[Amps] 3-500Z plate durability

[Pete Smith]

At 06:32 AM 12/10/03 -0800, Joe Isabella wrote:
>In my amp, when I transmit (espeically in the typical long-winded 350W 
>carrier AM transmission),
>my RF Parts 3-500ZGs get quite red (almost orange).  After 1 year of 
>pretty consistent use
>(abuse??) like this, they still run full output.
>
>I think the BIG difference between these and the sweep-tubes you reference 
>it is that they're just
>not transmitter tubes and aren't built handle it.


I'm a little surprised to see this even being questioned.  Every 3-500Z 
I've ever seen has been cherry red or brighter at key-down rated 
output.  The ones in my SB-220 are at least 10, more likely 20 years old, 
and still deliver near-rated output in heavy contesting service.  On the 
other hand, the only time I ever saw a sweep tube go red was right before 
the tube envelope melted on my old FTDX-560.


73, Pete N4ZR
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