Homebrew - Show us what you are building

[Lucas McCain]

Here is a balanced L tuner I am building. It is with the least possible metal around it. The baseplate is delrin, the case is ABS, The space in front is for the drive system which will also be all plastic. By eliminating as much metal as possible, I have reduced the stray capacitance ant therefore raised the "Q" of the circuit. The inductors are 18 microhenries at 10 amps and the vacuum variable capacitor in the center is 500 picofarad at 5KV. The device in the back is the 1:1 current balun.



More pictures to follow.

 

[oneswithfunes]

Nice job. Is that rg 142 in the back? If so that is good stuff. Hopefully some time next year I can get back building stuff. I do not have the space currently.

 

[Lucas McCain]

It is 6 turns of RG-400 on 3 powdered iron cores. RG-400 is equal in performance to RG-142, but has a stranded inner conductor with a layer of Teflon insulation. This makes it great for a balun because of the dielectric withstanding at high voltages.

 

[oneswithfunes]

Hard to beat the PTFE and double silver braid. I have a bunch of rg400. Really good stuff but pricy.

 

[C-pher]

Man, I have a lot to learn.

 

[cockpitbob]

Man, I have a lot to learn.

Me 2, and doesn't Lucas do nice work!

LUCAS, great thread idea!

 

[Lucas McCain]

Man, I have a lot to learn.

The way you learn is to ask questions, I am always glad to teach someone something I know. So ask away.

 

[Lucas McCain]

Extended double Zepp

Here are some pictures of my extended double Zepp antenna just before it ascended into the aether. It is cut for 40 meters but will operate on 40 and above with a tuner.



It is very simple, it uses 450 ohm window line and a WA1FFL (gotta love that call) center insulator. The wire is 12 gauge solid copper with PVC insulation. I had the wire and the window line in my junk box so the only cost was the center insulator from HRO, I think it cost me around $10.

 

[matt]

Nice work on the tuner. I've got a bunch of junk 1.5kW autotuners for 13.56mhz at work I want to scavenge to pull the vacuum caps out of. Unfortunately, no roller inductors in there. There's a 3kW 400khz generator in the pile too, but I don't know what to do with it yet. yet...

Not quite home brew, but home built: I've been wanting to build up a rockmite or equivalent qrp CW rig. I was making steady progress on CW, but life got crazy and I haven't had time to practice. It will be my reward after I have my first cw successful qso on my main rig.

 

[Lucas McCain]

It's done! And it works pretty damn good. The first picture is the finished internals and the second picture is the wavenode display showing the SWR and the L and C values for this particular frequnecy (10.115). I have been able to find matches for 80,40,30, 20 and 15 meters. I love it when a plan comes together

ETA: The last picture shows the feedline choke on my 5 gallon bucket.