Vacuum Tube Mobile HF Linear Amplifiers

These relics were made on the 1960's and early 1970's and were popular with truck drivers for CB as well as amateur radio operators for 6 and 10 meter operation. A low-pass filter is a definite must-have on these. High voltage for the tubes, often 600 to 1100 volts DC, was generated using an inverter with Germanium switching transistors. The switching frequency was predominately either 60-120Hz or 1-3KHz, depending on whether a laminated or toroid core power transformer was used.

not for sale. not for use on CB band. for educational display only.

Sonar BR-2906
Inverter: two HEP-600
PA: two 6JU6
Safe Output: 80W PEP

Holden Electronics Co. M-300C (Houston, TX)
Inverter: four 2N1522
Driver: 6JU6
PA: three 6LQ6
HV: 900/450VDC (hi/lo)
Safe Output: 165W PEP

modifications: downdraft fans and internal cover baffles, 6VDC bias on driver cathode, 12VDC bias on PA cathodes, additional padder across PA loading capacitor, neon lamp inserted into driver plate PI-coil ?!?, input attenuator.. well it has seen better days. Glad to have been able to rescue this one, just to give an example of several people's handiwork in the same box!!. Someone really loved this old amp to keep it alive through all this.

PAL Electronics 200MDX
HAM TEM SERIES
Inverter: yes
Driver: 12JB6
PA: tWO 8950
Safe Output: 120W PEP

note higher quality PA tuning capacitor, ceramic resistors bolted to chassis, driver tuning slug coil, overall somewhat better quality than most "CB" units. Bias provided by 7V zener diode in cathode, works with positive or negative ground although under-chassis uninsulated inverter transistor cases are connected to negative side of supply.

Palomar "Pulsor"
Inverter: four 2N1522
with box!!
PA: 8950
HV: 700VDC
Safe Output: 65W PEP