Mike,
The Array Solutions device also uses the transformers to increase the
voltage at the diodes then steps it back down which means that the diodes
are not doing their limiting at 50 ohms. Therefore, your set of 2 series
diodes or even one diode each direction is limiting at a higher power level
than the Array Solutions device.
>From the QST article.
"The transformer increases the voltage level to allow limiting by a pair of
back-to-back diodes and then another transformer matches the output to a 50
ohm receiver input."
Jim - KR9U
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Mike
Waters
Sent: Sunday, August 30, 2015 6:23 PM
To: marcom@centrum.cz
Cc: topband
Subject: Re: Topband: KD9SV-OK1RR relays ??? (RX Front End Protector)
That's similar to mine, but mine has two 1N4148 diodes in series,
back-to-back, total of four diodes.
However, after I did that, I got to thinking that it would be better with
only two. Or that there was no need for four. (Don't ask me to explain, it's
been a long time since I've thought about that.)
73, Mike
www.w0btu.com
On Sun, Aug 30, 2015 at 5:00 PM, Martin Kratoska <marcom@centrum.cz> wrote:
> Array Solutions offers a 'RX Front End Protector' based on
> back-to-back
> 1N4148 diodes.
>
> Schematic:
> http://www.ok1rr.com/public/rxfep.png
>
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