Wednesday, December 29, 2010

Successful outcome

I finally solved the problem with the cable I was trying to make to interface my VX-8GR with the computer, as described in my last post. As I had begun to suspect, the trouble was caused by the 2.5mm jack plug not fitting properly in the VX-8GR data port socket.

As suggested by one of my readers, I tried the cable in the COM port of the TH-D72. Although I couldn't figure out how to make data appear on this port, I did see some output when turning the TNC on and off which suggested my cable did work.

I then tried it back on the VX-8GR and used my oscilloscope to look for anything digital. I didn't see anything. I then tried another 2.5mm jack with the sleeve off so I could get the 'scope probe on the solder tags and with a firm press it went in with a click. I now saw -5.6 V on the TX pin - clearly an RS-232 signal level.

The jack I originally used had a plastic sleeve or cover and the diameter of the base was just a bit too much to allow it to go all the way in. One with a metal sleeve had a slightly smaller diameter base. The metal sleeve itself interfered with inserting the jack, but I could put the plastic sleeve on that jack and it would still go in. So that, finally, is what I did, and I now have a VX-8GR PC cable that works. It also works with the COM port of the TH-D72 should I find a use for that.

As a ham and electronics enthusiast I don't believe in buying things I can make myself, but sometimes making it yourself can turn out to be more trouble than it is worth!


Lynn (D) said...

So, for the end of the story, did you ever see any data coming out of the VX-8GR, particularly data that might be construed as being APRS packets?

LY2SS said...

I'd like to tell the DIY related story...
I have a home made, very nice DL4YHF's PIC-Keyer with memory which I use with my FT817. I also made connecting cable - some screened wire and 2 cheap (0.20p each) 3.5mm phone jacks. One day I plugged cable into FT817 and noticed CW stopped to work... First I thought that the cause is battery in keyer (there's no power-off button in that keyer as it draws uAmps when not used!), but it wasn't. I suspected that something wrong with the cable - I pulled it out from the trcvr and ouchhh!...that cheap jack's tip left disassembled and trapped deep inside FT817's cw key socket, surely pressed with tip's contact in the socket. I was dancing (without wolves, but with needles hihi) around that puzzle about an hour (trying to release tip's contact). Then I decided to push the same broken connector with some force hoping that it will "self-assemble". And it did!!! I pulled out tip successfully! After that i bought factory-made cable for CW hihi.

Happy New Year Julian!

Tony G4IOQ said...

Yes, but you always learn something!
73 for 2011 de Tony G4IOQ

rct said...

The Yaesu connectors tend to be a bit recessed to assist with making them water proof or at least water resistant. This makes it important to select a plug with a small diameter housing. The electrical part of the plug is still the same.

For what it's worth, you seem to be using the terms plug and jack interchangeably and I believe somewhat inconsistently. The end you were supplying and soldering on is typically called the plug. The fixed connector on the radio is the jack.


* Plug (connector), commonly refers to a movable connector, often, but not always, with the male electrical contact or pin, and is the "movable less fixed" connector of a connector pair

* Jack (connector), commonly refers to a surface-mounted connector, often, but not always, with the female electrical contact or socket, and is the "more fixed" connector of a connector pair.

I know this won't really be a help to you but may help sort things out for others reading this.

Jim said...

Thank you for posting the information. Good stuff. Can you program the radio via this cable or does programming require a different cable?

73 Jim KD8BZS

Julian said...

Yes, it works with the FTBVX8 software.