[Hallicrafters] Dow Key Antenna Changeover Relay Info

[Bill Pancake]

Hello all... Just an FYI regarding some info an ELMER sent me regarding adjusting the relay contacts on a dow key antenna changeover relay. I found it very helpful and much appreciated. I don't think the author will mind me forwarding it on to the reflector.

RE: Dow Key Antenna Relay 

by WB2WIK on November 24, 2003 

The factory adjusted them for the correct spacing, so if nobody's played with it, it should still be set that way. 

If someone has played with it, here's what I do: 

Loosen nut on "receive" side (normally closed)connector, unscrew it until it loses contact with the relay lever arm, then screw it back in 1/8" to assure good, solid contact, and tighten nut. Burnish both the SO-239 and the lever arm contacts with a very fine burnishing tool, which has a grit about equivalent to a piece of paper. 

Now, loosen nut on "transmit" side (normally open) connector, and adjust it so that the relay lever arm travels 1/4" total from "RX" to "TX" and tighten nut. Burnish both "TX" side contacts as above. 

If anyone had ever taken a file or sandpaper or anything gritty to those contacts, they're probably shot forever at this point and need to be replaced. The original surface was coin silver, which is soft and cannot be filed or sanded. The normal burnishing tool is a dollar bill! 

I've owned an awful lot of these over the years, and have visited the factory where they're made several times. (Used to be in Minnesota many years ago, but has been in Santa Barbara, CA for a long time now.) 

WB2WIK/6 


--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
The reason this message is shown is because the post was in HTML
or had an attachment.  Attachments are not allowed.  To learn how
to post in Plain-Text go to: http://www.expita.com/nomime.html  ---