I am a new ham and just trying to get my first HF rig up and running. My father in law said he had this 'HAM radio antenna thing' in the rafters of the garage, but he's not a ham, so i dont know how he came across it. Anyway, it is an 'Isoloop'. Its an ABS plastic body around some kind of motor, with a circular band of aluminum in a 'halo' around it.
My question is: is this something i can use, and how? I dont have an antenna tuner yet, and wondering if this can shortcut that step - or should i just forget about it, and go on building a homebrew dipole and find a used tuner somewhere?
Yes, you can use it, but probably not immediately. As described, it sounds like the remote control box & power supply are no longer there. The Isoloop is a reasonable radiator, especially in portable and stealth situations, but doesn't perform as well as a dipole at the same height. It has a very narrow bandwidth, although retuning is straightforward if you have an SWR meter in the transmission line. I think that an automatic retuning mechanism was available, which greatly simplified the operation. I'm not I'm not sure, though, if it was for that particular model of the Isoloop. Getting the remaining parts for the system will be your biggest problem; with luck, the WTB forum here might locate those items for you.
Regardless, I recommend that you grab the Isoloop, do some research for the needed parts, and eventually you can put it on the air. It would be worth the experience. If the rest of the system turns out to be unobtanium, then advertise yours for sale; someone else might need it.
In the meantime, build a dipole. That would be a more effective antenna, and require less investment (time and money) than the Isoloop. BTW, if you make a single band, coax fed resonant dipole for any band between 40 and 10 meters, you probably won't need an antenna tuner. Same for a coax fed fan dipole (parallel resonant dipoles with a common feed point).
For your reading pleasure:
eham Isoloop reviews
An older Isoloop model described
Last edited by K9ZMD; 11-06-2010 at 04:58 AM.
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All AEA Isoloops had a built-in tuner which was motor driven. The tuner and the motor are inside the ABS housing. You really cannot use this antenna without the controller (either the original AEA one, or a copy of it), as it will only work on the one frequency where it happened to be last tuned before the controller was disconnected. It's very high-Q and very narrow-banded, so when it is "tuned," it's good for about 10-20 kHz operating bandwidth, and that's about it. One setting won't even nearly cover an entire amateur band, let alone multiple bands.
Originally Posted by K9ZMD
Ask "dad" if he has the other part, which is the controller. It's just a small box that normally sits on your desk near the radio.
An Eye-Sore Loop has about the same gain as a heat lamp.
"The more you know, the less you don't know."
First of all, welcome to ham radio!
Originally Posted by KF7ACN
The IsoLoop antenna was made by AEA as a limited space antenna for 30-10 meters. I have used one in apartments and condos and currently have it in my attic space. If you don't have the control box, you'll need to find one, because that is what's used to tune it. It sits on the desk and you have to tune it for the frequency you are on. It isn't a bad antenna, I've had good luck with it, but it has very narrow bandwidth so if you want to change frequencies, even within the same ham band, you'll have to retune.
If you can put up a dipole or other type of antenna, you'll probably do better that that than you will the IsoLoop. If you can erect a long dipole, you feed it with twinlead or ladder line then use a good tuner to match it to your rig and you will be able to get on multiple bands with it. If you can erect multiple dipoles, you can set one up for each band you want to work and you won't need a tuner at all.
MFJ makes a clone of the IsoLoop under the same SuperLoop. I've never used one, and they are a little pricey, so I can't comment on how they perform. If you can set up a dipole, I'd say go that route. If you find the control box for the IsoLoop, it might be fun to just set it up and play with it to see what it will do. I currently still use mine because my multiband half wave open loop seems to be weak to the northwest on 20, so I use the IsoLoop for that.
Good luck, and again, welcome to ham radio.
Jonathan Helis, KB5IAV
Baton Rouge, Louisiana, USA
I also am trying to get an old ISO Loop working. My Dad (WB9PBO) had one, and after he died, I gave it to a friend who is unable to put up any other kind of antenna and is financially unable to purchase. Frankly I did not pay any attention to the ISO Loop when I briefly had it. Now that Mick has it, I am trying to get it going, to help out a good friend.
His ISO Loop has the automatic tuner, but it does not work so I am looking for one of the old manual controllers (the LC-1 or LC-2).
The worst case, is that you can build a stepper motor controller, which is exactly what the controller box does. I have found several kits on-line for under $30 that will do the trick, but then you have find a suitable container and get suitable switches and a power supply.
My interest in small magnetic loop antennas has peaked now that I am involved in getting one going. There are drawbacks (very narrow and the ISOloop housing does not weather well), but the performance looks to be very good, comparable to a dipole. If kept inside (attic or inside the house), the unit should not have the housing issues others have reported.
As others have said, I would go ahead and get the unit if it is available. If nothing else, it could be a fun project to make your own controller.
Here is a kit for $40.00 that should do everything needed ($50.00 w/power supply) http://www.ramseyelectronics.com/cgi...tion&key=SMD1C
Update: I built one of the controllers, and that works fine. BUT - the ISOloop had a major manufacturing defect which causes an internal plastic gear to crack and fall apart. My friends ISOloop suffered from this problem and after we got the controller hooked up, it wouldn't tune. I tried glueing, but the gear was in 8 pieces and it just did not work. Open the unit and check the gear before you put any $$ int o it...