AVS Forum banner
Status
Not open for further replies.
1 - 7 of 7 Posts

·
Registered
Joined
·
173 Posts
Discussion Starter · #1 ·
Probably a stupid question, but here goes:


I just got a CM 4248 UHF antenna connected to my DTC100 and I was able to pull some decent signals from the WTC NY (CBS and Fox). I was wondering, instead of adding a rotor to point the antenna to PBS (opposite direction) I'll just add another CM4248 and connect the two together to a single cable line. Will this work?

I know that you can connect a VHF antenna to the CM4248 to get the lower channels.

Any comments?
 

·
Registered
Joined
·
357 Posts
I do just that with a radio shack bow tie and my channel master 4221. They sit in an upstairs bedroom with the 4221 leaning against a bookcase while the bow tie sits on the bookcase pointing about a 45 degree angle difference. I hooked the bow tie into the 4221 and run one cable down my stairs to a Mits HD500. I can pick up all Washington DC stations at a signal strength of 100.
 

·
Registered
Joined
·
6,643 Posts
Well, it would all depend on what signal levels you currently have. If you can NOT get the PBS station with the antenna pointed at FOX, and you can NOT get the other two stations when pointed at PBS, then if ALL signals you get from all 3 stations are good enough to overcome the 3DB loss of the combiner, it should work.


If you CAN receive stations in the opposite direction, off the back of the antenna, combining them may cause multipath which may or may not cause problems with reception.


It would be nice (and may be possible, I havent checked), if the new boxes had two or three RF inputs, and allowed you to program them to tell each channel which RF input to use. That would allow two or three antennas, and no worry about turning a rotor.



------------------

SVR-2000 2.0 130 hrs

HDR-112 2.0 62 hrs

REplay 3020 20 hrs
 

·
Registered
Joined
·
2,150 Posts
What exactly is a "signal combiner"?


Can't you just turn a standard 2-1 splitter around and use that to combine 2 UHF signals?


Curious, as I was going to do the same thing. I get all 4 major networks with 75-90 signal strengths w/o having to adjust my RS 100" antenna, but I was considering adding a double bowtie to increase my signal strengths on all channels (ABC, 88 strength, has some audio drop out).


[This message has been edited by jdiehl (edited 04-26-2001).]
 

·
Registered
Joined
·
516 Posts
I would recommend that your 2nd antenna be a Blonder Tongue model BTY-10-U yagi http://www.blondertongue.com/WebPage...ingleCh_01.pdf

and using a Channel Master 0585-x UHF Join-Tenna channel combiner
http://www.channelmaster.com/pages/cjs1.htm

to share the downlead to your receiver. Besides almost loss-less coupling compared to a 2-way splitter, the Join-Tenna will eliminate multipath on the off-axis channels.)


You can also get a UHF/VHF splitter/combiner to add VHF signals with the UHF signals (which also has way less loss than a 2-way splitter used backwards).


------------------

George at WNDU
 

·
Registered
Joined
·
407 Posts
I got a Join-Tenna and it does what is supposed to do with one caveat. I got the Join-Tenna to combine channel 48 (which is HBO carried by Time Warner Cable over its cable wires as an 8-VSB signal) with the rest of my OTA stations. The Join-Tenna is programmed to let only channel 48 through on one input and to block channel 48 on the other input. The problem is that there is some channel bleeding and the Join-Tenna is blocking, at least partially, channel 45 (ABC) and channel 44 (Fox). If I get ambitious I may try to order another Join-Tenna specifically for channel 50, which should allow 48 to work and not effect 44 and 45.


My suggestion is to keep this in mind if ordering the Join-Tenna and speak to someone at either Channel Master or the store where you order to confirm that channel bleeding won't screw anything up.


Does anybody know if there is any way to tweak an existing Join-Tenna to change the frequency filters?


-Brett
 

·
Registered
Joined
·
516 Posts
Brett,


I was able to retune a Join Tenna from ch. 38 to ch. 42 but it took a spectrum analyzer and a little green screwdriver and a small pair of needle-nose pliers yet I got good results. You could probably use the same to "improve" one (or to retune one...but only within their band of channels: Model 0585-1,Channels 14-29; Model 0585-2,Channels 30-49; or Model 0585-3,Channels 50-69).



------------------

George at WNDU


[This message has been edited by George Molnar (edited 04-27-2001).]
 
1 - 7 of 7 Posts
Status
Not open for further replies.
Top