Solarcon Antron 99

Evening all,

Well, I just received my new A99. Hoping to get it up early next month.

Seems like a very good quality antenna which won't suffer in high winds.

Middle section was a bit tough to screw into base section - very tight thread for which I needed a spanner and grips (and the lock-washer was too tight and had to be prised open a little to fit over the thread) - but that aside it certainly looks good.

Got it up approx 8' on temporary ground mount for test. SWR 1.1 at high end of UK FM. Otherwise 1.0 across the board, so I'm really pleased with it.

Will go up on house, 20' at base.

Any advice from anyone before I throw it up would be greatly appreciated.

Rory

Fibreglass can craze and splinter with time so a coat of wood varnish does help but for more protection i wrapped electrical tape around each section down as far as the metal part while the varnish was tacky.

Ive had mine 7 years and use it portable and its still working perfectly,mine is now green and blends in with the trees while up in the air (just for fun).

Each section can still come apart of course so i can pack it in the car but wont craze or splinter to stop water ingress.

I used mine homebase for 6 years and while they can bring in noise if you site it right and are lucky you will get zero noise as i do.

Expect some to say but its just a piece of wire in a fibreglass pole and no better than a silver rod and maybe not but mine withstood 80+mph gusts of wind during various storms without any issues.They tune away from 11m with little effort and have a flat swr on 11m...I rate them a lot and would have another for portable all day long..

Thank you Cozzmik. Yes, the reason I bought this one was because it is fibreglass so that it can withstand some wind battering. We get quite a lot across here.
Siting I have only one choice, so it is a pot luck install. I get what I get.

Cheers for the tips!

Just swopped mine for 18ft of wire.

73s Tom 26CZ455

Does anyone have any advice regarding spacing of T&K brackets?
How far apart would you put them.

I know aerial installers say leave at least 4 layers of bricks above the top one, and 2" of space between them per foot of pole - but that is with basic TV antennae, not with an 18' rod.

What do you guys use / have?

My brackets are spaced approx 40" apart (not strictly TK as homemade and slight difference) and well below the top line of bricks and the last 7 years my antenna has been totally fine even thru some strong storms with winds of 80mph recorded on my weather station.
Vector 4000 and 6 metre galvanised steel tube here now and Solarcon a99 used before..

I like to see the pole move as well as the antenna during wind load so there is plenty of pole above the top bracket,personal choice and i have seen a debate where some say let the antenna take all the strain by having less pole above the top bracket.

No fear of any damage to others here as my antenna can only fall onto my land so i sleep easy knowing that my way works for me..

Thank you Cozzmik,

I agree. I think a bit of flex on the pole is a good thing. A bit like a pine tree, they rarely fall because they just flex in the wind.
You seem to be using the spacing that I was advised to do, 20’ pole so 40” spacing.
If mine falls it will hit my conservatory - fibreglass vs plexiglass
will probably just make a loud slap; more drama than damage!
Thank you for your replies, they are really helpful

*self amalgamating tape over the joins and over the cable connector also a good idea to keep rain out.
*(like with car battery terminals) protect the TK bracket nuts once tight with small blob of grease or something similar. (The day you do decide to upgrade you'll be thank full).

The Doctor wrote:

Thank you Cozzmik,

I agree. I think a bit of flex on the pole is a good thing. A bit like a pine tree, they rarely fall because they just flex in the wind.
You seem to be using the spacing that I was advised to do, 20’ pole so 40” spacing.
If mine falls it will hit my conservatory - fibreglass vs plexiglass
will probably just make a loud slap; more drama than damage!
Thank you for your replies, they are really helpful

Welcome buddy,

And i agree with Trevor (Ranger) re amalgamating tape and grease where possible..

I always grease nuts (ooh matron) and do so on car wheel nuts too,always easier to remove..

73

Get the ground plane kit. Despite beliefs to the contrary all end fed antennas need a RF ground, there's a fundamental law of physics called Kirchoffs Law you can't get around. If you don't put in a RF ground the antenna system will try to use the mast and coax to compensate with all the negatives that can mean such as noise on receive, garbled transmit audio, causing interference to TVs etc (yes even digital terrestrial freeview). You may be lucky and the combination of pole and coax may be OK and you get away with it but one of the reasons some people say antenna X or Y that don't come with decent radials is crap whilst others swear by them is down to whether or not they were lucky with the lengths of mast they used.

Also put in a RF choke at the antenna feedpoint. 5 turns of coax 4.25" diameter will do the job.

