I just shipped an Eimac 8877/3CX1500A7 date code 1981 from England to Northern Ireland. I used a genuine Eimac foam filled box. it arrived with an open circuit heater. Is this a common failure? Are t
I have two of them where the heaters measure open when they are upside down but normal when upright. That way up they work fine as long as the heater supply doesn't have high inrush current. They are
Author: gudguyham--- via Amps <amps@contesting.com>
Date: Sat, 25 Mar 2023 17:32:47 +0000 (UTC)
If it were me Id want to see for myself that the filament went open! Sent from the all new AOL app for iOS I just shipped an Eimac 8877/3CX1500A7 date code 1981 from England to Northern Ireland. I
Makes sense. Odd about the other fellow with TWO that is open, or closed, depending on orientation. Do these have a tilt-switch built into them?? Kurt _______________________________________________
Absolutely.....sounds like a flim flam to me! 73 David Harmon K6XYZ Sperry, OK Makes sense. Odd about the other fellow with TWO that is open, or closed, depending on orientation. Do these have a tilt
He is returning the tube for me see for myself. And yes, I know the date code on the one I sent him :-) 73, Alan G3XAQ -- Alan Ibbetson alan@g3xaq.net _______________________________________________
I wonder if there could be a subtle way of marking items? One way I ID items is to compare surface blemishes, but this would only work if you had photos of a good portion of the tube, especially uniq
The guy sent the open-heater 8877 back. Yes, the heater is open and yes, it is the tube I sent him (date code and serial numbers match). So maybe the valve really was broken in transit. One final que
Author: gudguyham--- via Amps <amps@contesting.com>
Date: Sat, 1 Apr 2023 12:05:09 +0000 (UTC)
No, the 8877 can run in an AL1500 with no anode voltage. That should not be an issue. Sent from the all new AOL app for iOS The guy sent the open-heater 8877 back. Yes, the heater is open and yes, i
Electrons are produced when the filament wire is heated above 2200 ^o C. Adding small amounts of thorium to the tungsten in the filament wire *reduces this temperature substantially*, to about 1700 ^
Crazy idea, as the filament is open, and tube shot, could a crack be located using higher voltage? Look for an arc, or a glowing spot at the crack? Kurt ______________________________________________
Alan, I don't know the AL-1500 but It isn't likely that running the filament alone without HV will damage the filament of a 3CX1500A7/8877 triode - unless the filament voltage rose up too high, when
The AL series uses a separate tapped transformer for the filament. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/a
Was this intentional or a funny accident? ' This has for many years made it imperative to handle "emergency spare" Broadcast transmitting tubes extremely genitally , without any bumping.......' 73 Co