Cecil Moore wrote:
Gordon wrote:
Well, I got an improvement, probably in spite of myself. The
setup gives better signal strength, and is less suseptable to
interfearence (people walking aroung the room) than just a single bowtie.

A mismatch can cause ghosting in an analog TV.
What does ghosting do to a digital TV signal?

If its bad enough it will wreck the reception. But the latest
processors can tolerate multipath that is only 1 db down.

They are getting better as they try to debug HDTV for mobile reception.

-Bill

On Jun 1, 4:49*am, Cecil Moore wrote:
Gordon wrote:
Well, I got an improvement, probably in spite of myself. *The
setup gives better signal strength, and is less suseptable to
interfearence (people walking aroung the room) than just a
single bowtie.

A mismatch can cause ghosting in an analog TV.
What does ghosting do to a digital TV signal?
--
73, Cecil, IEEE, OOTC, *http://www.w5dxp.com

It puts 'ripples' into the passband. The ripples happen because of
phase cancelations. The ATI HDTV Wonder cards can handle variations to
around 8-10 dB. After that it just freezes up.

Near the bottom of the page in the link there is an example of the
ATSC spectrum. Add random dips into it.

http://www.hdtvprimer.com/ISSUES/what_is_ATSC.html

G²

On Mon, 01 Jun 2009 06:49:20 -0500, Cecil Moore
wrote:

A mismatch can cause ghosting in an analog TV.
What does ghosting do to a digital TV signal?

Your worst nightmare. From 10 years ago:
http://www.businessweek.com/bwdaily/dnflash/aug1999/nf90826b.htm
(Note the sales predictions, which were totally wrong).
All DTV chipsets now have ghost elimination circuitry, which does a
good job of reducing multipath problems. There's a spec for it but
I'm too lazy to look. Here's the patent:
http://www.google.com/patents?id=XNp3AAAAEBAJ&dq=7038732
with references to others in citations. I won't pretend to understand
how it works.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:

I must say at the outset that I am hesitant to buy an antenna based on its
form-factor, but I'm forced by the local code to not display bare-element
type antennae on the mast.

As others have mentioned, this is mostly incorrect. The problem is in
the interpretation of the word "unreasonable", which might be
interpreted in a variety of ways. Without details on your situation,
I can't comment on this.

The FCC website has quite a bit of info on interpretation (from various
regulatory and legal actions) of what is and isn't unreasonable. Paint
color: reasonable, restrictions on location: unreasonable, restrictions
on form of antenna: unreasonable.




I do like the panel style for the reason that I can arrange 3 around a common
mast, aimed at remote cities, and join the outputs for increased coverage.

Mast? Welcome to "unreasonable". The FCC 47.1.4000 clause that
limits antenna installation has nothing to say about the supporting
structure. While the HOA may not be able to prevent you from
installing an antenna, they most certainly will have something to say
about the design and construction of the supporting structure. They
may also demand that it be installed by a licensed and insured
installer to protect themselves against subsequent litigation. I know
you don't want to hear about all this, but methinks you should at
least be warned before blundering onward.


Hah.. go look at the case of Stanley and Vera Holliday.. 5 masts 30 ft
high, multiple dishes and antenans...

http://www.fcc.gov/Bureaus/Cable/Ord...9/da992132.txt

an analysis at
http://dirt.umkc.edu//dd99/DD991025.htm

On Mon, 01 Jun 2009 06:49:20 -0500, Cecil Moore
wrote:

Gordon wrote:
Well, I got an improvement, probably in spite of myself. The
setup gives better signal strength, and is less suseptable to
interfearence (people walking aroung the room) than just a
single bowtie.

A mismatch can cause ghosting in an analog TV.
What does ghosting do to a digital TV signal?

In countries using COFDM (DVB-T), the symbol time is about 1000 us
(8k) or 250 us (2k), so in the worst case with minimal guard
intervals, you can still use mismatched coaxial cables longer than 1
km without problems :-).

With ATSC 8VSB it depends how well the equalizer is capable of
detecting the characteristics of the radio and coaxial path with a
known signal pattern.

Paul OH3LWR

Elmo P. Shagnasty wrote:
In article .net,
Usual Suspect wrote:

I must say at the outset that I am hesitant to buy an antenna based on its
form-factor, but I'm forced by the local code to not display bare-element
type antennae on the mast.

I don't believe the local code has any say in the matter.

But if you want to give up your rights...

This is true to a point. Local codes no problem, BUT in HOA territory
these rules do not necessarily apply. In most cases the HOAs have
modified their rules. The small direct satellite lobby started the
trend. Allowing these dishes they really had to include other TV antennas.

"Elmo P. Shagnasty" wrote:
In article m,
Radioguy wrote:

I don't believe the local code has any say in the matter.

But if you want to give up your rights...

This is true to a point. Local codes no problem, BUT in HOA territory
these rules do not necessarily apply. In most cases the HOAs have
modified their rules.

The FCC is the entity here, not local communities.

And neither HOA nor local communities can override FCC in this matter.

You SHOULD know better, Elmo. There are some restrictions an HOA can
place on a homeowner, but they are few. Here is a link to the FCC site:
http://www.fcc.gov/mb/facts/otard.html

--
-------------------- http://NewsReader.Com/ --------------------
Usenet Newsgroup Service $9.95/Month 30GB

Radioguy wrote:
Elmo P. Shagnasty wrote:
In article .net,
Usual Suspect wrote:

I must say at the outset that I am hesitant to buy an antenna based
on its form-factor, but I'm forced by the local code to not display
bare-element type antennae on the mast.

I don't believe the local code has any say in the matter.

But if you want to give up your rights...

This is true to a point. Local codes no problem, BUT in HOA territory
these rules do not necessarily apply. In most cases the HOAs have
modified their rules. The small direct satellite lobby started the
trend. Allowing these dishes they really had to include other TV antennas.
the FCC premption (aka OTARD rules) is the key thing here.. The HOA
can't really do anything if it fits in the FCC guidelines.. dishes 1
meter, OTA TV any size.

On Jun 2, 3:23*pm, Jim Lux wrote:
trend. *Allowing these dishes they really had to include other TV
antennas.

* the FCC premption (aka OTARD rules) is the key thing here.. The
HOA
can't really do anything if it fits in the FCC guidelines.. dishes
1
meter, OTA TV any size.

Nice thing about the Winegard SquareShooter is it resembles a dish
though my neighbors might think I don't have a clue how to aim it.
It's opposite where all the little dishes are aimed. They would have
laughed if they had seen the spectrum analyzer on the driveway next to
the car. I was on the roof with binoculars to see the screen.

G²

Sal M. Onella wrote:
"Usual Suspect" wrote in message
obal.net...

snip

I do like the panel style for the reason that I can arrange 3 around a
common
mast, aimed at remote cities, and join the outputs for increased coverage.

You may encounter some undesired affects from joining antennas. If it
works, fine, but if it doesn't, consider switching among the three at the TV
set(s).

The problem is that the prime signal will be "contaminated" by signal pickup
from the other antenna(s). The degree of contamination may or not affect
reception.

Good luck.


It will suffer phase distortion. In the good old days we called that
"ghosting", now it will be signal drop outs!

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Use only Genuine Interocitor Parts" Tom Servo ;-P