Supreme Audolyzer 562

Latest on the bench.

Supreme Audolyzer 562

Another piece of test equipment that is its own radio

The Supreme Audolyzer model 562 is used for signal tracing of radio circuits. It includes a five-band TRF tuner an untuned input stage and a tuned ouput covering from 95 KHz through 14 MHz, including just about every radio IF frequency. It also contains an audio amplifier with speaker as well as a vacuum tube voltmeter to observe signal levels from the TRF tuner and audio sections as well as the usual DC voltages. The device is similar to the audio and RF-IF channels of the Rider Chanalyst. as well as the NRI Professional Signal Tracer Model 33. Tubes are two 6SK7 for RF amps, 6SQ7 as detector & first AF, 6J5 for voltmeter amplifier, 6V6 for audio output and 80 rectifier. This version is an early one with the blond wood cabinet. A later version used a metal cabinet. See also the Supreme Model 570 Signal Generator that now also serves as a "broadcaster". It can now transmit to the Audolyzer.

Audolyzer 562 picture (54k)
Supreme Audolyzer playing music from AM broadcast station.
The Audolyzer is a complete TRF receiver with its built-in speaker. A length of wire is clipped on to the RF / AF probe to act as antenna. Connecting a larger antenna allows even weaker stations to be picked up. The lighted voltmeter behaves as a signal strength meter, enabling the testing of gain in every stage for checking radios all the way from the antenna to the speaker. The zero signal position for the meter is at center (adjustable by front panel knob). The deflection to the left of center gives the signal strength reading. The scale for the voltmeter may also be selected by front panel knobs.

The text of an early advertisement for the Audolyzer believed to date from 1940 can be found here.

Aud_mtr.JPG (16k)
A local broadcast station developed about 12 volts across the detector output.

After cleaning off a thick layer of dust, the set was found to be in very good cosmetic condition. The power cord was replaced as well as two electrolytics, about half the coupling and bypass capacitors, and a couple of resistors. The audio output jack is fed by a capacitor from the audio output tube plate. I replaced that capacitor to avoid high voltage on that jack from a leaky capacitor.

The power transformer was open on one side of the high voltage winding. I measured the high voltage on the half that was working and found a physical-size match with a near voltage match in my "boxe de junque". The replacement has a slightly higher lamination stack and had wire leads in place of the original's terminals but otherwise is a perfect fit. I added a terminal strip to make the various connections. After these repairs, the set did not make any sound although the meter showed movement as I tuned across the broadcast band. Found that the speaker switch was open. A temporary clip lead across the switch brought the device to life. A thorough cleaning with contact cleaner solved the switch problem.

The power supply circuit in this set is a bit unusual since both the choke and the speaker field coil are in the negative side of the supply. Such a power supply circuit reduces stress on the insulation of the choke and field coil.

A four-page description of the device appears in the 1956 Coyne publication "Latest Instruments for Servicing Radio and Television" starting with page 212. The Coyne description includes the two partial schematics below.

Coyne book cover (36k)
Audolyzer TRF schematic (41k)
Audolyzer VM schematic (28k)

The Canadian GE model KL-70 with "licence to listen" was the previous item on the bench.

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