>
>
>-----Original Message-----
>From: amps-admin@contesting.com [mailto:amps-admin@contesting.com]On
>Behalf Of Richard
>Sent: 01 July 2002 23:34
>To: AMPS
>Subject: Re: [Amps] 4CX250 IMD
>
>
>
>
>>
>>
>>> Compared to poor regulation, yes. Compared to a well-engineered zener
>>> shunt screen regulator, probably not a significant improvement. To
>>> arrive at good linearity with a 4cx250B/R/BC/7203, load for less screen
>>> current, use maximal anode supply V. and add c. 5-ohms of RF-NFB R in the
>>> cathode (Rk). See Fig 10 on my Web site.
>>>
>>> >G3SEK is vacationing in the states at the moment, but he gets
>significant
>>> >improvement in IMD suppression with the tube by holding the screens
>>within
>>> >millivolts using active regulation.
>>
>>You might take a look at his website, he compares the active regulator to
>>the active regulator with an 150 ohm series resistor to raise the impedance
>>of the regulation, (Probably no worse than the Z of VR tubes or zeners) and
>>a zener string with 100 uF to stabilize the transients (By far the worst of
>>the three tests).
>
>** Would you trust a stock buy recommend from a brokerage that gave
>salesmen a commission on stock sold?
>
>
>Huh what does that mean?
>
** I built a 2 x 4cx250 2m AB1 amplifier with a conservatively run zener
shunt screen regulator. It was as clean as Eimac claimed. // It means
that foxes should probably not be entrusted with hen-house security
evaluations.
> ...
cheers, Conrad
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
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