Solarcon A-99

[KG4CGC]

So I got a freebie a-99 already cut for 10m. OK, great. I go online and look for more information on it and it's just an end fed, half wave vertical with an impedance matcher, so to speak, attached to 16 ga wire in 3 sections.

Currently I switch back and forth between an inverted-V half wave dipole and a vertical half wave dipole.

Just for your edification on the construction method, I used 4 strands of insulated 12 ga wire, tightly twisted together to length for each leg of the inverted-V. For the vertical dipole I used insulated 8 ga wire and hung it in a tree with a rope also attached to the bottom leg and secured to the ground just so it doesn't blow around all over the place.

1) My question(s) is, should I expect a better gain figure with the a-99 over my dipole?

2) Should I attach a wire, cut to resonant (about 100.75") to the base of the a-99 and let it hang straight down? The a-99 will be hung from a tree in the spot that the vertical dipole occupies.

3) How is the manufacturer of the a-99 able to claim it is a half wave over a quarter wave radiator with a gain figure of 9.9 dbi while the dipole MIGHT be as high as 2.4 dbi?

Anyway, these are questions for greater minds than mine and any help would be greatly appreciated. Hey, did I mention it's free pour at bar?

[WZ7U]

Charles, I really don't know how they justify that gain figure, but they do seem to work reasonably well. The 1/2 over 1/4 wave thing throws me too. But really it is just as you describe. A piece of wire in a tubular radome.

Now, the one I had was mounted on a stick of 3/4 water pipe up against the house. It's possible that the pipe acted like the other half of a vertical dipole. Thinking about it, I'm almost certain that was what was going on. But I can't test the theory without a PVC mast or something. In your application, I think a piece of wire hanging as you suggest is a great idea if you want to keep the coax shield out of the equation.

Your price point is extraordinaire.

So, in order
1) no, not in sane and reasonable world
2) yes
3) cuz they smoke better shit that we do



Lemon vodka neat, please

[PA5COR]

I use the imax 2000 bit longer same network in the antenna same end fed antenna with 37 Pf C in the middle of the 2nd half of 3 parts.( middle section)
I run it on 10/12/15 and with tuner on 18.
On 10 and 12 5/8 on 15 and 18 1/2 wave antenna, i tried the ground radial kit from Imax, it only narrowed bandwidth, so now no radials, just some ferrrite about 10 feet from the feedpoint to keep rf from the coax.

Does it work? yes, 10 like any other 5/8 antenna, same on 12, on 15 running digital mode i get most continents in daily if it is a bit open.
Compared to the FD-4 wire a 40 feet up it is about the same on 10 depending conditions sometimes the Imax wins.
on 15 the Imax is a tad better as the wire.
Your 99 should also be quite broadbanded give it a try .

[N8YX]

I have an Imax up here; around 30ft at the base.

It has a homebrew radial kit - 3 bundles; 4 radials per. They're cut for 28.500, 27.200, 24.950 and 21.300. The 11M segment actually resonates around 26.700 as measured with an analyzer; Ch1 SWR is 1.7:1. I suspect a bit of tuning will help here. 10M resonates higher up the band (ditto tuning) and 12 and 15M are close to unity where I usually operate. Additionally, a choke balun was installed at the feedpoint.

The current 10M station is an IC-751A/R-71A/R-70 ensemble with either an AT-100 or AT-500 auto-tuner handling matching duties. I can also switch the antenna to the FT-102 station and operate 10M with it if desired. Neither the Icom nor Yaesu tuners have a problem bringing SWR to 1:1 so this tells me the impedance characteristics are well within specs. One day I'll sweep the thing with my antenna analyzer and post the results across the four bands of interest.

Many (a rather large percentage) of the local 10M Gang use this particular antenna for our net operations. The most power I'll put into mine is ~200w PEP (from the barefoot FT-102) and it's held together for years. It gets great reports as compared to some of my other 10M antennas, though some day I hope to have a Pro-67 or TH11DX in the air for DX.

