Off topic - Dow Key relay help

[Garey Barrell]

Jerry -

The "end" connector is the "arm" of the relay.  This normally goes to
the antenna.

The longer side connector is the receiver connection.  It is longer
because there is a double-break contact inside that gives higher
isolation to the receiver.  This connector is also on the side of the
relay away from the coil.

The connector on the same side of the relay as the coil is the
transmitter connection.

When actuated, the coil pulls the arm of the relay from the receiver
side to the transmitter side, connecting the antenna to the
transmitter.  When released the arm moves away from the coil, pressing
against the receiver connector, closing the internal break connection
and connecting the antenna to the receiver.

It is worthwhile to remove the plug button in the end of the relay
housing so you can see the contacts inside.  The two opposing
connectors are screwed into the housing and locked with the jam nut on
the outside.  I have seen more than one relay of this type where the
jam nut has loosened, allowing the connector to be threaded too far
into the body of the relay and effectively jamming the contacts
together.  This is not good!!  It essentially connects the receiver,
transmitter and antenna all together at the same time, usually
resulting in a blown input to the receiver.

So look at the contacts first and ensure that the arm is resting
against the button away from the coil and that there is a gap on the
other connector button.

Another potential problem is if the receiver connector has been
unthreaded too far, and there isn't enough travel to close the
internal double-break contact on the receiver side.  This results in
little or no RF reaching the receiver.

More than you ever wanted to know!

73, Garey - K4OAH
Atlanta


----- Original Message -----
From: "Jerry Kitterman" <kitt5 at EARTHLINK.NET>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Thursday, March 28, 2002 2:16 PM
Subject: Off topic - Dow Key relay help


>   Gentlemen,
>
>    I have a series DK60 dow key relay, spdt coax relay, 100 VAC that
I want
> to use with my DX-60 rig. It has the UHF connectors. One is on the
end of
> the body of the relay and I assume this may be the connector for the
input?
> and the other two are both mounted vertical on the other end. The
longest
> one is on top by the solenid? of the relay that has the connection
for the
> 110v and the other one is directly underneath the top one on the
same end.
> Are these two for the xmtr and rx? How can I make sure which one is
which
> without blowing it up? Thanks for any help and excuse my ignorance
of
> trying to explain the relay. Thanks es 73
>
>  Jerry..W9CTB
>
>
> --- Jerry Kitterman
> --- kitt5 at earthlink.net
> --- EarthLink: The #1 provider of the Real Internet.

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