Other than a trip which might get the odd mention I will detail projects I am working on, what I want to be working on and what I have otherwise to report on. I will update the individual projects as they advance. As asked I have started to catalogue the references I have follow the link on the left where you can obtain them too. Want to email me wander over to qrz.com and you'll find my email address there. Also twitter @m1kta_qrp
Sunday, 20 May 2018
Enclosure for the 3D printer and 3D CNC
Tuesday, 15 May 2018
Tuesday, 8 May 2018
CNC plotter from DVD
Just played with few old DVD had been given.
Once stripped the guts to the centre frame and stepper drive connected up to Arduino CNC shield.
DONT do what I did and pull off the connection on one of the stepper motors.
Donor DVD, old Woodpecker 3.0.2 board (faulty).
The sharp eyed in the last image might see an HP ESP120 and some bits for a W6PQL SSPA and some R3KO bits I am building for another.
Friday, 4 May 2018
A 3 way 1kW switch for < £20?
Couple of videos..
Tuesday, 1 May 2018
Binocular torroid transformer winding
I have deliberately used larger wire than you might normally and used two different colours to make it clearer.
The torroid, doesn't matter what type it is the principals are the same.
I didn't show the stage but sometimes the torroid has small sharp edges. If you are using wire that is effected (you will find out if you are) then the easiest option is to use a circular needle file and make sure the hole edges are rounded (just slightly you do not want to file away the torroid!)
Turn one. Pass the wire up through one side and back down through the other. That is ONE TURN.
Pull it tight.
Repeat for however many turns you need.
The free wire end
The other side of the transformer, you can start on the same side or the opposite side, most transformers in PA stages, ATU, the X-Phase eliminator etc prefer them starting on the other side.
Same process... through one side and back down through the other...
Pull tight... that is ONE TURN
Repeat as needed.
That's it. In this case a 2T:2T transformer, if you need a different number of turns wind a different number of times.
There are lots of other possible winding options the other frequently seen option is for a bi-filar or tri-filar winding. Simply take the wires and wind two or three of them together FIRST and then wind them through the torroid.
I note a lot of chinese ebay projects seem to use power feed line chokes often using a single winding with these binocular cores.
VSWR bridges sometimes use winding's about the outside of the torroid. You will find examples of these on this blog too.
You might see the winding's also using hardline, coax braid or even solid brass tubes and PCB ends soldered on but the photos above are for the wire version the X-Phase QRM eliminator uses. It has 2t:8t so two tuns on one side and 8 turns on the other. Here is a photo of mine as I fitted it.