View Single Post
Old 11-Apr-2019, 3:36 AM   #19
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,545
Quote:
Originally Posted by kb4 View Post
ok I got up on roof today and put up a temporary mount stand (no wind at all today) and found a winnegard uhf only antenna I think a 9032 in my storage container that i bought years ago to put up at a hunting trailer and never did.




Very brave. Thanks for the photos; they always help to understand the problem.

The trees will always be a problem until you can get above them.
Quote:
Questions:

1. rabitt73 did the pic indicating the hill blocking my antenna location show my antenna height of 35 feet I indicated.
That image in post #8 is from a WYJJ terrain profile done by TVFool. I added the arrow to indicate the approximate height of your antenna:
http://www.tvfool.com/?option=com_wr...dALLTV%26n%3d6
Quote:
If so I must be looking up at an angle that would end up more than 400 ft high or so 3.7 miles away. More out of curiosity than anything can you tell fairly easily how high the antenna would have to be to get out of the weak zone.
No, not easily because the vertical scale is exaggerated. When I have more time, I will do a profile with other software that might help.
Quote:
2. I am using a 100 foot RG6 and won't need that much at present height maybe 65 feet. I seem to remember that anything longer than 50 to 100 feet could benefit from mast mounted amp due to the cable run loss that was about 3db. I will try amp anyway but about how much signal loss is there in 100 ft rg6?
5 or 6 dB.
Quote:
3. About how much signal is loss in just a straight through connector such as to join two pieces of cable together?
The loss of an F-81 is less than a dB.
Quote:
4. About how much signal loss through a lightning arrestor/ground ?
If you mean a grounding block, about the same as an F-81. If you mean something like the TII 212, that has an active device between the coax center conductor and the grounded shield, they have been known to degrade weak signals.

https://www.amazon.com/TII-Broadband...s%2C179&sr=1-6
Quote:
5. I am sure the other local channels that are in same general direction as WYJJ would be overamplified if amp used, but would that cause any problem if I only tuned to WYJJ with this antenna ?
It might, because while the tuner is able to tune to a specific channel, a preamp doesn't have a tuned circuit, so it is wide open to all signals.
Quote:
6. Is the reason a splitter loses about half the power or about 3 db to each tv connected to it with assume same length cable run just because of sending half of signal power to each tv or is it a loss in the mechanism or switch itself ? For example, if you connected only one tv would the signal still be dramatically decreased to the one tv?
Each output of a 2-way splitter is 3.5 dB weaker than the signal into the splitter; 3 dB for half the initial signal plus 0.5 dB internal splitter loss. This equal division of the initial signal stays the same no matter what is connected to the outputs.

Attached Images
File Type: jpg kb4TVFhisUHFant_1.jpg (109.1 KB, 398 views)
File Type: jpg kb4TVFhisUHFant2_1.jpg (341.7 KB, 390 views)
__________________
If you can not measure it, you can not improve it.
Lord Kelvin, 1883
http://www.megalithia.com/elect/aeri...ttpoorman.html

Last edited by rabbit73; 11-Apr-2019 at 4:02 AM.
rabbit73 is offline   Reply With Quote