30 meter dipole down

high winds in the night snapped the poly cord holding the high end =(
it was old and sun affected.
need to rethink materials.
i've heard about dacron rope.
found none locally yet.

Kim VK5FNET

30 meter receive dipole up

On Saturday Karl, VK5FOSS came over and we hacked together a new antenna for 30 meters. Its amazing what a second pair of hands can help achieve, with masts and measuring. The dipole is for 10.140MHz receive for QRSS. Runs approximately North-South, so should have VK2ZAY broadside off the eastern lobe. Maybe VK1AA also.

I no longer have a dipole for 40 meters. To be honest I wasn't using it very much. There just isn't space at the moment. Everything on the work bench/kitchen table is a little bit crowded, aiming to take a week off work soon and get stuck into the painting in the spare room that will become a study for the XYL, then shuffle things around and prepare my study/shack.

Kim VK5FNET

just finished a colpits oscillator for the DC Rx

Spent a couple of enjoyable hours here on the workbench building up a colpits oscillator, which is very similar to the one recently build by Bill, N2CQR, see over at the SolderSmoke blog.

You can see the frequency counter, 10.13805 MHz. I spent some time mucking around with the variable capacitor in series with the crystal. At best all the options I had would move the rock up or down by 100Hz. Although later when I mounted the variable capacitor in parallel with the impedance matching transformer, I noticed that it would pull it a total of 4Khz. Not sure if this is the right way to tune it, but it seems to work for now. So set it up for 10.140MHz, assembled the LO board into the little case. Hooked the audio and power up to the peecee and fired up QRSS-VD.

So much noise! I turned off everything that I didn't absolutely need and went around rearranging cables. So now the capture is cleaner. However there don't appear to be any QRSS signals in the air ...

Will do more tinkering later and check the clipboard. May need to do a lot more work on the dipole.

Kim VK5FNET

QRSS receiver up and running

Well its taken a good long while, but I've finished off the QRSS receiver and have a grabber running. I'm not picking up any obvious signals. I have not checked the clipboard, but thought I'd tinker around anyway.

Seems to be something weird going on with the oscillator, I can't get the frequency counter to pick anything up under 66MHz, which is way out of the ball park. I noticed that when I bump the crystal or hold my finger on the crystal the capture changes significantly.

So may need to move the oscillator off the main board and box it up and put a high impedance buffer on it to be able to check the frequency with the external counter.

more work on the DC Rx

Spent several hours in the shack over the weekend. Heres the results;






Now need to add power, a 5V rail and the audio out.

More work on QRSS DC Rx and a photo

Its been a slow week, been home crook most of it. Done a few odd jobs around the house and have been meaning to post this image for a few days. Made a saw horse for working with longer lengths of timber. Getting the paint striping out of the way, so we can repaint the study. Along with lots of reading.

Have added some more components to the QRSS DC Rx. Took this photo before adding the front end capacitors. Spent some time working out a replacement for the T37-6 transformer. Came to the conclusion that I couldn't do it with the materials that I have. Terry has come to the rescue however, he has just received a parcel of various toroids, transistors, etc. Terry has offered to send me one, so I am expecting one in the mail any day now =) This has been along time coming. Really looking forward to getting this rig on the air!

Ooops, just realised that I've not yet put on the feedback resistors... More work to go =)

72,

Kim VK5FNET

Making a band pass filter, or I hate toroids

I have made some progress on the NE602 direct conversion receiver. I have layed up most the components onto a copper clad board and I now need to add the band pass filter and the front end interface to connect up to an antenna.

I hit a similar problem with the Pixie2 I made previously. I don't have access to any of the named toroids that you find in the HAM radio journals and books. You know, names like T37-6. So I'm doing the numbers to try to lash up a air-space coil instead.

I'm reproducing the 30m QRSS Receiver as built by Hans Summers, G0UPL. Its a hardware defined radio that outouts audio to a peecee to decode.

I have a handful of plastic coil formers that appear to be 1/4" x 1". They have a fiber board on the bottom with five terminals to connect you inductor elements to and your pcb.

So using the calculator at kitsandparts I worked out that following table;

Turns	Inductance
2	0.01uF
5	0.07uF
35	3.67uF

So I've spent half the day crunching the numbers to work out how to get an air-spaced to get the numbers to match the above... The numbers just don't work =/ I'm sure I'll find something and maybe I'll just have to put a bunch of cash aside and make an order to the US.

72,

Kim VK5FNET