Amateur Radio

1063 readers

1 users here now

A Lemmy Community to share links about and for amateur (ham) radio to advance the technology, and promote communication and international goodwill. This community IS NOT for CB, GMRS, MURS, FRS, etc topics unless they are related to ham radio in some way.

We won't tolerate personal insults, illegal activity, or anything contrary to good amateur practice.

If asking questions about regulations, please include your country because we recognize that, while the hobby is international, regulations often aren't.

founded 1 year ago

MODERATORS

TrojanHam@sh.itjust.works

Fishing for 40m NVIS antenna ideas. (reddthat.com)

submitted 8 months ago by pc486@reddthat.com to c/amateur_radio@sh.itjust.works

12 comments fedilink hide all child comments

I've got an itch to activate a particularly difficult-to-activate POTA park. The few who found success did so with a barely-qualifying amount of digital or CW contacts with the exception of two prominent and skilled phone operators (and one of them had to give it a second try another day). What brings the difficulty is the terrain: the park is a ~~RF pit of despair~~ beach with 20m tall shear cliffs into the surrounding mountains. It's also remote enough to make spotting difficult; there's no cell nor a APRS repeater for self-spotting.

There are a few strategies I could go for, like beaming into the ocean for KH and VK stations, but I think this park is just about the perfect case for NVIS propagation. I'll probably give my EFHW a shot in an inverted V or sloper configuration, but I'm also thinking of building:

A basic dipole since I could pump more power into it than my existing EFHW transformer can handle.
A one-wavelength loop antenna. In theory a low loop offers a more circular radiation pattern than a dipole and slightly better gain. However, it's twice as much wire to raise.

What kind of portable antenna would you choose to operate daytime NVIS? Do you have any other ideas or thoughts?

you are viewing a single comment's thread
view the rest of the comments

[–] pc486@reddthat.com 1 points 8 months ago

I hike with a FT60 too; it's simple and robust. It'll handle San Bruno mountain except for right along the top ridgeline. Walking 20 meters downhill will let it work again. That mountain is just a crazy bubble of RF.

I use two techniques to figure out if the handheld I'm carrying will work. First, if the S meter reads at S9 but the squelch isn't opening, then it's overloaded. The second is to call into a clearly viable and local repeater. Failing to open the repeater is a pretty good sign of overload.