Antron 99 question

[Badge19]

Good Morning,
I am currently using an Antron-99 which is mounted to the chimney and is about 40 feet in the air; I've seen that there is a ground plane kit for this antenna; any advantage to adding this..??

Thanks

[narfedwards1]

If it works for ya now no TVI I'd just leave it...so little difference withs rads man...save yer$$$...for a beam dude
....enjoy

[ Post made via Mobile Device ]

[MDYoungblood]

I always thought the ground plane kits for both the Antron A-99 and the Imax 2000 were afterthoughts, if they were effective on the antennas they would be sold with them, not as a kit. Looking at the kits the radials aren't physically long enough (electrically shortened) to create an umbrella effect under the antenna.

3's

Greg

[LION EYES]

I have an imax on a piece of 12" channel off the porch rail no GP kit been working great. When I rarely try to run more than 100w through it I would here myself on my computer speakers. ordered a GP kit thought it might help and wanted to try it . Heard a tap on the screen door took me about 4 seconds to get to the door. Fed Ex was already pulling away There was my kit leaning against the jam with about a 15 deg L all 4 radials completely broke in half. Wasn't meant to be haven't reordered Ya gotta laugh to keep your sanity A I did some reading on GP kits for the 99 and Imax the higher percent of people that experimented say it doesn't make any improvement. but are great antennas without them

[MDYoungblood]

I have an imax on a piece of 12" channel off the porch rail no GP kit been working great. When I rarely try to run more than 100w through it I would here myself on my computer speakers. ordered a GP kit thought it might help and wanted to try it . Heard a tap on the screen door took me about 4 seconds to get to the door. Fed Ex was already pulling away There was my kit leaning against the jam with about a 15 deg L all 4 radials completely broke in half. Wasn't meant to be haven't reordered Ya gotta laugh to keep your sanity A I did some reading on GP kits for the 99 and Imax the higher percent of people that experimented say it doesn't make any improvement. but are great antennas without them

Don't ya just hate that, Fed Ex would have got a ear full that day.

3's

Greg

[LION EYES]

Maybe we could start a thread on shipping horror stories. I've got a few I could laugh at someone else's misfortune instead of my own LoL

[MDYoungblood]

Maybe we could start a thread on shipping horror stories. I've got a few I could laugh at someone else's misfortune instead of my own LoL

Granted we all have stories about shipping mishaps but "no bashing" is one of the rules of the forum, sorry, I would have a few funny ones myself.

3's

Greg

[Firebreather]

I ran one years ago with and without the radials. There was no difference. Don't waste your money.

[Blue Ox2]

Well, with all the equipment I have been gathering lately,
I have figured I will take the McKinley, the Tram 1499, a coil of
coax, and the power supply with an extention cord
and set-up my station on the deck at my condo
in the Poconos.
This will be at the end of October and I'll
hope to be making some good contacts from the mountains.
I'll take a mobile log book along too.

73

Mike

[ Post made via Android ]

[Tweetybird]

I ran one years ago with and without the radials. There was no difference. Don't waste your money.

I did not use a GPK with a A99 but with an Imax and I can tell you the GPK got rid of my Electric noise.

[MDYoungblood]

I ran one years ago with and without the radials. There was no difference. Don't waste your money.

I did not use a GPK with a A99 but with an Imax and I can tell you the GPK got rid of my Electric noise.

I have heard a couple claims the ground plane kit helped reduce some noise but when questioning the poster they did other things as well like additional grounding etc., so it is hard to say it helped, was there anything else done at he same time? One poster said he removed an insulating piece of PVC because he thought the antenna should be isolated from the mast, when he removed it, it was a world of difference on both RX and TX.

3's

Greg

[darklife]

The GP may change the radiation pattern slightly but otherwise it's not doing anything more than your coaxial cable is already doing.. making a return path for the end fed half wave dipole that is the A99. Given that this antenna is fed from the end and the transformer inside the base of it sets up to make an unbalanced feed point the only way for the actual antenna element to radiate is to have to push against something, whether that is a short length of your coax or a ground plane doesn't really matter to it. If you have it mounted to a metal pole or tower and the coax against that it will simply use the metal structure as a return point.
You know these types of antennas are working good when the metal structure it's tied to is lit with a bit of RF and it will effect radiation pattern but that's the price you pay for that bit of return path with a high voltage feed at the end of the antenna rather than a middle current feed of a normal dipole. There is no 1:1 balun coiling you can do with coax that will help this. Best case scenario you have a half wave dipole vertically in the air, worst case you have a dummy load.

