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Old March 4th 04, 05:00 AM
Bob Haberkost
 
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Why?

And then, as I said, each antenna system is different at close range. It could be
only a volt or two per meter, it could be several tens of volts...close enough, you
might even be able to draw an arc off of the metal pieces.

It's too undefined a question to give you a definitive answer.
--
For direct replies, take out the contents between the hyphens. -Really!-



"Jianhong Wang" wrote in message ...
Thank your guys for all your answers. As scott mentioned, I want to
the possible max power (dBm) a receiver can get no matter it works or
not. I know it depends on a lot of things, like receiver antenna
efficiency. But could you give me a empirical number assuming that
reciever's antenna is most efficience in the thoery.

Thanks
(Scott Dorsey) wrote in message

...
Bob Haberkost wrote:
That question is a non-starter. A poorly-designed reciever will probably freeze

up
within a mile of a 50kW antenna, while a superb one could likely take several
volts-per-Meter and not even squeal, even when within the tuning house or at the

base
of the tower..


I think his question is how many dBm would be received at the front end
when sitting at the base of the tower. Not how many dBm can be received
and still use the radio.
--scott




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Old March 5th 04, 01:26 AM
Ron
 
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On Tue, 02 Mar 2004 15:58:39 +0000, Bob Haberkost wrote:

That question is a non-starter. A poorly-designed reciever will probably freeze up
within a mile of a 50kW antenna, while a superb one could likely take several
volts-per-Meter and not even squeal, even when within the tuning house or at the base
of the tower..


Seems like the old Mod Monitors would take 10v.
Usually from a tap in the final amplifer.

Ron

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Old March 6th 04, 05:45 PM
Bob Haberkost
 
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Well, exactly...sortof. I don't think the question is what was the maximum
that any "receiver" would take, as I also considered the various
off-the-transmitter modulation monitors as the top end of that range. What
he's clearly asking is how much RF any given receiver would be exposed to at
close range. But how close? And with what antenna (what wavelength)?
Series or parallel fed? Etc., etc.

The question needs many more parameters to get a hard answer, and that hard
answer is of no significance since the scenario isn't a real-world question.
And the final indication that this is a non-question is the reference to
dBm...for dB, one needs an impedance of the load. AM receiving antennas do
not conform to an impedance, unlike FM and other VHF and up sets that
usually use either 300 or 75-ohm feeds. With those one can take field
strengths and convert them to power....without a corresponding impedance,
the AM question is undefined. And in the interest of the truth (even for a
purposeless question) I wouldn't presume to assume to specify an answer
which has no basis in reality. -- For direct replies, take out the contents
between the hyphens. -Really!-



"Ron" wrote in message ...
On Tue, 02 Mar 2004 15:58:39 +0000, Bob Haberkost wrote:

That question is a non-starter. A poorly-designed reciever will probably
freeze up
within a mile of a 50kW antenna, while a superb one could likely take
several
volts-per-Meter and not even squeal, even when within the tuning house or
at the base
of the tower..


Seems like the old Mod Monitors would take 10v.
Usually from a tap in the final amplifer.

Ron



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