[Milsurplus] SG-34 AN/GPM-15

[Nick England]

AN/GPM-15 manuals are available from Vintage Manuals, Tucker Electronics,
etc.

Info from MIL-HDBK-172A

AN/GPM-15
FUNCTIONAL DESCRIPTION:
A portable, general purpose set which supplies crystal-controlled RF
signals for all Loran channels. It is used to
perform the following preflight checks on Loran receivers: accuracy of time
delay measurements; receiver alignment and sensitivity; timer performance
and crystal oscillator frequency; stability of sweep generating circuits;
receiver distortion due to insufficient signal handling capacity on all
receiver channels; video distortion; performance of "Gain" and "Amplitude
Balance" controls; and performance of "Left-Right" control.

TECHNICAL DESCRIPTION:
Circuit Information
A small pulse and/or continuous wave generator is connected through proper
cabling, adapters, dummy loads, and a 50-ohm coaxial line, to the antenna
terminal of the set being tested, and simulates a Loran transmitting
station. The various output and frequency selections enable the test set
to check the performance of the radar set being tested.

Power Supply
115v ± 10%, ac, single-phase, 50 to 1000 cps, 38 va, supplied from a
receptacle on a Loran receiver, or can be supplied separately.

Frequency Range
(1) 100 kc (2) 180 kc (3) 1750 kc (4) 1850 kc (5) 1900 kc (6) 1950 kc.

Type of Transmission
: Cw or pm.

Output Voltage Range
: 15 microvolts, 1 mv, 1 v, calibrated.

Output Impedance
: 50 ohms, nominal coaxial.

Output Pulse Repetition Rate
: 303.03 pps.

Accuracy
0.0065% frequency.
: 10% voltage.

Temperature Range
: -40° C. (-40° F.) to +55° C. (+131° F.).

TUBES, CRYSTALS, TRANSISTORS:
1 JAN-OB2, 1 JAN-6X4W, 2 JAN-5751, 2 JAN-5814A, 1 JAN-12AT7WA, 1 JAN-5814A
1 JAN-5654/6AK5W, 1 JAN-1N34A.

REFERENCE DATA AND LITERATURE:
TO 16-30 GPM 15-2 (Operation and Service Instructions).
TO 16-30 GPM 15-4 (Illustrated Parts Breakdown).
USAF Spec. MIL-G-4477