Well, that's certainly true, Lee. I was just wondering aloud, if the
transformers were indeed 1:1, if the point might be common-mode isolation
like we work to achieve in the transformers of our flag, pennant and KAZ
antennas - although in those cases the matching transformer also matches the
50/75 ohm feedline to a higher impedance of 800-1000 ohms.
73, Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Lee K7TJR
Sent: Monday, August 31, 2015 12:17 AM
To: topband@contesting.com
Subject: Topband: KD9SV-OK1RR relays ??? (RX Front End Protector)
Sorry Charlie, I don't think I made my thoughts very clear.
James was quoting from a QST article that there was an impedance
transformation because of the transformers.
This was to make a higher voltage at the diodes. My point was that if the
transformers being used on their circuit board are 1:1 then there is no
impedance transformation and the diodes are fed with the straight RF from
the RX antenna at the 50 ohm level. The design must have changed after the
QST article or something. The QST description is incorrect if they are using
1:1 transformers as shown in their circuit board pictures.
Lee K7TJR
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