Search results

10 meter modification for the Ameritron AL-811 and AL-811H amplifier. This mod apply to other Ameritron AL Series RF amplifiers and allow extension to 10 and 12 meters band.

W7TDC modification of the Ameritron AL-80A power amplifier

Pictures of the Ameritron AL-811 modification for 10 meter band extension by km5ps

This page describes two modifications W8WWV made to his AL-1200 amplifier. The mods were obtained from Ameritron, so they are official.

Are you experiencing very high SWR with the 10M Modification to Ameritron AL-811 amplifier ? This is a good forum topic to fix this problem.

A collection of modifications and improvements to the Ameritron ALS-600 ham radio RF power amplifier

Modifications to an Ameritron ALS 600 power amplifier by AF6SA

This resource details **cooling modifications** for Ameritron AL82, AL1200, and AL1500 HF amplifiers, specifically addressing heat issues encountered during high-duty-cycle digital mode operation. The author, WD4NGB, observed excessive heat in the tank area and band switch on an AL82, attributing it to insufficient exhaust over the 3-500 tubes and a complete lack of exhaust over the tank area. The modifications aim to prevent common failures such as damaged band switches and deformed insulating materials by increasing airflow and exhaust area. The page describes adding five holes to the chassis for enhanced cooling to the band switch and tank area, alongside enlarging the exhaust area over the inner 3-500 tube and the tank area on the amplifier cover, utilizing expanded metal for safety and RF shielding. The original cover featured 26.25 square inches of exhaust; the modified version significantly increases this to 48.5 square inches over the tubes and introduces an additional 15 square inches over the band switch. These changes are intended to resolve heating problems encountered during heavy, 100% duty cycle use in modes like RTTY or long SSB contests, which typically generate substantial heat. The article also discusses upgrading to a higher output fan, such as the G2E085-AA05-21, and modifying tube sockets for improved airflow and reduced back pressure, citing Tom Rauch (W8JI) of CTR Engineering as a source for parts.