Need to replace a 40 year old television antenna wall jack - help!

Hi,
I live in a 44 year old apartment building in Manhattan. I'm currently doing renovations and I've removed an old, dented, paint-encrusted TV antenna wall jack from the living room. I'd like to replace it with its modern equivalent so I can use the building's roof antenna for HDTV and FM radio reception.
I don't know exactly what this thing is or how to replace it properly. Ideally I'd like to have a standard 75 ohm coax output. Any help would be appreciated. Here's a description of the old jack:
The jack accepts 2 coax cable inputs at the back. and provides 2 screw terminal outputs on the front. The screw terminals on the front are presumably for the old standard 300 ohm TV wiring. Here's a schematic:
COAX 1 COAX 2 | | | | resistor 1 no connection | | resistor 2 no connection | | | | screw terminal screw terminal 300 ohm 300 ohm
Please reply to dschwarz but do not spam me - my email domain is verizon dot net.
Thanks,
Dan
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My best advice is for you to print you own email and take it to you nearest Radio Shack. They will put you on the right track.
--james--
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Yeah, tried that. The local Radio Shack clerk stared blankly at the old jack then led me to a rack of 75 ohm coax TV wall jacks. Right output... wrong input. The local store has absolutely nothing like this.
Dan

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If we presume that the poster who says it is part of a distribution system is right, and I have no experience with that setup to either agree or disagree, let me propose a simple solution, which if it doesn't work will have not caused any real grief.
The screw terminal are 300 ohm twin lead, right? You want 75 ohm cable, right?
Go back to the yo-yo at RS and tell him you want an Indoor/Outdoor 75W to 300W Matching Transformer Catalog #: 15-1230
This will set you back 5.49 plus tax. The installation will be obvious. Open the package carefully and if this is not the answer take it back for a refund.
Charlie (who spent 3 years as a retiree peddling stuff for RS)
You've got questions, we've got answers (Please notice that NOBODY ever said they were the right answers)

nearest
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040513 2051 - Dan posted:

Here is the Winegard WebSite, with a selection of splitters and wall outlets. If the system you described is part of a complete distribution system for the apartment building, removing the wall outlet will eliminate the signal to the outlets after it. It sounds like the outlet that you have is a feed thru outlet that comes from an outlet either above or below -- probably above -- and then continues the signal on to the next outlet. You could send an Email to the Winegard company and let them know what you want to replace and then go from there. Instead of the screw terminals for the 300 ohm cable outlet, you could go with the 75 ohm coax output. Be sure you ask for the feed thru type outlets.
http://www.winegard.com/offair/splittersoutlets.htm
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Dan wrote:

Sorry, but I can't make much sense out of the drawing. The resistors (where are the other ends??) and the "no connects" are a big mystery from this end.
Any clue as to Coax 1 / Coax 2, which is the input feed and which is the outgoing feed? If so...
You need is a simple "Directional Coupler". Probably a 14dB version. A DC is an unbalanced 2-way splitter. Instead of both splits being -3.5 dB down like a conventional 2-way, one leg is very low loss ( typically < 1dB) and the other is high loss (-14, -16, -22dB etc.)
It has 3 female coax ports: IN / OUT / TAP. The distribution cables (the 2 on the back of your current gizmo) go to the IN and OUT, there is very little loss between them, the idea being to pass along as much signal as possible to the next guy.
The TAP port is the "high loss" leg which will poke out through your new wall plate, having a single hole in the middle for your coax connection. You secure it to the plastic plate with a hex nut.
--
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