I’ve been working on a cure for a problem encountered during long RTTY QSO’s where the transceiver will drop out of transmit and lock up. Initially, I thought this might be due to RFI. So I tried some ferrite clamp-on devices on the K3 to P3 to Computer control cables. Next I read up on RFI cures and came across K9YC’s suggestion to use CAT-5 or CAT-6 cable rather than standard RS-232 cables. So, I set about on a small adventure building a set.
The first approach I took was to adapt converters for RJ-45 connector to DB-9 connector. This would allow me to use standard RJ-45 CAT-5 or CAT-6 cables. I was able to make up one set but really had trouble on the second set. So I abandoned that approach and purchased DB-9 solder connectors. This morning I was finally able to build the two cables needed to connect the K3 to the P3 and then P3 to the computer.
The cables work great but the problem remains. Now I’m not sure it’s due to RFI. Plus, an interesting twist has been added, perhaps an improvement. With the RS-232 cables the K3 would lock up and I’d have to shut down N1MM and turn it back on to recover. With the CAT-6 cables I’m now able to just switch to receive and get it back up and running. That could be an improvement or perhaps I just didn’t tumble to this recovery option in past attempts. Gee whiz. At least with the short QSO’s in contests I do not encounter this problem. More later on this adventure.