Is there anyone in the group who has a 1980 ARRL handbook who could
scan and email me the circuit of the xtal calibrator/marker generator.
I've a friend building replica glowbug regen receivers who needs this
info to help get his unit operational.

Maybe the following will be of help:

QST page:
* 12, May '37: "A 100-Kc. E.C. Oscillator for Frequency Checking"
uses a 24A tube
* 53, May '37: "100-kc. Calibrating Oscillator" uses a 6L6 tube
* 40, Jan '39: 1000 Kc calibrator uses 6F6 tube
* 34, Sep '41: 50-, 100-, and 1000-kc oscillator uses three switched
LC combinations and one 117L7GT tube
* 52, May '45: "Battery-powered one-tube 450- and 1500-kc. signal
generator" (1G4, 1H5, or 30 tube)
* 31, Oct '51: Uses both halves of a 6SN7 dual triode to produce
50-kc signals
* 68, May '52: "Simple crystal marker oscillator" uses a 6J5 tube
plus two resistors and 'most any crystal.
This is the SIMPLIST calibrator circuit I've seen!
* 41, Jun '52: "...Frequency Standard...Oscillator" uses a 6F6
oscillator, both halves of a 6SN7 as a multivibrator,
and a 6K8 buffer/mixer to give 100-kc and 10-kc points
* 43, Sep '52: "Fig. 2 - Oscillator circuit for a simple 100-kc crystal
standard" uses a 6AU6 tube and NO inductor!
* 40, Jul '54: Uses a 6AK5 to produce 100/50-kc harmonics
* 14, Mar '55: "Frequency Marker with 50-Kc. Intervals" uses a 6AK5
and both "halves" of a 6U8 to provide harmonics up
to 30 Mc.
* 61, Jul '59: "100-kc calibrator with 1-kc markers" uses a 6AU6
oscillator and an NE-2 sub-harmonic generator
* 30, Mar '62: Uses a 6AU6 oscillator at 100 kc and a 12AU7
multivibrator to also give 50 kc markers
* 33, Jan '65: Uses a 6AQ5 oscillator at 100 kc and a 6AS6 10-kc
sub-harmonic generator (no diode and NO inductors!)
* 34, May '65: Uses a 6AU6 oscillator at 100 kc, a 12AU7 multi-
vibrator for 10 kc points, and another 12AU7
ACCURACY: multivibrator for 1 kc points!


CQ page:
* 35, Jul '47: "A Simple Frequency Standard" uses both halves of a 6SN7
and one semiconductor diode (an easily-hidden 1N34) to
produce 1000- and 100-kc signals up to about 60 mc.
* ??, Apr '55: "500-kc Marker" uses a 6AU6 tube
* 29, Dec '55: "A Heterodyne Crystal Calibrator AND CODE PRACTICE
OSCILLATOR" uses both halves of a 7N7, 6SN7, or 12AU7
(or pairs of many triodes) and two crystals to give
marker signals at the DIFFERENCE of the two crystals

RADIO-ELECTRONICS page:
* 34, Oct '55: "Dual-Frequency Crystal Calibrator" uses a dual-
frequency crystal and a 6AK5 to produce outputs at
1000- and 100-kc. Adds a 1N34 diode and a 6BE6 tube
to make a harmonic generator. Adds an NE-51 as a
relaxation oscillator to make the marker points
more-easily recognized!
* 52, Sep '66: "Crystal Calibrator" for CB; uses a 6C4 oscillator

If those aren't enough, I can also cite several "utility oscillators"
(which are usually coil-less).

--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
NRA Life Member & Certified Instructor for Rifle, Pistol, & Home Firearm Safety
Also Certified Instructor for the Kansas Concealed-Carry Handgun (CCH) license