Sunday 25 April 2010

Introducing Felix - the Station Cat

After all the recent discussion of dead mice, it seemed only natural to get a cat!

Let's be quite honest about this - I don't like cats. Principally because I am allergic to them (more precisely, I am allergic to most of them). What's more, in truth, I find most cat owners mildly irritating too!

Still, this time I decided to put aside my prejudices, make an exception and allow a cat into the shack...

The cat in question isn't the allergen mentioned above - rather a Computer Aided Transceiver ("CAT") interface for the new FT 817.

I started off experimenting with a fancy circuit, using a MAX232 chip and some opto-isolators (loosely based on OK2FJ's work) but I was getting nowhere in a hurry, so I abandoned all and went back to KISS principles.

Here's my final schematic, which derives power from either RTS or DTR on the PC's serial port (selected by jumpers) or from an external supply and retains optional RTS control for PTT (which I was using previously)...



I designed a PCB using the excellent Eagle CAD package...



and made a few PCBs using the toner transfer method...



Here's the final system (not yet had time for a box etc)...



I had to swallow hard and prise open the m0xpd wallet to buy an 8 pin mini Din (Maplin code JX06).

The CAT works a treat - I can use Ham Radio Deluxe to control the FT 817 ...



and I even tried DM780 to make some BPSK31 QSOs....



Not a bad afternoon's work.

Now for the boring legal bit: please don't copy my CAT - invent your own! Your rig, your computer, or both may be strongly allergic to my CAT - caveat plagiarius

...-.- de m0xpd

1 comment:

  1. I have to admire your dedication to building it yourself, but these days rig interfaces are so cheap (from Hong Kong on eBay) it hardly seems worth the bother. You did a nice job, though.

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