# combining 2 or more antennas



## ibooksrule (Feb 16, 2003)

i want to combine 2 antennas but dont have an antenna combiner. what can i use to do this or do i need a antenna combiner? and if so where might i find one?


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## KKlare (Sep 24, 2004)

If you mean OTA antennas, then a 2-way splitter/combiner is fine. Look for a rating of 850 to 950 MHz and -3.5 to -4 dB. Signals can go either way. If combining UHF and VHF use a frequency splitter for less loss.

If you mean signals from your satellite dish, then you need a switch with a few exceptions. Use Legacy SW21 for the simplest or SW64 for up to 3 sat. and 4 out. For Dish Pro (DP on the back of the eyes) use DP21 or DP34 or DPP44. The 21's are unpowered, the rest may require a power inserter.

For more details, give your configuation from the Sys Info screen, model etc. Press that button on the front of your receiver. Cancel and go to the point dish screen and write down what switch you have and satellites you receive.


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## ibooksrule (Feb 16, 2003)

where do i pick up a 2 way spliter/combiner my local distrubiter does not have one they just have spliters and diplexers. thhis is for 2 OTA not for satellite


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## Neil Derryberry (Mar 23, 2002)

Wal-mart. This is a generic part, even the local grocery store carries them.


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## ClaudeR (Dec 7, 2003)

I was told that if you should have two identical antennae, and just connect them using 300 ohm (flat style) wire, then use a 300:75 ohm transformer and downfeed with RG6 cable.. I will be doing this with two of the $25 Radio Shack UHF yagi antennae.


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## KKlare (Sep 24, 2004)

If a channel is picked up by both then you must be careful with phasing. You can double or null the signal. When they point in different directions, remember the signal are just what they are but the noise keeps adding.

The simplest way to "add" two is to use equal length twin leads and observe the polarity like you would for batteries. The result will be an impedance mismatch -- 2 "300" ohm signals to a 300-to-75 transformer. Do not wire-by the the second antenna terminal. It will never match at all frequencies.

Untried: wire the two twin leads directly to the 75 ohm cable with a one-turn choke (iron core) around the cable to convert balanced to unbalanced. With short leads the reflections may not overwhelm you -- hard to be short enough for UHF.

Safer, use 2 300-to-75 transformers (<$2 each) and feed them into a splitter/combiner ($2-3). If second antenna does not help, try reversing one transformer twin lead.

BTW, the splitter for my cable modem is rated 5-1000 MHz, and 3.5 dB. The best you can do is 3 dB or 1/2 power.


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