[Elecraft] loss of RX sensitivity

[hawley, charles j jr]

I've worn a BNC out on a Tek scope once or twice in 35 years...

Chuck Hawley
 c-hawley at illinois.edu

 Amateur Radio, KE9UW
 aka Jack, BMW Motorcycles
________________________________________
From: elecraft-bounces at mailman.qth.net [elecraft-bounces at mailman.qth.net] on behalf of Wes Stewart [wes_n7ws at triconet.org]
Sent: Tuesday, September 18, 2018 12:51 PM
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] loss of RX sensitivity

It's difficult to argue with Frank's experience and expertise.  That said, fools
rush in...

I own some network analyzers, 1) an N2PK which I built with type N connectors,
2) a DG8SAQ VNWA-3, supplied with SMA connectors and 3) a RigExpert AA-55 Zoom
with a SO239.  Professionally, I've used analyzers with type N, 3.5mm (beadless
SMA) and K connectors. With the exception of the AA-55, which only goes to 55
MHz, all of these can be calibrated with "precision" calibration kits that can
cost thousands of dollars.  So far, Frank is right, not a BNC in the bunch.

But that has changed with the introduction of the DG5MK's FA-VA5, one-port
vector analyzer.  I am on the reserve list to buy one of these.  The thing to
note is that it is supplied with a BNC connector.  There has been a lot of
anguish, heartburn, etc about this on the VNWA Yahoo group but the consensus is
that it will be fine and BNC calibration kit has been developed and tested
without issue. https://www.youtube.com/watch?v=X8Z7veGV57o

There are tens of thousands of BNCs on oscilloscopes and other instruments and
I've seldom had an issue with them in 30+ years of lab work.  For quick
disconnect I also use short jumper cables with BNCs to break the connections
between the hardline running to the tower and the cable entrance to the shack
during lightning season.  Admittedly, I'm only running 500 W.  When I can leave
them more permanently connected I revert to type N.

Wes  N7WS