Date: Sun, 2 Nov 2025 06:03:39 -0500
From: "Bob D." <ajamas.rn@gmail.com>
To: amps@contesting.com
Subject: Re: [Amps] 12 KW CCS ON 160-15M....USING THE 3CX-6000A7.....
PART 35
>Please correct me if I'm wrong. I'm an old fart but novice amp constructor.
>If amp is to be used strictly with a modern exciter that employs
>"pre-distortion", I can do away with a lot of filter capacitance. Then no
>need for soft start and glitch protection, if needed at all, will not need
>to be as stout.
>Considering for my 6m amp project using a gs35b. Also, plan to use metal
>film caps in the supply. Very low ESR, self healing, don't dry out, and are
>becoming competitive with electrolytic caps, thanks to electric vehicles
>use.
>73, Bob ah7i
Pre-distortion, like the ANAN 7000/8000 if wrapped around the amplifier,
results in reduced IMD.
Nothing to do with the B+ supply filtering.
Watch out with those metal film caps. I looked at this a few months
ago.....and when they cut loose, they really go kablamo. They are not
polarized. I looked at several brands, and they all say 'low ESR' yet
don't spec the exact resistance at 100/120 hz. And none of em had a
listed spec for leakage current nor the most important spec of all.....
CCS ripple current at 100/120 hz. We are only interested in the 100/120
hz ripple current spec...not the 10 khz ripple current spec.
Without a ripple current spec, they are off my short list...at least for
now. I can't find anybody who has used the metal film caps.
Get on the https://groups.io/g/ham-amplifiers group. I posted 25 x
pix of a 2 x GS35B 6M amp. The 6M amp does 5 kw out on 50.125 mhz.
Originally it started off as a single GS35B.
There is also a hb 8877 6M amp on there, again, with several pix.
Jim VE7RF
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