volt keying line which
this relay wouldn't do.  All other transmitters worked FINE - including
amateur cathode transmitters, grid block and transistor (newer) types.  This
relay can basically key any ham radio I've ever seen - and all that I know
of since 1960.

I've used one of these for years (at least 20) in my MFJ Grandmaster keyer.
It still works!

I have all my other keyers converted to use a C.P. Clare relay HGJM series -
which is 50 VA and will handle 2 amps.  I needed this high current and VA
rating for some of the high power transmitters I used on ships.  This is a
mercury wetted reed relay.

Magnecraft also made a good relay - this type was mercury wetted reed relay.
----- Original Message -----
From: <CW@alliedinformation.com>
To: <CW@mailman.qth.net>
Sent: Saturday, March 20, 2004 9:53 PM
Subject: Re: [CW] Bug Adjustments


> Larry:
>
> This will do the trick. Its pretty simple, but if I am not describing it
> well enough, let me know. I can whip up a quick drawing and send it to
you.
>
> I'm not sure about terminology for a relay, but I think the two types of
> terminals are called "contact" terminals and one pair of "coil"
> terminals.  The coil terminals control the relay and when current is sent
> through them as a closed circuit, the relay electro-mechanically closes
the
> switch inside for the "contact" terminals.
>
> Basically, I made a simple cable for my FT-100D's key socket and ran the
> two leads onto two contacts of an el-chepo relay. In its natural state,
the
> relay is not active and the contact terminals produce an open circuit. I
> then ran a lead from a 12 volt power supply to one terminal on my bug.
> Another lead goes from the other terminal on my bug to one of the coil
> terminals on the relay. The other coil terminal on the relay gets a lead
> for the negative 12 volt power sully connection (or ground).
>
> Thus, when I throw the bug pendulum, it closes the circuit. This in turn
> activates the coil in the relay which snaps shut the contacts and makes a
> closed circuit for the keyer circuit in the rig. The 12 volts and the
> nature of the relay gives me an instantly crisp and razor sharp open/close
> of the rig's keyer circuit.
>
> Here's a web page with a great picture of a relay and its workings.
>
> http://www.kpsec.freeuk.com/components/relay.htm
>
> I hope that explains it. I have had people suggest capacitors across the
> terminals and other such ideas to get a clean contact, but nothing worked.
> The second I put together my relay contraption, it worked fantastic and I
> have not used anything else.
>
> All you need to do this is a 1/4" (or 1/2") male jack for your particular
> rig's key connection, some wire, a 12 volt wall-wort (or less if the relay
> needs it) and a simple relay (12 volt or whatever you can get.) Its pretty
> simple. It works really with any manual key (bug or otherwise) It cleans
up
> even my old J-44 straight key nicely. But if you still want a drawing or
> some pics of my setup, let me know. Happy to send you some.
>
> 73'
>
> Matt, KB8WFH
>
>
>
>
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