Looking for some advice. Currently I use the PAR EF-20 (Mono) and EF-40 (Mono) for my SOTA activations.
They work well. However as the weather gets colder, I’m wondering if using a 9:1 with a random length would make things easier, (no antenna changes mid activation, would I lose performance?
I’ve also heard a 49:1 offers better performance over a 9:1 random wire. But how much more? I’ve read for a 49:1 work well it needs to be a half wave. I know some prefer a “linked EFHW” but right now it doesn’t seem possible.
Some have said if you use a 49:1 with a 60’ wire (It will not require a tuner for 10/20/40). Wondering how efficient this is
I know some prefer a “linked EFHW” but right now it doesn’t seem possible.
Why shouldn’t this be possible? You cut a wire for 20m, then connect a suitable length for e.g. 40m. A half-wave end-fed is possible for any wavelength, if you have one for X meters, it is also resonant on X/2 meters, X/4 and so on. By connecting pieces of wire you can construct other wavelengths: ~10m (1/2 wave for 14 MHz) + ~5m gives you 1/2 wave for 30m.
Some have said if you use a 49:1 with a 60’ wire (It will not require a tuner for 10/20/40).
Isn’t this the PAR EndFed for 40m? (But I think their transformer is a bit higher 1:64 instead of 1:49).
My experience with my HyEndFed antenna (~20m) is that with the Xiegu tuner, I can work very well on 17m also.
The PAR mono band antennas specifically state they are only designed for the band they are made for and use on any other band could damage the matchbox. (EF-20 and EF40)
Here is the point of this post. I’m not looking make or build any other antennas. I have plenty. I am trying to see if it’s possible to achieve the best performance with what I have and which combination would work best.
In an ideal world I would like to try the following
49:1 antenna with 66’ wire and no counterpoise. (No tuner needed) operate on 10/20/40 but I would also like to use 17m also. If I use a tuner with this setup will I be ok? Will performance be sub par?
However , is this the MOST efficient antenna vs the others I have (PAR EF/or 9:1 with tuner)
Is a resonant 49:1 antenna better then the above? 49:1 with 66’ wire?
Don’t know this one, but the following works best on 20m, with less efficiency on 40m and with some additional lobes on 10m:
I bought this one (or similar) and created a similar low weight version that I always carry with me as backup antenna, additionally with one link for the 17m band.
49:1 with 66’ wire (no tuner)
When using a 49:1 (better for higher bands) or 64:1 (better for lower bands) coupler, you have to cut the wire for resonance to lamda/2 minus velocity factor and end effect, e.g. about 20m long for the 40m band. An antenna analyzer is really helpful.
The antenna works also on multiple harmonics, not exactly, but good enough, albeit with additional lobes.
For the upcoming Challenge, I tried a super simple vertical EFHW antenna for 10m that worked just great: about 4.5m wire hanging down from a 6m tall glass fiber pole, fed by a 49:1 coupler and some meter of coax.
9:1 with 60’ wire and counterpoise (with tuner)
I have no personal experience with this one, but it seems to work for many activators that use a tuner.
The length of the radiator might be a bit to long (should not get close to lambda/2 on any band) and the number, length and setup (on ground or elevated) of the counterpoises need to be taken into account.
I’m writing a document about a 20m long resonant 7-band EFHW antenna using only one switchable coil to change between two band segments.
Once the document is backed with enough data, I will post the corresponding link here.
Building antennas is so much fun, and I like to analyze them nearly every time I do an activation.
Hi,
I can demonstrate it’s not a poor choice after several activations, lots of contacts and many DX.
I can’t say if the other transforming ratio you are considering will be any better than my 10m long wire to a 9:1 unun, this really works fine.
I also carry a 21.5 m length of wire in my activations. I assure you it’s easier to deploy a 10m length and I don’t see any substantial difference in performance compared to the 21.5 m length, at least on 20, 30, 40m, which are the bands I mainly work on.
