I am just about to retire a 4CX250B that was second-hand when I put it
into service on 144MHz in a homebrew amp. That was in mid 1998, since
then it has been powered up continuously- ready to go at a second's
notice, with the odd power outage being the only break .i.e 99.9999% of
the time as it restarts automatically.
In that timespan this valve has worked 41 DXCC and 194 grids on 2metres
and always provided the RF (250W) when needed, despite long periods of
inactivity on standby and also some severe abuse.
I calculate that this valve has been running (with heaters and HT) for 5
years or 43800 hours plus any other use it had in it's previous life.
I find this amazing. Is this normal or was I just lucky?
73 Steve G8IZY
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