I have only used it for 50 ohm loads, though.
I don't know how it would work outside of that
impedance.
It has served me well with QRP ham rigs and
my carrier current transmitter. It's very good
for SWR readings.
I did not build it. I had OHR assemble it
for me. It was worth it. I didn't want to chance
it because of my vision problems. I think it is available
from other companies in assembled form. I also think
there are many of them out there, but I don't know for
sure.
Oh I forgot... I also used it to tune up my 13.560 MHz Part 15 transmitter.
But since the transmitter impedance is unknown, the meter readings
are probably not corrent. But for relative readings, that's OK.
Bruce
If a technically literate member penned a little side-pamphlet describing how to modify the meter for a range of impedances maybe we could get what we need.
Come back?
Any of the "50 ohm" instruments commonly available for measuring SWR, RF power, and impedance are certainly useful for all the ubiquitous transmitter/antenna installations used in ham and commercial radio where the transmitter feeds an antenna or antenna tuner via a 50 ohm coax cable.
Trouble is, all the common Part 15 transmitters are designed to feed an extremely electrically short antenna which doesn't present anything close to a 50 ohm resistive load. In fact, the antenna equivalent circuit is a capacitor in series with a resistor and presents a complex impedance with a resistive part ranging from 1 ohm to several hundred ohms (depending on ground loss resistance) and a capacitive reactive part of several thousand ohms (depending on the frequency and antenna length and diameter). There is no coax. The antenna is connected directly to the transmitter output with a short wire. If you insert one of these common instruments in series with the short wire to the antenna, you will severely detune the antenna. Even if you readjust the transmitter tuning to compensate, you will still get highly inaccurate readings due to the severe impedance mismatch to the instrument.
and you sure are qualified to do that.
By the way, my AMT-3000 is one of my
most prized possessions.
Bruce