RxTx Case

I finally got my RxTx 6.3 Software Defined Radio in a case. I mentioned in the weekly net that I had built it and I was invited to bring it to the next club meeting (which is tomorrow). I'd already clipped off the connectors in preparation for putting it in a case so I really needed to finish that off today so I can show it off tomorrow.

The case I finally chose was an old KVM switch and it fit in really nicely. There's very little wiggle room, but it's still tall enough for the PA filters and not too difficult to take apart.

I'm pleased with the old presta bike valve dust covers that I used as spacers to get the PCB above the metal mounts that were already in the box. The USB socket is from an old wireless router and I covered the unused holes with leftover water heater earthquake strapping. I used Epoxy Resin, but it was pretty old. I plan to file it down and then use body filler to fill in the empty spaces if I can ever be bothered.

All that yellow wire is for the DB9 connector, I didn't have time to cut it short and re-solder it to the socket so I just scrunched it in there. I'll get to that at some point too. After I got it all in the case I fired it up and it worked great. I even manged to decode some PSK31 signal and saw some folks talking about 'working New Zealand' sadly I didn't pick up a callsign so I don't know where they were from.

Soon I need to try and work this thing in Tx and actually try and call someone.

A few more pictures are in the Gallery.

RxTx receiving!

A few days ago I finished the 30/20/17m PA Filter and so my RxTx board is all complete. I put on the connectors and powered it up and plugged it in and... nothing. I got noise and the same stuff if I had the board plugged in or not. Bummer. However the frequencies in Rocky didn't jibe with what I was trying to listen to and after some help over on the Softrock forum (or email reflector as the Hams seem to like to call it) I was on my way. Seems you need to run Rocky once, then you get a Rocky.ini file which you can then edit to have the frequencies you're interested in. I was also a little clueless about the dip switches on the board (which you don't need if you're using an I2C controller like I am, but I finally found this page:
SW1 Settings which helped a lot. Anyway here's a copy of my Rocky.ini file in case it helps anyone else out.

Armed with all of that I fired up the RxTx and my crappy old windows laptop running Rocky and I heard stuff! I was able to make out some voice (although barely copyable) and also heard a lot of CW (Morse Code) which I'd expect on this band. Sadly I can't understand CW yet and I haven't worked out how to have it automagically decoded by the computer. Searching for PSK31 signals didn't yield anything legible.

But it worked and that's the big deal!

Next up is to either set up a proper enclosure with real connectors on it so I can use shielded audio cable, or try a little harder and try and make a contact on it. I'm loathe to try and put it in a container without testing transmit unless I can take it out easily!

RXTX Main Board Complete

Today I soldered the very last component onto my rxtx board! I still have the PA Band Filters to make but the main board is complete (except for connectors). O.K. there's too many disclaimers in there, but it's a big accomplishment for me to get this far so I wanted to share. The blurry picture is one I took with my phone so I could immediately send it off to Micah (KI6TWP) who I'd been building my board with. He's been slacking recently and not coming with me to 'play radios' so I've been charging on ahead. I want to have the full rxtx complete by the time my parents visit in a week.

Softrock RXTX 6.3 ordered

You remember in that last post how I said I had no intention of getting a radio that would let me use my new band privileges? Well the biggest hurdle was time and the cost of another radio. Luckily while reading QST (or it could have been Radcom (thanks G4HON)), I stumbled across the Softrock project and their RXTX 6.3 board. It was cheap and low power and I could build it myself and the instructions looked really good. So with a co-worker I ordered two kits with full band pass filters since no one on the email list at work would tell me what would be the best bands to try. Total cost around $120 which is well within the playing around with things budget. Our plan is to work on it two hours a week after our team meeting in the electronics lab at work. I've never had much success with building electronics, let's hope this one is different.