73,
The “EF-nn” EFHW antennas have an LC impedance matching network, tuned to the center of the band in question. The transformation losses with this type of impedance coupling are very low, but the couplers can only be used for one band.
Every solution with a broadband impedance transformer is much more lossy, but these couplers can be used for several bands.
Making generalized judgments as to whether an antenna with a 9:1 transmission line transformer or a 49:1 conventional transformer is “better” can at best presume “Internet experts”… Such comparisons always require the consideration of the entire system, consisting of the feed line, impedance coupler, antenna radiator, geometry of the antenna arrangement and, last but not leased, the radiation characteristic.
Which solution you choose depends on your individual needs and expectations.
Yaesu 891 usually run about 20w to save battery
Antenna thrown in tree as inverted L about 40ft in tree
50ft rg8x coax
SSB only
What is the best antenna for
20/40/17m
If the choices are
End fed 9:1 58ft wire and 17ft counterpose wire touching ground
End fed 49:1 60ft wire (using coax as the counter poise
Par EF 20 and par EF 40 (I realize for 17m I would prob just add that band to a 49:1 balun)
That’s that my question is
Using the above equipment in the above scenario, what would work the best and be the most efficient.
If the answer is , monoband so be it.
If I only need to use one of the multi band options with a tuner , even better BUT if the efficieny goes way down , then I will stick with monoband.
I just am trying to see if I can save effort and time with going multiband but not compromise on antenna efficiency
You will definitely save effort and time going multiband. Your activation will be more comfortable and given the fact that you will be the DX, your compromise multiband antenna, less performing than any monoband, will surely give you the chance to be heard and chased by many, many chasers, no matter how little your output power.
My advise is don’t worry too much about having the best performing antenna. You just need a good enough one.
73,
Well I use a 9:1unun and 50 foot of RG58 coax it acts as a counterpoise with my sloper antennas with a tuner then I use a 49:1 transformer with my EFHW antennas for 20m 30m 40m in a inverted L configuration no tuner required using 20 foot fiber glass pole and tree limb works great use it everyday chasing summits hope this helps some it works for me good luck 72/73 Bud w8bud
I posed a similar question to w1zr, Dr. Joel Hallas and an editor for QST…he recommended the OCF Windom instead of the endfed dipole. Incidentally I’ve been using the 9:1 endfed dipole for a couple of years and had good results. Like Kurt Sterba (RIP) use to write in his column a garbage can will radiate RF so just get something in the air and start operating.
After 55 years as a ham, I would never ever leave home without an ATU…HI HI
Your Par mono 40, have you tried a swr sweep with an analyzer? Chances are it would be close on 20,15, and 10 metres as well.
I use a 67’ with a coil 6’ from the transformer for 40-10 metres. Works well once tuned.
Malen
VE6VID
OK, since your not using an ATU, and you have plenty of power on hand, I would go for the 49:1 transformer; 20m of wire and traps for 20m and 30m. Some inefficiency in the 49:1 transformer is not so important as you are using more power.
73 de OE6FEG
Matt
I would just make them both to compare on a summit, I have a storage box for my antennas collections/spares, you will always be wondering how the other would have compared. This is one of my many enjoyments of being an activator is having the space on a summit with no restrictions to setup and try different antennas.
Could be worse you could be looking to purchase a new rig so many choices these days.
My list
Linked dipole 40/30/20/17
Trapped EFHW 20/30/40
EFHW cut for 20m
Norcal Doublet
Another doublet for 80m
20m ¹¼ vertical
Buddipole clone Jac3 antenna
A 100m roll of sotabeams antenna wire (gonna need a bigger box)
A 9:1 with random wire and medium-long length of coax is a lossy system compared to EFHW. Yes, you’ll make contacts, but it will be many dB down from a resonant EFHW. For multi-banding, you’re much better off feeding the random wire and counterpoise directly into the rig’s antenna terminals/ATU.
