MaverickNH
NES Member
There is a 2m Winlink gateway just 5mi away in SoNH that I can regularly hit with portable or base radios but I cannot reliably hit 40m/80m Winlink HF gateways as my main antenna is a 43ft vertical. Even ground wave to HF Winlink stations is very rare, as propagation within a few 100mi is poor on 40m/80m and most 40m/80m antennas are horizontal. I’ve read polarity losses are -20dB or more. That said, polarity randomizes at some point. My vertical just doesn’t send much up at an angle that will reflect back down within a few hundred miles.
So I built a Near Vertical Incident Skywave NVIS antenna with loaded coils to shorten the inverted V dipole legs to fit in my yard. It’s on a 15ft telescopic fiberglass mast. I hammered a galvanized pipe down a few feet with a threaded junction just below ground level, so I can screw a 2ft pipe on to hold the mast up. It’s under a rock in a garden bed, so my wife doesn’t freak out. I just put it up and take it down as needed.
Tuning is rather meticulous as the resonance is pretty steep - about 10kHz per inch of dipole leg. But I got it down to ~1:1 SWR at the Winlink frequencies. The whole rig is vehicle portable - about 6ft long collapsed with dipoles spooled on winders.
Now I’m thinking a used Icom IC-7000 All-Band transceiver to fit in an ammo-can Go-Box with a battery, Win10 tablet, SignaLink and ATU in another small Pelican box.
Why you ask? Why not!
So I built a Near Vertical Incident Skywave NVIS antenna with loaded coils to shorten the inverted V dipole legs to fit in my yard. It’s on a 15ft telescopic fiberglass mast. I hammered a galvanized pipe down a few feet with a threaded junction just below ground level, so I can screw a 2ft pipe on to hold the mast up. It’s under a rock in a garden bed, so my wife doesn’t freak out. I just put it up and take it down as needed.
Tuning is rather meticulous as the resonance is pretty steep - about 10kHz per inch of dipole leg. But I got it down to ~1:1 SWR at the Winlink frequencies. The whole rig is vehicle portable - about 6ft long collapsed with dipoles spooled on winders.
Now I’m thinking a used Icom IC-7000 All-Band transceiver to fit in an ammo-can Go-Box with a battery, Win10 tablet, SignaLink and ATU in another small Pelican box.
Why you ask? Why not!