10 meter antenna

[wpwx694]

Is tuning antenna better than using a tuner?

 

[mmckenna]

Yes.

The antenna tuner hides the mismatch from the radio.
Actually tuning the antenna will make it radiate more efficiently.

 

[wpwx694]

Thanks

 

[AC9KH]

Yes.

The antenna tuner hides the mismatch from the radio.
Actually tuning the antenna will make it radiate more efficiently.

Actually, if the antenna is resonant but has high SWR it won't make any difference. Resonance and SWR are two different things. An EFHW is resonant and radiates beautifully, but has a feedpoint impedance ~2,800 ohms.

It's pretty hard to get an acceptable match across 1.7 MHz of radio spectrum on 10 meters unless it's a low-Q antenna. I prefer to adjust an antenna for 10m to electrical resonance at the middle of your expected operating frequency range, then see what you got for SWR. If the SWR isn't right due to antenna design or the matching coil or transformer is off, and adjusting the feedline length can't "fix it", then use the tuner on it. Any "losses" at HF on 50 ohm coaxial cable is so low that it doesn't make a difference anyway.

Adjusting or "tuning" an antenna out of resonance to get a SWR match actually defeats the purpose of matching your antenna system to the radio output impedance.

 

[RU55]

Is tuning antenna better than using a tuner?

What exactly do you mean by "tuning antenna"?

An antenna "tuner" is a device that matches impedance between to devices.

Feed point impedance is the relationship between voltage and current at the feed point. If there is a mismatch, radio frequency energy will be reflected.

Tuning an antenna could mean tuning it's resonate frequency or tuning it's feed point impedance or both.

It is best to have an antenna tuned (resonant) at the desired frequency and a good impedance match to the feed line.

 

[K6GBW]

The Solarcon A99 antenna can very easily modified for use on 10m and it works very well. If you need an easy and effective base antenna it’s a good option.

 

[K9KLC]

The Solarcon A99 antenna can very easily modified for use on 10m and it works very well. If you need an easy and effective base antenna it’s a good option.

Yep that and the iMax 2000 both work great on 10 meters.

 

[K6GBW]

I keep wondering about the iMax Optimizer (same thing as the iMax I guess). Maybe when the A99 finally needs replacing I'll try that next. My last 10/11 meter antenna was a Radio Shack 1/2 ground plane. Freaking antenna was absolutely great! If they existed today I'd buy one in a second. But...we are relegated to what we have at hand. I've been using the A99 as a 10-11-12 meter antenna for a few years now and honestly, it's been really great. I can press it into 15 meters with the tuner but I doubt it's working well there. Still, for talking for more fars...the 10 meter band is awesome. I've talked to Indonesia, Australia, Chile and Argentina. About a month ago I got my first European and Middle east contacts on it. For a little over a $100.00 bucks I think all hammies should have 'em!

 

[K6GBW]

Actually, if the antenna is resonant but has high SWR it won't make any difference. Resonance and SWR are two different things. An EFHW is resonant and radiates beautifully, but has a feedpoint impedance ~2,800 ohms.

It's pretty hard to get an acceptable match across 1.7 MHz of radio spectrum on 10 meters unless it's a low-Q antenna. I prefer to adjust an antenna for 10m to electrical resonance at the middle of your expected operating frequency range, then see what you got for SWR. If the SWR isn't right due to antenna design or the matching coil or transformer is off, and adjusting the feedline length can't "fix it", then use the tuner on it. Any "losses" at HF on 50 ohm coaxial cable is so low that it doesn't make a difference anyway.

Adjusting or "tuning" an antenna out of resonance to get a SWR match actually defeats the purpose of matching your antenna system to the radio output impedance.

He makes a really good point. Too many people get wrapped around the axle about SWR, when that isn't the end all be all of antennas. First thing to accept in your antenna brain is that every antenna is a compromise. Second thing to accept is that SWR isn't an indicator of how well an antenna is working. Personally, I prefer resonant antenna simply because they are easier to deal with, but that doesn't mean non-resonant antennas can't work well. All things being equal, I prefer an antenna that can be tuned to be resonant with a decent SWR without using a tuner. Simple is better in my experience. I'm an old military man and simple worked where other complications just created friction to my mission. But...circumstances dictate!

