# Will a cm7777 help lock in stations



## hojo

I have an 811 dish reciever. I am about 27 miles from my network stations. I recently placed a CM 4228 in my attic and get my fox affiliate(Uhf 50 ) at about64-65% CBS 69-72%. with stable pictures. nbc,pbs and wb (all uhf) however will show 49% and sometimes bump up and down but are not quite strong enough to lock in to get a picture. I just ordered a CM 7777 preamp to see if these stations will lock in. Just wondering if it will help?

Just an aside, My Abc affiliate broadcasts vhf channel 9 and is 12 miles from me and 60 degree southwest of the other stations. I was unable to recieve it with just the 4228 so I placed a rabbit ears antenna roughly perpendicular to my cm 4228 right through the middle of my 4228 with antenna ends extending in front and back of the 4228, and attached the leads to where my balun for the 4228 attaches and now get Abc @ 74-78%.


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## Fifty Caliber

If you can, take the antenna out of the attic and install it on the roof. The pre-amp might help, or it might not, you won't know untill you try it. Getting the antenna out of the attic and up higher will help more than any pre-amp in most cases.


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## ibglowin

It did for me and I live around 45 miles from the towers. I have the CM4228 as well. of course the towers for me are on top of a 10,000 foot mountain with not much else in between. What I'm trying to say is YMMV!


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## AcuraCL

hojo said:


> I have an 811 dish reciever. I am about 27 miles from my network stations. I recently placed a CM 4228 in my attic and get my fox affiliate(Uhf 50 ) at about64-65% CBS 69-72%. with stable pictures. nbc,pbs and wb (all uhf) however will show 49% and sometimes bump up and down but are not quite strong enough to lock in to get a picture. I just ordered a CM 7777 preamp to see if these stations will lock in. Just wondering if it will help?
> 
> Just an aside, My Abc affiliate broadcasts vhf channel 9 and is 12 miles from me and 60 degree southwest of the other stations. I was unable to recieve it with just the 4228 so I placed a rabbit ears antenna roughly perpendicular to my cm 4228 right through the middle of my 4228 with antenna ends extending in front and back of the 4228, and attached the leads to where my balun for the 4228 attaches and now get Abc @ 74-78%.


A preamp is designed to amp the signal to overcome long cable runs. If your signal is marginal, it will still be marginal since the error rate does not change by adding a preamp ... if the digital bits are missing from the signal, the preamp isn't going to change that. If you put a preamp in a RG6 run of 10 ft, the signal attenuation wouldn't be significant enough to need to be overcome. If you put it in a RG6 run of 100 ft, there could be enough attenuation that the preamp will help.

I hope that made sense ....


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## ibglowin

Here is my real world experience. Cheap preamps can add more noise to the signal, a good preamp will give you a stronger signal (with only a slight increase in noise)

I was only getting around 75% signal on my OTA stations with my CM4228. I was having dropouts on several channels. I added the CM7777 and my signals are now 90 -100% on all OTA stations and I have no dropouts whatsoever. This is on a 921 with a cable run of around 50ft.


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## hojo

thanks for the input. My cable run is about 95 ft. of Rg-6. I could probably reduce it by about 10 ft. or so. but I didn't think it was that big of a difference. I had tested a 30 foot run and found not much difference in a 30 foot run and a 100 ft. run. I guess I'll find out tommorrow when my cm 7777 arrives if I can lock in on these other stations.


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## Michael P

If you are getting signal dropouts on digital OTA stations forget the preamp. You really need to get a clean line of sight to the transmitters. If there are a lot of trees between you and the trannsmitter that is the problem. The trees affecting your reception could be miles away. UHF signals get attenuated by leaves, as well as aluminum clad insulation and aluminium siding. You need to get higher up and definitly out of the attic.


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## hojo

Just an update. I now get my nbc and wb affiliates my other stations are stronger(abc, cbs and fox). I did have to seperate my antennas and direct seperate inputs into the amp. I can't seem to lock in on PBS but that's OK. I'm happy now with my setup. Jay Leno looks uglier in HD but Salma Hayek looked stunning. I love HD. Can't wait till SEC football. Just wish I had done this sooner.


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## ibglowin

That's great!

I knew it would help despite what others were trying to tell you.



hojo said:


> Just an update. I now get my nbc and wb affiliates my other stations are stronger(abc, cbs and fox). I did have to seperate my antennas and direct seperate inputs into the amp. I can't seem to lock in on PBS but that's OK. I'm happy now with my setup. Jay Leno looks uglier in HD but Salma Hayek looked stunning. I love HD. Can't wait till SEC football. Just wish I had done this sooner.


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