Tim,
That’s good but the extra real estate and tripping hazard with radials for quarter waves has to be considered.
I would argue it’s a half wave not a quarter wave with one radial.
While the Sun is active 10 m is still worth a spin with a flowerpot. Then either an EFHW or a 300 ohm feed doublet would be my next choice.
73
Ron
VK3AFW
That’s a great point!
Using SSB (inefficient) or antenna tuners (lossy) is right out when all you have is 5W of power and you want to make contacts at 5000km+. (I had one to PY the other day!)
Living in G/M is no doubt wonderful but very different from 9N, here we are surrounded by huge masses of land and lots of cheap Chinese QRM generators masquerading as consumer electrical devices.
That’s a really good idea. The L-match should significantly reduce losses compared to a transformer.
60dB signal range may be the case in most locations, but it is not the case when you have thousands of kilometers of land between you and most QSO partners (except for B and VU, of course).
Most digital mode contacts here happen at -10dB SNR or worse.
The long distances mean it is indeed practical to think about antenna orientation in order to target a specific area. In many situations it is critical to think about antenna orientation in order to get a signal out of a valley or avoid large obstructions (mountain ranges).
Switchable diversity is a good idea, thanks.
RX-only antennas not practical due to the need to carry a minimum of equipment and weight (my transceiver only has one antenna port!).
@mm0efi Complex antennas are fine as long as they are straightforward to set up and don’t require specialist parts or ATUs.
@VK3AFW inverted-V antennas producing vertical radiation (for NVIS contacts) are not useful here as there are very few people to talk to in the immediate vicinity.
What is a flowerpot antenna?
@g5old Thanks, building 1/4 wave verticals and (better) dipoles is likely next.
Consider a monoband delta loop. They are not heavy, so you can carry more than one. I have one for 15m, and my friend Simon @GM4JXP uses them to good effect for DX SOTA. Gain is 3.5dbi at a nice 20° angle.
I can’t lay my hands on the paper Simon sent me, but it gives dimensions for construction on different bands.
Try this in the meantime
…link for 10m Flowerpot antenna-
Geoff vk3sq
Hi,
5 W of SSB was the most common transmission mode in VK for many years. It’s quite respectable.
It has doubled in the last few years to 10 W ssb due to new rigs coming on the market.
Population centres in VK are typically 300 to 3,000 km away from summits. In VK we don’t count on EU dx to qualify. It’s too far and bedtime for most of them when we are out and about.
I have worked into the UK many times with my FT817 on 20 m with a basic wire doublet. This Sunspot cycle my operating times are more suitable for W and JA contacts. I’m very happy with BY contacts and would be pleased with some VU contacts but they aren’t appearing.
NOTE. I was talking about vertical polarisation of the signals not vertical incidence. My apologies for not making that clear. Having both polarizations maximizes your chances of taking advantage of conditions for best dx.
The more often you are on air on a summit the luckier you get with dx.
73
Ron
VK3AFW.
Why not a very classic 1/4 wave ?
You can get a 5m telescopic whip on Chinese markets for very little money.
You can also build your own with wire but you will need a mast and guy lines.
You don’t need any RF parts. You will not have 40m and lower but if you don’t have local contacts that’s not an issue. Just put it in the ground or between rocks, plug the radio and boom, you are ready for long distance contacts.
@mm0efi wonderful, thanks for the link to the antenna designer. That should work nicely.
@vk3sq that ought to be doable, if I can find some 50 ohm coax. Maybe I can hang it in a tree. I doubt I can find a 5-10m long fishing pole to use as a mast, squid poles are not used here.
@vk3afw Well done. I have not had such luck running QRP SSB. Perhaps it is the high levels of QRM due to the lack of any EMI/EMC regulations. For VU contacts, try very early in the day before townspeople wake up and turn on their QRM generators.
I’ve read that an L-match can be as much as 95% efficient. How does that compare with the seemingly more common transformer match?
Denis,
There are so.many versions of the common transformer match that a definitive answer is not possible. Well designed and constructed matches will be in the range 80% to 95% for both types.
