Swedish military warmed- up transmitting tubes with a few years interval
when in storage.
73s de Hans
>Från: "Ian White, G3SEK" <G3SEK@ifwtech.com>
>Till: amps@contesting.com
>Ämne: Re: [AMPS] heating tubes....
>Datum: tor 7 sep 2000 11.05
>
>
>measures wrote:
>>
>>>
>>>measures wrote:
>>>>? I have tested many metal anode-cooler 3-500Z tubes that g/fil. shorted
>>>>after a big-bang. The majority had under 3uA of grid/anode leakage at
>>>>8000v. The subsequent autopsies revealed no arc marks on the grid.
>>>
>>>The reasons for observing low gas currents if you delay more than a few
>>>seconds after the event have been explained many times - "it's the
>>>gettering action".
>>>
>>In almost all cases, the mains breaker or mains fuses opened at the
>>big-bang. .
>>
>>>Does testing 3-500Zs cause amnesia?
>>>
>>Gettering in cold 3-500Z's?. Only in the Rauchian world.
>
>If there is a chemically active surface (hot anode), gettering in a tube
>the size of a 3-500Z occurs on a timescale of seconds.
>
>It only takes a very small release of trapped gas impurities to trigger
>an arc. If the tube was running and the anode was hot, that gas will be
>mopped up again before the anode cools. By the time you can get the tube
>to a hi-pot tester, the gas will probably be long gone.
>
>But you've been told that several times before: hence my comment about
>amnesia.
>
>
>73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
> 'In Practice' columnist for RadCom (RSGB)
> http://www.ifwtech.com/g3sek
>
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