Yagi Antenna
 

Dave Platt wrote:
In article ,
Allodoxaphobia wrote:

So all this bu$$sh!t about freeing up spectrum, or improving reception,
or yaa-daa yaa-daa yaa-daa is just that - BU$$SH!T!

The transition _does_ free up spectrum. The UHF spectrum between 700
and 800 MHz is being taken back from TV broadcasting, and is being
reallocated for other purposes. Public-safety users get a bunch,
commercial users get a bunch.

As to "improving reception", that's debatable. It's probably a win
for most urban users, and likely a big lose for rural users who are
already in fringe-reception areas (they'll get no picture, rather than
a snowy/ghosty analog picture).

It just turns out to be the case that the FCC is not attempting to
force _all_ stations up into the remaining UHF-band, and reclaim all
of the VHF TV band. Doing so would probably have forced some stations
off of the air or greatly reduced their broadcast coverage area, due
to the fact that some urban areas have so many TV stations that there
wouldn't be good conflict-free UHF channel assignments for all of the
VHF stations. It'd also have cost the existing VHF stations more
money to move, since they'd have been forced to scrap their existing
antenna systems.


I think the freeing of spectrum has been partly mis-understood. Yes,
there appears to be some new efficiency in the upper UHF. However, real
issue is that the spectrum for both analog and digital will not be
supported in parallel. The broadcasts are not compatible, unlike
previous transitions such as adding color. Digital is inevitable. The
"freeing" of spectrum is primarily resulting from the killing of analog,
not from the fact that digital may be more spectrum efficient.

73,
Gene
W4SZ

Yagi Antenna
 

"Duane Allen" wrote in message
ink.net...
John wrote:
Gents,
Bit of a "ring in" question here but I cant think of
anywhere/anyone else who may know. I,ve put up a yagi TV antenna with
from memory about 19 elements plus reflector. It seems to be too
directional so I can get one signal source perfectly and one poorly
because they are in slightly different directions. Question is, if I
remove some of the elements ( the way the thing is made I can unscrew the
front seven or so) will that make the antenna less directional?. Or if
not, is it able to be done?
Cheers
John

If your using the antenna for HDTV, you need only the UHF elements, which
for many TV antennas are the shorter elements at the front end of the
antenna. The VHF elements will not be needed when all OTA TV stations go
to HDTV.

That information could be more incorrect, but not much. When the switch-over
to all-digital takes place, there will still be VHF and UHF stations. There
is no mandate for TV stations to go UHF only, in fact, 2 of our 4 locals
will be going BACK to VHF when the switch-over date hits. Depending on your
area, you may have UHF only or a mix of VHF and UHF when the all-digital
switch is mandated. This makes it important to know what your locals plans
are before spending money on an antenna for HD (actually for digital, HD has
nothing to do with it)

Yagi Antenna
 

On Jul 19, 6:35 am, "John" wrote:
Gents,
Bit of a "ring in" question here but I cant think of
anywhere/anyone else who may know. I,ve put up a yagi TV antenna with from
memory about 19 elements plus reflector. It seems to be too directional so I
can get one signal source perfectly and one poorly because they are in
slightly different directions. Question is, if I remove some of the
elements ( the way the thing is made I can unscrew the front seven or so)
will that make the antenna less directional?. Or if not, is it able to be
done?
Cheers
John

YUP.... the directivity is related to the number of director elements
and also their spacing. You may effect the gain as well? So, if the
gain is an issue you may wind up defeating your plans. Worth a try
though, since your not hurting the antenna. Good Luck