Search found 3 matches

by N3CFX
Tue Feb 11, 2025 7:09 pm
Forum: Questions & Advice
Topic: EFHW UNUN test
Replies: 1
Views: 4408

EFHW UNUN test

I recently built a EFHW UNUN from a K6ARK kit (and I asked about the capacitor I broke in another post). I hooked it to a NanoVNA and a 2.2k carbon film resistor, swept 3 to 30 MHz, expecting to see a flat SWR. Instead, the SWR was about 1.5 at 3 MHz and rose a lot - to over 8 - at the higher freque...
by N3CFX
Fri Jan 31, 2025 3:48 pm
Forum: Field Kits and Reports
Topic: k6ark efhw capacitor
Replies: 3
Views: 38821

k6ark efhw capacitor

Assembling a K6ARK unun for EFHW, I broke off and lost the surface-mount capacitor. Anyone know its value? 100pf? Several online reports suggest the capacitor is not essential on a EFHW at 20 meters and lower frequency. I will pair this with a SW-3B (40-30-20meter), so am inclined to to finish assem...
by N3CFX
Tue Dec 03, 2024 6:20 am
Forum: Questions & Advice
Topic: SW-3B and Straight Key
Replies: 3
Views: 14506

Re: SW-3B and Straight Key

Another option - modify your key. If your straight key has a 3.5mm TRS socket as many do, and it's accessible, connect (solder probably) a very short jumper between the ring and sleeve terminals on the socket. I did that with one of my straight keys. Easier to just use a mono (TS) cable, of which I ...