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FM wire antenna to coax adapter? (balun?)

dietermoreno

Dec 30, 2012
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Is it possible to build a FM wire antenna to coax adapter?

Every Hi-Fi FM receiver under $100 that I have seen in real life and on the internet only has antenna terminals for an FM wire antenna.

Like this one: http://www.ebay.com/itm/Sony-2-Chan...93?pt=US_Stereo_Receivers&hash=item20df5bccfd

Which used is only $38 for pretty much the same thing: http://www.ebay.com/itm/Sony-STR-DH...38?pt=US_Stereo_Receivers&hash=item2ece61c502

However, a little wire antenna is inferior to connecting a coax to a TV antenna.

I read here that its not really possible without taking apart the radio and changing its impedence sensitivity to match the antenna impedence: http://answers.yahoo.com/question/index?qid=20070711105250AAK5kj0


Would it be possible to build an adapter that converts the impedences like a balun is used in audio to connect an XLR cable to a 1/4 inch guitar cable?

The idea is, the Hi Fi receiver has an antenna terminal and a ground terminal, and you connect two wires to the terminals, then solder those 2 wires to a balun (maybe), and then the ground wire is electrically connected to the shield of the coax via the balun and the antenna wire is electrically connected to the conductor of the coax via the balun.

I'm not sure if using an amplifier makes a difference in the impedence. I would be connecting the coax to an amplifer that is connected to another coax connected to the antenna. I'm building this amplifier, so it can handle both analog and digital signals on all bands from 500khz long wave to 1GHZ microwave with low noise <4 db good for digital signals and amplification of 16 db with "50-75 ohm impedence" it says, I'm not sure if that is input or output impedence http://www.ramseyelectronics.com/Ramsey-Broadband-Preamp-Kit/dp/B0002NRKYY?field_availability=-1&field_browse=6290131011&id=Ramsey+Broadband+Preamp+Kit&ie=UTF8&refinementHistory=brandtextbin,subjectbin,price&searchNodeID=6290131011&searchPage=4&searchRank=salesrank&searchSize=12
314G9QHJ2CL._SS270_.jpg

More bands supported, both analog and digital supported, and at a quarter the price of low end digital TV amplifiers.


Actually, as soon as I changed my search terms from "FM antenna wire to coax adapter" to "FM antenna wire to coax balun", Google came up with this:

COTRAN.jpg


http://www.summitsource.com/steren-...ion-adapter-converter-part-200500-p-8190.html

Is that the balun I'm looking for to connect my Hi-Fi receiver to my TV antenna (with the above amplifer connected in between)?
 

Harald Kapp

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Nov 17, 2011
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This receiver has, as all receivers I know, a standard 75 Ohm coax antenna connector. You can directly connect it to the coax output of a suitable antenna.

There may be a misconception on your side:
The receiver is typically delivered with a strand of wire that is supposed to be connected to the center pin of the coax connector. This is only a substitue for a good antenna but will suffice in many environments where there are stron radio stations nearby. Nevertheless, the antenna connector is a complete coax antenna input.
 
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