>? Hej! You made a three letter mistake Rich when you, in your answer to the guy
said " Up to about 200kHz, it is possible to construct a grid-driven
neutralized, triode amplifier, providing you use a triode with a Mu of 5
maximum." It should have been "NOT neutralized ", of course. Yes, in them
good old days hams used TPTG ( tuned plate - tuned grid ) triode
oscillators even at high powers. Some of those tubes used are listed in the
book I mentioned.
With some well shielded multigrid tubes , however, there is usually no
neutralizing required grid driven on the lower short wave bands. But you
have to reduce external feed back paths and use good shielding. More of this
in the RCA TT-5 Technical Manual on transmitting tubes.
Grid driven neutralized triode linears where often used in the fifties, even
commercially. JOHNSSON made a such a linear with 300W out using 811A's. I
know - I just sold mine, hi! I believe it was very often used with the
popular CENTRAL ELECTRONICS 20A that delivered the 20 watts pep needed for
this linear.
Hej daa! de SM5KI Hans
>
----------
>Från: "Hans Goldschmidt" <sm5ki@algonet.se>
>Till: measures <measures@vcnet.com>, AMPS <amps@contesting.com>
>Ämne: SV: [AMPS] figuring tank Zbased on loaded Ep?
>Datum: fre 22 okt 1999 08.02
>
>
>You must be joking Rich? I have in front of me en old manual on transmitting
>tubes: The RCA AIR COOLED TRANSMITTING TUBES from 1938 and plenty of
>grounded cathode neutralized finals there. We used neutralized high mu
>triodes til up in the fifties, remember. Nothing unusual then, Rich?
>
>I will try to test a grounded cathode, grid driven and a( high mu triode
>connected ) 8072s or 8122s with 50 or 22.5 ohms dummy across the input.
>Eventually with undecoupled cathode resistors to improve linearity and
>stability. At least at 80 meters it may be stable. On other bands it may
>eventually oscillate.
>
>The above manual is for sale. Any bids?
>
>Hej daa! de Hans SM5KI
----------
>Från: measures <measures@vcnet.com>
>Till: "Hans Goldschmidt" <sm5ki@algonet.se>, "AMPS" <amps@contesting.com>
>Ämne: Re: SV: [AMPS] figuring tank Zbased on loaded Ep?
>Datum: fre 22 okt 1999 11.07
>
>
>>
>>You must be joking Rich?
>
>? no
>
>>I have in front of me en old manual on transmitting
>>tubes: The RCA AIR COOLED TRANSMITTING TUBES from 1938 and plenty of
>>grounded cathode neutralized finals there. We used neutralized high mu
>>triodes til up in the fifties, remember. Nothing unusual then, Rich?
>>
>? I remember that they were Class C. Is Class C linear?
>
>cheers, Hans
>
>>......
>
>- Rich..., 805.386.3734, www.vcnet.com/measures.
>
>
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>
>
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