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Saturday 30 April 2016

7"LCD for the Raspberry PI for KX3 Panadapter and SDR display

Finally managed to get the 7" TFT and touch screen to work with the V2 RaspberryPi B model and it seems to run as a pan adapter for one of my KX3 fine, I also tried using it with an RTL SDR  USB dongle and it runs FB.

I had this running using a tiny 2.8" TFT which was fine but not terribly usable.

I might see if I can get the SDRPlay working using it as well. Photos and video later.

Using a HDMI connector from the TFT to the Raspberry Pi not the Pi's own DSI (ribbon cable). I have done this as I expect this might see use when DX trips urge me to use another display.

Technically I stood on so many shoulders to get this working I will not list them all but this used a 7" TFT 800x600 AT070TN92 based display (was cheap off eBay) and then used a recovered display driver board VS-TY2662-V1from a defunct PC display (thanks to research from my Dad as to exactly which board it was) so I have VGA, composite (so those Hotel TV's can be used as well!) and HDMI.... The board allows both TTL or LVDS output so you 'can' use many different TFT panels as long as they have one or other of them... still trying to find a decent data sheet, and list of panels it works with,  I tried (for fun) with my junked laptop which I ripped the screen out of it is some 16:9 1366 x 768 resolution, and it will drive that as well. There are a few other connections on the board but not worked out what they are yet or what they do.

The display driver looks very close to this one which seems to do the same thing.

The numbers mean on the image (comparing to mine as well)

1. 12V display (will actually work 5v to 15v)
3. VGA
4. Composite output (normal TV... seems to work about channel 36)
5. ??
6. Mine has a ribbon to a series of buttons
7. TFT ribbon connection
8. TFT connection
9. No idea!
10. No idea!

The  touchscreen used with the TFT is a separate USB powered 'thing' from Alibaba.

The 7" displays  and touch screens I think were possibly for use in GPS or tablets and the recent explosion in their availability and use has seen prices of some models tumble sharply.

SCC renewed... M1K lives another 3 years

At least one QRP SCC that will be on the air again... the renewal came through this morning.

Thursday 14 April 2016

4SQ / Four Square Antenna Controller relays

The relays arrived yesterday...

I just tested one..

So will be looking to built a prototype tonight.

They have 240V AC 10A contacts so should be fine for a qrp 4SQ, even up to 150W I believe.

Wednesday 13 April 2016

Scrounged RC5

What scrounged RC5 and controller look like. to get that 23cm stuff working for summer.

SDRPlay & KX3

This is going to be a bit of fun...

I have an new SDRPlay... was just going through what it can do by itself. Next is use it with a TX as a sort of pan adapter. I use sound card based SDR usually with my KX3 and an ELAD T/R switch so I'll use that.

However the SDRPlay uses a USB virtual audio driver so I will split the RX signal and feed 1/2 to KX3 and 1/2 to it.... the how will be to use the above.

Tuesday 12 April 2016


OK lots going on (over most of the summer).

I have an ultra light weight G3TXQ DX 6 band Hex beam being built for me, will be just 6KG. Near the sea verticals will win always but if inland this might be better, when DX will use a DX wire 10m HD pole. Will almost certainly use at home QTH, using a Racal 9m (or 11m) pump up mast.

After a lot of reading ON4UN book about low band DXing and lots of conversations I will build a portable 4 square setup for 17m and 15m (as well as could be used on 20m/30m and 40m with a change in control box and transformer lines). Another version is here

Next time when I find the Oceania and JA openings from islands in EU or vice versa I might stand a chance to work the DX op against the wall of callers who are 180 in the opposite direction. The major disadvantage with omni vertical antennas.

The key will be the phasing box and the diagram of the one I will use with a Collins Hybrid Coupler is shown. T1 and T2 will be using T106-2, T130-2 or T157-2 cores, I will see if they get warm. The dummy load I will use will be  50W chip resistor attached to a 1U CPU heatsink but at QRP power levels I do not expect, if the antennas are built correctly, to have a high reverse current. If two antennas they will be Attached to Ant 1 and Ant 4 and the transformer lines are 1/4 wavelength and light weight low loss 50 ohm coax. If using all 4 then I will use ex-virgin media (new) cable TV cable which is double foil wrapped and has 75ohm impedance. I will use F type connectors for the transformer line to control box connections. Each vertical will be using a fishing pole (5m for the higher bands) and I will craft a connection 'plate' that will sit on the pole support or raised above ground level. To this the radials, transform line and element will be attached. I intend using non-latching relays. So if the power goes the antenna defaults to one location.

For 23cm looks like I have managed to scrounge an RC-5 rotator (might do double duty at home QTH with the HexBeam) and controller, will need new cable between as they hacked the old one off apparently when removed. I expect I will ground mount this so will use a thrust bearing higher up.

The 23cm antenna just to play initially might either be a 23el Tonna (G7SOZ will probably have that) or a 28el quad loop. No photo yet but they will come. the 28el quad loop should look like this one from G6GVI

I will retire the central support in the garden, the pump up mast will go at the bottom and should be far enough away from the trees on the East side of the garden (chain saw will fix stray branches) and move the end support (where the Racal now will go) to where the centre one used to be so can still put up 80m dipoles etc. I suspect I will add a 12.5m pole support in same location of the pump up mast and use that with an inverted L configuration for 160m and 472KHz.

The 6BTV will go and I suspect the unused YP3 3el portable yagi will be sold off as well. That trims down the antennas (and adds a few!)

The workshop will see the cobweb (6,10,12,15,17,20) go back up so I will have a HF antenna for testing and the TV antenna that is there right now (unconnected) I may remove from the mast.

The WX stations will see new batteries and one might have a web cam fitted.

Friday 1 April 2016

Don't mount your antenna pole on single skin wall of bricks put up with lime mortar!

Mentioning gable end antenna mounting.

Got to laugh... neighbour, who rents his house put up a TV pole with not one but three separate Digital TV antennas on it...didn't ask permission either it seems. He took the H&K bracket off the main house wall (I have no idea how!) where it was fine, moved it to the gable end of the old downstairs toilet. Every house on street uses the house wall but he knew better obviously and that also meant he could do it with a low ladder.

Up come the high winds... he discovered why everyone was telling him it is a really bad idea to put it there, it is lime mortar single skin brick so it will not hold a loaded 20ft pole in high winds in a million years. Needless to say the obvious happened... few days after the w/e high winds but was only a matter of time it seems ... timber.... over it goes, pulling the roof with it.

Rats was too slow with the camera this morning (I was laughing too hard to be honest). Emergency roofer has covered the collapsed wall and caved in roof with a sheet. Spoke to a roofing guy, who honestly was laughing too said some tiles went through the ceiling and trashed the bathroom below too! I guess that is his security deposit gone then!


Not picked it up here at M1KTA but seems that QRPLabs Ultimate 3 has been heard.