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Guys!


Below was my situation and John Stephens advice, also got advice from bdfox18doe.

Quote:
John Stephens,

What can you come up with on this senario?

Right now Ch.53-1 is N,NE of me. My old 10 foot mast antenna(20 year old preamp and antenna) 25 feet high is fixed directly North(broken rotor), old RG59 cable about 60 feet long(replacing it all).


With the DST3000 I get an average signal strength fluxuating between 0 to 12. Some nights late and early mlornings it peaks into the 50's for about 15 to 45 minutes.


I want to get channel WRAL-DT 53-1 out of Raleigh: I estimate about 77 Miles away. Wooded areas between. Land basically flat. One or two buidings possibly but not sure.


Antenna: Channel Master Crossfire 3671B, Gain of 12.5 on ch.52, UHF average gain of 10.0, Antenna height aproximately 25 feet high. Aproximately 60 feet of RG6 Quadshield coaxial cable from Radioshack. Material unknown.


My Address: 7570 Highway 711 Pembroke NC, Longitude West=79.1769, Latitude North=34.6920(probably not exact Long/Lat).


Tower Location Facilities: 2063'(feet) 200 kw

Transmitter: 35° 40' 29" N 78° 31' 40" W

Address: 5033 TV Tower Rd, Garner NC


Here are my choice of amps:


Channel Master

CM7777

VHF Gain = 23, VHF Noise Figure = 2.8

UHF Gain = 26, UHF Noise Figure = 2.0


Winegard

AP-8275

VHF Gain = 29, VHF Average Noise = 2.9

UHF Gain = 28, UHF Average Noise = 2.8


What are your thoughts? Can reception be improved enough to get 30+ signal strength most of the time? Any help would be much appreciated.


Here's Johns advice,

Quote:
Daryl,

You are 77 miles from the transmitter and the horizon is 65 miles. So you are 10 miles beyond the horizon. A mysterious lossy zone. You need, therefore, to pull out all the stops. Expect low field strength at your location. If we are lucky,we may get 33 dBuV/m field strength at your site. This is 15 dB below what I know WRAL can do at the horizon which is at 65 miles. In any case, with that tiny signal, you could get robust reception using the following:


CM47775 Preamp G=26, NF=2

CM4248 or CM4228 Ga=12


Expected S/N with 32 dBuV input is 16.8 dB. Try that and let us know. If need be, we can get a few more dB by using the parascope.

At these high frequencies, the only thing I know that can 'bend' the signal is a waveguiding effect that can occur in going from a denser atmosphere to less dense(read higher dielectric constant to lower or equivalently refractive index). This would be consistent with your late night early morning phenomena.

Do not use a combination antenna, use the UHF only as recommended. Use a separate antenna for your normal reception. Use a DTC-100 with its two antenna inputs. Mount your antenna as high as possible 30 feet or more. Some users have also found that in this situation, pointing the antenna slightly upwards helps. All for now and let us know your results.


Regards,


John Stephens
FINAL RESULTS

The antenna guy just left an hour ago. I went with the CM3671 antenna and CM7777 preamp and new RG-6QS cable. Before equipment upgrade my signal on WRAL 53-1 was about signal strength of 6. Now at 77 miles away WRAL(CBS) 53-1 is at 65-72 strength, WTVD(ABC) 52-1 IS AT 65, WNCN(NBC) 55-1 is at 44. It started raining after antenna guy left so I expect it to get better after it clears up and later in the evening so WRAZ(FOX) 49.1(now at 27-30) should come in later. Thanks again guys, and everyone else!!! I'm alread tuned to CBS for the NCAA game! Yeah I luv it! http://www.avsforum.com/ubb/biggrin.gif


[This message has been edited by Daryl L (edited 03-31-2001).]
 
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