Hi Rich,
I didn't mean to imply the RG58 needs to be cut to a magic length. Just use
a lot of it...an infinite length would create a perfect match to the
exciter, wouldn't it?
And BTW I was only kidding. It was a way to get in one last and final beer
joke...okay, I'm done with that!
"Each success only buys an admission ticket to a more difficult problem." --
Henry Kissinger
> -----Original Message-----
> From: 2 [SMTP:2@vc.net]
> Sent: Tuesday, October 09, 2001 8:25 AM
> To: Steve Katz; 'Steve Thompson'
> Cc: 'amps@contesting.com'
> Subject: RE: [AMPS] Tuned Input, what me worry
>
> >
> >Rather than build resistive pads, which involves calculating and
> soldering,
> >it's easier to just coil up a bunch of RG58/U and cut it to the right
> length
> >for the attenuation needed; then, open a beer and relax.
> >
> In my experiences, a longer length of RG-58/U seems to decrease input SWR
> of G-G amplifiers. However, there is no, single, magic length of coax
> for the nine HF amateur radio bands. The simplist solution is to use a
> tetrode (preferably with handles), neutralized, operating in Class AB1.
> When the grid's variable inductor resonates the grid-C on the operating
> frequency, SWR is minimal, and the tube is neutralized at the operating
> frequency.
>
> later, Steve
> cheerz
> >
> >"Each success only buys an admission ticket to a more difficult problem."
> --
> >Henry Kissinger
> >
> >> -----Original Message-----
> >> From: Steve Thompson [SMTP:g8gsq@qsl.net]
> >> Sent: Monday, October 08, 2001 11:48 PM
> >> To: amps@contesting.com
> >> Subject: Re: [AMPS] Tuned Input, what me worry
> >>
> >>
> >>
> >> -----Original Message-----
> >> From: Steve Katz <stevek@jmr.com>
> >> To: 'KG6DV@cs.com' <KG6DV@cs.com>; amps@contesting.com
> >> <amps@contesting.com>
To: <amps@contesting.com>
> >> Date: 09 October 2001 00:03
> >> Subject: RE: [AMPS] Tuned Input, what me worry
> >>
> >>
> >> >
> >> >Ron, doesn't a 1dB pad only provide 1dB of impedance stabilization?
> >> >
> >> >Think about it, and then have a beer. I'll have one, too!
> >> Nonono, beer first!
> >>
> >> Anyway, a 1dB pad provides a 2dB improvement - drive power goes through
> >> the
> >> pad, some or all gets reflected, goes through the pad again before the
> >> driver sees it. With 3 dB pad, you can't get worse than 3:1 VSWR, even
> if
> >> the output end is open/short/any phase. A 6dB pad guarantees you about
> 2:1
> >> max.
> >>
> >> Steve
> >>
> >>
> >> --
> >> FAQ on WWW: http://www.contesting.com/FAQ/amps
> >> Submissions: amps@contesting.com
> >> Administrative requests: amps-REQUEST@contesting.com
> >> Problems: owner-amps@contesting.com
> >
> >--
> >FAQ on WWW: http://www.contesting.com/FAQ/amps
> >Submissions: amps@contesting.com
> >Administrative requests: amps-REQUEST@contesting.com
> >Problems: owner-amps@contesting.com
> >
> >
>
>
> - R. L. Measures, 805.386.3734, AG6K, www.vcnet.com/measures.
> end
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
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