Scanners and Shortwave and superimposed hum.
 

I've recently moved, escaped crime, but put myself in radio reception heII.

1. My selection of scanners to use dropped dramatically. Using an outdoor antenna similar to the AntennaCraft ST2 my BCT7 reception was destroyed by intermod. And though my BC785D in combination with the AntennaCraft ST2 was the solution to intermod at my old location (relocated antenna from front of home to rear, and intermod disappeared) alas, after being reassured it was working right, periodic pager Intermod was noticeable. Finding the offending frequencies, I prepared to build a Coax Stub Filter.

Link: Coaxial Stub Notch Filter Designer

Lo and behold, looking for the coax to do this with, I found one I built in the past for the BC785D and using a T connector, mounted that, it seems to work fine now.

But the BC785D was moved upstairs to replace the BCT7, so I needed a living room radio. With the BCT7 and several other radios, I'm stuck with poor reception and occasional intermod of the radio's telescoping antenna or great reception and endless intermod off the outdoor antenna.

So I bought a Whistler WS1065 and Discone Outdoor Antenna, it works with no problems. But I have several radios I'd like to use and can't because of the intermod. Ugh!

2. My Shortwave radios, they're afflicted with what appears to be a 60 cycle hum impressed into the signal, and usually only the signals I want to listen to. One is a radio in the living room with a wire antenna partially around the ceiling. This is a 2 story frame home with vinyl siding. The other a PAR End Fed wire antenna mounted outdoors. The radios are Yaesu FRG-100, ICOM R-75, Palstar R30, and Yaesu FT-840 HF Transceiver. This hum permeates the house, so that the indoor antenna and outdoor antenna are similarly effected, but with the outdoor antenna, the hum is usually less objectionable because the signal is stronger. And the hum is noticed in all 4 radios.

Using a small analog radio, I noticed a strong hum in areas of the living room, and truth be told, when I shut off the power to the living room, the hum on the portable went away. I've even disconnected the wiring to the doorbell transformer completely and no change. Tried unplugging things in the living room but couldn't find a culprit. It's frustrating, many shows on other frequencies I'm not interested in come in clearly. This hum seems to be mixing with certain frequencies, it's maddening. I could see if it was across the dial, but it's not. I could see if it's on the inside antenna, or outside antenna, located on diametrically opposed areas of the house on different floors, but it's on both, and both are on different branch circuits.

I'm considering the MFJ-1026 Deluxe, Noise Cancel/Ehancer/Antenna,

Link: MFJ Enterprises Inc.

but it's a little pricey and I'm not sure it'll work.

Any ideas on this signal hum?