812A Transmitting Tube, Taylor Tubes
Type 812A is a variant of type 811 with a coarser grid and a lower μ of 29. This meant that the negative grid bias for Class C operation, and hence the RF input voltage, had to be increased but the overall result was slightly more efficient. A further variant (Type 812H) had an even heavier anode construction, allowing 85W dissipation and up to 225W of output when run at 1750V, 170 mA. However, this version was limited to 30 MHz and was thus in competition with numerous other HF types. Types 812/A/H were (and are) much less common than the original type 811.
Made in China
|Made in the USA||No|