[KG4CGC]

OK wow and it's listed as a 1500 watt antenna!
My main reasoning with this piece of equipment is, will it hear better that a half wave dipole?
If not, I will string up an aluminum ground plane. The reason I'm not hopping on that right away is because I have yet to see if the ground radials will clear some of the branches in a tall black walnut tree. The supporting branch is about 12 feet out from the main trunk but of course, there are a few small branches along the way up.

[N8YX]

My main reasoning with this piece of equipment is, will it hear better that a half wave dipole?

If everyone in your area is vertically polarized, yes. If they're using horizontally polarized antennas and are located in one general area relative to you, I'd put up a dipole. Another option is to put a 10M loop for omnidirectional coverage using horizontal polarization.

Go look up the Avanti Sigma antenna. It was a 5/8w CB vertical with a full-wave loop configured into the radial setup. The operator could switch between polarities and talk to the crew around town on the vertical section or work DX via the loop. An area CB buddy had one and it worked rather well for what it was.

[KG4CGC]

Yes well I use an inverted-V as well. pulls in the horizontal signals very well. Antenna switch in the antenna tuner. Use the tuner just for convenience of switching antennas and also for when the OCF dipole goes back up.

[N8YX]

On which frequency or frequencies does your group hang out, Charles?

[W3WN]

I have an Imax up here; around 30ft at the base.

It has a homebrew radial kit - 3 bundles; 4 radials per. They're cut for 28.500, 27.200, 24.950 and 21.300. The 11M segment actually resonates around 26.700 as measured with an analyzer; Ch1 SWR is 1.7:1. I suspect a bit of tuning will help here. 10M resonates higher up the band (ditto tuning) and 12 and 15M are close to unity where I usually operate. Additionally, a choke balun was installed at the feedpoint.

The current 10M station is an IC-751A/R-71A/R-70 ensemble with either an AT-100 or AT-500 auto-tuner handling matching duties. I can also switch the antenna to the FT-102 station and operate 10M with it if desired. Neither the Icom nor Yaesu tuners have a problem bringing SWR to 1:1 so this tells me the impedance characteristics are well within specs. One day I'll sweep the thing with my antenna analyzer and post the results across the four bands of interest.

Many (a rather large percentage) of the local 10M Gang use this particular antenna for our net operations. The most power I'll put into mine is ~200w PEP (from the barefoot FT-102) and it's held together for years. It gets great reports as compared to some of my other 10M antennas, though some day I hope to have a Pro-67 or TH11DX in the air for DX.
What's involved in creating those radials? I really should add some to my A 99, although it works pretty well as is.

[N8YX]

What's involved in creating those radials? I really should add some to my A 99, although it works pretty well as is.

Calculate as 1/4 wave at the frequency (or frequencies) of interest. This exercise was done primarily as an experiment to de-couple the feedline from the radiating portion of the circuit - something the Imax is noted/notorious for. The area CB denizens claim their usable bandwidth goes way down when the Solarcon accessory radial kit is installed, and this lends credence to the theory that the feedline is being made to radiate at frequencies far off resonance.

I cut mine for the mid-point of the 10M "SSB" (<29MHz) band, the mid-point of 11M, the mid-point of 12M and the mid-point of the 15M phone band. A group of four was attached to a ring terminal then the wires were tie-wrapped together. Make three or four bundles, connect the ring terminals to the clamps which secure the antenna to its mast and slope them away at a 45 degree angle.

Mine wasn't tuned any further but I highly advise doing so at the primary frequency of interest (e.g., 28.400, 27.200MHz) - wherever you'll operate the most. The other bands are easily matched with an antenna tuner.

[KG4CGC]

On which frequency or frequencies does your group hang out, Charles?

28.372 and sometimes 28.402. Really though, 28.402 is if a couple of us want to pop up there to get away from the drone of certain politics.

What I'm trying to do though is overcome some geographical issues. Directly south of me the terrain increases in altitude 100' over a distance of 3/4th of a mile. This is also true SSW and SW. The feedpoint of the inverted-V sit up at close to 70' but it's not a true V. It's closer to being a horizontal dipole than it is a true inverted-V in all its glory. I'm good with that one and I'm going to leave it be since it hits the DX good from the West coast when starts rolling, a lot of the time. I still have issues overcoming some stations unless I'm the first one in there before everyone else discovers that the band is open.

