Inverted V vers Vertical on 10m

Yes indeed, sorry for the confusion - I’ve edited my post to make that clear :grinning:

Cheers, Rob

I performed a few similar tests some weeks ago. I wanted to compare my linked EF Sloper / inverted V (2x10m long) with a 1/4 wave vertical (2.5m long + 2 radials 2.80m). I used pskreporter on FT8.

My experiment was not rigorous by any means :

  • The sloper / inverted V antenna is not especially tuned for 10m band, so the SWR are not comparable.
  • The 3 tests were performed at 20min interval, propagation could have changed by this time …

I will probably make another experiment soon using a tuner to be a bit more consistent.

Results here

Location : South West of France, JN02
Power : 10W
Sloper / Inv V oriented South-West 225° (red on the map)

Vertical antenna (1.1 SWR) :

Sloper antenna (1.8 SWR)

Inverted V antenna (2.7 SWR)

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Thank you for the many reactions.

Today’s test was again very indifferent as yours, Rémy.
RBN gave much more feedback with the vertical, but the states only via inverted vee.
In the subsequent spot, the states were only audible and worked vertically. Both running 3-5Watts.

I will now throw both antennas into the trees when activating.

73 Chris
Zwischenablage-1

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Plotting the results can also help for visual comparison:

From my first test we can see that:

  • only vertical manages to get positive reports
  • vertical is much more consistent at reaching long distances > 7000 km
  • skip zone is very similar with the 3 antennas (~2000 km)

I will do a second test in the next few days, with tuner and identical SWR.

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Very impressive. I have the WSPR Beacon App for Android on my smartphone and will use it for my next competition.

73 Chris

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Brian,

My experience indicates that when you are on a summit with an inverted Vee the nulls are not as deep nor is the gain as great as the simulation suggests. Having the inverted Vee with an included angle between 90 and 120 degrees results in some significant vertically polarised radiation. This helps fill in those nulls.

I have taken to using a 10 m flowerpot. After two activations, I will have worked most of the workable VK and ZL stations and that is it for them for the year as the rules say one contact per station per year. So nothing under 3,500 km will count. To make subsequent 10 m activations viable it is necessary to go for the best practical DX antenna, hence the end fed half wave on a 7 m mast.

Of course if I want to work the locals then an inverted Vee 20 m long and 7 MHz and 14 MHz is the choice.

73
Ron
VK3AFW

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I have pondered about whether the need for two short masts is worth the few dB gain of an end-fed half-square antenna for ten. It would also make a reasonable antenna for 20m as a bent end-fed half-wave. That few dB of gain might make all the difference for DX.

Brian @G8ADD,

I would say take 10mtr mast if you have one and hang vertical high.

I compared EFHW4010 setup as HalfSquare, with vertical single band EFHW10 but Xformer is at 5mtr and also EFHW4010 as inv-L where apex is at 10mtr.

Results of simulation below

EDIT: radiation patterns at 10deg take-off angle

Its easy to see that hanging monoband EFHW10 very high gives good performance. You can better it with inv-L but this is tricky to setup and you need second mast or a tree.

73 Marek

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That is very useful, Marek. Compared with the vertical EFHW10, the inv-L EFHW4010 seems to give 5dB gain on its main lobes, but the nulls are 8 to over 20dB down on the main lobes and would probably be deeper at a higher installation. Considering that long path signals mean that wanted signals can come from any direction, the vertical EFHW10 might be better for F2 propagation but if you expect mainly Es (during the summer months) then erecting the inv-L with a main lobe directed towards distant prospects would be the better choice, or at least that the major null at 180deg is pointed in a harmless direction!

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Hi Armin,

Like you, I also tested different antennas for 10m, focusing on DX:

  1. 1 wavelength long EFHW (10m long, as inv.-7, on a 6m tall glass fiber mast).
  2. 2 wavelength long EFHW (20m long, as inv.-7, on a 6m tall glass fiber mast).
  3. A J-pole, vertically mounted on a 6m tall glass fiber mast.
  4. A full size vertical with a ground spike and 8 quarter-wave ground counterpoises (Marconi antenna).

I mainly compared them RX-wise, and under different conditions and then max. 3 types at a time. So no scientific comparison, only to get a gut feeling :wink:.

My conclusion until now is that “it depends”.

I also expected that Nr. 3 should be best for DX, but this was usually not the case. Maybe because on all the tests I was surrounded by tall trees? I don’t know, but I guess that the partly horizontal wire of Nr. 1 or Nr. 2 in a forrest has some advantages, compared to a purely vertical radiator.

On average, Nr. 1 performed best overall and in general should be preferred over Nr. 2 for DX.

Nr. 4 is really convenient for setup time and weight-wise when working only 20m and up, especially if there is a lot of wind (OK, under such conditions, I only extract it to 2.5m for the 10m-band). Last week in EA8, I worked the world on 10m with this handy antenna, even a S2S with Arizona was possible (10W SSB). But as we all know, conditions are much more important than the antenna…

In the future, I definitely will repeat some comparisons of the listed antennas.

73 Stephan

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Hey Stephan

Today I had great QSOs again… including an S2S at 10m in SSB with ZS… I’m quite happy with my Endfed.

But you know: I like to tinker and I already have plans and materials to improve myself a bit.

I’ll tell you on Wednesday :wink:

73 Armin

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I have used the WSPR beacon app on my last few activations and, while the results are interesting, I find the time involved really frustrating. Each WSPR transmission is just under 2 minutes. To run two WSPR tests on one antenna then two tests on a second antenna is a minimum of 8 minutes, more likely 10 or 12 minutes allowing time for the antenna changeover.

Along with the low number of WSPR reporters that are using half-decent antennas, I found the number of meaningful results quite small.

An alternative for antenna comparisons could be to use FT8 where one could call CQ while being monitored by many more stations who generally have better antennas as they too want to make QSOs.
The time for each FT8 cycle is shorter, just under 30 seconds, and you may get one or two QSOs in the log as well.

I don’t have a great FT8 set up for SOTA yet, but something involving an Android tablet and Bluetooth connection to my FT817 would be good.

YMMV
Peter VK3ZPF

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Certainly the better approach, Peter. I initially thought of WSPnet. But FT4/8 is actually the better choice at the moment because there are significantly more reception points. With the FT8CN app it has become very easy to activate digital on a summit.

73 Chris

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Or if you’re not interested in working the digital modes, you could use the SOTAmät App to place your spot for an SSB or CW QSO and then later take a look at pskreporter to see what strength you were received by all of the SDR receivers that got your FT8 signal. If you don’t want to place a spot, you could use the email generating option and send yourself an email, the generated request signal will still go via FT8 to PSK Reporter to the sotamat.com server. Of course less SDRs pick up the special format packets from Sotamät than pick up the standard CQ FT8 packets so as always YMMV.

73 Ed.

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I’ve done six 10m activations so far this year - all with 10W CW from a KX2 with internal ATU - and all from G/LD summits. The first five were with a 40/20/10 EFHW configured as an inverted-L or inverted-7 (not inverted-V) and today (on G/LD-037) with a Chameleon MPAS Lite vertical with two 8m counterpoises (yes, I know that’s longer than needed for 10m but I was working 30m afterwards).


(C) Google Earth 2024, radio paths courtesy www.adif.uk

Some of the six US chasers today were the same as on the previous 10m activations. I would be hard pushed to say whether the reports I gave (mainly 529 – 569) and received were any different with the vertical than with the EFHW. Unlike before I didn’t get any west coast chasers but that’s almost certainly because I activated more than an hour earlier (1323 to 1333 utc) than previously.

The S0 noise on 10m made it a joy to work even the weaker N/A stations despite my frozen fingers. With freezing temperature and a dusting of light snow today I certainly appreciated the quicker setup (with gloves on) of the MPAS vertical.

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Hello Tim,

with only one “radial” you have more or less a preferred direction, with 3 (really) radials you should have no difference over 360 degrees. One “radial” is really a radiator. It affects the fare field.

73, Ludwig

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Thanks - That makes sense, I sort of figured that its more a V dipole, the way I mount it. (Pic below) I normally point the radial in the direction i’m most interested in (USA). Question I have is whether there is any meaningful performance difference in this direction or should i increase the mountain ‘faff’ and put two more radials on ?

Thanks
Tim

Tim, Looking at your picture, the “radial” seems rather high and slopey. Have you tried keeping it parallel to the ground 1m up? This should exhibit some gain in the direction of the horizontal wire.

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Hi Fraser,
I certainly could try that. Yes, its high, must be about approx 3m high on a 6m mini, maybe sloping at 30deg down from the horizon. Feels so much more of a dipole than a GP maybe.

Had so much fun on 10m with this antenna, its all I had to start on 10. but guess most of that is conditions :slight_smile:

[later]. BTW, The radial is about 10% longer than the vertical.

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Well it does feel like a bit of wet string will get 10m contacts at the moment, however a more efficient and directional antenna will get you better ones!

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