[Elecraft] Using Elecraft KPA-1500 for 2 radios

[john at kk9a.com]

N3RD (a fellow contester) is very responsive and knowledgeable on Top Ten
products.  You should contact him if you have any questions or concerns.  I
am bringing a Top Ten Decoder and 6 way switch to Bonaire for WPX SSB later
this month. 

John KK9A - PJ4R


Tom Georgens W2SC wrote: 

Hi Jim

I bought a bunch of these for my station in 8P.  When you reported your
findings with these devices, I was very concerned.  I had one in 8P with me
at the time and I measured it in my AIM 4170.  I could not reproduce your
observations and used it on 10M with no obvious issues.

Since I have been home, I took another set of measurements with my DG8SAQ
VNA.  They were essentially identical to what I measured in 8P.

Just so we are clear on definitions, I measured them in in both directions
using both ports and a precision 50 ohm load.  In-A had a steadily rising
SWR with frequency, maxing out at 1.1:1 on 28Mhz.  In-B was slightly worse
with the same shape and a max SWR of 1.15:1 at 28 Mhz.  It was the same in
both directions and did not change if the unused port was terminated or
open.  The isolation was essentially as advertised, over 80 dB up to 28 Mhz.

Admittedly 1.15:1 is not world class, and could be better, but I don't
consider it unacceptable and I plan on using the switches I bought.  Are we
drawing different conclusions from the same data?

If you had different measurements, I would be curious if there was some
design change along the way.  I did not open them up.  The units I have were
bought from another ham, but they were unused.  

They also make a product called an Op Swapper that has some other
functionality.  What I am testing is the A/B station selector.

73, Tom W2SC