[amsat-bb] Antenna COnnectors ARGH!

[Bob Bruninga <bruninga@xxxxxxxx>]

Over the years I have had occassionaly intermittant handheld satellite
comms during spur-of-the-moment demos.  But on bench testing, sometimes I
can reproduce the bad connetion, sometimes not.  Always suspecting it was
in my connectors, I re-did them a number of times.  But sooner or later it
happened again.  Like today.

This time I was determined to figure out what was going on and
narrowed it down to the right-angle SMA going into my TH-F6.
Then i measured carefully how far down an SMA would have to go
to be get everything flush and realized that because of my
frequent antenna changing, I was never really torquing down on
the SMA, but only twirlling it on until finger tight.

Duh.. today I realized that is only the point where the
concentric grounds (and center pin) BEGIN to make contact.  It is
a full almost 1/8 inch beyond that that is necessary to fully
mate the connectors...  Sure enough,  If I continue to torque the
connector, it goes another 2.5 turns!

That has been my problem all along.  This was my first time using the
TH-F6 and so the conector was new and so the fit was tight at first.  So
what was "finger tight" and OK on my TH-D7 (well worn connector) was
stopping way short on the new copnnector.  This also expalins why the
problem also aleays seems to fix itself.  When the connector wears down a
bit, then "finger tight" is a different ballgame than before...

ANyway, for what its worth..
Bob


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