Re: PD526 Duplexer Tuning
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Remove all cables and tune each cavity individually - tune the pass for best match (return loss), then set the notch.? As long as the notch wasn¡¯t far off from where it needed to be, adjusting the notch will not ¡°pull¡± the pass.? Then harness everything back together and check the results ¨C it should meet or exceed spec. ? The factory tuning instructions assume you only have a signal generator and some means of detection.? It is decidedly a dumbed-down approach that is going to lead to mediocre results at best. ? ??????????????????????????????????????????????????????????????????????????????? --- Jeff WN3A ?
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From: [email protected] <[email protected]> On Behalf Of Part 15 Engineer via groups.io
Sent: Wednesday, April 23, 2025 9:02 AM
To: [email protected]
Subject: Re: [repeater-builder] PD526 Duplexer Tuning? Well, per the suggestions here I did get it tuned up and it looked textbook on my r2600 but when I put it on the quantar the quantar went into pa fold back high vswr. I've never had that happen before when a duplexer looked good on a service monitor. Back to the drawing board. Try different known good cabes and retune it and see if maybe I had a bad cable throwing off readings. ? Found the instructions here: Instructions used an RF millivolt meter for some of the adjustments but I used an HP 8920A service monitor with 6dB pad at the end of the test cable.?
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