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Discussion Starter · #1 ·
I recently repositioned my Channel Master yagi type deep fringe antenna, and managed to improve signal strength significantly. Now KCET PBS comes in in the 80s on the Sony box, whereas before it was breaking up and in the 60s.


A few days later, I noticed that the top half of the rear of the antenna, one of two pieces that you need to expand into the open position before mounting, had collapsed down and was touching the main horizontal shaft. I realized that that happened when I rotated the antenna.


I went back up on the roof, repositioned the upper mast into the open position, and found signal levels decreased. NBC, ABC, KCET, and Fox were breaking up.


Just relowered the mast, and found that the Fox signal, which had been around 47 and unlocked, is now in the 60-70 range and locked. Other channels also slightly higher.


You never know what you have to fiddle with, when it comes to DTV.
 

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Not sure what you're saying here...did lowering the antenna improve reception, or did collapsing the upper part of antenna improve reception or BOTH?
 

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I hope you won't find such a basic question offensive, but are you sure that you have the antenna pointing in the right direction? I don't pretend to be an expert on antennas, but it sounds like you might be pointing at the tranmitter with the back, rather than the front of the antenna. That would explain why lowering the reflector (and reducing rejection of signals arriving at the back of the antenna) would increase your signal strength.
 

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Discussion Starter · #4 ·
I did not lower the antenna; justs collapsed the upper portion of the rear (one of two elements that collapse so you can fit the antenna in the box).


No, I don't find it offensive, but I am pointing it in the right direction. Even checked w/Channel Master before I mounted. Found that I get the best reception when pointing the antenna as per the antennaweb web site.
 

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Discussion Starter · #5 ·
I doubt it would be overload, as I'm so far from the transmitter. I'm wondering if I'm not really looking directly at the signal, but am picking up a reflected signal. I'd like to try and reorient the antenna again, but I don't think I can ask my wife to sit in front of the TV for the 4th time; I'll have to recruit a tech friend and try, one of these weekends.


I'm also planning on switching out the amplifier, currently a Terk, for the CM 7775, which people say is the best.
 

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If you are handy with simple workbench tools, you might want to try the modified Channel Master antenna found at

www.projectorexpert.com


Read the article under "DTV" titled "The Long, Strange Trip".


This may solve your reception problems. Or, check out the other articles on the site for more DTV reception information.


KC
 

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Quote:
Originally posted by Eric:
You never know what you have to fiddle with, when it comes to DTV.
Eric, you did not post the model number, so I will assume it is the 4248. This antenna has a VHF pass through connection (terminals with the bars). Do you have your feed line connected to these terminal? If so, it is the wrong ones.




------------------

Wendell

Technical Services Supervisor

MAETV
 

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Eric,


Could your problem be overload (either real in the tuner, or just non-optimum for the equalizer)?


I experimented with my Channel Master UHF yagi, trying to see if the default lock position was best, and collapsed I lost lots of gain, esp. at the lower UHF channels.


You might try an attenuator, and see if you can get the same effect, with

the antenna full open.
 

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Discussion Starter · #9 ·
I've got the CM 3023 (it might also go by another number); it's UHF only. Everything's connected properly. Last night, the strength stabilized, and all channels coming in w/o breaking up.
 
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