[Amps] How about a Solid State MARS amp

[kg7hf at comcast.net]

Hi Chaz,
Well, I think it is possible.  It has been done, there are pleanty of good designs that are available.  I sugest that you might read the ALS-500 manual, it says in the first paragraph that it covers the full frequency range from 1.5 to 21.6 Mhz, and looking at the front cover, that does seem to be the case.  It's not too hard to get 500 watts out of an FET these days.  Tokyo hipower is producing a legal limit solid state amp, and I know for a fact that the design they use can operate on 5 Mhz.   As a second fyi, I have an old 3-500z amp from Amp Supply, and just playing around, I could tune it on 5 Mhz pertty easily by selecting the 80 meter band select, and I could get about 900 watts into the dummy load.

Are you trying to build one or more, or what is the end goal?




-------------- Original message -------------- 
From: schuetzen <chasm at texas.net> 

> I know that one of our listmembers designed or helped to design the 1500 
> class of tube amps for Ameritron. I spent some time talking to the 
> techs at that site...hoping they know what they are talking about... and 
> they said that nothing they make is going to work on 5mcy or on 10-14 as 
> just a couple of examples. We were talking both tubes and solid state. 
> so, it looks as if it needs to be designed for continous 1.8-30mhz 
> "tuning". Can it be done? We know that supposedly the amps provided 
> the embassies, etc had them for their frequency hopping needs and I 
> would assume that Harris, Micom and others still make such amps. 
> 
> It is possible to create such then. the problem is how to do it and 
> make it portable without a 70lb+ transformer and give up autotuning or 
> whatever else is non essential in order to get the SRP down to the point 
> where the average volunteer would be able to afford such. 
> 
> so, the question still exists... can such an amp be designed ?? 
> thanks 
> chas/k5dam 
> 
> 
> kg7hf at comcast.net wrote: 
> > 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