----- Original Message -----
From: Steve Eldridge <g8izy@eurobell.co.uk>
To: <Amps@contesting.com>
Sent: 19 June 2003 15:28
Subject: [Amps] Longetivity of 4CX250B
> 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?
I'd guess it's not out of the ordinary in situations where the valve is
properly cooled, and has proper heater voltage regulation. I've seen 15 year
old PMR gear with original valves that still delivered full performance.
Steve
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