I do switch back and forth between the two antennas to pull in stations better and use the one getting a louder signal. All was well and good but now I have something else to experiment with and before I go hoisting sails, that what I call pulling an antenna up into a tree, I'm wondering if this is worth the effort or if the A-99 is a garbage project. I will be adding a heavy gauge wire attached to the base of the antenna where the mounting hardware would usually go and include the dimensions of the base in the length of the wire. Like the dipole it will replace, there will be a rope attached to that wire just as a type of anchor.

So yeah, on local talk, there are some guys to the south that I struggle to hear but guys further away to the east I hear fine. All that being said, not all stations are equal BUT, stations to the south and to the east lose 100' to 200' in altitude because of geography etc, although their decline in altitude is not as dramatic as the hill that is very close to me.

Also this has also made me want to do a mobile set up and go hit a mountain top.

[WØTKX]

The drone of dystopian ammosexual fantasies.

[kb2vxa]

Hi Charles,

I'll answer your original questions in order to avoid confusion. I hope you haven't mounted it yet, you'll see why soon.

1) My question(s) is, should I expect a better gain figure with the a-99 over my dipole?
Most certainly, a dipole has unity gain and is the de facto standard reference (dBd) for gain measurement. An end fed half wave, 5/8 wave and .64 wave in order of increasing gain flatten the dipole's V pattern extending it outward toward the radio horizon thus increasing "gain" actually a wider coverage area. It's also much better for DX hitting the ionosphere at a shallower angle increasing distance where it's refracted back down.

2) Should I attach a wire, cut to resonant (about 100.75") to the base of the a-99 and let it hang straight down? The a-99 will be hung from a tree in the spot that the vertical dipole occupies.
Keep it away from trees that absorb signal, and mount it on a mast away from obstructions, earth counterpoise coming soon.

3) How is the manufacturer of the a-99 able to claim it is a half wave over a quarter wave radiator with a gain figure of 9.9 dbi while the dipole MIGHT be as high as 2.4 dbi?
Advertising puffery just short of lies that are illegal. You're comparing apples to oranges here, refer to my first answer. Manufacturers puff up gain figures by using dBi which is only a mathematical construct, theoretical radiation spherically from a point radiator. As you learned in school before the No Child Left Behind policy went into effect, a point is another theoretical construct, an infinitely small "dot". If you want to know true gain, Gain in dBd = gain in dBi - 2.15 dB and I still don't trust advertizers, especially when the reverse is true, Gain in dBi = gain in dBd + 2.15 dB.

Last but not least, if you want that antenna to be at its peak of performance add the radial kit that SHOULD be sold with it so it operates properly with earth counterpoise and you won't be disappointed. Here is the TI2MAS installation with radials, Antron is a brand of Solarcon sold as a CB antenna easily re-tuned below and above 11M. That sucker's expensive at a hunned anna qarters to a hunnerdfify buckaroos so don't expect the radial kit to be cheap, I got a $70 price on it... OUCH! Oh BTW it's rated at 2KW to handle today's CB leenyars. (;->)

Every ham worth his salt knows that all verticals are ground plane types that if mounted on the ground use true Earth counterpoise with radials on the surface (best) and AM broadcast standard practice, or buried shallow (second best) Amateur standard practice, which is the other half of the antenna. Smaller verticals mounted above the ground have radials too at the base, again the other half of the antenna that raise Earth up to it electrically. You won't be as happy with the antenna as you can be with the radials and mounted in the best location away from obstructions that absorb signal.

"I do switch back and forth between the two antennas to pull in stations better and use the one getting a louder signal."
That's exactly what we did on Field Day with a 1/2 wave vertical and a dipole as the changing ionosphere causes polarization shifts. It was a 2 man operation as FD is, the operator had one hand on the PTT bar and the other on the coaxial switch, the other person logging.

Good luck Charles, I wish you the best!

17524

[KG4CGC]

Thank you for the constructive input, Warren. I appreciate it.

With regard to mast mounting it, that's not an option unless I go with a tower and that's not happening either. Mast material these day is too thin walled compared to the stuff I used in the 90's and more so compared to the stuff I salvaged from the 70's. The old 70's metal tubes finally succumbed to the weather about 10 years ago. If I try a mast mount today the best I can do is 20 feet max before everything folds over on itself.

