designer; Clint Hurd, KK7UQ
by Ernie Mills, WM2U.
Please print this article and use it as a hand out at Club talks and lectures
last piece in the PSK puzzle. A meter that will read your own
transmitted signal IMD. Perfect! Now you can operate without worry of
splattering the bands and annoying other PSK users.
The IMD Meter is a stand alone device,
hence you need no connection to your computer at all. It measures the
IMD of your signal
while you are transmitting. It has a small whip antenna which picks up your transmitted signal, amplifies
it with an AGC controlled RF amplifier (50 dB dynamic
range capable of QRP to High Power operation), detects the wave form, feeds the low
frequency continuous function from the detector to a
controller A/D, performs analysis of the wave form
and calculates the IMD of the transmitted signal. It displays the IMD on a 3 digit LED display.
It works on BPSK31 QPSK31 BPSK63, and covers 160 to 10 meters.
more do ya! want?
Unfortunately this meter is no
longer available in kit form. It is however available fully assembled and
tested by Jim Nuytens, N3JJA at
While you are there, check out the
latest Digital Interface, The Navigator Interface. I've heard
So what ya! waiting for? Go and get the IMD Meter and stop relying on 'judgment' signal reports from QSO's. Think about it! your PSK station is not complete until YOU know what YOUR putting out.
Hope to see your clean trace in the waterfall soon eh! Enjoy, Ernie WM2U