A nice design, with a multivibrator
circuit that allows you to receive calibrated markers or "pips" every
100 or 10 kcs. As an example to locate the
bottom band edge of forth meters you would
select the 1000 position and tune the set to
7.000 kcs, to operate on 7040 kcs, you would
then select the 10 position and simple count up 4 pips.
A side view, the spare valve is not in its holder.
When I found the calibrator and opened it up I discovered that someone had pinched the crystal. This crystal is s a problem to find a replacement for because the crystal is a special cut device, designed to oscillate at 100 and 1000 kcs.
Photo from Louis Meulstee's web site, see link at the end of this page.
I checked for the availability of the special cut crystal and was shocked by some of the prices. So I opted to just install a 100 kcs crystal and use the 100 and 10 pip positions. I would do without the 1000 Kcs marker.
Then it dawned on me. Why not put a 1 Mcs and a 100 Kcs crystal in parallel. It was an old trick used years ago. Same input circuit but different tank circuits. Look at the test setup complete with sockets and because of the low frequencies involved and the excellent design of the circuit this lashup worked.
You can use the crystals in parallel because of the selected circuits.
Pot 213A is on the rear. . This is the one you adjust to get the correct number of "pips" using the multivibrator function on the 100 and 10 position, "You gotta get the correct number of pips or you will be pippen out of the band sport."
Just wire em up parallel-----
-------and solder them in place with short leads.. The longer crystal is the 100 Kcs rock, the smaller one is for 1000 Kcs. ***
Megahurtskies are not recognized on this site, only real radio terms are used.
Power for the calibrator comes from the main supply line.
.
A
shot of the units connector with the "grill clamp"
Do not accidentally transmit into your unit, to prevent this you can try a small antenna and couple it to the receiver.
Wireless
for the Warrior
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