F Plug A input not working?

[G4EWJ]

The 12v and F socket pins are accessible on the underside of the pcb inside the Serit. That's the side without the Serit logo.

I put a loop of wire in the feed to act as some sort of inductance, but there's so much signal level, you can afford to lose quite a bit. I can select Plug B and the RF PWR drops by 30dB while the MER drops by 1dB. I didn't see any significant change in RF PWR after doing the mod.

I also added a poly fuse. This one is 750mA, which is too high, but it was all that I had immediately to hand. Keep everything off the pcb, as there are many vias.

Brian

100_0902.JPG (831.65 KiB) Viewed 3177 times

[G4EWJ]

>> I also added a poly fuse.

. . . although a low current quick blow would probably be better, depending on what you're connecting to it. I measured the Octagon consumption as 130mA at 12v.

Brian

[G1BVI]

Thanks for that Brian, and the very clear picture. It would seem this is not an uncommon problem.

I was a little surprised because until a few days ago I had never actually used the top Input.

73
Nick