In article le.org,
says...

On Mon, 27 Feb 2017, wrote:

On Sun, 26 Feb 2017 22:17:57 -0500, "Michael A. Terrell"
wrote:

wrote:

Seriously, I have heard of using AM transmitter tubes for audio amps.
I don't know what those tubes are numbered, or how much power they output,
but I know that many AM radio stations have power output in the
thousands of watts range. But to use that kind of tube would require
custom output transformers that would likely mimic the pole transformers
used to feed our homes....


A pole pig would wave been useless, since they weren't designed to
pass DC, and they aren't center tapped on the primary. On top of that,
they would have a horrible frequency response, because they were
designed to operate at 60Hz.

Thats right, no center tap.... Back to the drawing board


A 25KW, plate modulated AM transmitter would produce 12.5 KW of
audio but you would have needed to a hundred amps of three phase 480VAC
to power it. Something I doubt that was available on that farm, or from
portable generators. You could move the modulator from a 5KW AM
transmitter, but the modulation transformer weighed over a ton. We had
to abandon one from a Gates transmitter that was bought from WQBQ for
spate parts. Sadly, it was only a couple years old, and one of the
premium replacements from Peter Dahl.

Too bad you abandoned that transformer. You should have rented a skid
loader or farm tractor with a loader. My 1959 farm tractor, which is
small compared to modern ones, lifts round bales of hay all the time.
They weight anywhere from 650 lbs to 1800 lbs. It struggles on those
1800 lb ones, but a larger tractor could easily handle a ton or more. (I
dont buy or make bales larger than 1500 lbs).


And just for historic value, the original 1969 Woodstock concert ran
Somewhere between 3500 watts to 12,000 watts, using Mcintosh mi350
monoblock tube amps for their PA system. The article below seems to
conflict whether it was 3,500W or 12,000W.
Either way, that PA system had to cover a very large area, and
apparently it did the job.


Those Mcintosh amps were not designed for that type of service.

I thought that same thing, but they apparently can and did handle that
abuse, The Greatful Dead,"Wall of Sound". Was entirely run from Mcintosh
MC3500, Tube amps, and the MC2300 solid state amps, having a total of
around 28,000 watts. Not the intended use, but they held up....



http://www.mylespaul.com/forums/showthread.php?t=100811

These Mcintosh MC3500 power amps have EIGHT power output tubes
6LQ6/6JE6B. These amps had an output of 350W. (mono).

The RCA TTU-1/TTU-25 UHF TV transmitters used 16 6146 tubes in
parallel for a video amp with a response from DC to over five MHz. It
was a 'Distributed Amplifier'.

Im not real familiar with transmitters, but I know that tube is used in
Ham transmitters and is similar to a 6L6 (or am I thinking 6LQ6?).

The 6L6 was seen in ham transmitters quite a bit.

But I think you're thinking of the 807 (and there was also the 1629, I
think I got that number right) which was similar, and there was a long
supply of them in the surplus market well after WWII.

The 807 and 1625 were very similar. The 807 had a 6.3 volt filiment
and the 1625 had a 12.6. They were cheap on the war suplus market after
WW2. Still plenty of then around up to atleast 1975 or so. Many home
built ham transmitters used them. They were also used in some high power
audio equipment.

Many of the commercial built transmitters of ham and public service
started using the 6146 series of tubes as they were not that expensive
and would go to about 200 MHz with no big problem.

When color TV sets started using the 6LQ6, 6JE6 and a few other sweep
tubes they were very inexpensive compaired to other power tubes and
could put out a lot of power for the cost in SSB usage that was
becomming popular on the ham bands.

During that time many ham transceivers put out about 100 watts and it
took a pair of the 6146 or 6xx6 series of tubes. As the TV sets started
going all solid state and the 6xx6 series quit being made in large
quanties the price started going up. About that time transistors that
could put out the same power were comming down and would work off 12
volts DC were comming down in price. That killed off the market for
those tubes in new equipment.

Now transistors and othe solid state devices that can handle 500 and
1000 watts at RF are comming out, it is starting to kill off the market
for tubes in that power range. Very few tubes are being made in the US
now,and lots of replacements for the older tubes are comming from
Russia, and China.