Anntenna Question

Boy, I wish I had asked here first! I didn't know there was any other sort of antenna, honestly. The antenna was cheap, but all the parts, mounting, ground spike (8' in the ground!), skilled labor to put it up.... Yikes.

This antenna is not a Yagi, it's designed for FM, a two loops crossed. I will have to check back and see how "directional" it is said to be.

I'm not actually splitting the signal -- RG6U goes everywhere but is mostly unused currently. I will check for continuity though.

Thanks again everyone.

- Eric

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.

You do not have to have components connected or turn-on in various rooms of the house. The fact that you have all that wire going everywhere weakens the signal.

Let's take another look at the initial installation. That antenna is an omni (circular reception pattern) so as long as it's not mis-installed (somehow grounded to the mast) or defective, it should perform much better than the interior dipole. It likely has 300 ohm terminals (unless self-baluned with a coaxial type F connector) so there should be a 300 ohm to 75 ohm balun between the antenna & your coax type F connector. Make sure it's a single run of coax from antenna to tuner, with no kinks or tight bends, no splitters or anything in between. Any other coax in the house is then irrelevant. RG-6 coax is very good for this application so don't wory about that one bit. Weatherproof any external connections. On your receiver, connect the coax shield to that right "ground" terminal & the coax center-conductor to that middle "75 ohm" terminal. Ensure that none of the shield's fine wires are shorting to the center conductor (both inside & outside) that would kill the signal completely.
Using a multimeter (resistance scale) with the inside coax disconnected from the receiver you should be able to look into the cable & see that balun up top. It may appear to be 75 ohms (or perhaps considerably less impedance at DC) but there should be some continuity present.
Failing all that, your receiver's 75 ohm tap may not be working? Since you know the 300 ohm tap works with the dipole, try another balun inside & connect it to the 300 ohm inputs. Failing that you may even have a defective antenna? Try connecting it into a TV set tuned to mid-VHF channels 4, 5, 6 etc. to see if any signal at all is coming down the pipe. The FM band falls right in between there so if you have no TV signals then that probably explains the lack of any FM.

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.