10GHz experiments

I had a quick fiddle with the box of bits that should by now - in fact by a year ago - be a 5.6Ghz ATV transceiver. I now have a couple of Gibeon flat panel antennas which claim 24dBi as mentioned in the excellent resource on this topic at http://5-6ghz-atv.co.uk/ So, let’s have a play. I got a rather old fashioned Sandisk Photo Album, a slab of plastic that takes 5V and will present photos (and videos and sound files) to a TV via an AV output and the typical red, white and yellow RCA plugs. First off I  needed to make sure this worked. So, what has an AV input… er… Bedroom TV? Nope. An older Sony TV in another bedroom does and so it was plugged up. And nothing. Problem 1, it seems to take an age to turn on in response to its remote control. No switch of course. Problem 2, it would not read anything on the SD card I had with a test card image on. The only clue is it needs a ‘JPEG (Baseline, up to 16 Megapixel)’. No idea what I had produced via GIMP on the Linux box but it would…

I’ve been planning for a while now to put up an antenna in the garden, but where is the question. I have a 20m wire and 9:1 unun to set up somewhere - ideally I’ll run this up the garden but that goes under the phone line, or actually the end of the wire would be under it. What stopped me was the impending changes for EMF as the unun would be mounted outside pretty close to our bedroom window. So, for a laugh I got another unun to experiment with (yes I know I can make one but the ferrite I had is lost in the workshop moves). Looking at the ‘ideal wire length’ chart 36 feet comes close enough to the distance between the bedroom/shack and the hedge so I cut 36 feet of bell wire and launched it across the utility room towards the workshop as a measure. Tied to the bedroom window reached almost to the far side of the workshop. I reckon I can attach a pole there and attach the unun to the wall outside the shack - there is a convenient airbrick nearby. But, for a laugh I attached said bell wire to…

After some fiddling I now have a decent amount of signal coming down from QO100, but also questions. The azimuth was already correct and I had adjusted that to maximum signal strength on a TV channel with a GT Media V8 Finder. But the elevation is numerically wrong, or the markings on the dish are wrong, which is more likely. Fiddling with elevation got the strongest beacon signal at about 26db and 26 degrees marked, but the AMSAT info says it should be around 23 degrees at my QTH. Mind you, for all I know the garage wall is not perfectly vertical! All SSB signals look good now except for one or two that are difficult to hear. However, having got that far, no adjustment to the position of the POTY in the arm or its skew make any noticeable difference, so I've left that one. Also, when transmitting a tone from SDR Console it actually peaks higher than the beacon so I had to reduce the drive appropriately. An SSB signal test showed very poor audio and no adjustments in SDR Console got it to where it needed to be. Turning the mic gain up in Windows itself cured…