AM Radio Hum (on some stations and not others)

I'd call it an intermittent hum that is not always present - and it shows day and night. With a weaker radio/antenna I'll get static and fade - but there's some sort of weird sound (I'll call it hum) that comes with it that fades in and out over-riding the signal.

It's not something from a light fader, or computer/TV interference. I try to keep this stuff shut off when listening.

It's not "low frequency" either. Almost like a feedback type sound, more ringing I'd guess I'd call it. And it also shows itself on 780 and 890.

Another caveat - I'm not there right now, cabin's closed for winter.
 
Adding on - I sometimes get these stations pretty clear. This issue isn't always present. I can have a strong night signal that this "sound" fades in and out for say 2-3 minutes at a time. I'll change from 670 during a Cubs game to 780 and 890 and it's also there - but not say on 1120 or 1100 etc.
 
Interesting. I think this is the same phenomena I'm experiencing. Interesting that it is just the Chicago stations for you and also you are father away and are still experiencing it (at times). So 1120 is KMOX and 1100 is WTAM, you never get hum on those stations at night when they are strong?
 
Nope. Not at all. Those are two of the best clear channels I get up there. While I can pick up 1540 and 1040 during the day, because the bluff is literally right behind my cabin, then never come in as well as 1100 and 1120 do at night.

The whole reason I bought the CC Radio antenna was 670 and 1120 at my cabin (don't really need it in CR) - I'm a Cardinals fan. I could get them prior, just not as well as I wanted. That way I can get all night games from KMOX, and Cubs games on the side. Those MLB blowtorches is what I usually search for, and fall college football games too. Cincinnati 1530 is an ESPN affiliate which also comes in handy. I can stream MLB audio, but given the river valley, I tend to get frequent drops.

The Chicago issues after the new antenna to this day perplexes me considering their proximity. I get them always, I just never get them as well. I do notice, I get the gong effect quite a bit, and it usually is between 540 and 800 - but these issues with the Chicago's aren't this.

I wish I was there so I could describe it more accurately - I'll try to remember this thread when I open the cabin back up in late March.

The sun is down now obviously, let's see what I get right now.

I have my Sony STR-6055 on right now here in CR (this receiver orients east/west), it's about 5 feet behind me, only using the stock bar antenna. WTAM loud and clear, WHAS is coming in pretty goodWJR 760 Detroit loud and clear. 850 KOA Denver coming in. WRVA 1140 in Richmond VA coming is a bit. 1180 WHAM Rochester NY (!) is weak but coming in. 1530 in Cincinnati, pretty strong.

670, 780 and 890...iffy but I can make them out (no hum like at the cabin). Ridiculous. WTAM sounds as good as WMT 600, which is 5 miles away. The 3 Chicago's...meh. Rochester NY is coming in as well as those 3!

Now, let's look north/south with my STR-6050 (a year older, very similar), closer to my PC/monitor (adding a high pitch whine to everything). WSM 650 Nashville, excellent (cool country song on too, Cumberland Gap by David Rawlings apparently). WWL 870 New Orleans is coming in fine (Georgia/LSU MBB). KMOX loud and clear. I appear to be getting WSB 750 Atlanta fairly well (also Georgia/LSU lol). WOAI 1200 San Antonio, pretty good.

I admit, this AM tuner is not nearly as sensitive, but it also might be too close to the PC. But hey, New Orleans and San Antonio ain't bad.


I've used both of these at my cabin, so I know the tuners ain't the issue. The KT-615 usually is even better.
 
I have a similar AM radio hum issue that is fairly wideband affecting most of the dial but worse on the lower end. It affects both a handheld battery powered portable as well as my component tuner. Turned out to be a rheostat in the kitchen. As long as the light was off - no noise. Any power level from low to high causes noise. My listening room is above the garage at least 30 ft away from it.
 
Dlrhawks, I completely love your AM nerdieness. :) I'm sure the Chicago stations don't have cheap equipment or a loose ground. On the other hand, it's interesting in certain situations only THOSE stations hum at least for you and me (at times). I've been listening to AM radio since the 70s and I don't remember this ever being an issue until the last several years (not exactly sure when). I've been resurrecting my interest in radio lately with restoring tube equipment and this hum thing has been nagging at me. A problem on solid state stuff too but tube more so. I'm not an engineer so I'm at a loss as to what the deal with this is.

