"Garrett Wollman" wrote in message
...
In article ,
t.hoehler wrote:
I wonder if there are any 50KW AM vacuum tube transmitters in use
anymore?

They are certainly dwindling. I've visited a few sites that still
have Continental 317s active, but for the most part these transmitters
are being retired rather rapidly now, in favor of new Harris and
Nautel solid-state units.

But aren't there still a lot of tube 50s in backup role? A couple of years
ago WTOP still had a tube rig as backup.

In article ,
R J Carpenter wrote:

But aren't there still a lot of tube 50s in backup role? A couple of years
ago WTOP still had a tube rig as backup.

At a lot of the sites I've visited, this used to be the case but has
changed in the not-too-distant past (or is scheduled to change soon).
A lot of the effort is due to IBOC, but even in its absence I've been
told that the advantages even of the ``Destiny'' over the original
DX-50 are sufficient to make it worth stations' while to buy one and
move their DX-50s to standby status. (It's a great racket for Harris,
certainly....)

Ten years ago it was pretty common to see a DX-50 as the main tx with
a Gates or Continental tube backup, but now -- among the full-timers
at least -- the usual state is two solid-state transmitters. Some
stations (particularly the ex-I-As) made a substantial investment in
solid-state transmitters and bought a pair of DX-50s when they came
out, or have a DX-50 and a 3DX-50, and alternate on a weekly or
monthly basis.

-GAWollman

--
Garrett A. Wollman | As the Constitution endures, persons in every
| generation can invoke its principles in their own
Opinions not those of| search for greater freedom.
MIT, LCS, CRS, or NSA| - A. Kennedy, Lawrence v. Texas, 539 U.S. ___ (2003)

"Garrett Wollman" wrote in message
...
In article ,
R J Carpenter wrote:

But aren't there still a lot of tube 50s in backup role? A couple of
years
ago WTOP still had a tube rig as backup.

At a lot of the sites I've visited, this used to be the case but has
changed in the not-too-distant past (or is scheduled to change soon).
A lot of the effort is due to IBOC, but even in its absence I've been
told that the advantages even of the ``Destiny'' over the original
DX-50 are sufficient to make it worth stations' while to buy one and
move their DX-50s to standby status. (It's a great racket for Harris,
certainly....)

Visit 980-Washington the same day as WTOP. They has 3 solid state rigs. A
Harris DX=50 for days, a Nautel 5 kW for night, and a Nautel 10 kW for
spare. Greater Media had done almost everything in at least triplicate. The
station was sold shortly thereafter and I wonder about the present
situation.

But aren't there still a lot of tube 50s in backup role? A couple of years
ago WTOP still had a tube rig as backup.

710 WOR in New York City had a Continental 317C as their main
transmitter until about 1997, when they replaced it with a Harris
DX-50. The Continental is now their backup transmitter. They use it
weekly during Joe Franklin's show -- the last music show left on WOR.

WOR also used the Continental during that big blackout a few weeks
ago. They chose it over the Harris because it's less sensitive to
power fluctuations. (Northeastern NJ had its power restored more
quickly than the City itself, but people reported voltage swings of
their household AC all the way from 50 to 148 volts, and I doubt the
three-phase power at WOR's transmitter site was any better controlled
at the time.)

(WBRW) wrote:

The Continental is now their backup transmitter. They use it
weekly during Joe Franklin's show -- the last music show left on WOR.

Oh, now that is interesting. Is there that much of a difference in the
sound of these transmitters?