Kenwood TL922 Amplifier simple question

[AB3FL]

The stock fan in the TL-922 is pretty weak. I actually put in a 12V PC fan that moves twice the air and only a tiny bit more noise. I did have to put in a small 12V transformer and bridge and cap, but it was worth it. I had no problem running 200+ watts on AM being driven by a Ranger (low power). The amp doesn't even get warm. All the hot air blows out the back.


Tom - AB3FL

[W8JI]

While the 922 absolutely needs more cooling, cooling should never be a guess.

The case temperature or exhaust temperature is meaningless for tube life. You need either templaq paint or a tempilstik at this link:

http://www.bjwe.com/tempil/0tempil.htm

The seals are rated at 200C for the base and 220C for the anode.

I know of amplifiers (Amp Supply) that go over these seal ratings with NO drive and just quiescent current, even though the outlet feels cool.

The only way to know about the seal temperature is to paint or mark the seals with proper crayons or paint.

73 Tom

[AG3Y]

Tom knows what he is talking about !

If you want to see a transmitter that is running a real 1KW AM, look at this web page:

http://www.oldradio.com/archives/hardware/Gates/1T.htm

My first radio station used a BC-1T, and I can vividly remember those 833s glowing like is shown in the picture. The blowers made a lot of noise, too !

What the pictures don't show was the Mercury rectifiers in the bottom of the cabinet. They had a glow of their own, but it was blue ! ! It was a very "colorful" transmitter !

[AB3FL]

Tom knows what he is talking about !

If you want to see a transmitter that is running a real 1KW AM, look at this web page:

http://www.oldradio.com/archives/hardware/Gates/1T.htm

My first radio station used a BC-1T, and I can vividly remember those 833s glowing like is shown in the picture. The blowers made a lot of noise, too !

What the pictures don't show was the Mercury rectifiers in the bottom of the cabinet. They had a glow of their own, but it was blue ! ! It was a very "colorful" transmitter !

MAUL!!!!!

Tom - AB3FL

[KA4DPO]

When I went to work at Harris in 1976 there were two guys on our engineering team that had worked at the Gates/Harris facility in Ohio. They said the company was working on 1KW solid state transmitters when they started there in 1973. They also said that there was a High Power team working on development of 50 KW and higher solid state transmitters in 1976. It was only ten years or so after that Harris went all solid state.

Too bad, I miss seeing the little cooling pond with the fountain bubling steamy water in front of KFI back in the old days.

[W9GB]

When I went to work at Harris in 1976 there were two guys on our engineering team that had worked at the Gates/Harris facility in Ohio.

I was not aware of an Ohio facility. Gates Radio HQ and factory (where the BC-1T was built) was in Quincy, IL.
They also had a broadcast console business in Quincy as well as a facility in Indiana.

Harris may have acquired a plant in Ohio in 1960s or early 1970s.

w9gb

[KA4DPO]

I was not aware of an Ohio facility. Gates Radio HQ and factory was based in Quincy, IL.
They also had a broadcast consule business in Quincy as well as a facility in Indiana.

Harris may have acquired a plant in Ohio in 1960s or earliy 1970s.

w9gb

They did but I don't know exactly when. the Radio and TV headquarters is in Mason, OH and the manufacturing is in Quincy, IL. From what I understood the Ohio unit was primarily Sales and Marketing but did ( I assume still does) have some engineering development work going on when my friends worked there. I don't know if they have a facility on Indiana or not. I only worked at the Government Systems Group in Palm Bay, FL and at the RF Comm facility for short periods in Rochester, NY so I have never been to any of the commercial facilities.

Harris is amazingly diversified. They started out building printing presses, then went into locomotive controls, bought Radiation Corp and turned it into Government systems & RF Comm, they bought Farinon Microwave, Lanier business machines, oh and 3M too. At one time we though Chrysler Corp. was going to buy Harris. As we were leaving for lunch one day a limo with Lee Iacoca and some big mafia looking body guards drove up in front of us and went into Building one (HQ).

[WB2WIK]

My experience with Harris is almost all in Rochester, NY at the RF Communications Division.

Tons of hams worked there (maybe still do) and it was great fun working with them on transmitter projects -- this was mostly stuff for the government.

I had a ball there in my many visits.

[W9GB]

Harris is amazingly diversified.
They started out building printing presses, then went into locomotive controls,

Yes, in fact some of the early Harris/Gates gear is labeled: Harris Intertype / Gates ... show that heritage.

I grew up in west-central Illinois -- about 50 miles NE of Quincy ...
there are a number of amateurs in Quincy area and I have toured the Gates/Harris plant a few times!
The shortwave HF multi-cabinet transmitters were always of great interest ...
the 5 - 10 kW ceramic tubes used as DRIVERS in the transmit chain would satisfy any amatuer !

It was very rare for any TV or radio station in the area
not to be using Gates/Harris transmiiter or studio gear in that area (you could drive to plant for service parts!)

the company was working on 1KW solid state transmitters when they started there in 1973.
They also said that there was a High Power team working on development of 50 KW and higher solid state transmitters in 1976.

In the 1980s, I saw one of the first production solid-state Harris VHF TV transmitter models installed at Channel 12 (West Branch, IA) for Iowa Public TV ..
replacing a 1950s General Electric TV transmitter that had to be cut up to get it out of the concrete block transmitter building.

That was an impressive piece of gear for that era.

w9gb