[mythtv-users] OT - Antenna tuning/aiming

[Brian Wood]

On Nov 2, 2006, at 4:16 PM, Brad Fuller wrote:

> Brad Fuller wrote:
>>> Unless you are a fair ways from the transmitter I doubt that you
>>> would actually see much difference though, but it might help in a
>>> highly reflective urban environment like Manhattan. This effect  
>>> would
>>> be more noticeable on the higher channels.
>>>
>> I'm near the santa cruz hills and most of the transmitters are in
>> pretty much the same direction but at different distances from me.  
>> The
>> farthest being about 45m the nearest about 16 miles. Here's the list.
>> (hope it comes thru ok.
>>
>> Should I target a few of them to tune? How would you recommend the
>> procedure?'
>>
> that didn't work! Let me edit it a bit:
>
> Call Sign 	Channel 	Compass
> Orientation 	Miles
> From 	Frequency
> Assignment
> KKPX-DT 	65.1 	303° 	41.2 	41
> KGO-DT 	7.1 	306° 	45.4 	24
> KPIX-DT 	5.1 	306° 	45.4 	29
> KTSF-DT 	26.1 	303° 	41.2 	27
> KBWB-DT 	20.1 	306° 	45.4 	19
> KRON-DT 	4.1 	306° 	45.4 	57
> KNTV-DT 	11.1 	302° 	41.1 	12
> KMTP-DT 	33.1 	306° 	45.4 	33
> KQED-DT 	9.1 	306° 	45.4 	30
> KDTV-DT 	14.1 	355° 	17.6 	51
> KSTS-DT 	48.1 	355° 	17.6 	49
> KTEH-DT 	54.1 	356° 	16.8 	50
> KICU-DT 	36.1 	356° 	16.8 	52
> KTVU-DT 	2.1 	306° 	45.4 	56
> KCSM-DT 	43.1 	306° 	45.4 	43
> KCNS-DT 	38.1 	306° 	45.4 	39
> KSMS-DT 	31.1 	132° 	16.4 	31
> KFSF-DT 	66.1 	306° 	45.4 	34
> KBCW-DT 	44.1 	306° 	45.4 	45
> KTLN-DT 	47.1 	315° 	72.1 	47
> KTFK-DT 	64.1 	346° 	43.7 	62
>


You lucky Dog! I have precisely two digital O/A signals here in  
Cheyenne, one of which is Fox in SD, the other is CBS in HD  
(sometimes), and neither has anything I'd want to watch. I bought the  
HD-3000 card for QAM.

You could try and be "scientific" about antenna setup, in which case  
you would need to know the theoretical beamwidth of your antenna. If  
the 3db. beamwidth is 60 degrees or more then you would probably not  
see much difference due to varying directions, remembering that  
antennas are more directional (narrower beamwidth) as you go higher  
in frequency.

But in the real world "field factors" usually outweigh the  
theoretical performance issues, and I suspect a pragmatic approach  
will work as well as a "scientific" one. I'd just try aiming in the  
middle of the azimuth range, if you're anything close to line-of- 
sight you should be OK on most if not all channels. You might also  
want to try just aiming for the best signal on the most distant  
channel (KTLN?) and see what you have on the others.