TRANSMITTERS & TRANSCEIVERS

Type 38S Transmitter

DATE OF DESIGN

1. TX 3Q L/F - 1924.
2. TX 3K H/F - 1930.
3. TX 3Q Low Power 1924.
4. TX 6D - 1929.
5. TX 6F - 1930

FREQUENCY RANGE

1. TX 3Q L/F - 100 to 1300 kc/s.
2. TX 3K H/F - 5770 to 26000 kc/s.
3. TX 3Q Low Power - 100 to 1300 kc/s.
4. TX 6D - 66 to 666 kc/s.
5. TX 6F - 100 - 900 kc/s

POWER SUPPLIES

1. TX 3Q L/F - 2 x 3kW Motor Alternator. Filament supply - 1.25 kW Alternator
2. TX 3K H/F - 2 X 3kW Motor Alternator. Filament supply - 1.25 kW Alternator.
3. TX 3Q Low Power - 2 x 1.25 kW Motor Alterntors.
4. TX 6D - 20 V Battery.
5. TX 6F - 2 x 3kW Motor Alternator

POWER TO FINAL STAGE.

RANGE IN MILES

1. TX 3Q L/F - 600.
2. TX 3K H/F - World Wide at times.
3. TX 3Q Low Power - 100.
4. TX 6D - 40.
5. TX 6F - 100.

TYPE OF SET (VALVES USED)

1. TX 3Q L/F - 3.
2. TX 3K H/F - 3.
3. TX 3Q Low Power - 1.
4. TX 6D -
5. TX 6F -

WAVEFORM

1. TX 3Q L/F - CW and ICW.
2. TX 3K H/F - ICW.
3. TX 3Q Low Power - ICW.
4. TX 6D - SPARK.
5. TX 6F - SPARK.

METHOD OF PRODUCING OSCILLATIONS

SELF

WHERE USED/FITTED

Type 38S It is a medium power valve set arranged on many panels. It is a modified Type 37S and for the most part behaves like it. The modifications are "within" (wholly technical and not operator oriented). This set is fitted in the Main W/T Office of Flotilla Leaders.

Other transmitters in the series. Types 38M, 38P. Again, fitted in 'Leaders only' these sets were multi-facetted, including a mixture of MF, HF and Spark on mains power (one of the Valve sets being Low Power) and a second Spark but on battery or ships 20V low power ring main. The difference between a Type 38M and 38P was that the 38P had the sophisticated transmitter 4T fitted, and it gave a low power output of only 25W (range 40 miles), 20V battery supplying motor generator with 600V DC output & a 4V battery for filaments, but it was Master Oscillator controlled and capable of CW, MCW (1kc/s tone) R/T {where approved} from 100-18000 kc/s. Other than that difference, both sets covered 100-670 kc/s 800-1364 kc/s 3000-20000 kc/s 100-900 kc/s 100-670 kc/s 100-1364 kc/s, CW/ICW/Spark, Self oscillations, with power outputs ranging from 450W to 10W and ranges from 350 miles to 12 miles.

ASSOCIATED WAVEMETER

1. TX 3Q L/F - 1492B or G9.
2. TX 3K H/F - G13 or G8 and G7.
3. TX 3Q Low Power - 1492B or G9.
4. TX 6D - 1492B or G9.
5. TX 6F - 1482B or G9.

FURTHER READING

IMAGES, PHOTOS, DOCUMENTS, SCHEMATICS ETC.

Type 38S Photos and Schematics (also see Type 37S photos).

NOTES.

Photo 1 - Type 38S.
Photo 2 - Type 38S Low Power Schematic.