There is the Svetlana 572B 572-160 with a plate cap that is for RF and
audio. They have a smaller anode area than Cetron and Chinese and have been
out of production for years.
The 572-3, 572-10, and 572-30 without the plate cap are an audio tube and
also no longer in production.
They were not actually built by Svetlana but another Russian company.
Carl
KM1H
----- Original Message -----
From: "kingwood" <k5jv@kingwoodcable.com>
To: "Amp Reflector" <amps@contesting.com>
Sent: Saturday, March 23, 2013 11:39 AM
Subject: [Amps] bad 572B's
Greetings to all,
Last week, I received a case (10 tubes) of new Chinese 572B tubes
from a distributor that I have bought tubes from for over ten years.
These tubes were new, from the latest production. I plugged two into a
SB-200 and was disappointed to see a bit less than 50 % of the expected
power. I tried another pair and got the same results. I went through the
entire case and found them all to be way, way, down in emission, but, I
must say, they were extremely well balanced. HI Hi
I had a pair of 572B's, from the same source, that I bought about
two years ago, in another amp. I plugged them into the test amp and got
the normal, expected, output. The entire case of new 572B's went back to
the distributor. I wonder if they mixed up some low Mu tubes with their
Hi Mu, 572B's at the factory.
There was some discussion about the Svetlana the 572-160, in one
post. They are excellent tubes for audio work. They have, basically, the
same internal structure (large graphite anode) as the 572B, but, without a
plate cap, they would not be an simple job to install them in an SB-200,
FL-2100, or Ameritron amp. But, for the AM'ers, they make a great
modulator tube.
73 de Lon, K5JV
Lon W. Cottingham
1110 Golden Bear Ln.
Kingwood, TX 77339
281-358-4207
281-795-1335 Cell
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1430 / Virus Database: 2641/5698 - Release Date: 03/23/13
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|