No recption at all

ajcjr68

DTVUSA Rookie
#1
I am using a CM3671 antenna w/ a CM7777 pre-amp , all mounted 23' off the ground (which puts it a little over 10' higher than the peak of the roof). I am not getting ANY reception at all , no matter where I point the antenna. I'm thinking that I should get at least a couple channels because about a year and a half ago I WAS able to pick up WBAY's digital broadcast (they were the only one's broadcasting a digital signal at THAT time) , but nothing now...

Here's my TVFool link:
http://www.tvfool.com/?option=com_wr...b7c895663737e8

Thank's for any help or advise
 

IDRick

DTVUSA Member
#2
Welcome to the forums!

Could you please repost your tvfool link. There appears to be an issue with your existing link (tvfool says page does not exist). It'll give us a better understanding of your reception challenges and opportunities.

Have you checked your connections at the antenna? They can go bad if water gets inside the connection. Is the balun still attached properly to the antenna? Can you switch out the balun with a new one?

Rick
 

FOX TV

Contributor
#3
not getting ANY reception at all

I am using a CM3671 antenna w/ a CM7777 pre-amp , all mounted 23' off the ground (which puts it a little over 10' higher than the peak of the roof). I am not getting ANY reception at all , no matter where I point the antenna. I'm thinking that I should get at least a couple channels because about a year and a half ago I WAS able to pick up WBAY's digital broadcast (they were the only one's broadcasting a digital signal at THAT time) , but nothing now...

Here's my TVFool link:
http://www.tvfool.com/?option=com_wr...b7c895663737e8

Thank's for any help or advise

My initial thoughts are, a bad amp, a badly made, or shorted F connector, a failed or open balun, a broken conductor in the coax (You can can test this by using an ohm meter and shorting together the conductors on the other end with a test lead or alligator clip).

Make sure your coax is not water damaged. Water can get in the coax and freeze, and possibly break the center conductor, and the ohm meter test will show this, and all splitters need to be removed for this test to work, as DC voltage will not pass through most splitters unless they were made for satellite use, as those types were designed to pass DC for the LNB power.

Take the amp out of the system and try the antenna with out it. Look at the antenna itself for broken or corroded parts. If there are any splitters in the system, take them out of the system too. The goal here is to strip everything down to the least amount of failure points, and if you get a signal, you will know something you took out of the system is bad. These are just a few initial things to check, and without the TV FOOL data, this is all I can offer.

As mentioned above, your TV FOOL link was bad. Please re-post it.
 

ajcjr68

DTVUSA Rookie
#4
TV Fool

The antenna , amp , balun , and rg-6 are all brand new and just put up this afternoon , so no water damage. The rg-6 was bought not made , but I guess I can check it , and I put the antenna together , so I know there aren't any broken or shorted connections. Let me know if you need the tvfool link again.
 

Don_M

DTVUSA Member
#5
Your TVFool link works just fine now. I'm presuming that you're attempting to pull in Green Bay, correct?

Two additional suggestions:

• Double-check the aim.

The end of the antenna shown in the upper right-hand corner of this image should be pointed at the stations. At 171˚ actual, Green Bay is a tad to the "left" of due south.

• I have no personal experience with the CM 3671, but it looks as if it should have "phasing lines," two metal wires above and parallel to the boom that cris-cross one another between each element. Check to make certain any phasing lines aren't touching one another anywhere. At your distance to the stations, this short circuit will kill all reception. The phasing lines can be bent back into the correct alignment gently by hand if needed. Don't use tools to do this, as spacing of the gaps where the lines cross is important.

PS: I checked what another 12 feet of height might do for you, and the answer is, "not much." Among the network affiliates, some stations are a bit better, others are a bit worse. It's not worth the added expense and hassle IMHO.
 
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ajcjr68

DTVUSA Rookie
#6
I checked the pre-amp's power supply output voltage , and there was none. Opened it up and found a bad solder connection on the center conductor of the F-connector that feeds 18VDC to the pre-amp. Not just a bad solder connection , but a really bad repair attempt. I fixed it and now get all of the Green Bay networks (didn't try rotating the antenna to see about any other channels). I bought the pre-amp from Solid Signal , so.... buyer beware.
 

FOX TV

Contributor
#7
TV Fool

The antenna , amp , balun , and rg-6 are all brand new and just put up this afternoon , so no water damage. The rg-6 was bought not made , but I guess I can check it , and I put the antenna together , so I know there aren't any broken or shorted connections. Let me know if you need the tvfool link again.
Ok, you did not originally state that it was a new system, and this statement "a year and a half ago I WAS able to pick up WBAY's digital broadcast (they were the only one's broadcasting a digital signal at THAT time) , but nothing now..." made me ASSUME that it was an old installation.

Your TV FOOL data looks on average, just like most of the ones I see in my own area. You will need a good installation to do the best job it can. I would still try an remove the amp and see if you can get anything off of WDHS Channel 8. If you have an antenna electrical or mechanical problem, a VHF channel would likely be more easily received, and that channel is the strongest of them all in signal power.

Just because parts and pieces are new, doesn't mean they can't be problematic, especially with all of the poor quality products we get these days from China. I will bet that your balun ( if your antenna uses one) was made in China.
 

Don_M

DTVUSA Member
#8
I bought the pre-amp from Solid Signal , so.... buyer beware.
Glad to hear that cleared everything up!

CM has long had a good reputation for quality equipment. Let's hope their QC isn't slipping now that pretty much all of their stuff is made offshore. :eek:
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#9
I checked the pre-amp's power supply output voltage , and there was none. Opened it up and found a bad solder connection on the center conductor of the F-connector that feeds 18VDC to the pre-amp. Not just a bad solder connection , but a really bad repair attempt. I fixed it and now get all of the Green Bay networks (didn't try rotating the antenna to see about any other channels). I bought the pre-amp from Solid Signal , so.... buyer beware.
--------------------------
:welcome: ajcjr68,

You aren't the first person to run into problems with Channel Master components. Per recommendations on another Forum thread, I checked three CM Join-tennas (passive devices then allow a UHV and VHF antenna to share one coax) and every one had loose female coax fittings that could spin on their circuit boards and snap the center connector's wire. I'm glad you found the problem so quickly.

Jim
 

SWHouston

Moderator
Staff member
#10
ajcjr68,

Could you return to TVFool, and redo your chart at a higher height.
Just to see if you can get rid of a few of those "Edges", that might help.
Like put in a height of 50', and see what happens.

Have a good Day ! :)
S.W.
 
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