HF Antennas

motormayhem

New member
Hi All,
Looking for an HF antenna for my FZJ80 I can mount on the front bumper or tire carrier. Something that can take some tree abuse or be easily broken down when not in use. I'd primarily like to use it while at camp for winlink / SSB phone. I'm also open to something I could setup quickly at camp without trees. I'm tired of the setup required for a wire antenna in the trees.
 
Since it sounds like you care to only operate stationary then I would recommend Hi-Q Antennas or Ham Sticks.


 
Hi All,
Looking for an HF antenna for my FZJ80 I can mount on the front bumper or tire carrier. Something that can take some tree abuse or be easily broken down when not in use. I'd primarily like to use it while at camp for winlink / SSB phone. I'm also open to something I could setup quickly at camp without trees. I'm tired of the setup required for a wire antenna in the trees.
Scorpion SA-680 is as good as it gets for 10-40m, IMO.
 

DaveInDenver

Expedition Leader
You don't mention what bands you're most interested in using. It does make a difference. You mention Winlink but you might focus only on a couple of bands to improve your chances over nimbleness with an antenna that doesn't perform particularly well on any one band.

Winlink is handy because a station usually offers a 80m or 40m frequency but also a 30m or 20m and 10m. So you're not chasing a station potentially operating on just one band and therefore the flexibility to jump bands isn't necessarily a critical feature. But of course propagation is going to vary across location, time and weather, so that's the rub.

A random length wire such as you're doing now is about as good as you can do short of a properly tuned vertical or dipole placed high.

On 40m and 80m a high Q coil will help improve the performance but at the longer wavelengths anything physically short in length is a compromise. You're talking relative here, so a good screwdriver might be 5% efficiency (based on ERP, so 100 watts from the radio is 5 watts radiated) or Ham Stick at 0.5% but compared to a random length wire or nonresonant doublet with a tuner that might achieve 30% or a dipole 80% energy actually radiated.

FWIW the Scorpion is about a $1,000 antenna. They are very well made and about as good as it gets for a screwdriver configuration. Don't expect miracles and there's a significant compromise for the convenience.

And don't overlook the ground or radials. A screwdriver against a poor ground (e.g. a truck body) is a double compromise.
 
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I agree 100% with Dave. Operating mobile or portable the antenna is always a compromise. A lot depends on time of day and band conditions. If the band is short and the station is close by ( within 200 miles) then a low hanging dipole is the best. Band goes long and station is farther then 200 miles then some type of vertical is going to be the best.

One trick that might help you from hanging wires is a dipole conversion plate. Basically it is a plate mounted on a short pole (usually 10-20 feet) that will allow you to run either 2 ham sticks or 2 screwdriver type antennas 180 degrees opposed of each other in a dipole configuration. Tuning with screw driver type antennas can be difficult the first time as you have to balance them ( get them in sync with each other). Not a hard job just time consuming. Something you can do at home before heading out.

This will give you the option of using it as a dipole in NVIS configuration when band is short and as a vertical for longer band conditions.
 
Oh wow I just went and checked out Scorpions website since it had been awhile. Everything I just mentioned is on Scorpions product page. First two items, a dipole antenna and a home antenna. I would contact them as you just need the Dipole package and then the bits and pieces to convert it to a home package. I like there ground counterpoise for vertical operation. It is a pair of telescopic elements that set of the band desired. The standard counterpoised adapter is 8 ports meaning you can setup 4 bands. They do make an adapter with 16 ports giving 8 BANDS!!

A guy could hand a blast running local digital during the day and at late afternoon and night chasing grayline dx. I know off topic but what a portable setup that would be with plenty of options.
 

motormayhem

New member
Thanks all. Right now Ive been using a Chameleon TD light antenna setup usually in an inverted V configuration (not NVIS). I’ve been tinkering around with 20m ssb phone and 40m winlink. My primary use would be 40m/20m and maybe some 30m aprs and 10m if possible.

I knew mobile antennas were a compromise, but I didn’t realize the radiation efficiency was down around 5%.

The scorpion is neat, but a bit on the expensive side. Id probably want to spend around $500.

Im assuming an antenna such as the little tarheel II is going to be similar as far as durability/radiation efficiency goes? Has anyone tried the Chameleon MPAS 2.0 system? Specifically the vertical antenna arrangement looks pretty quick to setup once stopped vs stringing wires all over. It could be mounted to the bumper or spiked into the ground.

Another option I was considering which doesnt help with NVIS or reduce setup complexity would be a mast setup. This would be to allow my wire antenna to be setup without trees. If I did a mast Id likely want to put a 2m antenna up top, but it seems most masts can barely support a wire at the top.
 

DaveInDenver

Expedition Leader
There's never a single perfect solution to all the things you want to tinker with in ham, is there?

