HF vertical antenna matching.
Posted: Mon Dec 30, 2024 11:51 am
One old and long project here.
But I going to get up new vertical on spring, after snow has gone.
It will be 24-26m long, enough buried radials to get it from MW to say, 35M band.
Only problem what I have is to get it tuned on that wide range.
I set target for myself to get linear tuning from 1.6Mhz to 10Mhz, tuning should at least handle about 1kW of AM carrier, and should be remote controlled, I dont want that coax to be part of that antenna.
Pre-made ATU for this powerlevel is more expensive than my house, and I have good set of soviet made vacuum variable capacitors, roller coils etc.
I have done couple tests just using 25 wire top of an tree, and for radials, I have used mains grounding around the buildings and between them.
On this case, radial network seems to be far superior than what I going to build, but simple coil and polyvaricon did give some promising results on NanoVNA.
I tried to search what Govt etc use as tuner on verticals, but no luck.
If you guys have any ideas, just trow them here, still about 4-5 months of snow here, so no need to hurry.
Btw, my friend has an USA army antenna base for mobile whip, it promises flat SWR from 2Mhz to 70Mhz. There is huge 50ohm resistor inside it, and that huge aluminium mount is just for cooling it...
It says 500W max....
But I going to get up new vertical on spring, after snow has gone.
It will be 24-26m long, enough buried radials to get it from MW to say, 35M band.
Only problem what I have is to get it tuned on that wide range.
I set target for myself to get linear tuning from 1.6Mhz to 10Mhz, tuning should at least handle about 1kW of AM carrier, and should be remote controlled, I dont want that coax to be part of that antenna.
Pre-made ATU for this powerlevel is more expensive than my house, and I have good set of soviet made vacuum variable capacitors, roller coils etc.
I have done couple tests just using 25 wire top of an tree, and for radials, I have used mains grounding around the buildings and between them.
On this case, radial network seems to be far superior than what I going to build, but simple coil and polyvaricon did give some promising results on NanoVNA.
I tried to search what Govt etc use as tuner on verticals, but no luck.
If you guys have any ideas, just trow them here, still about 4-5 months of snow here, so no need to hurry.
Btw, my friend has an USA army antenna base for mobile whip, it promises flat SWR from 2Mhz to 70Mhz. There is huge 50ohm resistor inside it, and that huge aluminium mount is just for cooling it...
It says 500W max....