hi, I have been unsubscribed to towertalk, but got your message about
dowkey relays , a fortuitious thing, as thought you may NOT know, that dow
key relays , on the recieve side , have a device in the center of the so239,
that, when changed to xmit, SHORTS the recieve connector to ground! these
were notorious for this problem, as after few (months, years), they had a
tendency to STAY in the shorted position, even when de-energized! will need
to get another of their so239 fittings, as 1), the part that does the
shorting is inside the connector, itself. slight pressure on the center
conductor (it is spring loaded) is what activates it., and, 2) like stated,
if filed, will further compound the problem. you can also replace this
with a bulkhead mount so239 (the threads are the same), if you are not
interested in the additional isolation from the shorting of the recieve
connector (at 100 watts isolation should be adiquate, but dont think want to
try with 2KW !) as info, jim nn7k
----- Original Message -----
From: "Thomas Miller" <ac5tm@bellsouth.net>
To: <w7ts@attbi.com>; "vhf reflector" <vhf@w6yx.stanford.edu>
Sent: Saturday, December 14, 2002 4:18 PM
Subject: Re: [Towertalk] Dow-Key dirty contacts. & SO-239 Covers
> Do not use a file!!!!!!!!! Use some sort of soft cloth or similar
material.
> Most likely they are silver plated and filing will remove the plating plus
> make the surface rough. If the contacts are pited or burned you need to
> replace the contacts your problem will come back quickly. If it is just
> surface crap plolish like you would any fine silver dish etc. Contacts
> should be rounded so they are self wiping(cleaning). I am sure someone
will
> go into finer details than this.
>
> Tom AC5TM
> ----- Original Message -----
> From: "Ken Kinyon - W7TS" <w7ts@attbi.com>
> To: <towertalk@contesting.com>
> Sent: Saturday, December 14, 2002 1:04 PM
> Subject: [Towertalk] Dow-Key dirty contacts. & SO-239 Covers
>
>
> > Hello to all.
> > Here is a real bargain: two questions in one message.
> > 1. I have a few Dow key relays in my antenna switching set up. One of
> them
> > when de-energized, is not making good contact (signals very weak). Hit
> the
> > key once even with 30 watts RF and it works again. I am planning to
> remove
> > the small hole cover on the end and clean the contacts wit an automobile
> > ignition contact file. Please tell me if this is not a good idea for
some
> > reason.
> >
> > 2. Is there a cover available to coverSO-239 connectors outdoors. I
just
> > bought a remote switch for the top of the tower and will not initially
use
> > all positions? I was considering filling some old used connectors with
> > silicon seal, but prefer a more elegant solution.
> > Thanks in advance,
> > Ken W7TS
> >
> > -------------------
> > Kenneth E. Kinyon
> > 34 Princeton Circle
> > Longmont, CO 80503-2106
> > Voice: (303) 684-0037
> > Fax: (303) 776-5088
> > E-mail: W7TS@attbi.com
> > W7TS@qsl.net
> > W7TS@arrl.net
> > ALPCA #8339
> > ARRL-LM
> > -------------------
> >
> >
> > _______________________________________________
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> >
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>
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