[kb2vxa]

The brackets look like they'll handle a 10ft section of heavy wall aluminium EMT available at your local electrical supply house. Jack WA2V (SK) and I used it for mast, IIRC the next smaller size slips into the next larger to make a longer mast if necessary, drill holes and pin it. You can test what you need if they allow you near the rack. I also used Rat Shack steel TV mast that just slips together. Alas poor Rat Shack, I knew it well, but Tandy succumbed to something rotten... mismanagement.

[N8YX]

I also used Rat Shack steel TV mast that just slips together. Alas poor Rat Shack, I knew it well, but Tandy succumbed to something rotten... mismanagement.
They offered telescoping TV mast as well, and Rohn still does. Any higher than 15ft extended definitely requires guying, though.

[KG4CGC]

All wonderful suggestions. Thank you.
It's going in the tree. I can get the feed point close to 60' up.
The top half will be poking out in the clear.
The rest will be 12 feet out from the major parts towards the center.

[kb2vxa]

Well, the tree isn't ideal, but a natural tower isn't too bad. Before Jack and I were hams we were CBers and it was a good place for cutting radio teeth if you do more than talk. We did a lot of experimenting, mostly with antennas, building a few too, and modifying ham transmitters made before 1960 with 11M. My last station was Heathkit twins, an Apache transmitter tweaked for 11M and a Mohawk receiver. There's nothing like an M derived pi section filter following a clipper for punch without audible distortion and splatter. To the point, we had an antenna in the tree behind his house at the shore, we had a lot of fun there and the signal covered Atlantic City to New York, we didn't "shoot skip" because there wasn't any propagation.

Telescoping mast, my base station house had only a 16ft roof peak so I had to go up, compounding the problem was only the legal 2Ft setback from the property line. We put 3 heavy wall brackets on the side holding a 50ft mast telescoped down to 40ft to give several walls thickness at the top bracket. The mast sat on a concrete block and the earthing stake 10ft into the ground connected to the mast with a conductor thick as your thumb scrounged from a transformer installation saved my life one night when the antenna got smacked. It stood up to a hurricane so I can say it was good material and installed well even though unguyed.

Going mobile Charles isn't a bad idea either, I knew two 10M Mobileers, one the owner of a 10M repeater and the other one of the 10M CBers who parked at the Point Pleasant Beach Inlet watching the boats go by. When I was still active I QSOed with a guy on 6 USB parked on a mountain in Pennsylvania 120 miles North By Northwest of me. Yeah, it's also the name of a Hitchcock thriller. He lived in a valley so VHF from home was impossible. I used to go hilltopping in the VXAmobile, one time I called on 145.250 and kept hearing a tiny signal answering, barely audible. I thought it strange, so I ran a test of a sequence of long and short transmissions, they came back as sent. AHAAA! One of those silly simplex repeaters only this LID put it on the calling frequency! GGGRRR!!!

[KG4CGC]

I don't remember all the reasons behind it but 145.250 was a point of contention in our area as the old analog cable system of the 90's and 00's used that frequency in their lines ... that leaked!

[W3WN]

I don't remember all the reasons behind it but 145.250 was a point of contention in our area as the old analog cable system of the 90's and 00's used that frequency in their lines ... that leaked!
Back before they were absorbed by a predecessor of what's now Comca$t, local cable company had an issue on their (analog system) Channel 19, which included 2 meters. Definitely picking all sorts of Land Mobile communications; cabs, power company vans, and so forth.

I once called in the issue. 1st Tier Support asked what community I lived in. Told her. Was then informed that it HAD to be caused by that "damn ham" who lived on my street who was running "too much power." I asked to speak to her Supervisor; she asked why, and I then told her that I was that "damn ham", I didn't operate when watching TV, and that she had just violated several FCC rules and regulations by accusing me of interference without proof... and without knowing what power levels I was legally allowed to use... so either put me through to her Supervisor, or I'd file a complaint with the FCC.

She put me through without another word.

I did get an apology from the Supervisor, but they never did fix the problem. At least, not before I switched to DirecTV (back when they were still part of Hughes and a decent company)