>
>----- Original Message -----
>From: 2 <2@vc.net>
>To: <bearlabs@netzero.net>; AMPS <amps@contesting.com>
>Sent: Saturday, January 11, 2003 1:34 PM
>Subject: Re: [Amps] Re: Thunderbolt
>
>
>>
>>
>> >2 wrote:
>> >
>> >> >
>> >> >Around here Bill, KC2IFR (iirc) just put one on the air - AM, 75m.
>> >> >
>> >> >One of the things he found was that the input is a 350 ohm resistor...
>> >> >which makes matching to solid state trancievers a bit dodgy... He
>ended
>> >> >up using a matchbox between his rig and the Johnson...
>> >> >
>> >> >He says he tried changing it to just a 50 ohm resistor and it did not
>> >> >"work"... seems like it should have, but I wasn't there.
>> >>
>> >> A 200-ohm grid terminator fed through a 1 to 4 bifilar transformer
>should
>> >> work ok with c. 100w drive.
>> >
>> >Sure... should work fine... but he wanted to switch to a 50 ohm resistor
>> >in the slot - he said the thing wasn't happy...
>> >I'm not sure why actually
>> >and didn't look for too long at the schematic.
>>
>> ** A 50-ohm terminator needs to see c. 200w drive in order to provide
>> enough peak grid V in order to drive a 4-400 in AB1. It's no more than
>> basic Ohm's-Law.
>
>So it would seem, but he claimed to have way too much drive available as
>it was...
** 350-ohms is about right for 40W of drive.
>so he wanted to knock it down. That's what he said. As I
>mentioned, I wasn't there...
>
** The number of Extra-Class Hams who do not understand Ohm's Law is not
small.
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
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