I love a good T2FD antenna and have built a good few. There’s a few variations but they all work well and are easy to construct. I’ve been asked a few time about the length and spacing so I made a small Excel sheet to work it all out and provide data for the 3 most popular variations.
Free free to download and use. The sheet is protected to prevent the formulas from getting messed up but if you would like to experiment with alternative formulas then please just contact me for the password. All I require is for my original credit to remain on any derivative works.
M0LMK T2FD Calculator
I usually get static build up on my HF doublet due to sand particles (I live above the beach) in the air so have been thinking about a way to bleed off the static and provide some protection to my TS-590SG. After a little research, I came up with this, a lightning arrestor/static bleed device that provides a permanent path to earth for DC whilst allowing RF to pass and providing protection from nearby lightning strikes. Continue reading “Ladder Line Surge Suppressor”
A common fault on the SGC range of antenna tuners is a reduction in receive performance as they get on in years. This can be attributed to contamination on the relay contacts since SGC stoped using fully sealed relays. Any small condensation inside the tuner makes it’s way into the relays and causes contamination on the contacts as they are hot switched. The best thing to do is to replace all 26 relays with new units…
Continue reading “SGC-230 relay replacement”
I’ve got an ever increasing noise floor at my QTH so I thought I would try an active HF loop to see if I can null out the worst of the noise.
I found a simple design on-line and used it as the basis of my loop. The original site unfortunately no longer exists but I did manage to save the design here. Continue reading “Active loop antenna for HF”
Another part of my antenna experimenting equipment. A simple ugly choke for HF made with 30 turns of RG213 coax around a 4″ plastic pipe.