[AMPS] AL-1500, AL-82, AL-1200, QRO???

[Andy Cook, G4PIQ]

Rich wrote :

>> The 3cx1200A7 is virtually immune to grid/fil. shorts.  3-500Zs are not. 

I'd just like to counter that by saying that in 15 years of looking after 
the amps for our multi-multi contest group the ONLY fatal tube failures 
which I have seen have been 2 grid-filament shorts in 3CX1200A7s. I've 
probably been through 30 amps with various tubes in including

3CX800s with and without grid current trips (Alphas, Amp Supplies, K1FOs at 
VHF and many Ten Tec Titans),
3-500Zs (TL922, Amp Supplies, Tokyo Hi Power)
4CX800s (Alphas)
8874 / 8877 (Henrys)
4CX250Bs (home brew, Tokyo High Power)
and a bunch of other similar stuff.

Just my experience, but they are most definitely not imune to that problem.

Andy Cook, G4PIQ





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