TimPerry wrote:

Michael A. Terrell wrote:
TimPerry wrote:

Michael A. Terrell wrote:
TimPerry wrote:


This could just be way farout, heavy, trippin, and totally
groovy.

Mark


Use a pair of 4CX1500 (or larger) tubes. ;-)

3CX2500F3 even?... problem is the forced air cooling is so noisy.


Not if you build it right. The fans are usually vented outside
the building when used for AM broadcast transmitters. I know of
several stations where the air cooled transmitter is close enough
for the operator to see the meters while they are ion the air, yet
you can't hear them in the control room.

but not IN the studio. the newer solid state stuff is a lot quiter
but still has fans running.

have you noticed that as power amps are now being made bigger and
bigger that there are now speaker systems bening made that claim to
handle the power? for example the peavey QW series.

Sure, they are extremely inefficient. I used some very efficient
music grade drivers and horns back in the '70s that could be heard
clearly over five miles away, with a 65 watt amp. When I built a 70
watt transistor amp in the late '60s, the largest paper speaker I
could find was 20 watts.

Have you ever seen the insides of one of the Harris digital AM
broadcast transmitters?

not yet. i was given a BE digital to install.

WQBQ, The last station I visited that had one
in service had a pile of badly damaged output modules from lightning
strikes.

probably from the power lines, unless thier lightning prot was screwed.

Probably started as EMP damage from repeated lightning strikes on the
towers. It is in an part of Florida that can exceed 1000 strikes per
hour, and lots of those are on towers. The building is old precast
concrete and cement blocks. The newer transmitter was installed by the
station's engineer. From the way things looked he spent all of an hour
connecting the power, antenna and audio to it. He used a piece of 4"
copper strap, but the joints were really crappy.



I dismantled and moved their original 5 KW Gates BC-5
transmitter to WLBE in leesburg, Florida.

i need an audio section for a BC-5 - it shoots flames out center hole where
the power resistors join.

I can ask the next time I hear from their engineer, or you can call
the station and see if they still have what you need. In fact, I think
they just retired the other BC-5, and may have a complete transmitter
for sale, as well. Believe it or not, but their engineer doesn't have
an e-mail address. I have tried for years to get him to at least get a
free account that he can check from the different stations. WLBE
doesn't seem to have a website, either.

http://yellowpages.superpages.com/ffile.jsp?N=wlbe&STYPE=S&L=FL&R=N&LID=0087308945&d isplay=1

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida