[CMTL]

hello there,

after hours of reading on this forum, i decided to go and buy the cm4228.

but i'm a bit dissappointed since i'm getting only wptz (5-1) from mt. mansfield. i'm getting no signal from the other channels that are at the same location.

my question is should i rise up more the antenna (actually it is at 15') or get a pre-amp (i'm running a 100' cable)

thank you

 

[Tower Guy]



Quote:
Originally Posted by CMTL /forum/post/12965957


hello there,

after hours of reading on this forum, i decided to go and buy the cm4228.

but i'm a bit dissappointed since i'm getting only wptz (5-1) from mt. mansfield. i'm getting no signal from the other channels that are at the same location.

my question is should i rise up more the antenna (actually it is at 15') or get a pre-amp (i'm running a 100' cable)

thank you

Unless height would get you over a local obstruction, I'd start with the preamp. You can try different antenna heights on www.tvfool.com to see how much benefit you'd get from height.


WPTZ-DT is on channel 14. The cable loss is lowest at 14, but the 4228 is weaker on 14.

 

[CMTL]

at 15' it is at roof level.

now i can analyse better the tvfool chart based on what you said on the last sentence.

does that mean that the higher channel number, the higher the cable loss?

here is my tvfool. oh, i forgot to mention that wcfe (38) is received as well.

 

[Falcon_77]

A pre-amp will probably be needed, but with local stations at 7 miles, it will be tricky to avoid overload. I don't know how many of the Montreal stations are currently broadcasting in digital, but it appears that there are several analog stations to contend with as well.


If the 4228 is pointed towards Mt. Mansfield, UHF signals from Montreal may not be too serious, but the CM4228 is almost bi-directional for VHF on some upper VHF channels. As such, you may need to split out the VHF side of the 4228 to avoid overload. However, as WVNY/ABC is on upper VHF as well, this presents another problem...


A directional VHF antenna is probably going to be needed to supplement your CM4228. A CM7777 pre-amp can accept separate VHF and UHF inputs, but I'm not comfortable about avoiding overload, even with local stations in off-angles/nulls.


A Winegard HDP-269 pre-amp may be a safer option, but depending on how long your cable run is and how many splits you have, it may not be strong enough.

 

[TheIceMaster]

With an 91XG, pointing at Mt. Mansfield about 165 degrees away from the Mt. Royal (Montreal transmitters, ~10 miles), I was still overloading a CM7777 with CFJP/CIVM when I was doing testing.


In that situation, an option may be a Notch filter, like the dual channel UT2700, to reduce both of these channels and hope that no other channel will manifest itself overloading the preamp. You could also look at PreAmps with a higher overload tolerance like the HDP-269 or TinLee's MA line of PreAmps.

 

[Tower Guy]



Quote:
Originally Posted by CMTL /forum/post/12965957


I'm getting only wptz (5-1) from mt. mansfield. I'm getting no signal from the other channels that are at the same location.

Your tvfool chart indicates that you should receive all the Mansfield stations using the 4228 without a preamp or more height. Check your antenna aiming and all connections.