On Wed, 13 Oct 2004 05:17:47 GMT, Rick Frazier
wrote:

er... these articles didn't happen to originate around April 1 did they?

Bill wrote:

many years ago I read a very good article on the "rusty bolt effect"
that went into great detail, even as far as warning about corroding coke
cans in the undergrowth.

The rusty bolt (intermodulation) problem can be quite severe e.g. with
repeaters in a commercial site with lots of high power transmitters.

Are the coke cans made of iron ?
Anyway, there would have to be a metal to metal contact that has
oxidised in order to have this kind of junction problem, so I do not
understand how thrown away cans could normally create such junctions.

Paul OH3LWR

In message , Paul Keinanen
writes
On Wed, 13 Oct 2004 05:17:47 GMT, Rick Frazier
wrote:

er... these articles didn't happen to originate around April 1 did they?

Bill wrote:

many years ago I read a very good article on the "rusty bolt effect"
that went into great detail, even as far as warning about corroding coke
cans in the undergrowth.

The rusty bolt (intermodulation) problem can be quite severe e.g. with
repeaters in a commercial site with lots of high power transmitters.

Are the coke cans made of iron ?
Anyway, there would have to be a metal to metal contact that has
oxidised in order to have this kind of junction problem, so I do not
understand how thrown away cans could normally create such junctions.
It was maybe 20 years ago that I read this article so I am a little
vague on the details but I seem to recall that it was a build up of
coke, drinks, cans that was a problem. So yes it would be metal to metal
contact.
Another problem it highlighted was the effect of guy ropes. Where a guy
rope is cleated and anchored there is often a short piece of the rope
left over that runs either beside the guy or just hangs there. Not a
problem if it is rope but if it is a wire guy then you can have a 1/4
wave aerial immediately attached to a corroded junction.



Paul OH3LWR


--
Bill

Dissimilar metals can rectify, if not very conductive anymore, then you get
some harmonics, or generate IM.

"stoploss" wrote in message
...
Dissimilar metals can rectify, if not very conductive anymore, then you
get
some harmonics, or generate IM.

Re rusty connections!
Apparently there was a situation in UK many years ago where an electric
heater with the old fashioned heating 'coils' was picking up radio waves.
Also a poor connection became a rectifying junction (something like an old
time crystal detector) and the metal of the heater became a sound box.
When some interference problems were being investigated the elderly lady who
owned the heater was asked why she hadn't mentioned or complained about it.
Her reply was that she enjoyed hearing the voices and the music that came
from the heater!
Cheers. Terry.

"Terry" wrote in message
...

"stoploss" wrote in message
...
Dissimilar metals can rectify, if not very conductive anymore, then you
get
some harmonics, or generate IM.

Re rusty connections!
Apparently there was a situation in UK many years ago where an electric
heater with the old fashioned heating 'coils' was picking up radio waves.
Also a poor connection became a rectifying junction (something like an old
time crystal detector) and the metal of the heater became a sound box.
When some interference problems were being investigated the elderly lady
who
owned the heater was asked why she hadn't mentioned or complained about
it.
Her reply was that she enjoyed hearing the voices and the music that came
from the heater!
Cheers. Terry.


Love it! AND... it's plausable, too.

--
Steve N, K,9;d, c. i My email has no u's.

"Paul Keinanen" wrote in message
...
Are the coke cans made of iron ?
Anyway, there would have to be a metal to metal contact that has
oxidised in order to have this kind of junction problem, so I do not
understand how thrown away cans could normally create such junctions.

Cans are made of aluminum now, but 30 years ago they were steel. Back then
it took some hand strength to crush a can, now a little girl can do it.