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:[email protected]] On Behalf Of Mike Waters Sent: Sunday, August 30, 2015 6:23 PM To: [email protected] 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 <[email protected]> wrote: > Array Solutions offers a 'RX Front End Protector' based on > back-to-back > 1N4148 diodes. > > Schematic: > http://www.ok1rr.com/public/rxfep.png > _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
