Why not just use an ALS500 from Ameritron? It should be fairly easy to retune
to MARS. I would even suspect that it could be used without rework at all. My
guess is there is no input band filtering, and it's likely the output filter is
simply a high pass filter for each band. Since it probably has good 2nd order
suppression, only 3rd order would be the requirement for the cutoff, that is
why many band selection switches include two or three bands on them at the same
time. Am I off base here or ? There are lots of solid state amps and plans
out there of sound design which are being used day in and day out. Tokyo
Hipower just to name one other vendor.
73s,
Paul
> ------------------------------
>
> Message: 2
> Date: Tue, 09 Oct 2007 23:09:02 -0500
> From:
> Subject: [Amps] How about a Solid State MARS amp??? fwiw
> To: amps@contesting.com
> Message-ID:
> Content-Type: text/plain; charset=us-ascii
>
> On Tue, 9 Oct 2007 12:35:13 -0400, "EP Swynar" wrote:
>
> >
> >The secret is a rotary tank coil, & flexible switching --- both OUT, as well
> >as in! --- of the plate tuning / plate loading capacitors...
> >
> >Happily, I have yet to find the resonant frequency of the plate choke,
> >because it's still intact! Hi Hi.
>
> I am now looking for the Dummies Guide Amplifier Jargon... no idea what you
> just said. would be glad to talk long range shooting, various aspects of
> intelligence analysis, 4GL SQL programming (what little I still remember of
> it) and hey, how about Carcinoid and other NeuroEndocrine Cancers???
>
> But I really need the basic book on amplifiers, how they work, why they work,
> etc. Hardly remember all that i learned about vacuum tubes from when I was a
> kid in the 40s and 50s. oh well. guess I need to lurk and keep searching for
> a good book.
>
> >The MARS freqs would be a cinch because of their close proximity to
> >"traditional" Ham bands.
>
> actually, I am not sure that 5mcy is within 1mcy of high or low of most band
> switches. (Mike at Ameritron techsupport said that their amps would hangle
> 1mcy either side of the markings on the band switches) Perhaps the low end
> might but the high end certainly is not.
> At least the high 6mcy freq would be reachable from the 40m band. But almost
> no radio or ham oriented amp will even consider 10 - 14mcy.
>
> there are probably about 20 freq just in those bands.
>
> About 7 of them in the 60m, etc. Really, you have to use a separate tuner
> between the txcvr and the amp to try to tune the radio to the point that the
> amp has a chance at matching - and that is especially for the tubes. which
> have narrower band width as we all know, than does the SState
>
> I do appreciate your confidence EP, but I would love to see a SS MARS
> amplifier built for a reasonable price. It would be capable of
> base/mobile/portable use and able to put out at least the MARS maximum of
> 500W. If that was possible, it would be worth buying a second amp for the Ham
> bands since there is a plethora of them. In fact there would doubtless be a
> market for a 2 or 3kw MARS or MARS/HAM amp just for the Feds
>
> I really think that quite a few of the 5,000 MARS stations would like very
> much to own one of these 500-600W amps as would most Fed agencies and many
> emcomm organizations which also access some freqs which are outside the Ham
> bands.
>
> Is it even possible to build such an amp? for about a $1 per watt SRP?
> It would need to be capable of HF phone and digital.
> 2m capability would be nice also just to keep from having to own a 3d
> amplifier..
>
> The amp would not have to have autotuning, or sensors to drive an adjustable
> antenna or a preamp, or other neat stuff A manually tuned amp would be quite
> acceptable and would help to bring the price down. Actually, just to show my
> ignorance some more, I would like to take the inductance selector from my
> Dentron MT3000A and use it to set freqs for a 10 pill amp which could be
> built
> into the chassis (wishful thinking) ... but heck, the Dentron tuner has
> transmitter matching caps as well as antenna matching ... all we would need
> would be to set the amp in the middle of those tuning devices (in my fantasy)
> for superb tuning . How to do it with all that bias stuff you all talk about
> is beyond me but dang! that 3000A will tune my 480HX into my BWD90 or my
> DX-CC almost to 1.125:1... iow, I need a magnifying glass to actually see if
> it isn't really flat.
>
> sigh, what dreams. but how about a MARS solid state amp??? oh heck, while we
> are wishing, how about a conversion to drop that amp into the 3000A ??? hihi
>
> This reflector is probably home to the most eclectic, best qualified amp
> designers, builders, etc of any discussion group on the internet. If such an
> amp as this which many of us would like to see built is possible, this groups
> has the knowledge and skill to do it. Just wish we could find a way to
> motivate the members.... well, thanks to all again.
>
> cheers
> 73/chas
> --
> K5DAM Houston EL29fu AAR6TU
> aar6tu@mac.com
>
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