Paul:

TRW PT9703:

Max. Frequency: 400 MHz
Power Output: 10 W
Gain: 10 dB
Vceo: 30 V (intended for 28 V supply)
Vces: 55 V
Thermal resistance (junction-to-case): 8.8 deg.C/W

The lead with a diagonal cut corner is the collector. No, I don't
have a data sheet, just an old short-form catalogue, so that's all the
info I have (apart from a dimensioned drawing of the case).

Steve