No Radials vs Very Small # of Radials?

[eorange]

I have a Hustler 5BTV with no radials. It performs adequately for my expectations. Now, due to 2 trees I'm about to have removed...I need to pull up the feedline and take down the antenna. This will give me the opportunity to change some things.

The antenna is directly behind a wood shed, like 3 feet away. 3 more feet back is a steep overgrown hill. That's the West to East picture. 2 feet North of the antenna is a large woodpile and then a lot of open space. South has unobstructed space.

You might see where this is going. I could lay out maybe 3 radials to the south on flat land. And with some difficulty, some to the east up that steep hill. West is a no go. North...well the radial could go under the woodpile because that sits on a wood pallette, otherwise I'd have to curve the radial around the woodpile and none of those would be completely straight.

At most I'd be looking at maybe 7 radials. Is this even worth doing? With no radials I've easily worked eastern Europe and WSPR has taken me to South Africa and Hawaii and the Antarctic. I'm not a DX chaser or contester, just occasionally like to get on and see how far I can get out.

 

[prcguy]

Yes add radials! It turns out a bunch of short radials are better than a couple of full 1/4 wavelength radials. Research shows the distance between radials is important with some number like .02 wavelengths being a goal and the longer the radials, the further apart they are at the ends, so the longer they are the more you need to keep the ends close. A bunch, like 10 or 20 short radials 10ft long can work better than four 33ft radials or two 65ft and two 33ft, etc.

Better yet can you lay down some lengths of 4ft wide chicken wire? Make an X with two strips of chicken wire as long as you can fit, maybe 25ft long each giving you four 12.5 ft long wide "radials". That is super effective and I can point you to an article on chicken wire vs wire radials and their effectiveness.

The last time I experimented with this was with a 43ft vertical, first with stock 4:1 balun then later with an auto tuner at the base. I installed the vertical with no radials and did some VSWR checks and on air checks, then added four 33ft radials. Night and day going from none to four radials. I then went to 8 then 12 then 16 then 24 then stopped around 32 radials. I noticed improvements adding more but going from 24 to 32 was very small compared to smaller increments. Ditching the balun and going to an auto tuner right at the base was like a completely different antenna like it had been sleeping and finally woke up.

 

[eorange]

Wow, now this is sounding better. I don't think I could do the chicken wire but more shorter ones sounds right for what I have. My main concern, whether this is founded or not, was the radials I could put down would be on one side of the antenna only for the most part, and most would be going up a steep hill & the remaining few would be on flat land.

 

[prcguy]

I say put as many as you can fit going any direction.

Wow, now this is sounding better. I don't think I could do the chicken wire but more shorter ones sounds right for what I have. My main concern, whether this is founded or not, was the radials I could put down would be on one side of the antenna only for the most part, and most would be going up a steep hill & the remaining few would be on flat land.

 

[eorange]

Excellent. Thanks much, will do!

 

[prcguy]

If you have some cooperating line of sight hams available have them take S meter readings on as many bands as possible before and after. If they are close you might have to lower your power to just a few watts and use the exact same power level after the radials are down.

Excellent. Thanks much, will do!

 

[eorange]

Ah good idea, but unfortunately no LOS like that to anyone I know. I was already back there yesterday afternoon planning the radials and untangled my 160ft ball of radial wire.

 

[Golay]

Interesting. It's been a little while since I ran a BTV. I think it was a 4BTV. Seems to me the documentation said not to run radials. Drive a metal mast so far into the ground. Mount the antenna and talk on it. It worked well for me over the winter. Took it down in the spring. Maybe because the ground was covered with snow much of the time, it played well without radials.

But that must of been the original documentation.
I just looked up the manual on DX Engineering's website. They have 3 choices (I think DX modified the original manual). The first two involve radials. The "least desirable" option is to drive a 4' pole into the ground, leave 18" sticking out, and mount the antenna without radials.

https://static.dxengineering.com/pdf/hustler_4btv5btv_instl.pdf

 

[prcguy]

Installing any of the 1/4 wave trapped type verticals without radials is introducing lots of loss and the antenna will not perform well. You can drive a pipe in the ground and some of these antennas will have a useable match but that doesn't mean they are working to their fullest extent.

Interesting. It's been a little while since I ran a BTV. I think it was a 4BTV. Seems to me the documentation said not to run radials. Drive a metal mast so far into the ground. Mount the antenna and talk on it. It worked well for me over the winter. Took it down in the spring. Maybe because the ground was covered with snow much of the time, it played well without radials.

