The Type 39 was an experimental set, so was known as the Type 39X.

It came in two forms {both Valve} as [A] 1 Panel with an M/F only transmitter, and  [B] 1 Panel with both an H/F and M/F transmitter.

It was fitted into Submarines Oberon, Otway and Oxley only and all three boats got the [A] and [B] packages.

When the [A] package was being used, the M/F transmitter was of high power and achieved ranges of 600 miles - it required a 220V DC fed alternator with a 20kW output, 500 c/s, 300V AC. When package [B] was in use, it was classed as low/medium power, the M/F part achieving a range of 150 miles and the H/F part potentially world wide at times but nominally 50 miles - it required a 220V DC fed alternator with a 3kW output,  500 c/s, 150/200V AC.  With only one submarine aerial,  only one configuration could be used at any one time.

Emissions for package [A] were CW and ICW, and for package [B], ICW only.

Frequency range M/F = 100-500 kc/s: H/F = 7500-16700 kc/s. Note the high starting frequency of the H/F transmitter!