>Roger, Rich; I'm still where I have been :
> I think the only question is what wattage rating to use for the resistor,
>and I don't have anything of that nature anyway. Seems it might have to be
>at least 50 watts, maybe more.!! However, considering the "on " time , for
>SSB maybe not.!!!
** The typical duty-cycle for SSB 2-way is c. 15%. I stock some
low-L,3W-CCS @70?C Matsushita MOF resistors that will easily do 15w each
in SSB service. With the ultra-fast diode shipment, I will include
enough of these resistors to series/parallel and make a 50-ohm, or
60-ohm, or 70-ohm termination at 100w pep SSB. // These resistors are so
durable they can be operated glowing dull-red in the dark, which is 12w
continuous diss.//
.
> what's your guess??
> carl / kz5ca
>----- Original Message -----
>From: "2" <2@vc.net>
>To: "carl seyersdahl" <carlseye@tampabay.rr.com>; " AMPS"
><amps@contesting.com>
>Sent: Friday, May 02, 2003 10:06 AM
>Subject: Re: [Amps] G-G Amplifiers With No Tuned Input.
>
>
>>
>>
>> >Rich: that sounds like an interesting idea.!!
>> > I'm working on a gla1000, plain model, modified with
>> >EL509's, and would love to test such an idea. I have tried several other
>> >things, like tuned inputs, a broadband input transformer, and not had
>much
>> >luck . what is the no. of the diode you mentioned.???
>>
>> ** I purchased ten of 'em to distribute free for R and D. Are you still
>> at 7509 Wakulla Dr. ?
>> -- My guess is that the input terminator R that the diode goes in series
>> with should be 50 - 75 ohms. If you try the idea, please post your
>> findings on AMPS. Need a termination R ?
>>
>> have phun, Carl
>>
>> > carl / kz5ca
>> >----- Original Message -----
>> >From: "2" <2@vc.net>
>> >To: " AMPS" <amps@contesting.com>
>> >Sent: Thursday, May 01, 2003 3:27 PM
>> >Subject: [Amps] G-G Amplifiers With No Tuned Input.
>> >
>> >
>> >> Amplifiers such as the MLA-2500, SB-230, 374, 78, and 76PA have no
>tuned
>> >> input. This is not a problem when such a g-g amplifier is driven by a
>> >> tube-output radio such as the TS-830S. The reason is that although the
>> >> input Z of a cathode-driven triode fluctuates from roughly 1/3 of the
>> >> average driving Z on negative peaks to a virtual open circuit on
>positive
>> >> peaks, the Pi-network tuned circuit in a tube-output radio acts as a
>> >> flywheel to smooth out the Z fluctuation at the cathode/s. However,
>with
>> >> modern solid-state radios there is no tuned output, so something is
>> >> needed to smooth the Z fluctuation. A possible workaround, short of
>> >> adding a bank of tuned input circuits, might be to put a ultra fast
>> >> recovery diode in series with the input terminating R. The diode is
>> >> oriented so that the terminating R conducts only when the driving
>> >> potential is positive -- which is when the tube is not conducting..
>> >> Thus, on the negative half of the driving cycle, when the tube has a
>low
>> >> driving Z, no driving power is lost in the terminating R and the driver
>> >> should see a lower SWR.
>> >> - - Unfortunately, I do not own such an amplifier to test the idea on.
>> >> If anyone out there has such an amplifier and is willing to test this
>> >> idea, please inform me and I will send you a freebee 2A, 35nS, 300v
>> >> switch diode.
>> >>
>>
>>
>> - R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
>> www.vcnet.com/measures.
>> end
>>
>
>
>
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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