Kenwood TL-922

This is both a little repository of information about the Kenwood TL-922 and TL-922A amplifiers that I’ve found online as well as a list of repairs I’ve done to my own unit.



Here’s a list of modification sites and what seems good/bad.


W8JI has a great analysis of modifications done to a TL-922. Some are good; some are bad.

As well as a great writeup on protecting your metering circuit and the reasoning behind it.

The modifications that look sensible here include:

However, the suggestion to disconnect the RL-2-1 normally closed contact seems a bit questionable. Others have pointed out that the tube should be biased high when not in use so it doesn’t become a white noise generator. So, perhaps instead a fuse should go between the filament transformer primary and the mains supply.


Now, if you’re interested in where the modifications W8JI disagreed with came from, here’s a great starting point.

There are a bunch of what look like useful and not quite useful modifications here.

The useful modifications:

The not-quite-useful modifications:


Note that so far I’ve been unable to find an output power peak using load on 80m and 160m; I may need to re-check the bandswitch and padding capacitors.

Also, don’t try to run the amplifier at the load knob at 0 or 1 right now; it may be too little coupling there and grid current could get a bit hilariously big and cause things to go “pop!”. It can also lead to higher grid current than needed and cause the output to go non-linear. So, don’t do it. Over-couple things a bit and just don’t run too much power too long!

My local repairs

I’ve done the following to my amplifier.

The TODO items.