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Old 23-Mar-2013, 4:38 PM   #1
Alan909
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Stacking MXU59 UHF Antenna Question???

I have noticed on my MXU59 UHF Antenna it has 2 connection places, one on bottom and one on top, both with wing nuts to accept 300 ohm wire or a balun...the top connection according to the directions is for adding another antenna...SO...this got me to thinking...

"What is the chances of using a 300 ohm wire to connect both MXU59's, then to a 75ohm balun,3 ft RG-6 coax to a UHF Preamplifier???"

Wouldn't that minimize the db loss ??? than using an antenna combiner???

P.S. not interested in vhf at the moment...
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Old 26-Mar-2013, 3:27 PM   #2
tripelo
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Quote:
Originally Posted by Alan909 View Post
I have noticed on my MXU59 UHF Antenna it has 2 connection places, one on bottom and one on top, both with wing nuts to accept 300 ohm wire or a balun...

"What is the chances of using a 300 ohm wire to connect both MXU59's, then to a 75ohm balun,3 ft RG-6 coax to a UHF Preamplifier???"

Wouldn't that minimize the db loss ??? than using an antenna combiner???

...
Alan909,

According to Antennacraft, what you describe is a:

"Built-in VHF feed thru feature allows you to add an MXU antenna to an existing VHF antenna."

http://www.antennacraft.net/Antennas/AntennasUHF.html

In other words, allows you at add a VHF antenna to your antenna. Probably it is designed to block UHF signals that may be picked up via a VHF antenna.

This is (was) a common design practice, since UHF signals from VHF antennas tend to distort the beam pattern of the UHF antennas.

If so, the connection would not be good for stacking two UHF antennas.

Last edited by tripelo; 26-Mar-2013 at 3:52 PM. Reason: correct a typo
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Old 8-Apr-2013, 8:04 AM   #3
GroundUrMast
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That being the case, It's still quite likely that you could successfully stack a matched pair of antennas such as the MUX-59. Rather than using 300Ω twin-lead, you'll need 450Ω twin-lead or a home-made equivalent... You will need two sections 1/4 wave length long (electrical length) at the frequency of interest. The two sections will act as impedance matching transformers. Each of the matching sections would connect to the UHF terminals of the MUX-59. At the opposite ends the antenna output impedance will have been transformed from 300Ω to 600Ω. Join the two 600Ω ends in parallel and you then have a single output with a net impedance of 300Ω.

Take a look at the information here:

http://forum.tvfool.com/showthread.php?t=1024 in particular, see: http://www.kyes.com/antenna/stackluge.html and http://en.wikipedia.org/wiki/Quarter...ce_transformer

The following may be of help also:

http://forum.tvfool.com/showthread.php?t=1464
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Last edited by GroundUrMast; 8-Apr-2013 at 8:20 AM. Reason: more details & link
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