[net.ham-radio] RF GENERATORS

rjr@mgweed.UUCP (Bob Roehrig) (03/14/84)

Regarding the inquiry about signal generators:

The problem with RF generators is stability, dial accuracy, and output
level calibration. All three are expensive. I am not familiar with the
Heath RF generators, but I know of one of their solid state audio
generators that drifts badly.

I picked up a used Boonton 202C. I usually see at least one at a hamfest
in the $50 to $75 range. They originally were about #1500. They cover
50 to 220 Mhz, have the output calibrated in microvolts (50 ohms) and
have both AM & FM modulation. To use on 2 meters or anything requiring
precise frequency accuracy, I use a counter on it but after 15 minutes
it is quite stable. There is a matching mixer unit that provides 100 Khz
to 50 Mhz output.

The most cost effective RF generator is the old surplus BC-221 hetrodyne
frequency meter. I always have mine on the bench. They can be had for as
little as $10 (without the calibration book, which is not really needed
if you have a counter). The Navy LM meter is practically the same. Dial
accuracy and drift are excellent but the output is high impedance
uncalibrated level. It covers 200 kHz to 20 MHz on fundamentals and
higher on harmonics. Fair Radio usually handles these. You may have to
come up with a power supply (6.3 volts and 150 volts dc regulated).
There is a higher frequency version of this unit that goes from 20 MHz
up, but I am not familiar with it.

Another good one is the Gertsch FM-3 type frequency meter. It is really
a commercial version of the BC-221 and does not need a calibration
chart but has direct dial readout. THey operate from 20 MHz up.
Hetrodyne freq meters both generate and detect signals so they can be
quite handy.

Bob K9EUI