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Old 10-Jan-2016, 8:58 PM   #5
ctm
Junior Member
 
Join Date: Jan 2016
Posts: 2
Wow, thanks for the advice!

Ganging two DB-8e antennas may be the way to go, or at least worth testing.

StephanieS, here are the reports
at 50'
http://www.tvfool.com/?option=com_wr...5134f391ff6ac3
at 75'
http://www.tvfool.com/?option=com_wr...513463f81f46f8
and at 100'
http://www.tvfool.com/?option=com_wr...513442cc7e53b9


The two strong stations are at 111-112 degrees, and the weaker one's are at 136 degrees.
Is that utilizing the null in the lobes 20-22 degrees off center?
When the antenna first went up, I had mistakenly pointed it at 150 degrees, but that was before the preamp, and it did show a significant drop in signal for the two strong stations, but no useful signal for the other stations.
I'll be rotating the antenna and taking more measurements - after the winter weather clears a bit.

Below are some of the measurements I made while testing the DB-8e antenna.
Im going by the signal strength indicator in the HDHomeRun's software, hdhomerun_config_gui.app.
The signal percentages have been consistent over the past few days.

At 136 degrees, I recorded these signal strengths.
M1 = no preamp; M2 = with preamp; * = picture

Channel M1 M2
17 - 50%
19 - 49%
22 - 34%
23 - 37%
27 54% 66%*
31 63%* 90%*
32 75%* 100%*
33 - 43%
34 39% 65%*
36 - 29%
44 29% 51%*
50 - 26%
51 - 36%

(apologies, looks like the forum's html doesnt like multiple spaces, Ive attached the chart as a jpg)

Looks like the 'digital cliff' needs more than a 50% signal in the hdhomerun to get a picture.
The preamp in the circuit gets a picture for three more stations, unfortunately, not the one's Im going for - but still a good surprise.
It looks promising that (maybe) ganging two DB-8e antennas would improve the signal over 50% on several channels enough to get a picture.

I first started my testing with a 91x antenna, which only got a picture on the two strong stations. The DB-8e seems to work much better in my situation.

I know the biggest issue Ive got is the trees. Currently, the antenna is facing right into them. Im estimating I'd need a tower 60' or better to clear them.

Cutting trees may be an option, but I'd estimate it would be taking down around 20-30 trees for a narrow 'window'.
Another option is to move the antenna site about 300'-400' from the current location into a field at the top of a hill behind the house, where there are minimal trees in the way.
None of these options are out of the range of possibilities, but it does get into "effort vs. diminishing returns".
hmmm... maybe it's time to play the powerball lottery! ;-)

Sidenote...
I have a Panamax surge surpressor for the equipment, and it has surge protection in/out connections for coax.
When it was in-line, the signal drops by at least 10-15%!
It's out of the circuit in the above measurements - and will remain out!

Again, THANKS for the help!
Attached Images
File Type: jpg antenna.jpg (13.7 KB, 358 views)

Last edited by ctm; 10-Jan-2016 at 9:04 PM.
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