On 7/19/22 4:26 PM, Lux, Jim wrote:
On 7/19/22 3:04 PM, Joe Subich, W4TV wrote:
On 2022-07-19 4:34 PM, Lee Hiers wrote:
>
Does anyone know of a commercial stack-matching box (for 2 antennas)
that will send the unselected antenna to another port?
MicroHAM stack Switch would do that for two or three antennas. AFAIK,
the product has been discontinued.
I believe the Array Solutions Stack Match will do that *with* the
optional external relay. However, since I don't use those products
I suggest contacting the manufacturer for details.
73,
... Joe, W4TV
On 2022-07-19 4:34 PM, Lee Hiers wrote:
Hi all...
Does anyone know of a commercial stack-matching box (for 2 antennas)
that
will send the unselected antenna to another port? As in: I'm using the
high antenna on radio A, and that makes the low antenna available
for use
on Radio B. And vice-versa.
I envision two antenna connections and a stack output and an
alternative
output...something along those lines.
I thought I'd seen a commercial product that did this, but I can't
find it
now. I'm sure something could be rigged up using external relays
(and I'd
love to hear from anyone who's done that as well), but I would like to
evaluate other options.
Thanks,
Some other things to think about are "port to port isolation" and
"fail safe" .
You want to structure the switch matrix (e.g. if using SPDT switches)
so that the radios are always isolated from eachother.
If all you have is 2 antennas and 2 radios, what you want is a
"transfer relay" or, in microwave parlance, a "baseball switch", or
for DC motors, a "reversing switch". It's a DPDT set up to swap paths.
THey're available surplus for moderate powers (and, I suppose high
powers), but they're designed so that you never inadvertently have
output from Radio A going into Radio B.
here's a fairly beefy vacuum transfer switch.. I can't find a data
sheet, but I believe it's rated for kilowatts. what you'd also want to
know is the isolation. 60 dB isolation with a kW on one path would be 1
mW on the other path, which probably won't blow up your receiver.
https://mgs4u.com/product/rly-lc-01/
fwiw the transco 700C70400 on the mgs4u website is only rated for 20W.
You see a lot of those and similar ones surplus.
here's a test report from 1972 (back when Deep Space Network was still
called Deep Space Instrumentation Facility) on a bunch of different models:
https://ipnpr.jpl.nasa.gov/progress_report2/XI/XIW.PDF
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