It is a high pass and a low pass filter. You're checking DC continuity. A high pass will block DC so it won't beep.

Not sure why you're troubleshooting the 70 cm side if you can't hear ISS SSTV transmissions which are on a 2 m downlink at 145.800. Always check the ISS status page (google "ARISS station status") before you try to work the ISS, or if you have trouble hearing anything just to confirm that the stations aren't shut down for a docking/undocking/space walk. This happens regularly including during SSTV events. No sense tearing things apart if they're just QRT up there. Cool to see the duplexer guts though.

At 2 meter side, resistors in series connection but the 70cm side, capacitor in series so there will be no continuity reading.

@watson946

Жыл бұрын

Not resistors, they are inductors, but as you say, 2m will show continuity and 70cm won't👍

Thanks for taking your antenna apart. I always thought it was just straight up metal

@FuzzThePiGuy

Жыл бұрын

👍

A simple test with two 2m radios is to set up an HT on 146MHz with rubber ducky antenna and another radio setup on 146Hz connected to the 2m side of the arrow antenna (reconnect the Diplexer's antenna connections). Transmit on the HT at lowest power setting about 25 ft from the arrow and listen on the Arrow's radio on same 2m frequency. Perform the same test on UHF band for both radios. Increase TX power to maximum 5W and check Radio's RX signal level against calculated level. An oscilloscope measurement at various points along the 2m low pass filter chain can show where there may be a bad component, short or open. Repeat for the 70cm filter chain.

I was curious about this. You've done a great job. Appreciate it

@FuzzThePiGuy

Жыл бұрын

👍

Fuzz did you ever get it sorted out.