Note
HA-201 1974-1977 $29.95
HA-201A 1978-1983 $39.95
Released on the heels of the popular HA-202, this tiny amp was designed specifically to boost the signal from a handy-talkie. It provides about 8 watts of output with 1 to 3 watts of drive. The HA-201(A) is fully solid state, no mechanical relays are used in switching. The amplifier will withstand infinite VSWR without failure but is not indestructible.
The HA-201(A) tunes up with a VTVM or SWR bridge, a dummy load, and a broadcast band receiver (to listen for oscillations). The A version was a major redesign that reduced the possibility of instability, simplified tune-up, and replaced the RCA jacks with SO-239 connectors. Both versions, however, work very well, and are easy to fix. The HA-201(A) is painted one-color green.
Caution: Do not exceed 3 watts of drive or you may damage the final (2N6081 or CTC B12-12).
Note: The length of cable used to connect the amp to your HT should be cut to odd multiples of 1/4 wavelengths of the frequency you use most often.
Note: there is no RF bypass around the HA-201(A) when its power is off. If the amp is in the RF line it must be powered up or no RF will get through.
References:
Review. CQ. Jul 1975, p. 51.
Carrier operated relay. QST. Jul 1978, p. 32.
Carrier operated relay (more on). QST. Nov 1978, p. 32.
HA-201 Specifications
Frequency range: 143 to 149 MHz
Power output:
1 watt drive: 8 watts
1.5 watts drive: 10 watts
Power input: 1 to 3 watts
Input/output impedance: 50Ω
Maximum load VSWR (non-catastrophic): infinite
Conducted spurious and harmonics: not specified
Operating temperature range: not specified
HA-201A Specifications: All as above plus:
Maximum stable VSWR: 4:1 referenced to 50Ω
Conducted spurious and harmonics: –60 db
Operating temperature range: –22 F to +140 F
Power requirements: 12 to 16 VDC, 2.2 amps maximum
Photos, general information and specifications from "Heathkit: A Guide to the Amateur Radio Products," by Chuck Penson, WA7ZZE. Used with permission.
