26-Sept-2017 SHF UKAC – 2W on 13cm

I had hoped to get two projects finished this summer: upgrading the 3cm box with amplification & a circular waveguide feed and upgrading 13cm.

As it is, the 3cm box is still not finished & the waveguide is in pieces & 13cm still has only 2W.

I put 13cm in action for the UKAC. Towards the end of the contest I could hear Jon GM4JTJ. He was copyable on CW/morse code. With a lot of patience on Jon’s part, we eventually completed. Jon is the first Scottish station that I’ve heard on 13cm & I was very surprised to work him on 2W. I recorded the details on a paper log correctly and then typed his serial number (or rather Gordon’s G8PNN’s serial number!) into the computer log. Oh well, it’s only a contest!

I was using the SG-Labs transverter with about 1m of coax into the 34 element Wimo.



NEFF V6320X0G washer-dryer not drying

I keep getting distracted away from radio projects in order to sort out things in the house.

The washer-dryer had proved effective and reliable over a few years.  It started flashing an error code & refused to wash, though it had a tub full of water. It turned out that it had a blockage in the trap. It has a drain tube for manually draining the machine. This is hidden behind a bit of white plastic plate at the bottom of the front of the machine. The plate is held on by a couple of plastic plugs mounted in the plate. With a bit of prising with a screwdriver, it came off. I opened the trap & removed the coins & the rubber band which had tied itself around the pump’s impeller. This got the washer part working.

Then I found the heater in the dryer part wasn’t working. I guessed that the pump not working meant that the water condenser had stopped & the heater had over-heated & a TOC (thermal overload cut-out) had tripped. I hoped that I could manually re-set it.

The machine was tightly fitted between the oven cupboard and another machine. It is chocked up on bits of wood & work-surface. It is a heavy machine. No wheels!

It took two of us to drag it out of the cupboard. The water tubes were stretched tight.

Removing the lid was easy & it all looked in good order inside. The concrete counter-weights look solid. They looked heavy. They are heavy!

The heater assembly is nicely accessible at the top. I checked the continuity on both the heater elements & they were fine. A little TOC attached to the hot air channel was open circuit. It had a little red button on it. I pressed it and although it hardly moved, it clicked in: continuity restored.

A test showed the dryer worked again.

It took two of us to manoeuvre the machine back in place and we did not manage to get it back into the original position. A visiting engineer would have had the same problem, though a low-level trolly-jack might have helped. I’ve had to leave the cupboard door off.

Kitchen designers please note: machines need maintaining. If you are going to bury them in pretty cupboards, then let them pull out on rails. Be kind to engineers!


Graves radar, moon reflections (EME), doppler

The moon reflections seemed weaker tonight and of course, I had to wait a bit later to find the signal.

21:45 GMT:  moon 16.9 el 182 az. Pictured scale starts at -146dBm (on P3’s SVGA screen), 2dB horizontal lines. 2kHz screen width, 1kHz listening pass-band. Dial frequency: 143.050,000 MHz. “MKR A” is the thick green cursor to the left of the dial frequency cursor. I could hear the Graves pulses gently rising a few dB up and down as seen in the waterfall in the photo below:


21:51 GMT: I set MKR A to the moon reflection frequency: 143.049,870 MHz. So it was 130Hz lower than the Graves frequency. Another photo:


21:51 GMT. Some fading (QSB) on the moon signal. Another meteor ping about half way down the screen:


22:00 GMT. The moon frequency has drifted 10Hz down to 143.049,860, so about -1Hz per minute.