KENWOOD TL-922A AMPLIFIER - HOW DO THEY COMPARE?

[CDX-007]

Just a little post to open up dialog regarding the overall quality of the many 1KW-2KW 3-500Z amps available on the used market.

Starting with the Kenwood TL-922A, What's your opinion?

- I've heard / read it said many times that it's basically the Heathkit SB-220 design, but what isn't the same as most others which use the same tube compliment? There's only so much that can differ in a two-triode amp, and after all it's the tube which does the work.

I really like mine, but I want to know if anyone had one and then swapped it out for a different amp. If so, what do you like better about your new amp?

If you now have a 922 how much power are you getting, AM or SSB, and at what drive power and what kind of meter are you using?

Eimacs?

73

 

[W5LZ]

CDX-007,
The '922 is a very nice amplifier as long as you don't expect miracles out of it. If run as suggested, it should perform just dandy (as you know, right?). One of the biggest 'oops!'s with the '922 is the band switch, it can/does tend to short/burn if the amplifier is really pushed very hard. Finding a replacement wafer section or the complete switch assembly is a real trick, best not to have too.
Certainly doesn't hurt to do some of the 'Major's mods if you get the chance. And it's probably the best built commercial amplifier you'll ever see (mechanically, not the circuitry).
The only other complaint I had with the one I had was the type of fuse used. Not really all that expensive, but the price sure scared the @#$% out of me the first time!
If you should decide you just don't like it anymore, I'll gladly take it off your hands...
- 'Doc

 

[CDX-007]

Hey Doc,

Thanks for the post. I know what you mean about well built & smooth, I never knew from seeing pictures that I would be so 'wowed' by a 922

...until I saw one in person.

On a Bird 43 I've seen 1430w CW, driven into a 3kw dummy load (No, not an Antron) by a TS-430S at 97w drive CW on 20m, but typically I get about 1100 pep output as my IC-751A only drives it with ~75w pep.

I'll have to find/ make time to get inside the 751 and roll it up to at least 110w pep. I believe that's about what the 922 requires to provide a full legal 1500w pep.

I have a 4500v @ 1A dual 4-400C amp I built a couple of months ago from 'schtuff' I had lying around plus a few other items a friend of mine provided, which is much bigger, louder, and by comparison, darn UGLY amplifier!
But if I decide to offer the 922A up for sale I'll be sure to throw a 'heads-up' your way.

You know, over the last 4-5 years I've had a few amps, Heathkit SB-220 & 221, Henry 2KD Classic desktop, 2KD Classic-X console, a set of Drakes L4B & L7, a Swan Mark II, & a Dentron DTR2000L, but the TL-922A is by far my favorite and outperforms all of the above for output power except for the DTR2000L with it's 3cx1500a7, and the 2K Classic-X which had 3900v on the plates.
...but surprisingly, not by much!

I especially like the 5/8" thick C-N-C machined solid aluminum billet sides with the steel spring loaded handles, a real touch of class which makes carrying it around or moving it almost enjoyable. At 80lbs it would never be truly enjoyable to have to move it, though next time maybe I'll try using both hands... :roll:

I'll bet, more often than not, the reason the bandswitch toasts is due to an over-anxious operator who is in a hurry to get it tuned & loaded for a new band/ frequency and accidently grabs & spins the bandswitch instead of Load/ Tune while it's keyed and outputting a Kw or so as arcing the bandswitch at that level of output definitely won't do it any good.

This 922A is my 2nd as the first was rather a basket case which sat around for far too long and ended up with a toasted power supply transformer and tubes one day while only running about 500w on 40m. (play Taps here)

This one I've gone inside and set the filament V down to 5v and also added parasitic supressors.

I know I could never go back to that good old workhorse Chevy SB-220 series amplifier after driving this 'Lexus' around.

73