Author |
Message |
Goat373
New member Username: Goat373
Post Number: 7 Registered: 3-2005
| Posted on Thursday, April 07, 2005 - 1:37 am: |
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Has anyone heard of these antennas. good?...bad?. waste of money?? looking to get one...ive heard good things about them but wanted to know if anyone has any real-world info on them |
Racer_x
Intermediate Member Username: Racer_x
Post Number: 279 Registered: 2-2005
| Posted on Thursday, April 07, 2005 - 8:24 am: |
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They're about as close to an isotropic antenna as you can get. They have 0 gain. Probably negative gain. If you have no other way to get on the air then I guess they're okay, but I'd use a mag mount on my refrigerator before I'd pay for an Isotron. |
Barracuda
Intermediate Member Username: Barracuda
Post Number: 295 Registered: 3-2003
| Posted on Thursday, April 07, 2005 - 9:30 am: |
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Goat, The Isotron is a productized version of what is known as a small transmitting loop. Do a google or other search for that term or Mag loop, which is another term used for them. There's lots of stuff on the net about them. Also, MFJ makes a gizmo to tune them. They need very high voltage capacitors to do that. Good luck, have fun
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Road_warrior
Intermediate Member Username: Road_warrior
Post Number: 456 Registered: 7-2004
| Posted on Thursday, April 07, 2005 - 10:25 am: |
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I have never used or seen one of these Isotrons. But, i have seen reviews from Ham operators that gave them a good rating. Other than that, I don't personally know. JIM/ PA/ CEF 375 |
Bruce
Senior Member Username: Bruce
Post Number: 2434 Registered: 9-2003
| Posted on Thursday, April 07, 2005 - 11:15 am: |
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Goat373 There NOT a bad antenna but not realy good either very narrow banded |
Bruce
Senior Member Username: Bruce
Post Number: 2435 Registered: 9-2003
| Posted on Thursday, April 07, 2005 - 12:50 pm: |
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http://www.isotronantennas.com/isorev1.htm |
Racer_x
Intermediate Member Username: Racer_x
Post Number: 280 Registered: 2-2005
| Posted on Thursday, April 07, 2005 - 5:21 pm: |
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Isotrons are not a loop antenna. They are a radically shortened dipole that uses large surface area elements, and large diameter coils to load them. Like I said, they are about as close to an isotropic antenna as you can get - which might be where their name came from. If you have no other way to get on the air it's okay, but I'd run coax to my car's antenna before I'd pay for an Isotron. |
Barracuda
Intermediate Member Username: Barracuda
Post Number: 296 Registered: 3-2003
| Posted on Friday, April 08, 2005 - 1:03 am: |
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Racer_x, you are absolutely correct. The Isotrons are not loops, my bad. When I read isotron I for some reason was thinking of the mfj hi-q loops. Sorry for the mis-information folks. 73 Loops are still interesting though. |
Racer_x
Intermediate Member Username: Racer_x
Post Number: 285 Registered: 2-2005
| Posted on Friday, April 08, 2005 - 5:55 am: |
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Loops are great antennas for the lower bands. I use a loop for AM BCB listening both during the day and at night. It's amazing how much more signal I get with that antenna. |
Airplane1
Intermediate Member Username: Airplane1
Post Number: 376 Registered: 5-2004
| Posted on Saturday, April 09, 2005 - 12:29 pm: |
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what is AM BCB? |
Bruce
Senior Member Username: Bruce
Post Number: 2446 Registered: 9-2003
| Posted on Saturday, April 09, 2005 - 1:08 pm: |
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AM ( 6540-1700 KHZ ) Broadcast Band |
Bruce
Senior Member Username: Bruce
Post Number: 2448 Registered: 9-2003
| Posted on Saturday, April 09, 2005 - 1:36 pm: |
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OOOOOOOOOOOOOOOP'S 540-1700 khz DANG KEYBOARD ! LOL |
Bruce
Senior Member Username: Bruce
Post Number: 2450 Registered: 9-2003
| Posted on Saturday, April 09, 2005 - 4:09 pm: |
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When i get a chance i will be building a new crystal radio to replace the one ive used here for about 10 years. One antenna that COULD be used is a large loop since on the AM BCB large loops work well. Loaded loops can be found all the way from 50khz to 500 mhz ( http://www.ku4ab.com ) makes some nice VHF/UHF ones simular to the Isotrons. But remember a loop is never as good as a dipole or as broadbanded. |
405
New member Username: 405
Post Number: 7 Registered: 11-2003
| Posted on Sunday, April 10, 2005 - 11:49 am: |
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The Isotron 11 antenna received a complete review by Harold Ort [N2RLL],Editor, in the Sept. 2002 Issue of Popular Communications magazine. According to information from the designer [Ralph Bilal], "the antenna performs as a half-wave dipole", which is tuned by moving a counterpoise up or down slightly. I have used both the Isotron 11 and the Isotron 10 with fairly good results, when space was a major problem, [they measure only 16 inches long and are "omni-directional, with random polarization"]. They don't look like a antenna to the casual observer, which is great if you live where there are restrictions. It mounts horizontally on a regular mast, using a common U-Bolt. The Isotron 11 is highly recommended by Harold Ort in the review, where he tested it both locally as well as using sideband for DX. They do require tuning with the counterpoise and are not ground dependent, great for places where it is impossible to use a regular vertical type antenna. Once adjusted, they do a pretty good job for what they are. They are rather narrow banded, but can be re-adjusted to cover other frequencies below or above the standard 40 CB channels. Once set up properly, they will easily cover the normal 40 channels with a 1.5 SWR. They also offer a wide range of Amateur band models, including one for 6 meters. |