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Anntenna Question

Hi,

I recently had electricians put a Radio Shack FM antenna on my roof. It's wired with RG-6U cable through a couple of patch panels down to where my receiver is located. Probably about 100' of wire in all.

It doesn't help reception -- in fact, I've gone back to the little wire dipole anenna that comes with the receiver because it sounds better. I put a little Radio Schack antenna amplifier in the mix about 10' from the antenna, and that doesn't help either.

The problem is that I don't know of any way to check whether there's actually a signal on this wire! I have access to bench-quality DVM, but that's about it. Would I require an oscilliscope to check?

I'm also not sure this is the right type of wire, or that I'm hooking it to the receiver correctly.

Any advice appreciated. Thank you!

- Eric
ehart

Showing 4 responses by swampwalker

swampwalker's avatar
swampwalker
5,138 posts
 
Eric- Check your receiver manual if you have it, but I am pretty sure that the 75 ohm tap on the receiver should be connected to the coax, and probably has an F connector for that purpose. If you have one of those "transformers" that comes with a VCR, you can connect that to the end of the coax and then the twin leads of that to the 300 ohm tap on the receiver. If that works, then there is a problem in the receiver with the 75 ohm tap; if it doesn't, then you are probably getting no signal. The first place I would check if that turns out to be the case would be the patch panels (why are they there?).
swampwalker's avatar
swampwalker
5,138 posts
 
Eric- do you know if all of in-wall RG6 is intact? Could be your problem, antenna is basically a passive device. BTW, if you are able to get a halfway decent signal with the dipole, then you shouldn't need an amp on the rooftop and signal should be very good (unless you got a directional w/o a rotor).
swampwalker's avatar
swampwalker
5,138 posts
 
Eric- the crossed loop configuration is omni-directional, I believe. And the question about splitting the signal does not relate to whether there are any other devices on-line, just whether they used signal splitters at the various patch panels (one input and several outputs, like with your cable TV). Maybe you should ask the people who did the wiring.
swampwalker's avatar
swampwalker
5,138 posts
 
As always, Bob has analyzed the problem systematically. My gut, tells me the problem is in the multi-room coax installation; either in terms of multiple splitters (although that much coax would act as an antenna of some sort and you should get some kind of signal) or in terms of a break in the walls or at one of the panels. Either way, it seems to me that if you follow Bob's fault tree, you should be able to narrow the problem down pretty tightly.
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