Thanks Kevin,
This was a diplexer that was on my 443 repeater.? ?I bought the repeater/diplexer as a package years ago.
It always had a 25% reflected out of the transmitter.? ? I had been looking at some broadcast FM filters with notches, and before I put the Nanovna up, I thought this would be a good time to look at the WACOM.? The S11 looked horrible.. not at all as I expected.? ?I purchased the repeater years before the Nanovna was introduced.
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I found that the capacitors? were on the wrong frequency side of the notch? ( all these years ) .... After I saw the effects of the capacitor, it took a few back and fourths to get the null and the broad peak separated by 5Mhz .? ?By the way, the Nanovna-F was calibrated nuts-on on both 443Mhz and 448Mhz.? ? -1.35 and -21.25? were the single cavity readings.
Combined, there was some minor tweaking that had both notches aligned and both rejects aligned.? ? I tightened everything up and the notches stayed on frequency.
Back in-line and zero reflected on the transmitter. Great !!? ?I'm looking forward to seeing a much improved range on the repeater.? ? Thanks Again Kevin
Don W4DNR? ? WA4NPL/R? 443Mhz
