Yes it is a home made duplexer that appears to be the chief culprit. I tested the uplink solo and it has good swr at 146 but about 1.5:1 at the desired 145.9 so I need to play with the DE length. When I test it solo again with the splitter I'm back in the red. I'll lnk the splitter plans when I get home.
Originally Posted by WB3BEL
The antennas look kind of like WA5VJB cheap yagi. If that's what they are and you followed the dimensions accurately they should work fine.
But what looks a bit confusing to me is how you combine the 2m and 70cm antenna feedlines together. The image is a bit hard to see...
Is that some kind of diplexer in the middle where the coaxes join? Or is it merely a Tee splice of coax? If its just a Tee splice. Then it probably won't work.
Unless you specifically engineer the coax lengths and antenna impedance in the other band so that the joint forms a crude diplexer the mismatch from the other antenna and coax will mess up the VSWR.
Your plan to look at the VSWR of each antenna separately is a good troubleshooting strategy. Good luck with your project.
I haven't been able to test the 70cm downlink antenna SWR yet, but we (kids and I) just picked up the beacon from CO-65 with it. We heard the CW but not as a tone, it came through as squelch breaking static in CW pattern. Granted I don't know morse code, but know enough to recognize a pattern.
I had to retune due to Doppler and would lose the signal when moving the antenna so I'm certain we had the sat.
My question now is this... was I not getting the tone due to the antenna, or could it be related to the sat passing between my location and the sun?