Depending on the situation, I use either the internal antenna or an external antenna. Of the external variety, I have a "Select-a-tenna" and a McKay Dymek DA-5. If you have a radio with a ferrite core internal antenna or external loop antenna, you might want to try the Select-a-tenna (as it won't work with a long wire or direct connection to radio). You can pick one up on eBay for $35, take or give. When I was in high school in the early 80s on a camping trip with family I used it in northern Mississippi to pick up Larry Lujack on WLS during the morning. The catch was I strung 140 feet of wire between trees near the campsite and attached it to the Select-a-antenna and then I got the signal (barely but audible). The point is I think if you experiment enough, you'll get decent signal strength (hum problem being another issue).

To Dinger, I think your issue is garden variety electrical interference because you say it is wideband affecting most of the dial. I get that too when I have certain things on like dimmers, etc. But my hum problem is not that. The band is quiet and weak(er) stations are clean. It's the big Chicago stations that hum (depending) and I'm in the Chicago area. You'd think with all that power and my proximity they'd be immune to that. In fact, they are immune to dimmers when everything else would not be.
 
Oh yeah, definitely an AM radio nerd. FM too actually. More during the summer months though. Even Sirius/XM is near impossible because of that bluff's trees. And it didn't seem economically feasible to have DSL at $80/month when I was there at most 8 days a month.

I remember when my father passed in 2014, my brother (executor) told me to come over cause before we were going to start getting the estate sale set up, us 3 kids needed to walk through and pick out what we wanted. The first two things I grabbed and rushed to my vehicle before anybody could argue were the Grundig and the Trans-Oceanic.

I had been using my Sony early 2000's receiver for radio reception up there, which was nearly useless for AM - it really only picked up WMT 600 with the stock loop antenna that came with it. One day around 2010, I was throwing away some stuff and found an old clock radio from the 70's with AM only I forgot I had.

Plugged it in, picked up KMOX perfectly clear at night, and WGN pretty good during the day and great at night. An el cheapo 40 year old clock radio half the size of a shoe box, better AM than a $1000 modern receiver. So, my dad's radios were my sweet spot in the estate. Growing up, a typical Saturday up there when we weren't on the river was listening to the Cubs in the afternoon and Cards once the sun went down - on that Trans-Oceanic. That was my childhood at the cabin. So, I knew good reception was possible. The Grundig was icing on the cake - very good AM reception for a digital tuner.

So, in 2017 I thought about the select-a-tenna, but with my experiences with the loops I tried not working well, and the fact the twin coil ferrite has that tunable gizmo to cherry pick like the select-a-tenna as well as long cord connections - the "brick" to me seemed to be a better choice.

I'm curious how well it'd work here in CR. If I can get Rochester NY with a simple stock bar antenna, I'm curious what else I could receive here.

Shoulda brought it home with me when I closed the cabin down ;)
 
I think the god "ionosphere" determines most of the booty one gets at night on AM radio. In the 80s during the fall I used to get 640 KFI from LA in Chicago. Haven't been able to do that since. There can be great variability in sensitivity between radios. I envy the cabin on the river. I've crisscrossed over the Mississippi in that area, en route usually to places west, and the cliffs and forests are really stunning at and near the river. That cabin is in a quiet place AM wise and if you get the right set up, you will have tons o' fun listening for the obscure in a place like that plus some of the big city fare nearby.

As far as the Select-a-tenna goes, you know it's a tool in one's radio toolbox. It's not going to be appropriate for every listening situation or radio. However on a weak station received by a ferrite or loop antenna with relatively low noise, it will make a huge difference. And it's relatively cheap. :)
 
Also have same issue, mainly on the strongest stations during daytime. Not an individual radio issue, happens on the tube transoceanics, HD radio, portables, you name it. Btw, my sirius-xm docking station wall wart raises an ungodly amount of noise on any am radio in the house, worse on lower half of band. I shut off main power to the house, portables still picked up the hum, sounds like line freq. Maybe originating at the transmitters-?
 
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