Search found 3 matches

by GlowingTube
Mon Oct 08, 2018 10:31 am
Forum: FM Radio
Topic: Avarage life of a 3cx15000a7
Replies: 6
Views: 503

Re: Avarage life of a 3cx15000a7

What transmitter is it in and what power level? Armstrong used that tube in some of their 10kW's and it would last forever. It barely loafed. In the older CCA's running nameplate power, maybe 2 years. It are indeed Armstrong transmitters, between 10 to 20KW output power at around 7000V DC. We use m...
by GlowingTube
Mon Oct 01, 2018 1:06 pm
Forum: FM Radio
Topic: Avarage life of a 3cx15000a7
Replies: 6
Views: 503

Re: Avarage life of a 3cx15000a7

Thank you for you answer 1. What points are important at the installation? Last time when I replaced a tube, I cleaned the whole cavity room (plan to do this every year) and let the filament run for a hour before switching on the HV. Then slowly increased the power (tuning when necessary of course) ...
by GlowingTube
Mon Oct 01, 2018 10:38 am
Forum: FM Radio
Topic: Avarage life of a 3cx15000a7
Replies: 6
Views: 503

Avarage life of a 3cx15000a7

Since I while I am servicing tube transmitters, which is new (and pretty interesting technology) to me and I was wondering, how much hours can you get (avarage) out of a 3x15000a7 tube used in a FM broadcast transmitter? Is there a lot of difference between new (Eimac) or refurbished (Econco)?