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Old March 18th 08, 10:13 PM posted to rec.radio.amateur.antenna
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Default Do receiver antennas need matching or not?

Dave Platt wrote:
In article ,
Jim Lux wrote:


A home brewed double Gray-Hoverman. Apparently, they work pretty well
and if you build a really impressive one, the HOA will really get their
panties in a bunch.



And the best thing is that there's no size limit in the OTARD rules for
these antennas. the 1 meter limit is ONLY for satellite antennas. OTA
terrestrial has no size limit. Build that 20 bay curtain array.



There's no explicit size limit stated for the antennas. However, it
could be argued that building an antenna which is larger than
necessary for good reception is not protected... prohibited
restrictions include those which "preclude(s) a person from receiving
or transmitting an acceptable quality signal from an antenna covered
under the rule."

Hence, if you can receive an acceptable-quality signal on all channels
with a 1-bay antenna, the FCC *might* consider as reasonable a
restriction against putting up a 20-bay antenna.


And the FCC has carefully stayed away from defining "acceptable" . In
fact, in one case, they've said that it's in the judgement of the person
receiving the signal (The HOA wanted to make the homeowner put the
antenna inside the attic, claiming that since they were close to the
transmitter site, that an acceptable signal was available). (I can't
find the reference off hand.. it's in Maryland or Virginia, as I recall)

One might also want to look up the very interesting case of Stanley and
Vera Holliday (5 masts, 30 ft high, 3 dishes, etc.)
http://www.fcc.gov/Bureaus/Cable/Ord...9/da992132.txt

I spent a while trying to hunt down what "acceptable" might be in FCC
rules terms (e.g. what's a minimum performance standard for a Cable
TV).. It's pretty tough to find a numerical standard. There are
standard service contours which relate to RF field strength, but they're
also statistical.

For digital receivers, in fact, on 21 Jan 2001, the FCC: "Denied
requests to set performance standards for digital receivers, expressing
concern that the effect of setting such standards at this point would be
to stifle innovation and limit performance to current capabilities. The
Commission said it would continue to monitor receiver issues;" As
recently as June, 2007, an article in CED Magazine said:"The FCC has
never before adopted receiver performance specifications or interference
rejection requirements. It has the authority to do since Senator
Goldwater introduced a bill that became Public Law 97-259 in 1982, which
added the italicized language below to the Communications Act:..."


ATSC has a document A/74 which defines a recommended practice for
receiver performance, but it's kind of a clunky document, based on
technology that was available in 2003-2004, and not really intended for
this sort of thing. FWIW, the FCC assumes you need 7dB SNR for UHF and
10dB for VHF, with an assumed 7dB NF.

So, one could claim you need that 20x20 bay antenna to get enough signal
to compensate for your horrid transmission line and terrible receiver.


The rules also say "Masts higher than 12 feet above the roofline may
be subject to local permitting" and that the rules do not preempt
"legitimate safety restrictions".

The FCC has set a pretty high bar on safety restrictions. They have to
be clearly articulated and justified in the rules (i.e. no "in the
opinion of the architectural review board, that's unsafe"). The 12 foot
thing is a building code issue. The city or jurisdiction would have to
have a fairly specifically articulated justification.



It's clear that a blanket "no on-the-roof TV antennas" restriction by
HOR rules or CCRs is generally unenforceable.


Yep.. In fact, can't even have a "must put antenna in position X" or
"must plant or paint" rule, unless the cost of compliance is trivially
small (as in $5, see the Meade,KS case) and has ZERO effect on reception
 
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