From: Chris Wilson <dead.fets@gmail.com>
Date: Fri, 28 Apr 2017 15:31:48 +0100
Message-ID: <1169052721.20170428153148@gmail.com>
To: DK7FC <rsgb_lf_group@blacksheep.org>
In-Reply-To: <59034659.9000800@posteo.de>
References: <1106627522.20170427150315@gmail.com> <5901FD30.5010902@posteo.de> <1907129228.20170428123626@gmail.com> <59033D72.80705@posteo.de> <116328997.20170428142923@gmail.com> <59034659.9000800@posteo.de>
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Subject: Re: LF: Varistor spike management
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Status: RO

Hello DK7FC,

Friday, April 28, 2017, 2:40:41 PM


Amp circuit and info here:

http://www.w1vd.com/137-500-KWTX.html

I use the W1VD LPF set up too, a total copy of Jay's design

http://www.w1vd.com/LPF.html

This goes via RG-213 to a matching transformer outside to match to
tapped ferrite wound antenna impedance transformer, and then my big
loading coil, which in turn feeds a strapped ladder line vertical
feeder and my big horizontal quad loop aerial as the top hat. A
Scopematch shows perfect Volts to Amps balance when the variometer is
set to match TX frequency


Driver is a QRP Labs U3S, lots of people use these with the output
taken straight from the Si5351A device clock outputs at 2X frequency.

http://qrp-labs.com/ultimate3/u3s

Thanks Stefan

> Hi Chris,

> Maybe you can show a drawing of your whole PA schematic, including the
> driver and so on. I still don't fully see what you're doing there...

> 73, Stefan


-- 
Best regards,
 Chris                            mailto:dead_fets@gmail.com