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View Full Version : Recommendations for pulling in Rochester channel WXXI 21.3


dieselgg
29-Sep-2014, 11:18 PM
Hi,

The following is my TV fool report:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dd2437acbb72657

I would like some suggestions for improving reception of a few Rochester channels; specifically 21.3 WXXI (Create channel). Until about 2 days ago, I thought it would be impossible to get the channel as TV fool shows that the signal drops halfway across the lake. When I scanned 2 days ago in a different direction, I was able to get WROC 8.1. The tuner also picked up 21.3 WXXI after the autoscan. Yet, after the autoscan was complete, the picture came in for WROC but not for WXXI 21.3.

I changed my scan back to the original direction since I lost a few buffalo stations.

I currently have the Antennacraft HDView 360. It has a built in pre-amp and rotor.
The height of the antenna is approx 25 ft of the ground. Approximately the coax run is 30' and I have about half of that cable run just secured in a loop on the side of the house. At the time, I decided not to reduce the length of the coax run as I have been getting all the channels that I wanted up till now. The WXXI 21.3 is the last channel I would like to get. It has cooking and woodworking programming content.

Any suggestions would be appreciated.

Regards,
Gus

rabbit73
30-Sep-2014, 11:31 PM
Hello Gus,

WXXI-TV is listed as Tropo on your tvfool report. You will never get reliable reception of that channel that is 108 miles away, with a Noise Margin (NM) of -21.4 dB and a signal power of -112.3 dBm.

The reason you get it sometimes is because of favorable tropospheric propagation:
https://www.google.com/search?q=tropospheric+propagation&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb
http://www.dxinfocentre.com/tropo.html

To be reliable a signal must have a NM of no less than zero. WXXI is way below zero.
To be reliable a signal must have a signal power of more than about -83 dBm. WXXI is much weaker than that.

I don't go much by antenna distance ratings, but your antenna is rated at 40 miles for that channel. You would need an antenna with a gain of 21.4 dB to bring it up to NM zero----very hard to find. That is intrinsic antenna gain, not preamp gain.

dieselgg
1-Oct-2014, 12:56 AM
Thanks Rabbit73 for providing me with a better understanding of antenna limitations.

I'll try again during the winter time to see what else I can pick up.

Regards,
Gus