But that must of been the original documentation.
I just looked up the manual on DX Engineering's website. They have 3 choices (I think DX modified the original manual). The first two involve radials. The "least desirable" option is to drive a 4' pole into the ground, leave 18" sticking out, and mount the antenna without radials.

https://static.dxengineering.com/pdf/hustler_4btv5btv_instl.pdf

 

[Golay]

Installing any of the 1/4 wave trapped type verticals without radials is introducing lots of loss and the antenna will not perform well. You can drive a pipe in the ground and some of these antennas will have a useable match but that doesn't mean they are working to their fullest extent.

Oh I agree. I know I was able to work into Europe and the Pacific Rim when I had it up. I'm funny about HF antennas. I'll usually not have one during the summer. And the morning of November Sweepstakes, I'll put something up, work Sweepstakes, and leave it up until spring. I rarely work HF other than Field Day and Sweepstakes. Now that I'm getting ready to retire, I'm going to be looking at a more permanent HF setup.

 

[eorange]

I am using the revised DX Engineering guide. 5BTV is down and coax is pulled up in prep for tree removal. Actually a 6BTV is going up in its place on the ground with as many short radials as I can manage per @prcguy .

 

[tomhobbs]

courious. its been a couple months. how is the 6BTV working with the short radials? I looking for a vertical and thought the 6BTV would be a good one. really wondering about how the short radials would work too.

 

[mass-man]

all the chatter about radials is spot on. But we're ignoring one HUGE point from prcguy! The remote tuner at the base of the vertical. I can attest to a SGC tuner mounted at the base of a 43ft vertical made it seem like a different antenna. This was not mine but an install I helped with at a ham's summer home in SE NM! IIRC it was 16 22ft radials evenly spaced out, the tuner in a waterproof container right at the radial plate/antenna mount, fed with almost 100ft of RG 213! It was an RF monster!

 

[prcguy]

Was surprised once when I stuck an SGC auto tuner at the base of an insulated 20ft pushup mast (actually 19ft long) in the middle of my office building roof which was 125ft X 225ft of bonded steel roof. I couldn't believe how well that worked even on 80m. That same 20ft pushup at ground level with just a token ground rod would have been mostly a dummy load on the lower bands.

all the chatter about radials is spot on. But we're ignoring one HUGE point from prcguy! The remote tuner at the base of the vertical. I can attest to a SGC tuner mounted at the base of a 43ft vertical made it seem like a different antenna. This was not mine but an install I helped with at a ham's summer home in SE NM! IIRC it was 16 22ft radials evenly spaced out, the tuner in a waterproof container right at the radial plate/antenna mount, fed with almost 100ft of RG 213! It was an RF monster!

 

[eorange]

The 6BTV is up. It's mast mounted on the ground with 17 radials, each 10 feet in length. To be honest 10 feet was arbitrary due to a dense hill that goes east so I opted for a practical length. The radials are mostly evenly distributed in the east direction and south (flat). I ran out of nuts/bolts but could probably squeeze in 3 more to the south. I ensured the trap spacing was exact per the DX Engineering manual.

Short story, I haven't made any contacts mostly due to lack of a serious try yet. What I did spend time on was measuring the SWR across various bands. For reference my feedline of RG8X is about 180 feet with the tuner in the shack. Due to logistical constraints that's the way it is but I've been operating this way for years.

Anyway, I first measured SWR with a MFJ-874 across the bands using an IC-706MKIIG with the AT-180 autotuner. SWR was pretty good:

10m: 1.1:1
20m: 1.1:1
40m: 1.2-1.5:1
75m: 2.5:1

I then repeated the test with my IC-7300, both without and with the tuner and using the transceiver's meter:

Without:
10m: 1:1
20m: 1:1
40m: 1.1:1 (lower band), 1.5:1 (upper band)
75m: very ugly, way beyond 3:1

With:
10m: 1:1
20m: 1:1
40m: 1:1
75m: 1:1

The IC-7300 test tells me the 6BTV is doing a pretty good job achieving resonance with the traps except on 75m, predictably working harder to get a match there.

I tried a few phone contacts (unsuccessfully) to California and a very noisy Florida and Italy, but again didn't spend much time. I'll be trying WSPR soon because I know my footprint there based on the prior 5BTV with no radials, and then will try some phone contacts.

 

[mass-man]

Good looking results....remember the tuner is not bringing your antenna into resonance...it is showing the output of your rig an impedance match it likes.

Keep on experimenting...