Note
QST, Apr 1964, p. 5.
QST, Apr 1965 p. 119.
QST, Jan 1966, p. 108.
QST, Jul 1967, p. 127.
QST, Jan 1968, p. 125.
QST, Feb 1968, p. 121. (advertised as the "new" HXL-1) (inside photo)
QST, Nov 1969, p. 4.
QST, Jan 1970, p. 4.
QST, Nov 1970, p. 160. (this could be a factory close-out)
The HXL-One linear amplifier used a pair of 572A triodes in grounded-grid. It had a self-contained solid-state power supply. Hammarlund boasted that the amp could be run "key down for more than an hour" at a kilowatt input. It covered 80-10 meters and was rated at 1500 watts PEP on sideband, 1000 watts on CW, and 250 watts on AM. A later version using 572B tubes ran 2 KW PEP.
The HXL-1 shares physical styling and dimensions similar to the HX-50 transmitter.
The amp includes a built-in linearity bridge circuit. By comparing input and output RF voltages through 1N34A diode rectifiers, the meter reads zero when the amplifier is properly tuned and loaded for optimum linearity. A front-panel `BALANCE` control allows fine-tuning to compensate for slight bridge frequency variations.
– Drive Requirements: Requires approximately 60 to 70 watts of RF drive for full output, delivering a power gain of around 10 dB.
– Power Ratings:
SSB: Rated at 1500 watts PEP input.
CW & RTTY: Rated at 1000 watts DC input.
– Output Network: Uses a pi-network designed to match load impedances from 40 to 80 ohms.
A single front-panel meter provides monitoring via a multi-position switch:
Plate Current: 0 to 1000 mA.
Plate Voltage: 0 to 2500 V.
RF Voltage: 2 to 250 V (sampled at the output of the pi-network).
The unit features an internal power supply powered by a transformer with dual primary windings for operation on either 120 or 240 volts AC (50/60 Hz). The high-voltage DC system utilizes semiconductor rectifiers in a full-wave voltage-doubling circuit, filtered by a series bank of electrolytic capacitors providing 33 µF of effective filtering.
References
Review: QST, Jun 1964, p. 55.
