Search This Blog

Loading...

Wednesday, 13 October 2010

DigiModes interfacing

I dug out an old radio interface that I built some years ago, the design was actually part of an article on eHam.net:

http://www.eham.net/articles/7007

Anyhow I've had this bit of kit to pieces today and will be doing more fiddling with it tomorrow.

I have always had difficulty getting the TX and RX LEDs to function correctly so I've added some separate circuitry to do that today. Somehow I misread a relay and I've managed to regulate down the +13.8V supply going into the box to +5v - this is driving a 24V relay! Muppetry!

So tomorrow I'll play some more and swap out the relay for a 5V unit I have here.

Mark.

Tuesday, 12 October 2010

WSPR & The ATU Syndrome

Well, been back with the ATU today, and after some discussion have come away 20 quid worse off and with a Mostly Fine Junk (NFJ) 949E. This includes cross needle metering and an internal dummy load.

I've tried the tuner and unlike the previous one from Comet, it will actually tune my antenna on all expected bands, so I conclude that the other one was highly suspect.

More playing with the FT-950 today, and more menu items 54 & 55. I now have these set so that the radio is in PKT-USB and both 54 & 55 are set to 1000Hz, this seems to be working as expected and is accurately displaying the TX + audio offset on the radio. WSPR is now working find business and will be chuntering away to itself whenever I'm not using the radios inside the shack.

Trying to get to grips with Logger32 on digital modes now, so have printed some parts of the help file out and promptly ran out of ink in the printer. Guess I'll need to go get some tomorrow.

Monday, 11 October 2010

The Shack 11/10/2010

Here is a picture of the shack on 11-10-2010.

You will see that I have a lot of test gear; this is because I do quite a bit of homebrew and am very interested in QRP operation.

Starter Post

Well, as a licensed Ham for some years, I recently decided to get active again and thought my musings may be of interest to others.

Most recently I've got myself an FT-950 which I plan to use primarily for data modes.

Today I have been musing over the data mode on the FT-950 and most specifically menu items 54 & 55. It seems for the default settings of these menu items to work, you need the radio in PKT-USB mode; by default the data mode was in PKT-LSB. I was failing to decode signals I could hear in standard USB mode with that setting.

Seems that the radio will work well in the dedicated data mode, just some understanding of the carrier offsets involved are needed to figure out which mode the radio actually needs to be in.

I left the radio running WSPR for a few hours today, my signals (only 10W out) were heard far and wide including Japan, and I was receiving from all over as well.

I came home with a Comet CAT-300 ATU today, but it seems to be the most useless ATU I've ever come across. It wont tune anything and actually provides a higher best SWR when in-line than without the tuner at all. I conclude that it's faulty and will be taking it back tomorrow.

I'm going to take a picture or two of the shack and post them now.

Mark. G0MGX