Author: "John E. Cleeve" <g3jvc@jcleeve.idps.co.uk>
Date: Sat, 28 Jan 2006 13:07:42 -0000
Good afternoon gentlemen. I refer to the above subject posting, and thought that the resolution of the problem might be of interest to the group. For those who did not see the original posting. Brief
It sounds like you have solved the problem. Another good suggestion has been posted here before and that is to resolder the pins with silver solder. An alloy of 95% tin and 5% silver has a significan
Author: "Firson Maryutenli at home" <maryutenli@telkom.net>
Date: Sat, 28 Jan 2006 22:05:17 +0700
I got same problem with my EIMAC 4-400A on my homebrew amplifier. Soldered with 60/40 tin with 100 watt iron solder, seem solving the problem. Firson - YC0LZH ________________________________________
Something to keep in mind is that, in addition to insufficient cooling, one cause of this can be weakened clips in the tube socket, causing poor electrical contact. The pin gets hot, which may actual
ORIGINAL MESSAGE: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ That's very interesting. So the 60/40 solder is used as a sort of thermal fuse to protect the glass/wire seal? Time to change to ce
Hi Bill, The GS-35B wasn't built by Svetlana. It was built in a Union factory in Novosibirsk, Russian Siberia. It's a great tube though! 73, Tony W4ZT <http://gs35b.com> _____________________________
ORIGINAL MESSAGE: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Not Svetlana? OOPS. Way to go Russkies! :-) 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@c
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Tue, 31 Jan 2006 01:56:54 +0100 (CET)
The British (and a few other armies') D11 and D13 transmitters cooled 4-125 (D11) and 4-250 (D13) by blowing air from the top. They suffered badly from this socket problem. If you figure that Eimac d
That may have been the original intention, but other cooling methods may work as well. The "external anode" tubes have an interesting history as regards air cooling. Eimac developed the SK-600 air sy
Thanks to the laws of aerodynamics, blowing air from the side results in cooler operating temperatures of glass envelope, radiation-cooled tubes. However, for a 4-250A, et-cetera, at least a 150mm di
The 8874 data sheet specifically mentions that "the internal construction.. ..is such that heat transfer to the tube base is minimised...". Free convection is sufficient cooling. The '250 is rather d
As I recall, the E. F. Johnson socket for the 8877 has a center hole that passes air to the base. Richard L. Measures, AG6K, 805.386.3734. www.somis.org ______________________________________________
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Tue, 31 Jan 2006 20:57:02 +0100 (CET)
that passes air to the base.< I think that particular E.F.Johnson socket was the one developed for the 826, 829 and 832 series, all of which had an exhaust tube that poked through that hole. Like the