Re: VTTC from Eimac 8755 on eBay

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>

The specs sound amazing for such a small tube, but
when you look further down the datasheet, it says
something like:

Pulse duration: 6uS

So, rather than staccato, you'd probably want to run
filtered DC with something more like a SSTC
interruptor, since a half-wave at 60Hz lasts over 1300
times longer than 6uS! :-)  Then again, if you built
such a controller, it might be just the thing for
using other pulse-type tubes.  I have some radar
modulator tubes that are rated for short pulses at up
to 15kV.  Might be fun to try some of those and see
what happens :-)

Regards,
Aaron, N7OE


--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: westland <westland@xxxxxx>
>
> *I'd like some advice from the group on a VTTC ...
>
> There is an Eimac 8755 RF Triode available on
> eBay, which seems to me would work well as the
> core of a reasonably powerful VTTC.   135
> amplification, 3GHz max freq, Anode V 8Kv and Amp
> 7.5A ... apparently you can cool it with fluids,
> so it seems you could make a pretty powerful circuit
> with it.
> Would this be a good choice (with appropriate
> power source ... suggestions?) and John Freau's
> Staccato controller?
>
>
> Here are the **Eimac 8755 specs*
>
> *Amplification Factor (µ):* 135.0
> *Anode Current (A):* Maximum 5.0
> *Anode Voltage (kV):* Maximum 10
> *Brand:* Eimac
> *Cooling Method:* Forced Air
> *Filament Current (mA):* 1,300
> *Filament Voltage (V):* 6.300
> *Frequency (MHz) Maximum:* 3,000
> *Peak Anode Voltage (kV):* 8.000
> *Peak Cathode Current (A):* 7.500
> *Transconductance (µmhos):* 30
> *Typical Anode Current (mA):* 1,000
> *Typical Anode Voltage (V):* 1,750
> *Typical Grid 1 Voltage (V):* -100
> *Typical Power Out (W):* 650
>
> --
> ____________________________________________________
>
> J. Christopher Westland, PhD CPA
> Professor, ISMT, University of Science &
> Technology, HK Clearwater Bay,Kowloon, Hong Kong
> Tel: 852 2358 7643
> Fax: 852 2358 2421
> Mob: 852 9528 1745
> URL: ihome.ust.hk/~westland
> Mobile e-mail: chris.westland@xxxxxxxxxxxx
>
>
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>