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-   -   Connecting Two 4228HD Antennas to Boost Signal Strength in Same Direction (http://forum.tvfool.com/showthread.php?t=13496)

OTACanuck 30-Jul-2013 10:03 AM

Connecting Two 4228HD Antennas to Boost Signal Strength in Same Direction
 
For the last two years we have been running a 4228HD antenna attached to a CM-7777 amplifier using a 3ft pieces of coaxial cable. This setup has been great and is used on a daily basis without problem.

We recently acquired a second 4228HD antenna and we are hoping to combine the two antennas to boost signal strength from the same direction. I have mounted the new 4228HD antenna directly above the existing antenna (on the same pole). The bottom of the new antenna is spaced 4" above the top of the old antenna. Both antennas point in the exact same direction. Both antennas are connected to output sides of a 2-port digital splitter from PCT (not sure of the model number, but I think it is an indoor version) using 3ft pieces of coaxial cable. Another piece of 3ft coaxial cable connects the 2-port splitter (the input side) to the CM-7777 amplifier. From that point to the TV the setup remains unchanged.

Now with the new setup described above we don't receive any channels when we used to get 20+ channels with the old setup. Can you tell me if I have done anything wrong? Do I need to use a special splitter to combine the signals from the two antennas? Any help would be greatly appreciated.

GroundUrMast 30-Jul-2013 1:15 PM

Just some general thoughts...
 
Going from good reception to 'no' reception suggests one or more defective components. I'd caution against the urge to say, 'It can't be ____ , it was just working fine.'

Test the original antenna and amplifier with the new parts completely disconnected. Then test just the new parts.
Looking for the possibility of open, loose or shorted cables or connectors.
Has the preamp failed? Or lost power?
Successful combining is going to depend on the two antennas being identical. The 4228 design has been altered over the last few years... still, complete loss of reception suggests a short or open circuit... The two cables used between the antennas and combiner need to be identical also.

In the end, the net gain is not going to be much, 3 dB minus the combiner losses... and that assumes both antennas are 'illuminated' by the same amount and phase signal (an optimistic assumption at best).

Please post a link to your reception report, it would be helpful to see what signal conditions you're contending with.

Tower Guy 30-Jul-2013 2:49 PM

Quote:

Originally Posted by OTACanuck (Post 37344)
Now with the new setup described above we don't receive any channels when we used to get 20+ channels with the old setup. Can you tell me if I have done anything wrong?

I'd guess that one of the two antennas are connected out of phase to the balun. Try reversing the balun on one of the two antennas.

http://www.hdtvprimer.com/antennas/16bay.html

Stereocraig 30-Jul-2013 4:09 PM

Quote:

Originally Posted by Tower Guy (Post 37346)
I'd guess that one of the two antennas are connected out of phase to the balun. Try reversing the balun on one of the two antennas.

http://www.hdtvprimer.com/antennas/16bay.html


It would be nice, if a Mfr. would make the effort to mark them.

teleview 30-Jul-2013 6:21 PM

Stacking seperate antennas is a last resort for reception.

________________

What Tv stations/channels are you trying to get??

________________

Please provide a tvfool radar report and channel list.

Use the Exact address to make the tvfool report.

Make the antenna heigth in the tvfool report 25 feet above ground.

25 feet above ground is a reference antenna height above ground that provides information about what is receivable and what is not receivable at a resaonable antenna height , not to low and not to high above ground.


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