[Stoneman]

I had that kit back in the day, only thing I noticed was snow and ice like to bend the radials over, that's when I live in NY..

[51]

dont buy it, the ground plane kit is not even a 1/4 wave in length. so its rubbish, it wont do anything for you except empty your wallet.

[sonoma]

I tried a ground plan kit on a 99 antenna and did not notice any difference. the kit is laying on a trailer right now. like mentioned easrlier it collects ice real well.

[MDYoungblood]

This is my opinion and have said this many times in the past, the Antron is a "good easy to install antenna's" on it's own, same goes for the Imax, they both are made by the same company. The "Ground Plane Kits" were an afterthought for both antennas. The Antron doesn't need a ground plane as it is built in a dipole configuration with a shunt capacitor in the base to compensate for SWR, the Imax is an end fed antenna using a similar shunt capacitor for the same reason. The way I see it is if you add the cost of the antenna and the ground plane kit (don't forget separate shipping) you could buy a better metal antenna like the HyGain or similar.

3's

Greg

[51]

This is my opinion and have said this many times in the past, the Antron is a "good easy to install antenna's" on it's own, same goes for the Imax, they both are made by the same company. The "Ground Plane Kits" were an afterthought for both antennas. The Antron doesn't need a ground plane as it is built in a dipole configuration with a shunt capacitor in the base to compensate for SWR, the Imax is an end fed antenna using a similar shunt capacitor for the same reason. The way I see it is if you add the cost of the antenna and the ground plane kit (don't forget separate shipping) you could buy a better metal antenna like the HyGain or similar.

3's

Greg

true, any vertical antenna will work without a ground plane but they will benefit greatly from a properly designed and installed ground plane system. and as stated, the capacitor at the feedpoint in the antron 99 etc is for impedance matching, it does not create the "antenna image" needed to act a a dipole. only ground plane radials, the earth (if ground mounted) or the mast can do that. if you can install the correct ground plane system needed, do it! the benefits are large. if not, its not a deal breaker, you will just have a compromised vertical.

[The DB]

With the a99, and really any antenna that requires a matching network, the ground plane really doesn't do as much as people want to believe. In the case of the a99, if you get the ground plane kit, or even make a set of so called "proper radials", and you notice a difference, then you had a problem that adding said radials fixed. Nothing more and nothing less.

For this type of antenna, radials do add some benefits, namely fixing several potential problems, but most if not all of those benefits can be had by other means.

I would also not recommend getting the kit. I would recommend getting someone who knows what they are doing to take a look at your setup. And if they recommend getting a different antenna simply because you have an a99, get someone else. Their is nothing wrong with the a99 antenna, but they can be touchy in some circumstances...


The DB

[Lost Ram]

The biggest issue I see with these A99 or Imax is Common Mode (RF on the feed line), a good homemade ugly balun takes care of this issue.

[MDYoungblood]

The biggest issue I see with these A99 or Imax is Common Mode (RF on the feed line), a good homemade ugly balun takes care of this issue.

You could also use snap-on ferrite beads, at least 6 in a row are needed for 27mHz. Look for type 31 or 43 mix. The "dirty choke" mentioned , (an air wrapped choke, 5 turns at 4 1/2" in diameter) would be the cheapest way to go. Would never hurt to use both.

3's

Greg

[The DB]

I much prefer the ferrite beads, although I don't use the snap on beads. Its not a problem for me to thread the beads and use some thick heat shrink tubing to keep them in place, then put the end on the coax. It looks nicer, and ferrite chokes generally work better than the air wound chokes (the dirty choke mentioned above). Plus a few other nice thing about ferrite beads, the chokes they make covers a very wide band of frequencies (near all of the HF spectrum, and if you need more choking, unlike the air wound choke, you simply add more ferrite.


The DB

[MDYoungblood]

I much prefer the ferrite beads, although I don't use the snap on beads. Its not a problem for me to thread the beads and use some thick heat shrink tubing to keep them in place, then put the end on the coax. It looks nicer, and ferrite chokes generally work better than the air wound chokes (the dirty choke mentioned above). Plus a few other nice thing about ferrite beads, the chokes they make covers a very wide band of frequencies (near all of the HF spectrum, and if you need more choking, unlike the air wound choke, you simply add more ferrite.


The DB

I prefer the whole ferrites as well but only suggested the snap-on type for those with the coax already made up. Using heat shrink is a good touch, just need to what out not to over heat the coax.

3's

Greg