Yes, I agree, the ALS600 would be better, I'm not advocating for the 500, what
I was really trying to get at was there are good and viable options already
available. I was thinking the requirements were the ability to operate from a
12v battery. Now that I understand better, the requirements are legal limit,
and 110v operations, with the financial requirement of $1/watt.
My feeling is that $1/watt requirement is going to be difficult to do in a
commercial venture either in tube or solid state, so the requiremetns are
flawed from the begining. Throw price out of it, and now get the Tokyo
HiPower, the HL-2.5k (did it get type approved yet?) or look at the Dishtronix
Prometheus just to name a few easily found options.
I am not quite convinced that the Ameritron amps are "tuned" to ham bands.
From what I have seen of the solid state FET amps is that the input is
broadband matched, and the output if filtered using simple low pass filters for
each band. This is fairly evident in looking over the HL-2.5K schematics. My
unfinished homebrew HL-2.5K will definately work out of band. Looking at the
ALS500 and 600, it's likely this is the case there as well, and the amp could
easly be used on the mars bands.
One thing that I don't understand is the requirement for solid state. If the
request is to run from 110v and produce legal limit from 1.5 - 30 mhz, why not
go tube and a switching power supply? That could be done and be rugged and
light weight (probably not for $1/watt though). The real weight is in the
power supply anyway with either solid state or tube.
Paul
------------------------------
Message: 8
Date: Thu, 11 Oct 2007 07:23:46 -0400
From: "Tom Rauch" <w8ji@contesting.com>
Subject: Re: [Amps] How about a Solid State MARS amp
To: <kg7hf@comcast.net>, "schuetzen" <chasm@texas.net>
Cc: amps@contesting.com
Message-ID: <004c01c80bf9$35bcff80$640fa8c0@radioroom>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
> 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.
I would never use a ALS500M at home. It really is intended
for applications where you only have 12 volts and aren't
using a good station.
I would get the ALS600 FET amplifier. It is much cleaner.
By the way, contrary to misapplying books and rumors, ALL
type-accepted amplifiers have to pass FCC requirements for
harmonics. Any Ameritron amp will always be at least several
dB better than minimum requirements (around -45dBc) for
harmonics. The problem is odd-order IM products that create
splatter. Not all amps are equal, and it is NOT the
filtering that matters.
The tuned input of a GG amp, by virtue of the driving
impedance at harmonics, can greatly affect harmonic levels.
This is because the cathode circuit can affect waveshape of
the anode current on a fractional cycle basis.
73 Tom
>
>
>
>
> ------------------------------
>
> Message: 9
> Date: Thu, 11 Oct 2007 09:48:09 -0500
> From: schuetzen
> Subject: Re: [Amps] How about a Solid State MARS amp
> To: kg7hf@comcast.net, amps@contesting.com, chasm@texas.net
> Message-ID: <470E37A9.8020400@texas.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> kg7hf@comcast.net wrote:
> > 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?
>
>
> actually, I ran this thread idea past one of our state MARS nets Tues
> and got several people wanting to be kept abreast of what I found out,
> etc. As I stated in the beginning message for this thread, I would
> like to ask the list membership here to understand what we are wanting
> which is a broad tuning amp, preferably solid state for its mobility for
> base to mobile to portable set up and back again, and capable of running
> legal limit since it would be used for 1.8 - 30mhz. Continuously.
>
> Problem is, nearly all amps out there are HAM BAND tuned. MARS as most
> or all MARS members here know, operates on a bandplan outside of the HAM
> bandplan. Including bands from which hams are excluded. Such as
> 10-14mhz. This amp would be capable again, of operating on all HF bands
> to help the member or affiliate to justify the expense of the amp - he
> would be able to use it on ham bandplan also. So, a SSB, at least 1kw
> output, full HF bands and solid stste. isfai am concerned, it would be
> a 110VAC so that it would run off an inverter in the field or, mains in
> base mode.
>
> I would then like to ask the membership to design this and help me to
> find someone who would be willing to build as many as 5,000 of them or
> as few as a 100 or so. price should be held to a $1 per watt or less if
> possible.
>
> We have more than 5,000 volunteer affiliates now and I think that a lot
> of ARES/SHARES, etc would be very interested in such an amp.
>
> I really believe that there is a market for this amp if we can get it
> into production.
>
> I am not even about to try to build one from a kit even I know
> enough to electrocute myself trying to get it aligned or whatever that
> is called today.
>
> thanks for your interest and reply
> chas k5dam
>
>
> ------------------------------
>
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> End of Amps Digest, Vol 58, Issue 19
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