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Posted: Sun Mar 13, 2005 10:52 pm
by pcs
Hey, that's a great post!

I'm tempted myself to start building one, now.

Isotron Performance...

Posted: Sat Jun 11, 2005 4:29 pm
by erobertg
The antenna is weathering well after 6 months. I had my transmitter off for a couple of days and what do you know. A small hornets nest was hanging from under the top capacitance hat.

Right now I'm cranking out 10 watts at a SWR of 1.3 and it should be interesting what happens to those darn hornets...

Posted: Sat Jun 11, 2005 6:06 pm
by pcs
Do write a new post when you find out, I'd really like
to know :)

Do you have any high-power amps around?

Isotron Antenna...

Posted: Wed Jun 15, 2005 6:21 pm
by erobertg
Well, it appears the wasps went south. There's a blackened area about 2" dia on the side of the hive. :o

Will knock it off in a couple of days.

Antenna still works great. :D

Posted: Thu Jun 16, 2005 1:19 pm
by pcs
Now that's one expensive wasp killer engine :)

ISOTRON

Posted: Thu Sep 29, 2005 2:32 am
by fluke281
I also have an AM MAX with 24 volt supply producing about 10 watts. I recently purchased an ISOTRON antenna 200B. The antenna was a perfect 1:1 match mounted on a mast three feet above the ground. At 22 feet on the roof, the SWR at 1700 Khz is about 1.8. I plan to adjust this soon.

The range is not exactly what you would expect from previous posts here. I have used an antenna tuner with various AM antenna systems over the past six months. The ISOTRON is the best but the solid range with an excellent AM portable (grundig) or car radio is about one mile in the US.
The signal can be heard at least 7 miles (12 km) away on a clear frequency but not consistently.

This sort of performance is similar to what I have seen with the TIS (traveler's Infromation Services) in the US that use similar MW frequencies. They are permitted to use 10 watts of power and maximum of 49 feet as an antenna. Most of these use large loading coils and buildings with metal roofs as a ground. They tend to be located close to expressways and major highways or amusement centers. They use expensive transmitters and tuning equipment. The results are the same as the AM max and ISOTRON. About a mile of solid signal. The ground losses and electrical interference are a problem at these frequencies. At night, the recent skywave inference, even at 1700 Khz, is very severe.
Nevertheless, both the AM MAX and ISOTRONS are fantantic. Ralph Bilal is to be congratulated on these antenna products, although his explanations in the users manuals and use of the English language could be improved.

JD