Modes: SSB, AM, CW.
Freq Range: All amateur bands (Not WARC), 10 - 160 metres.
Modes: SSB, AM, CW.
Power Output: (Mk.1) SSB: 90W PEP, CW: 75W, AM: 45W. (Mk.2) SSB: 220W PEP, CW: 150W, AM: 60W
Power requirements: (Mk.1) 12V @ 2.5A, 700V @ 120mA, 203V @ 150mA, -90V @ 20mA. -50V @ 20mA. (Mk.2) 12V @ 2.8A, 800V @ 250mA, 230V @ 150mA, -90V @ 10mA, -75V @ 10mA.
Mic Input: High Impedance, 3-pin socket for pressel switch.
Valve compliment: (Mk.1) 6146 PA, (Mk.2) 6HF5 PA;
6CH6 driver
12AT7 2nd mixer
12AT7 1st Tx mixer
12AT7 Xtal osc
EF183 Tx IFamp
2xOA79 Balanced Mod
ECF82 VFO
12AX7 Mic Amp
12AT7 Cathode Follower
Circuitry: The Vespa is a double mixing type in which the SSB signal at 455kHz is first mixed with a 2.5-2.7Mc/s signal from the VFO and then with the output of a crystal controlled oscillator to produce the correct carrier frequency. Only 200 kc/s of each band are covered and some sections of the 15m and 10m bands are missing.
Filter: 455kHz Kokusai Mechanical (almost certain to be defunct now)
Carrier supression: 50dB
Sideband suppression: 45dB
Variants: Mk.1 and Mk.2 as detailed above.
Controls: VFO Driver Tune, Wavechange, OFF-USB-LSB-TUNE, Mic Gain, Send-Recv-Net, PA load, PA tune, Mic Soc. Key Jack.
Notes: The Vespa was made by KW Electronics, Dartford in 1966, and was soon superseded in popularity by the KW2000 transceiver series. The KW2000 employed the same transmit circuit as the Vespa and remains the main piece of KW equipment in common use today. The Vespa, in contrast was not a very popular transmitter mainly due to the power supply that came in a cardboard "box". It was the subject of many bad reviews at the time, despite the KW 'blurb' referring to it as a "lightweight safety cover" and suggesting keeping it under the operating bench, although the lead was too short. I prefer this little rig to the later 202/204 models, the cord drive tuning adding a vintage feel and the paddle type T/R switch is amusing in use.
(© G4BXM)