Dow Key relays ?

[Nick England]

One of the reason's to pick up an older ARRL Handbook from the late 50's
or early 60's is that there are lots of interesting and illuminating
advertisements in the back.

Anyway, Dow Key was a very successful manufacturer of antenna T/R relays
for ham gear in the era of separate receivers and transmitters. They
were co-axial relays with little effect on SWR and were rated for a
kilowatt or more. They weren't particularly fast (no QSK) but they
did make a satisfying ker-chunk when switching. Most often, hams would
have a Dow-Key relay with a 115 vac coil (because most transmitters
had connections to supply 115 vac when switched to "transmit") and a
set of auxillary contacts to mute your receiver while transmitting.

They pretty much disapppeared when SSB, VOX, and transceivers appeared
on the scene.

By the way, for QSK operation, hams usually had an electronic T/R
switch using a tube to clamp the receiver input when transmitter RF
input was present. Dow-Key made one of these too, but Johnson was
probably the most popular commercial unit. They weren't hard to homebrew,
either.

73 & Have Fun,
Nick England  KD4CPL  nick at cs.unc.edu   Univ. Of North Carolina
http://www.cs.unc.edu/~nick             Chapel Hill NC