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Gene, there are several way to get it done. You could transmit into an
antenna and put a second antenna on the counter, or you could get a 30 dB or
higher power attenuator and place it between the transmitter and the counter. I
have a 1 kW 40 dB attenuator that I use on my test bench, but these don't come
cheap!

A directional coupler would also attenuate the power into the counter, while
the transmitter power is going to a load. A sampling loop could also be
used, but it's hard to know how much power is getting into the counter input. A
loop can be made by getting a piece of coax that matches the counter input
connector, and making an insulated 1 inch loop on the other end, between the
center conductor and the braid.


A great safety measure is to us a fused device on the counter input, to
protect it from excessive power. You could make one with a small 1/8 amp fuse, a
small box and RF connectors. Many commercial ones are also around.



Stuart K6YAZ

Most VHF/UHF frequency counters use a terminated 50 ohm input, usually rated
at about 500 mW, and in this case, the fuse will provide protection, if you
do something that you shouldn't have done. If the input is a high impedance,
the fuse probably won't help, until the input melts.

Stuart K6YAZ

A great safety measure is to us a fused device on the counter input, to
protect it from excessive power. You could make one with a small
1/8 amp fuse, a
small box and RF connectors. Many commercial ones are also around.

The counter's input stage, whose geometry has about 1/1000 the size and
thermal mass of the fuse, will do a great job protecting the fuse. :) A
pair of back-to-back Schottky diodes, perhaps the kind rated for use in
switching supplies, might help if placed after the fuse.

An inline attenuator for the power/frequency range in question is really the
right way to go. Don't guess when it comes to protecting your test gear's
input stage. That's where we get all those auctions that say, "Removed from
a working environment! Powers up!!!11!"

-- john, KE5FX