Orr 19th says " Optimum linearity requires cathode-circuit Q that can
only be supplied by a high-C tank circuit. " ( parallel tuned )
Don WA4NPL
Quoting "David H Craig" <davidhcraig@verizon.net>:
> The Orr Handbook 23rd Edition lists it as 120 ohms on page 15-18. I
> agree with Han-san, a Pi is best. Forget the "T".
>
> Dave N3DB
>
>
> ----- Original Message -----
> From: "Han Higasa" <higasa@plum.ocn.ne.jp>
> To: <amps@contesting.com>
> Cc: "JE1BMJ Han Higasa" <je1bmj@jarl.com>
> Sent: Wednesday, March 24, 2010 9:19 PM
> Subject: Re: [Amps] Tuned Input for G-G 50Mhz amp
>
>
>> hi all,
>>
>> In the book "Linear amplifier design book for radio amateur"
>> by Eimac I found "nominal input impedance of 3-400Z is 122 ohms".
>>
>> I also found "A 2 Kilowatt 3-400Z Linear for six meters" by
>> William I. Orr, W6SAI in this book but it uses two 3-400Zs
>> and direct feed via one 1000 pF coupling capacitor to both tubes.
>>
>> Another operating examples show the value around 100-130 ohms,
>> and Cin is around 8.3-pF in GG configuration.
>>
>> I recommend pi (Q=2) with C1 = 122 pF, L = 0.15 uH and C2 = 92 pF.
>>
>> I am using a pi circuit for my kilo-watt amp for six meter and still
>> experimenting a -VC(series)-L(series)-VC(parallel)-L(series)- type
>> circuit.
>>
>> See you soon on the band!
>>
>> de Han JE1BMJ
>>
>> ----- Original Message -----
>> From: <4z4tl@iarc.org>
>> To: <amps@contesting.com>
>> Sent: Friday, March 19, 2010 7:11 AM
>> Subject: [Amps] Tuned Input for G-G 50Mhz amp
>>
>>
>>> Hello all
>>>
>>> Trying to decide between a "Pi" and a "Tee" input circuit, for a 50Mhz
>>> single 3-400Z amp.
>>>
>>> (formerly AL-80A with 3-400Z and not the 3-500Z).
>>>
>>
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>
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