Posts: 63
Threads: 29
Joined: Feb 2010
City: Richland, Michigan
I have a Philco Model 65 that I restored a couple of years ago. I'm recently noting that it receives better when I have a 60 watt light turned on the same house circuit.
Wondering if having the 60 watt bulb on changes some capacitance somewhere. Having a space heater plugged in does the same thing. Wondering what is happening.
Aside from this, reception has been great at times receiving KOA, Denver in Kalamazoo, MI in very cold conditions.
Posts: 15,306
Threads: 532
Joined: Oct 2011
City: Jackson, NJ
I have the same problem with my radios that I moved to the family room.
All of them have noticeable AC hum when receiving, but once I turned the lobby light on (8 pcs CCFL 7Watts bulbs) he hum goes down so much it is barely noticeable anymore.
What I suspect is that unloaded line that goes by the radios picks up noise whereas loaded (becomes low impedance) doesn't. How exactly the noise is produced, I do not know, but the effect is pronounced.
Possibly repositioning radios/antenna could help.
(This post was last modified: 12-26-2013, 05:39 PM by
morzh.)
Posts: 63
Threads: 29
Joined: Feb 2010
City: Richland, Michigan
This Model 65 is grounded to a dedicated earth ground separate from any ground in the house. Each side of the power line has two y caps from line to chassis. It also has an x cap across the supply line for noise suppression. I think I got that idea from Just Radios in their safety caps section. Thanks for your ideas. A better antenna would definitely help.
Posts: 15,306
Threads: 532
Joined: Oct 2011
City: Jackson, NJ
The line filter (X+Y caps) onlyh helps with what comes via the outlet itself and the parameters of the filter do not reaaly attenuate any audio frequency much, they are for radio frequencies or hi-frequency switching noise etc.
Also simple 60Hz hum has no way of getting through antenna. I think it gets in when a field created by 60Hz source (whatever it may be) is strong enough and oriented in a certyain way towards the audio circuits or detectors. Let's put it this way - if touching a grid of a tube results in hum, this is the suceptible circuit. So maybe just reorienting the radio or moving it away could help.
Posts: 2,128
Threads: 18
Joined: Oct 2008
City: Merrick, Long Island, NY
For those of us who have 220 (now 240) volt service, especially older homes, each 110 or 120 volt "leg" can behave quite differently, especially if, like in my area, the local transmission likes are still aluminum, and the joint to the house downlead which is almost always copper becomes leaky after decades. Thus by putting a little more load on that "leg" the connection heals a bit, light bulbs don't care, and you're good to go with the radio. Most utilities will come, measure, inspect, and fix outside connections upon request without charge. Once inside the house, it's not their problem. Well, been there, done that. Who knew?
