Repairing my TL-922

Making teflon washer

H7 type jewelry lathe
H7 type jewelry lathe

Repair phases

Replacing faulty bias diode
Before repairs
Substituted bias diode
After repairs
Component, teflon washers and terminal damaged
Old components
Component, teflon washers and terminal to be replaced
New components

About the TL-922

The Kenwood TL-922 is an amateur radio power amplifier designed for use with shortwave radio equipment. Here are some interesting details.

Output power: The TL-922 can provide a maximum output power of up to 1500 watts in SSB (Single Sideband) mode and 1200 watts in CW (continuous telegraphy) mode. This allows for higher transmission power, which can help improve signal quality and transmission distance.

Frequency Coverage: This amplifier covers a wide range of amateur radio frequencies, typically 1.8 to 30 MHz. This allows it to be used on multiple radio bands and makes it compatible with a variety of amateur radio equipment.

Vacuum Tubes: The TL-922 uses an amplification setup based on vacuum tubes (electronic tubes). Specifically, it uses a combination of two 3-500Z tubes in a Class AB2 linear amplifier configuration. These vacuum tubes are known for their durability and ability to handle high power outputs.

Protection and safety: The amplifier includes built-in protections to prevent damage in the event of a bad connection or improper operating conditions. It also has a cooling fan to maintain a suitable temperature during prolonged operation.

Additional Features: The TL-922 has output power adjustment controls, a built-in power meter to monitor output, as well as an SSB/CW mode operation switch. It also has antenna and input/output connectors for easy connection to radio equipment.

In this amplifier, the polarization diode of the two 3-500Z tubes has been replaced due to failure and the isolation washer has been replaced with a Teflon washer made identical to the original with the lathe as illustrated in the photo.