"Reg Edwards" wrote in message
...
This suggests that other folks are correct in asserting that
the mast, and the outside of the feedline are doing a lot of the
radiating.
============================

What's wrong with radiation from the feedline? It's just as useful as
radiation from elsewhere.

If I have a nice yagi array aimed at the moon and thus a low system noise
temp, and the feedline is allowed to radiate, I would think that might have
a bit of an effect not only on the array's pattern but also ruin the system
noise temp. The return loss then is also a function of cable length, routing
etc. Hardly a predictable array.
I can think of other examples. Although I admit in the case of the Isotron,
cable radiation is probably an advantage.

Dale W4OP

Reg Edwards wrote:
This suggests that other folks are correct in asserting that

the mast, and the outside of the feedline are doing a lot of the
radiating.

============================

What's wrong with radiation from the feedline? It's just as useful as
radiation from elsewhere.



If your interest is to spray your rf all over the place then a radiating
feedline is really FB.

If you have a $1500 tower, a $600 rotator, a $800 beam, a $3000
amplifier all connected to a $3000 transceiver, then you really want to
steer your RF in a controlled direction. Under these conditions a
radiating feedline destroys the nature of the antenna pattern and you're
not getting what you paid for.

What's wrong with radiation from the feedline? It's just as useful as
radiation from elsewhere.

Maybe for an Isotron, but not for a beam.

Or in cases where radiation coming off of the feedline would be
inconvenient for other reasons - e.g. the feedline runs in close
proximity to other wiring (RFI and telephone interference, or signals
getting where they don't belong in a multi-repeater shared site), or
metal pipes or metal-loaded walls (e.g. stucco).

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

In article ,
Steve Silverwood wrote:

Just for the record, Hank, I've had an Isotron antenna and it works just
like a very expensive dummy load. Provides a good SWR match but doesn't
radiate worth a darn, and it's deaf as a post for receive.

"But look at that beautiful plumage!"

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Dave Platt" wrote in message
...
In article ,
Steve Silverwood wrote:

Just for the record, Hank, I've had an Isotron antenna and it works just
like a very expensive dummy load. Provides a good SWR match but doesn't
radiate worth a darn, and it's deaf as a post for receive.

"But look at that beautiful plumage!"

It's "pinin' for the fjiords"...
__
Steve
KI5YG
..

Just for the record, Hank, I've had an Isotron antenna and it works just
like a very expensive dummy load. Provides a good SWR match but doesn't
radiate worth a darn, and it's deaf as a post for receive.

====================================

But that's exactly how it's supposed to work although the manufacturer
doesn't mention it in his specification.

And as every good amateur knows, the most important characteristic of any
antenna is the ubiquitous SWR. The ARRL and RSGB handbooks attach much
space to it.

"Reg Edwards" wrote in message ...
Just for the record, Hank, I've had an Isotron antenna and it works just
like a very expensive dummy load. Provides a good SWR match but doesn't
radiate worth a darn, and it's deaf as a post for receive.

====================================

But that's exactly how it's supposed to work although the manufacturer
doesn't mention it in his specification.

And as every good amateur knows, the most important characteristic of any
antenna is the ubiquitous SWR. The ARRL and RSGB handbooks attach much
space to it.

Also, a catchy name like "Isotron" helps...Sounds like some kind of
ray gun from a cheap 1950's sci-fi thriller...The combination of the
catchy name, and the low SWR, insure mo-tricity. :/ MK

Mark Keith wrote:
Also, a catchy name like "Isotron" helps...Sounds like some kind of
ray gun from a cheap 1950's sci-fi thriller...

Like the "Interositer" from "This Island Earth"?
--
73, Cecil http://www.qsl.net/w5dxp



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"Cecil Moore" wrote in message
...
Mark Keith wrote:
Also, a catchy name like "Isotron" helps...Sounds like some kind of
ray gun from a cheap 1950's sci-fi thriller...

Like the "Interositer" from "This Island Earth"?

The interositer worked..

The interositer worked..

It sure did, almost got that guy and gal killed by aliens. That thing was like
a giant Heathkit from outer space. I envied the guy in the movie getting to
put it together.
73 Gary N4AST