 

[AC9KH]

Yep that and the iMax 2000 both work great on 10 meters.

10m verticals are also quite easy to build for about $20 in materials. I use galvanized electrical conduit, pick sizes that will telescope together and use self-tapping stainless steel screws to secure the sections. I use a short piece of PVC electrical conduit for the base insulator with epoxy to glue the base insulator in a sleeve. This is a homemade 5/8 wave 6m that I built about 15 years ago now, made out of galvanized electrical conduit. It is a DC-grounded type with a base "tuning ring" that connects the radiating element to the groundplane. To make the base tuning ring I used a piece of 1/4" hardware 6061T5 aluminum rod and wrapped it around a 5 gallon bucket to form it.

Interesting finding after I built it, it resonates on 10m as a 3/8 wave and works quite well for local mounted on a 20ft tower stub. No tuner required on 10m below 28,700kH. On 30m it is a 1/4 wave because the tower becomes part of the antenna and the ground plane radials no longer do anything at 10MHz. So it becomes a shunt-fed 32' vertical on 30, and to get it to work on 30 I tied the coax shield into the ground radial system for my 127' vertical.

Only downside to it is that you don't want to touch the tower when transmitting on 30m. Even at low power it will bite pretty good if you touch the tower. On 6, 10 and 12m the tower is dead - no current flowing in it because the ground plane radials are electrically active at those frequencies.

Total cost in material back then was about $12 for the antenna itself, but about $20 would build it today.

I've never understood why ham radio operators would want to buy an antenna. You can build 'em out of just about anything, including electric fence wire. I've got a mile-long beverage antenna for 630 and 2200 meters that is just that - the top wire on our old line fence. And it works. It's situated east-west and I can pick up Europe on it on 160m any time. Old rusty barbed wire with electric fence insulators on the t-posts, stapled to wood corner posts, and terminated to a ground rod at the far end with a 450 ohm resistor. And the ground rod and resistor consists of an old t-post that I shined up with the grinder and tacked the fence wire to it with the MIG on my service truck. It ohm'd out at 450

I know another guy that loaded up the steel roof on his pole shed with a length of extension cord on 160m. He was on the local 160m net for many years with that setup. Why buy antennas?

 

[K6GBW]

Hmm...getting bit by an antenna. Yeah, back in 1991 I was working Lennox station and had a GE MPD portable radio that had the rubber cover torn off the very tip of the antenna. I transmitted, not realizing the inside of my bicep was touching the antenna tip, and about half a seond later a
very vulgar invective escaped my lips! Had to explain to the Sergeant why later... Even at 4 watts that flat hurt! Left a spring shaped mark on my inner arm for months.

 

[AC9KH]

Personally, I prefer resonant antenna simply because they are easier to deal with, but that doesn't mean non-resonant antennas can't work well.

That's right. A resonant antenna has a nice, predictable radiation pattern. A non-resonant antenna works, but can have a wonky radiation pattern. There are some exceptions like the venerable 5/8 wave vertical that has an extremely low radiation takeoff angle. That is why they work so good for local groundwave. But if you expect to use a 5/8 wave vertical for NVIS, you're gonna be disappointed because it won't work.

Another good non-resonant design is the 3/8 wave. Not quite as good as a 5/8 wave, but better than a resonant 1/4 wave if you want low radiation takeoff angle.

If you buy an antenna you are stuck with what you get. But if you build your own you can experiment for very few dollars and see what works. For instance, on 10m experience says a 5/8 wave works best about 50 ft above ground level. But if you can't do that, can only maybe get it 20 ft up, try a 3/8 wave instead, which has a little higher radiation takeoff angle to get your RF on the horizon. Even a 1/4 wave with drooping ground plane radials to get the feedpoint impedance up to 50 ohm might work better if you can't get the height for a 5/8 wave.

 

[AC9KH]

I think another thing to consider with 10m is that the band is only basically good for DX every 11 years when the sun gets riled up. The rest of the time, the band is dead except for a few brief "openings" during the day. So if you want to use 10m all the time, in most years you're likely going to be using it for local communications in between those cycles where the band heats up.

Most of the technology in 10/11m base station antennas actually comes from CB radio over the years. There's even been directional antennas with dual quad full-wave loop elements that can be switched from horizontal to vertical polarization built for 11m. Most of these can be re-purposed for 10m, but they come tuned for CB. I consider the real "experts" on groundwave communication on the 10/11m bands to be the dedicated CB operators, not ham radio.

