Help troubleshooting new base install

[rob_d]

On its own, no. They do have funky radiation patterns, which may mean it's hearing things from down in your home easier than the handheld will.

Moving it around the attic was going to be my next recommendation, but sounds like you already tried that. I'm thinking that the addition of the mount to the bottom half of the discone was probably making it pick up noises from in the house easier, but I could be wrong.

You could try shutting circuit breakers off one by one and see if there is a specific breaker that feeds something that is making the noise. Then just track down what device that is. Might be something you can relocate or replace.

So, sounds like two issues:
Local noise
Lots of coaxial cable adding to loss.

I think I ruled out the long run of coax by doing my testing with a 5 foot section of coax directly connected to the discone.

I think this is an electrical interference issue. Thanks for the suggestion of turning off breakers until the noise stops. That's my next step here.

 

[popnokick]

Something is not right with that discone. It would take a massive noise level to totally block all signals on all bands when your handheld scanner with rubber duck right next to it works just fine. What happens when you connect your 5 foot coax from the handheld and directly to the discone and tune in any of the NOAA Weather channels? If still fully blocked there may be an open or short present right in or near the base of the antenna at the coax connector. From the pics you posted I can’t see the coax connector at the base of the antenna. You also write about taking it off the mounting pole and putting it back on again… with changes in reception resulting. Again, this suggests to me an intermittent open or short right where the antenna connects to the coax.

 

[wtp]

is the discone needed, how does it work without it ?

 

[rob_d]

So here's a fun fact. Did you know that when trimming the coax, the cut specification for the center wire and shield is there for a reason? I was not following this spec and after crimping on the center pin, did not push it far enough into the plug. The center pin in my plugs was not protruding far enough and was not making contact with the female connector. So continuity checked out on my cables because the pin had a good connection to the center wire, but it just wasn't contacting the female center pin on the antenna.

I realized this when looking at some connectors online and watching some videos more closely. So I cut off all the connectors and reconnected them with the correct cut spec. It now works! The 90 feet of LMR-240 is just fine and I'm picking up some good signals.

I want to thank everyone for their suggestions and helping me troubleshoot. I'm glad it was only the connectors that needed to be done over. The antenna is great and working as it should.

Happy scanning!