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Ok, I'm tuning the pd526 on the nvna. I can't seek to get everything to line up on both reject and pass simultaneously. It seems to be one or the other. I have attached pic of my latest plot. This is the best I got it so far. I did tune cavities individually then hook them together. And I got multiple peaks and valleys on the plot instead on one nice peak on the pass and valley on the reject. Does anyone have a link to the plot for the pd526 and what it should look?like?

Thanks

On Thu, Apr 24, 2025, 6:47?PM Part 15 Engineer via <kc8gpd=[email protected]> wrote:

I think I finally got the pd526 tuned. It has 1db difference in sensitivity between direct input and going through duplexer and very little tx power loss coming out of duplexer. Probably only a few watts of loss. Tomorrow I will do some field testing to see if it gets put as far as the txrx 28-70-15h duplexer I was using. I'm not seeing any signs of desense yet.

On Thu, Apr 24, 2025, 10:05?AM Ralph Mowery via <ku4pt=[email protected]> wrote:

It will have the opposite effect.? To get more dynamic range you would really need an amplifier or a way to drive in more signal.? The pads are just to match the impedance as the output/input terminals may not be the nominal 50 ohms.? That is just for the notches.? If tuning the pass with a RLB do not use a pad as this will give a false match/very low RL .

Ralph ku4pt

On Thursday, April 24, 2025 at 11:28:09 AM EDT, Part 15 Engineer via <kc8gpd=[email protected]> wrote:

Will a pad give the nanovna more of a dynamic range to see? the notch depth? Iirc the dynamic range of a standard nvna is about 60 to 80db. So if I put a 10 or 15db pad that should help with tuning the notches?

On Thu, Apr 24, 2025, 9:14?AM Mike via <prcradio=[email protected]> wrote:

Pads can be helpful on the generate side of a VNA providing a good resistive match to the device under test. Many years ago working at Hughes Aircraft we always terminated our generate cables with a 6dB pad.?