Hi Dave and the group,
Indeed Motorola application notes have been of great benefit to builders of
solid state HF amps (VHF too).
What you need to ask for is the "RF Device Data" (DL110) book. Get the
latest revision. I get mine from Ron Kates of Penstock at 818 593-8456 or
page him at 888 512-9915. He can supply the devices too.
Solid state amps today have possibilities not available before. They can
handle more power into more difficult loads than ever.
For example, the HENRY solid state amps will let you do as you please and
will only do a self protect based on heat. So, if you operate into a bad
load at full power for contesting use you may get hot enough if the power
and SWR is high enough. But the point is you CAN operate there for a while
before the thermal sensor kicks in. I use a Force12 C4XL antenna and it has
nice SWR on 20-15-10 (and the portion of 40 it's tuned for) but 3:1 SWR on
12 & 17M. The antenna works there but just has high SWR. The HENRY works
just fine into these loads at full power.
Instant on with NO WAIT, and no tune that's what you'll get!
A popular no tune tube type design will click off if you even temporarily
hit it hard with a voice peak and has even a 1.5:1 or so SWR. I have seen it
at a friends station! Then he waits for warm-up again.
For $6K plus you could build yourself one heck of solid state amp and still
have money left to buy a few radios, and antennas and feedline
and.................
73, Dan Magro
Radiodan W7RF,
High quality Henry Radio RF Power Amplifiers for LESS!
http://www.radiodan.com RFpower@radiodan.com
A trip to our web site is worth the click!
-----Original Message-----
From: Dave D'Epagnier <DAVED@ctilidar.com>
To: 'amps@contesting.com' <amps@contesting.com>
To: <amps@contesting.com>
Date: Tuesday, June 02, 1998 7:48 AM
Subject: [AMPS] Solid State 1kw amp
>I'm intrigued by the prospect of not having to fuss with tuning every
>time I change frequencies and especially not having to obnoxiously tune
>up on the air.
>So, I'm looking into designing and building a 1-1.5kw broadband solid
>state amplifier that needs no tuning, and considering using Motorola
>MRF-150s and combiners. Has anybody out there done this? If so was your
>resulting linearity acceptable, what transistors did you use, and what
>sort of power supply did you come up with? Would you be willing to
>discuss your results with me?
>Also of interest is possibly a broadband tube amp design requiring no
>tuning on the HF ham bands, any input is appreciated.
>
>thanks,
>
>Dave
>
>--
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>
--
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