Ameritron 811 and 811H Upgrade Kits

Link to Instructions:

AL811 and AL811H Upgrade Kit Manual (Rev1)

These kits include all the parts to bring your Ameritron AL811 and AL811H amplifier up to date. We also sell quality 572B, 811A, and 3-500 tubes  and almost any other RF parts you might need.

Warning: All AL811 and 811H amplifiers sold with the pictured Cooltron fan have far too little airflow. Measured airflow is about 1/2 to 1/3 of required safe airflow for four 811 tubes in normal SSB and CW operation. Internal temperatures will have two to three times the safe thermal rise.

We offer a drop-in 12Vdc fan kit that flows adequate air for normal amplifier use.

This is the bad fan:

Bad Ameritron/MFJ Fan

This fan must be replaced!

Fan Kit AL811 and AL811H Fan Kit page


811KS Power Supply kit $49 plus shipping Order now

(Power Supply rebuild).) four better sized higher-voltage much longer-life 5000 hours 105c rated electrolytics
2.) four improved bleeder/equalizer resistors
3.) one large 6A grid meter protection diode
4.) four meter multiplier resistors. These resistors also correct a slight meter error

811 amplifier power supply

Ameritron AL811 Power Supply Upgrade Kit

811KP $29.95 plus shipping Order now

(Protection Kit) 811KP
1.) three application tested GDT tubes
2.) one large 6A meter protection diode
3.) one 100k 2 watt resistor
4.) two 3.9V 5 watt Zener diodes
5.) 10-ohm 9-watt CCS 10kV rated fault resistor

AL811 protection GDT kit

Amplifier GDT Protection Kit

Add on:
811R200K $18 plus shipping Order now

200-ohm 25-watt non-inductive load resistor, ceramic capacitor, with all necessary stainless hardware for Ameritron AL811 amplifier

AL811 200 Ohm resistor kit