[Hallicrafters] SX-71

[W5HTW at att.net]

Lots of those ham ops were WOMEN, too.  

And I, too, was just a boy

Used an SX-71 on CW in the very early 1960s with a Viking II, and a Dow Relay
with the extra muting contacts.  Worked very nicely.  Some guys used those
boat anchor receivers (they weren't boat anchors back then, of course) with
other rigs of that power level, by using contacts on the Dow relay to instead
switch in a resistor in series with the RF gain pot, to dramatically reduce RF
gain, to use the receiver as a monitor for CW.  Of course, that had to be
changed for phone ops, unless you kept the AF gain low as well, or used
headphones.  I never did that, but I knew some who did.  

On my rig today, using a Viking II and NC-109, I built my own relay, in a
metal box, with a barrier strip for the external muting contacts.  I used a
TPDT open frame relay.  One pole switches antenna, the second mutes the
receiver through the receiver's MUTE terminals, and the third actually shorts
the receiver antenna to ground.  Cost me a total of 9 bucks, mostly from the
junk box, but I had to buy the relay (8 bucks) from a surplus shop, and a buck
for a small metal (used) box that had holes I could use!  The three SO239s
came from an earlier project that was scrapped, as did the barrier strip.  It
won't work full QSK, for sure!  But the Viking has PTT, and the external relay
is controlled by the PLATE switch or the Mic level (D104.)  It is as good as a
Dow Key and a heck of a lot cheaper.  Plus has the extra, third set, of
contacts the Dow key doesn't.  

I can also switch the NC109 to "receive" and crank down the RF gain and use it
as a CW monitor, although I use the Hallicrafters HA-1 for keying, so already
have a monitor.  

The SX71 will work very well with your  Ranger, in other words!  Have fun!

Ed




Ed Brooks, W5HTW
http://w5htw.home.att.net/index.html
Active since June 1956 Extra since
Jan 1970