Just some other question about the A99, or improvement of my complete setup:
I use a switched PSU, where i've read about that somehow they have some different kind of grounding and on the other end there's my A99 mounted on a homebrew telescopic mast of which the top end used to be a fibreglass windsurfing mast. So the A99 has no ground except for the RG58 coax shield.
What can be done?
- Grounding the bottom of the A99 through a separate cable to the metal bottom of my telescopic mast?
- Grounding of the RG58 shield?
- Also read somewhere that the A99 doesn't need contact to earth, true? If so, what about wind static build up on the fiberglass?
Some other questions:
- Would replacing the RG58 by RG213 cable help for loss reduction? It's about 15m of cable, RG58 has a loss of about 2.5 dB in 30m. The gain of the A99 is about 9dB, so by using RG58 i throw away about 10-15% gain. Am i correct or is this too simple thinking?
- Any experience with Ferrite beads around the cable for noise redustion? I ordered 20 to place some around the cord from the 240V home power supply, to keep out interference from internet through the power net. Any use for them around the antenna cable?
- As i'm a DIY person, is it possible to make the ground plane kit myself?

A lot of questions, but i have almost no electrical background and hope to tap into the knowledge base which is gathered here.

73
Karel

Get the ground plane kit. Get or make a RF choke and put it at the antenna end of the coax and keep the coax off the metal mast otherwise it makes the RF choke pointless.

You're trying to create a RF ground not an electrical one so contact to earth is not relevant in this context, that's for electrical and lightning grounding AND STATIC.

For 15m of cable the losses between RG58 and RG213 aren't that much, around 0.8dB for 15m with a SWR around 1.2:1 and not worth bothering changing the cable for. A S point is typically 3dB on a CB.

The gain of the A99 is not 9dB, more like 1-2dB.

Ferrite beads definitely worth it but whilst you've not got a RF ground and your coax choked off so you are suffering common mode RFI then the main source of noise will still be there. In regards to mains cables and ferrite beads you're better getting a large clip on one or a ferrite ring and wrapping the cable round that several times. Two turns of the cable through the ferrite would give you choking equivalent to using several ferrites in a row with the cable just running through them.

The top part of my mast is a fiberglass windsurf pole, so no contact in the first 3.5 meters, but then... How far must the coax be away from the mast, are we talking mm, cm or more?

Don't remember where (my son married today, so been busy with other matters ), but yesterday evening i found info on the A99 stating it uses the first 9 feet of coax as kind of a radial. Therefore the choke should also be about 9 feet away from the antenna connector. BTW this site also stated a gain of ca. 2dB for the Antron.

Somehow i think this is consistent with your advice. Since the ground plane radials will take over the function of that 9 feet of coax i don't want any length of coax taking part in the resonance system. This would also explain the disappointing result i got from an "ugly balun" mounted directly beneath the antenna connector with the A99 as is.

As English is not my native language i didn't quite get the info on that site stating the A99 only needed about 0.05λ of "counterpoise". What is counterpoise? Radial length? Sounded interesting enough to me for making the GPK myself with 55 cm radials.

Thanks for the info. I'll post the results i got.

73

Counterpoise = ground plane (RF). Most people use it to mean using a length of wire as a RF ground with something like an end fed wire antenna.

0.1λ is the minimum length you want. 1/8λ is better and 1/4λ the best. The shorter the wavelength the radials are the more of those you want.

If you have access to the ARRL Antenna Book, in the section on grounding there are several graphs showing the difference in gain using different lengths (in wavelengths) of raidals, different numbers of radials and what happens if for example you can only put raidals on one side of an antenna.

I ordered the GPK, but it will be at least tuesday when i get it.

73

Just saw a bit of your post I didn't reply to, the part about how much to space the coax away from the mast.

Because you're using a fibreglass windsurf pole bit at the top which your antenna is connected to then you're fine to secure the coax to the mast.

If you are mounting the antenna directly to the metal mast then it only needs to be a small spacing, maybe a centimetre or so to be safe.

Thanks, i'll use that below the windsurf pole.

73

The GPK came in today. After mounting and adjusting SWR i suspect the SWR is a bit more flattened along the band. Got a little chat with my son just on FM 4W CB ch20. He received me with an S9 +30, which normally is just S9. I received him (3W) with an S9 which is normally S7-8. So it seems there's a little progress on the short distance, about 3 miles, both transmitting and receiving. He will come and visit us tonight, taking his analyser with him. We'll see if there are improvements after the last measurements.
I also tried an ugly balun as the ferrite beads didn't come in yet. SWR went from 1.1 to 1.5, so i removed that again.

73

If making the balun caused the SWR to change you're likely to see the same happen when you add the ferrite beads. 1.5:1 isn't anything to be concerned about.

Rory,

You got that A99 up yet?
Drive through your location often but not heard you yet?

T.

ranger wrote:

Rory,

You got that A99 up yet?
Drive through your location often but not heard you yet?

T.

No, it's not up yet. The location is not easy to access (irritatingly), so I need to wait for some help. My cousin is due soon with a three-section ladder, then it will go up.
Need to bridge a conservatory that covers the entire rear of the house.

Look forward to seeing how you get on with you 99, I have not gone for the ground kit, but I used an RF choke, no problems with tuning, very high floor noise though at around 8 S Point.