 

[K6GBW]

Yep, all true. In fact using 10/11 meters local was my first goal. Still is in a way. But 11m seems really dead these days for local communcaiotns. Most of the stations out there seem to be "big gun" stations running lots of power and aiming for skip. But, who knows, maybe it will pick up again after the solar peak dies down.

 

[AC9KH]

Yep, all true. In fact using 10/11 meters local was my first goal. Still is in a way. But 11m seems really dead these days for local communcaiotns. Most of the stations out there seem to be "big gun" stations running lots of power and aiming for skip. But, who knows, maybe it will pick up again after the solar peak dies down.

It likely will pick up after the sun dies down, but this is kind of geographically-dependent in the U.S. 11m for base-to-base local communications seems to be very popular down south, not as popular in the rest of the country. It could be that cell phones have largely replaced it? It could be that decent CB base station radios are no longer built, and those that still run them are using vintage/restored radios? There was CB base station radios built back in the day, who's receivers easily rivaled today's top-of-the-line ham radios. And most of these were crystal controlled tube sets that sound absolutely fabulous on AM.

I'm not totally sure why, but this still seems to be quite popular in the southern states in rural areas.

Edit:
And yes, "skip" is actually nothing but interference for people trying to do local communications on 10/11 meters. When the sun dies out so you can leave the squelch wide open on your CB base station without a bunch of noise coming out of it is when local communications are the best. Then you can actually hear a weak signal when somebody calls on it. So during the peak of the sunspot cycle you're not likely to hear too much local comms going on.

 

[KF0NYL]

And yes, "skip" is actually nothing but interference for people trying to do local communications on 10/11 meters. When the sun dies out so you can leave the squelch wide open on your CB base station without a bunch of noise coming out of it is when local communications are the best. Then you can actually hear a weak signal when somebody calls on it. So during the peak of the sunspot cycle you're not likely to hear too much local comms going on.

I live in Missouri and frequently hear a guy from Puerto Rico on 11m Channel 9 that sounds like he is sitting right next to me.

I would like to install a vertical antenna for 10 and 11 meter bands. Right now I have just been using my 10m inverted v dipole for both.

 

[K6GBW]

If you’re focus is primarily skip then the inverted V is actually darned good antenna. Cheap, wind resistant and easy to put up.

 

[KF0NYL]

If you’re focus is primarily skip then the inverted V is actually darned good antenna. Cheap, wind resistant and easy to put up.

I couldn't agree more and why mine is still up even though I have other antennas.

A vertical would nice for 10m FM since most use vertical antennas for that. And the great majority of people will also use vertical antennas for CB too.

It can be tough talking to someone using a vertically polarized antenna when you have a horizontally polarized antenna, especially when you can talk to them easily when you both are using the same antenna polarization.

 

[AC9KH]

It can be tough talking to someone using a vertically polarized antenna when you have a horizontally polarized antenna, especially when you can talk to them easily when you both are using the same antenna polarization.

Polarization doesn't matter once the signal bounces off the ionosphere. If you're interested in groundwave propagation vertical polarization is the only one that works. The attenuation on groundwave with horizontal polarization is so high it basically doesn't work. 10 meters is the highest frequency band where groundwave works, although it's not nearly as effective as say 160 meters. Groundwave propagation depends on RF currents flowing in earth to propagate over the horizon.

Vertical to horizontal, line-of-sight, will have 20dB of attentuation.

 

[KF0NYL]

Polarization doesn't matter once the signal bounces off the ionosphere. If you're interested in groundwave propagation vertical polarization is the only one that works. The attenuation on groundwave with horizontal polarization is so high it basically doesn't work. 10 meters is the highest frequency band where groundwave works, although it's not nearly as effective as say 160 meters. Groundwave propagation depends on RF currents flowing in earth to propagate over the horizon.

Vertical to horizontal, line-of-sight, will have 20dB of attentuation.

And it is local ground wave that I want to work since most others around me use a vertically polarized antenna. If it wasn't for that I would not worry about a vertical antenna for 10m. My inverted v dipole does just fine for everything else on 10m and 11m.