Unless the L match is up in the air or the antenna comes down to the match box it’s efficiency can be offset by line loss.
73
Ron
VK3AFW.
I needed an EFHW for the 15/12/10m bands, but I couldn’t construct a classic 1:49 transformer that would provide a 1:1 SWR. I’m not referring to a multiband design—just connecting three different half-wave wires for each band. The SWR was 1:2 or worse, which was unacceptable for me. Therefore, I started experimenting with an LC match, which seems to work quite well.
I compared the LC-matched EFHW for 15m side by side with an 8.8m random wire antenna (fed via a 1:8 UNUN and a tuner). Both antennas were set up in a vertical configuration. The EFHW clearly outperformed the random wire, showing a 6–12dB improvement, with more stations picking me up on the RBN.
I have measured the insertion loss of several different combinations of 49:1 transform and have come to the same opinion as Ron. There is around 1dB of loss.
There is loss in all antenna systems.
I feed my EFHW with a 2m length of RG58. I feed my linked dipole with a 7m length of RG174. I have come to the opinion that a linked dipole doesn’t offer any significant advantage over a EFHW.
The losses from 7m of RG174 on the higher bands are likely to be greater than those using the EFHW.
A 40m dipole set up as an inverted V on a 6m pole will likely present a feed impedance significantly lower than 50 ohm. The losses from 7m of RG174 with a poorly matched impedance are likely to be much greater than those using the EFHW.
Both options are a great antenna for SOTA.
Cheers, Kevin
Yep, it’s a compromise again but with much better angle of attack and gain than a sloping flower pot - Ideal for 20m DX ?
I’d like to try one, but isn’t the peak gain and angle of max radiation going to be much better for DX on a vertical ? I was erring towards trying a 5/8 10m vertical with horizontal radials. As that can still fit on a 7m pole. Problem is only 2 walking poles 
I do agree a flowerpot is super simple and easy to or up. A very good SOTA antenna
Very interesting and makes sense. Thank you.
Have you established optimal bands for your location?
I quickly looked at VOACAP.com site, and it seems that there are many things like time and direction, etc… which need to be taken info account.
Don’t have much experience on that side of the world, but here placing inv-L North-South or East-West in Central Europe will give you different “catchment area”, and we don’t have any 6000m+ mountains to consider.
I think before you look for different antenna option you should ensure that you used right band and right time for each direction. EFHW which seems you have is a good versatile option, however setup details might be as important as power/mode/band you operate.
I also assume that your 49:1 transformer up to the job, as there are plenty of poorly constructed models around. This goes for home made and company made version.
GL 73 Marek
@SP9TKW yes, you are correct, I should spend more time with VOACAP. Unfortunately operating often happens “spur of the moment” (though I hope to be QRV around midnight UTC today) without access to the Internet or much choice of antenna placement.
And my current combination of equipment limits me to 20m, though I hope to broaden my palette soon (ergo the discussion about antennas).
My transformer is hopefully up to the job, it was built (not in 9N!) according to the HB9SOTA guide and those fellows seem to have expertise in the subject.
For 20m band DX performance I often use HalfSquare made out of EFHW4010 (66ft wire). After tuning my EFHW I folded it in half and again and marker outer 1/4 lengths. I use two 6mtr fishing rods (300g each) set them 10mtr apart and then run wire from antenna from the bottom of first mast where 49:1 is to the first 1/4 marker then ~10mtr horizontal to second mast where second 1/4 runs from the top to the bottom. In reality bottom of each 1/4 is about 8-10inch (25-30cm) above ground.
This antenna is a killer broadside but has deep nulls to at vertical ends, so you need to be mind full when you set it up. Id has very good gain at low take off angle for 20m band but it still works on 40 NVIS and 15/10 with 4 lobes. If you thing this could be ok for you watch Tim G5TM YouTube channel https://youtu.be/cKbde0oRYxE?si=Hb6mTQ92DooOdfUC Timhas number of very good films about some verticals if you would like to go that way.
As for VOACAP I only use it once or twice a year to see how seasons might affect optimal setup for DX. Before major event like Trans-Atlantic S2S I will check it too especially considering current solar weather.
GL
