Vertical advice!

[K4LAU]

I am just getting back into HF after a long absence. I currently have a random wire antenna
@81 feet long at about 20 feet high into a tuner. ( No I can not easily get higher) Running about 100 watts ssb. It works, but not well and with a s9 noise floor on most days. I like to work 75, 40 and 20. I am thinking of getting a multi band vertical such as the Hustler 5btv. Any thoughts? I know this opens a big can of worms so please be civil. Also any thoughts on using electric fence wire for radials buried just below the grass.

Thanks for any and all help
K4LAU

 

[prcguy]

Put down a lot of radials. Its better to have a a bunch of short ones over a few long ones. Or lay down maybe two 4ft wide by 50ft long chunks of chicken wire in an X shape and plant the vertical in the center.

A vertical will work out to 50 to 75mi ground wave then you will have a mostly dead zone until the first skip bounce. A horizontal wire will work much better in the 75 to a couple hundred mile range due to NVIS, so choose the best antenna for the job.

 

[RadioDXfun]

I think if you have S9 noise on a horizontal it may well increase on a vertical. I would make a cheap easy 1/4 wave for 20m and test the QRM
at the QTH before spending out on anything. An efficient vertical tends to pull in a couple of S points more noise than a horizontal.

Your limiting factor is RX noise, S9 is a quite serious problem. 95pct of the DX contacts I make on a vertical are way below S9 for some context.

Worth a check before spending.

 

[K4EET]

Hi @K4LAU,

An “S9 noise floor on most days”? Wow! That is some serious noise! Have you “studied” that noise to see if you can identify any big noise contributors like solar panels, faulty power line equipment, etc.? There may be something that can be done to abate the issue piece by piece and get that down as much as is possible. I am clobbered by solar panel noise in the form of “broadband birdies” from my neighbors on either side of my house. An arcing insulator on a high tension power line was identified and repaired at the end of our street. You should be able to identify the major noise contributors to see if anything can be done to reduce or eliminate the noise. It takes some serious work but your ears will be forever thankful to you for your efforts.

As for vertical antennas, also give consideration to the Cushcraft R9. Now I realize that DX Engineering does not expect this antenna to be in stock until the first week of January 2023. I do not know about the availability elsewhere. I mention this antenna because it can be mounted above the ground on a mast instead of being ground mounted and it does not require radials like many other vertical antennas do. The reason it can function without in-ground or on-ground/under-grass radials is because the antenna is an end-fed design. It just happens to be vertically oriented. For those that do not want to take the time needed to lay out a good radial system or do not have the space for a correctly sized radial pattern, the Cushcraft R9 is a very good choice.

73, Dave K4EET

 

[K4LAU]

A bit of progress. I found that the noise floor exist even when the antenna is disconnected. So much for blaming my random wire! I also found that I have two cordless tool chargers in the same room as my station and connected to the same power mains circuit as my radio power supply. When I disconnected the chargers the noise dropped significantly on 80 meters. However when I reconnected them the noise did not immediately return. Puzzling?
I am thinking that maybe the chargers have a maintainer circuit that pulses the batteries to keep them topped off and only comes on after the batteries have been on charge a while. Or it could just be coincidence and I am following a false lead.

 

[RadioDXfun]

Top work K4LAU, that's the way to do it. Just keep narrowing it down and I hope you get as close to QRM free situation as you can.
It is the hobby killer for many and why I decided I am a portable station S6-S9 at home. New sources appear at random as neighbours get poorly made unfiltered cheap domestic equipment. Even my FM broadcast radio reception was knocked out by a small device used by a neighbour
on some evenings.

LED lights, switch mode PSU's, PLT (power line transmission / wi fi extenders etc.) check all those "wallwart" PSU's around the house. LED street lighting as well.

Once I worked DX with zero noise floor there was no going back. What you can do DX wise with zero noise floor is mind blowing. Endless streams of QRP 2-5 watts stations from 1,200miles way became a thing, even handheld users. And global DX on a wire no trouble at all.

Noise floor is the single biggest threat to ham radio hobby.

 

[K6GBW]

First question is what kind of communicating do you want to do? If you want "local" communications out to about 400 miles then the horizontal wire antenna is going to be much better. Since you said you want 80 and 40 meters you'd be NVIS on those bands anyway so the best best would be to build an antenna that resists the noise as much as possible. If you can fit 81 feet of wire I'm betting you can shoe horn in an EFHW that will be much quieter and more efficient. Then, make sure the coax is well grounded and choked to prevent common mode. If you can keep it well away from the house that will help a lot too. I'm currently running a HyEndFed M5 EFHW that is 73 feet long and does 80-10. I have two chokes on the coax, one about 16 feet from the antenna and one right before the coax enters the house. Then, just in case there was stray EMI in the shack I put five snap on ferrites on the coax right at the radio. This set up makes my very high noise environment pretty workable.

Switching to a vertical may actually increase noise so I'd try to improve the wire first, unless you want to work DX on 20 and above. Then it might be the way to go.