Thursday, January 12, 2012

Trials and tribulations

I'm sorry if you are one of the many people who have sent me email expecting a reply, but unfortunately answering emails is one of the things I very often never get around to. Although it might seem from the blog that I am getting back to normal, everything I do still takes me a lot longer than it did when I was fit and well and I'm more prone to making stupid errors. I'm happy that I'm still able to do some of my ham radio activities but what I achieve is often accomplished only after a lot of frustration.

Today the Simple Keyer Chip from Steve Weber arrived in the post. I verified the behaviour of the chip I'd programmed, then replaced it with the new one. I was pleased to find that it now operated at the correct speed - the sidetone was now audible to humans rather than bats and the default speed was rather more sensible. Obviously I'd messed up some setting of the programmer - but the keyer still ignored the dot paddle. I began to suspect that this meant there was something wrong with my wiring, but between my limited field of focus and my shaky hands it took the entire morning - culminating in a lot of bad language - before it eventually dawned on me what was the trouble.

To cut a long story short, the cause of the problem was the 3.5mm socket I was using for a key jack. It had three terminals which I thought were for tip, ring and sleeve, dash, dot and ground. But it was a mono socket! There was no ring connection. One of the three terminals was linked to the other and disconnected when the plug was pushed in, intended to silence a speaker when phones were plugged in. It took me an entire morning including checking the wiring of two morse keys before I discovered my stupidity.

I hunted in my parts drawers and eventually discovered a proper 3.5mm stereo socket. After connecting that in place of the other one I confirmed that the keyer worked as expected. But the frustrating search for the solution had made me tired so I decided to leave the task of drilling the box and finishing the keyer for another day, thereby adding to the list of unfinished tasks alongside the unanswered emails.

Another thing that annoys me is my Rapid Electronics HY3003D bench power supply. It has a rather inconvenient fault for a power supply that is used in a radio shack. The voltage regulation circuit suffers from RFI. If any of my radios transmits, the voltage increases. In some cases it could increase to a level that could damage the circuit I am testing, though fortunately that hasn't happened yet.

I don't always remember to put my APRS gateway or the WSPR (or Opera, which I have been testing today) beacon into receive-only mode whenever I'm working on something. (I've tried clamp-on RFI suppression ferrites on the mains lead and they made no difference.)
Post a Comment