Need advise with another CM7777 issue

Satbum

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Original poster
Aug 9, 2006
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I have a problem with my CM4228 and CM7777 pre-amp combo.
I just installed the CM7777 tonight and lost all signal in the process.
I have a 4-way splitter installed after the power source and the CM7777 at the CM4228 support pole 30' in the air at the top of my home. I am using the splitter as a way to distribute to OTA signal to 4 different HD TVs in my home. Prior to the pre- amp install I did have a decent signal but enough pixellation and periodic signal loss to be irritating. That was the reason for the addition of the pre-amp.

Once I installed everything I had no signal. Then I started trouble shooting the problem. All my cable connections are good. With only the power source connected I seem to have a slight improvement in my picture and signal strength.
Once I connect the CM7777 pre-amp I loose everything. I took the cover off and made every adjustment available (single, comb, FM trap) to see if that would help.
Each time I could not get a signal.

I have stations varying in distance from 25 to 60 miles that can be received in my area zip code of 32221.

TIA for any advise...
 
It sounds like you are suffering from overload. The CM 7777 is generally recommended for areas at least 35 miles fom the nearest transmitters. How far is the pre-amp from the antenna? You could try moving the pre-amp and power supply right before the distribution point to help relieve some of the overload.

Your next step would be to replace the 7777 with a pre-amp or distribution amp that can better handle the stronger signals that you are experiencing.

Did you ever try hooking the 4228 to just 1 TV with no splitters. If so, did you experience any dropouts or pixelization?
 
I just ran your zip code. Your system is severely overloaded. I seriously doubt that 7777 will ever work for you. You need the Winegard HDP-269 preamp; or some type of high input tolerant distribution amplifier.

Your situation will improve dramatically when the analog signals go dark; but will still need something other than the 7777; even at that time.
 
Sounds more like a wiring problem. Some of my stations are within 35 miles. I'm running a CM7777 AND a distribution booster and it works fine. From your description it's a bit difficult to tell exactly in what order your components are connected. Check the diagram below. Is that how your system is wired?
 

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No Static At All - No I haven't hooked up the CM 4228 to just 1 TV. That was never in my plans.
Like I mentioned the picture was pretty good even with everything hooked up before the CM7777. I really want all the TV's to get a good signal without the dropouts.
I read that you should have the pre-amp installed at the antennae, so that is why it is there. It is possible that I can just leave the barrow nut and boots connected as they are right now. I can then install the preamp close to the power source in the attic, if that is what you recommend.

Jeepguy that is exactly how I am setup. Except the Preamp is on the support pole and not the Bay area.
BTW: I also have the CM 4228 setup with a rotor assy.
 
I know it's not in your plans, but this will give you a good idea of how the system performs without any of the losses associated with 4 splits. If that scenario works well, then you just need to address distribution losses. Your antenna probably doesn't need additional pre-amp gain.
 
Wow quick reply. I didn't even get a chance to mod my last reply. LOL
I hate wasting money like it sounds as I did with this purchase...;)

Do you suggest a distribution amp instead if that works?
 
I would move the pre-amp further from the antenna and see what happens. The 4228 is a very powerful antenna already. Some people use a pre-amp like this to just address distribution needs.
 
I just looked at the FM stations in your area, and they are also a huge concern. I know the 7777 has an FM trap, but you have numerous 100,000 watt stations within 20 miles. They are killing your reception. The internal FM trap does not offer enough signal attenuation for your area. You can purchase an HLSJ filter(3.00 plus shipping) in combination with moving the pre-amp furthur down the line and that sould help considerably.

What TV stations are you having problems with?
 
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What TV stations are you having problems with?
WAWS, WTEV, WJXX, and DTV among others.

As a matter of fact, I did a new scan a little while ago and lost channels in the process. That shows me there may be a problem even though the picture looks pretty good right now.

Thanks for your help.;)
 
Jeepguy that is exactly how I am setup. Except the Preamp is on the support pole and not the Bay area.
BTW: I also have the CM 4228 setup with a rotor assy.

I'll ask the dumb question, is the antenna connected directly to the mast-mounted pre-amp UHF/Combined coax connection and not the VHF connection and the VHF switch set to "Separate"?
 
You may need an attenuator instead of a preamp. According to tvfool, there are 29 stations that are line of sight to zip code 32221.

In cases of overload, some have found that their antenna was mis-aimed to compensate for the strong signals.

If you aimed the antenna before you put in the 4 way splitter, try aiming it again now that the 4 way splitter has reduced your signal level.
 
I'll ask the dumb question, is the antenna connected directly to the mast-mounted pre-amp UHF/Combined coax connection and not the VHF connection and the VHF switch set to "Separate"?

I tried both separate and combined. I also connected the coax cable to each connection while switching between the 2 options. While hooked up to each I also switched the FM trap to see if that would help. All to no avail.


Tower Guy
In cases of overload, some have found that their antenna was mis-aimed to compensate for the strong signals.

If you aimed the antenna before you put in the 4 way splitter, try aiming it again now that the 4 way splitter has reduced your signal level.

I have a Magnavox Antenna Rotator M61415 of which the CM4228 is connected to.
The direction is not a problem (in theory) because it can be finely tuned or adjusted.
 
I think you've got a dead amp. I would take out the splitter and connect the coax direct to one TV. If you don't see anything then, I would guess the CM7777 is bad. You do not need attenuators or anything else to dumb down the signal. That's not the problem.
 
I believe your pre amp is bad. I had a CM7777 fail on me too. The amp will still work.
This is a new item right out of the box. I hope that isn't the case.

Question: Can the amp (power source) amplify the signal without the pre-amp?
I still have it still plugged in with power before the 4-way splitter and I seem to have a little stronger signal.

Thanks for the reply's. I will try the direct connection method without the splitter later and get back with the results.

Have a Great Day!
 
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Did anyone here except Tower Guy and myself look at Satbum's TV FOOL profile? This guy is doing more harm than good with the 7777. The 35 mile rule is not very good general advice. With the numerous LOS -20, -30, & -40 dbm readings on TV FOOL; a high gain amp is not a good idea.

Sure, some people at 25-35 miles can use the 7777; but signal levels can vary widely at that distance. I would imagine the zip code center I referenced is fairly accurate for Satbum, with the general lack of terrian issues in Florida.
 
CM4228 AND 7777

I have the same set up- with cm 4228 and 7777 and rotor. I had problems once be fore. On one of my connections the center of the coax was folded over and making no contact.


good luck with your search

My system works great


JOhn
 
Did anyone here except Tower Guy and myself look at Satbum's TV FOOL profile? This guy is doing more harm than good with the 7777. The 35 mile rule is not very good general advice. With the numerous LOS -20, -30, & -40 dbm readings on TV FOOL; a high gain amp is not a good idea.

Sure, some people at 25-35 miles can use the 7777; but signal levels can vary widely at that distance. I would imagine the zip code center I referenced is fairly accurate for Satbum, with the general lack of terrian issues in Florida.

Don't rely too heavily on TV FOOL. According to them I would need an antenna over 600 feet high to receive the Philadelphia stations. My antenna sits on top of my shed about 15 feet above ground and I get all the Philly stations even with a mountain several hundred feet high only 2 miles from my house and in a direct crossing line between me and the Philly towers. I exchanged emails with them and they had no explanation for their computer readout. They're not as accurate as you might think.

He is not doing more harm than good. The CM7777 is not overpowering his TV's AGC. In most instances the worst that happens if you over boost the digital signal is the picture develops a slight background pulse in darker areas of the image.
 

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