Hi-Gain Vertical Half Wave Antenna

[shuffy]

Yeah I remember the comment and I'm sure it will stop it melting.
My current configuration is a split air cored coil as per the original higher powered NRG, so the former material is not an issue. I think my coils are 18 SWG wire so that might need beefing up a bit.

[jvok]

Are there build instructions for the air cored one?

[Gigahertz]

Are there build instructions for the air cored one?

Yes Lee posted them on this topic, think its the 2nd or 3rd page that takes you to a drop box

[Frequent Lee]

A year after my first attempt, I finally had time to try the top end of the band.

The very early NRG verticals I bought from Stephen used to come with a cut down 2L fizzy pop bottle as a rain shield, I'd forgotten about that until you posted these pictures.

When he transitioned across to the plastic funnels he said he has to make a trade off with the length vs the weather protection, the longer bottle fully covered the feed point and coli components whereas the funnel only about a 1/4 of it & the longer angled funnel was to make water run off at a steeper angle, when the bottle version was used 24/7 the enclosed space of the bottle caused heat build up and would throw the matching out enough to trigger the swr protection in some rigs not built by him, ie the London ones. I guess the heat would make things expand and contract with the copper coils which are super sensitive to the matching circuit.

[Frequent Lee]

I do have a couple of brand new unused ones of the 50w version one is tuned to 88.1 and the other 94.6.

If anyone wants to make an offer one one we can sort something out.

I'm keeping one for that inevitable bank holiday weekend pop up pirate appearances maybe

[Gigahertz]

I do have a couple of brand new unused ones of the 50w version one is tuned to 88.1 and the other 94.6.

If anyone wants to make an offer one one we can sort something out.

I'm keeping one for that inevitable bank holiday weekend pop up pirate appearances maybe

Hmmm, tempted, just to have the original version as a reference point, but I'm sure others will bite your hand off!

[radionortheast]

Suppose a clear plastic bottle could get the sun shining in leading to a hot spot, the kind of sun shines in hits the paper weight kind of thing, if you up turn the cone, make a good chip warmer I was thinking from the above the coil was hearting up.

[Mongo82]

Great aerial, and would love to have go at making one, i think its within my skill set? Maybe... Never tuned it, just assumed it did what it was supposed too as it was cut to specific frequency when bought. Worked well from terraced house and also from a 4 story, but in a time when did things in a more carefree manner and certainly no inline swr meter. Never got busted using that set up though in near on 3 years. The old aerial is still standing... well some of it and after 18 years of weather, wish id salvaged it now.

Screenshot_20250629_133417_Google Earth.jpg

[Mongo82]

Suppose a clear plastic bottle could get the sun shining in leading to a hot spot, the kind of sun shines in hits the paper weight kind of thing, if you up turn the cone, make a good chip warmer I was thinking from the above the coil was hearting up.

I had to eventually replace the plastic cone, as the uv broke the plastic down over time. I did actually replace with a cut plastic bottle and a bit of insulation tape.

[Albert H]

The first couple of ones I built used cut down white plastic bleach bottles. One of them is still in use almost 40 years after it was made. The very first one corroded badly, so I retrieved the second one, and dipped all the relevant bits in pale grey acrylic paint. That's why it has survived the central European weather for so long, and why it's almost invisible from the ground (it's 11 floors up).

Last time I was there, I checked it with my antenna analyser, and it's just the same as when it was made! The coax outer has blanched in the sun over the years (it's UR67 of unknown manufacture), but it's still OK.