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Old 03-01-2015, 12:02 PM
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Arcanine Arcanine is offline
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Modulator & Antenna

So I was curious. I decided to unhook my Blonder-Tongue from my outdoor antenna and just connect it to a pair of rabbit ears inside the house, that way I can limit it's range to just my house. I cut the transmitters power in half and I still get an amazing picture and good distance from it.

The rabbit ears I use are just a very cheap pair of Radio Shack things.

I took the bottom off, and discovered a cheap little transformer built in to the antenna. I was wondering, should I delete this and just connect straight to the antennas them self?

I set them each to 26', to correspond with my usage of channel 13. But that transformer, should I delete it?
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Old 03-01-2015, 01:17 PM
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ChrisW6ATV ChrisW6ATV is offline
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Do the rabbit ears use coax cable, or twin lead? A basic dipole (such as rabbit ears) is about 75 ohms, so a transformer could be used to match to 300-ohm ribbon twin lead. Depending on how hard you want to work on this, you could install coax into the rabbit ears directly to the elements. If the antenna already has coax, I would just leave it alone, since it works well now.
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Old 03-01-2015, 02:39 PM
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It already has 75 ohm coax on it. It looks like the insides can deal with my modulator.

I'll just leave the transformer alone since it doesn't seem to be causing any harm. I have the modulator on a little less then half power and it covers my entire (small) house and most of the propriety.
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Old 03-01-2015, 08:34 PM
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That transformer is probably a balun to go from the single-ended coax feed to the balanced dipole, so don't remove it.
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Old 03-02-2015, 03:47 AM
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cbenham cbenham is offline
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I built an FM transmitting antenna using 75 ohm RG59 copper mesh shielded coax.
I removed the last 30.375 inches of the outer insulation and pulled the center conductor out. I stretched the shield one way and the center conductor the other, ending up with
a 60.75 inch half wave dipole with an impedance of 75 ohms. I installed it in some pvc pipe and made a three turn loop to keep reflections from the antenna down. It is used with a very low power RF source, probably about 50 milliwatts. Got reception in my car a block from home before the signal began fading. Came home and immediately turned the RF down to the lowest setting possible! It works great.
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