FWIW, though, I tried mobile HF and it's not something I really found compelling. But I drive a stick shift truck in the mountains so it's more a question of attention focus and simply having enough hands. I prefer to operate portable once I get to camp and with that caveat I figured there was no reason to arbitrarily limit myself to antennas appropriate for use mobile/driving that by necessity will be compromises in performance.

In that vein a mast of some sort would be a better (or rather less limiting) option IMO. It wouldn't take much to support wire antennas. Some years ago I bought the longest crappie fishing pole I could find at the Cabela's (15' as I recall) that supports a 24 AWG dipole without bending down much. That works for low power work fine, although does of course favor high angles like NVIS.

If you're considering a 2m vertical on it then something more substantial would be necessary. I have a set of military surplus 1.75" fiberglass tent poles that I can stack into about a 20' tower. It requires a set of guy lines at that height but is otherwise very stable.

There's other options, aluminum ones, staggered fiberglass push ups, etc. If you're willing to carry the weight this does give you a lot of options beyond a VHF antenna or large wire antenna. Such as perhaps a small beam for 10/15 or even a mini loaded 20m Yagi at the top.
 
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Take a look at DX Commander he has some excellent telescopic fiberglass mast vertical wire HF antennas. He has an Expedition model that collapses in a nice package. A few radials stapled to the ground and you are good to go. Being HF vertical it will be more noisier but it is for the longer distant contacts. He even shows in his videos how to string Inverted V antennas from his mast for NVIS work. HIs mast are top notch and not some chinese MFJ junk.
 
You said you want to mount it on your bumper or tire-carrier...

If you're just talking mobile base, it's going to take a lot of gear and money to do much better than a wire. I think the Chameleon antennas are pretty decent for what they are; better for RX than TX, but they work and are very compact. A counterpoise helps a lot, if you're not already using one.

The DX Commander stuff looks really cool if you want to go vertical. Would love to check one out.

One nice thing about a wire is that it's pretty low-profile, even though it's long. A thin black wire doesn't attract as much attention as a lot of other options. That could be a pro or con, I suppose, depending on the user.

Check out the Comet 250b. It's certainly a compromise, and it really needs a balun, but it goes up and down incredibly fast and is pretty decent for what it is. If you can store and carry the pieces, it makes a decent mobile base antenna.
 

motormayhem

New member
If you're just talking mobile base, it's going to take a lot of gear and money to do much better than a wire. I think the Chameleon antennas are pretty decent for what they are; better for RX than TX, but they work and are very compact. A counterpoise helps a lot, if you're not already using one.

….

Check out the Comet 250b. It's certainly a compromise, and it really needs a balun, but it goes up and down incredibly fast and is pretty decent for what it is. If you can store and carry the pieces, it makes a decent mobile base antenna.
Thanks everyone for the recommendations. It seems a good portable base setup is what Im after more than a bumper mounted unit. The comet looks promising, but I think for now I’ll give a fiberglass mast a shot as it provides the most flexibility without needing to find/setup in trees.

When you say the Chameleon antennas are better for Rx than Tx what do you mean? Any improvements to be made? I have noticed I can receive winlink data much better than I can send it.
 
When you say the Chameleon antennas are better for Rx than Tx what do you mean? Any improvements to be made? I have noticed I can receive winlink data much better than I can send it.
Wires in general; not just Chameleon stuff. Wires are inefficient transmit antennas. A balun or un-un separates the antenna wire from the feed line and improves the SWR that your amplifier sees, but it doesn't improve the efficiency of the actual wire. You also don't have much of a ground plane. Adding a counterpoise will help. You can cut a counterpoise from any wire for the band you plan on using, or cut multiple wires and set them up as radials. Stranded THHN works well and is readily available. Chameleon also makes a ready-to-go counterpoise radial setup if you want something off-the-shelf.
 
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motormayhem

New member
Ah gotcha, I thought the matching transformer was to help broadband the antenna. So its average everywhere and not great anywhere. Does that mean something such as dx commander SOTA type wire vertical would be better at TX? Is there anything better than a tuned length wire short of something directional? It might be a fun project to make something like the Dx commander.

I've typically run an inverted V so no counterpoise. But with a mast running a vertical/sloper I guess Ill need to make some up.
 
Ah gotcha, I thought the matching transformer was to help broadband the antenna. So its average everywhere and not great anywhere. Does that mean something such as dx commander SOTA type wire vertical would be better at TX? Is there anything better than a tuned length wire short of something directional? It might be a fun project to make something like the Dx commander.

I've typically run an inverted V so no counterpoise. But with a mast running a vertical/sloper I guess Ill need to make some up.
Not necessarily. With a mobile base rig you'll encounter various terrain, which will have a significant effect on propagation. What works well in one spot might not be great in the next, and band conditions will still play the biggest role. When the conditions are poor, no antenna is going to save you.
 
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