Inverters such as zantrex prosine or prowatt make nice clean power. If you are close to the inverter like 15 feet you will pick up a buzz.The cheap ones just another source of noise thur the line and over the air like 100 feet away.David
Hey, J. Have you tried to loop a jumper wire from the antenna lead and grounding it directly back to the chassis? The apartment building I live in is the worst in the world for rf interference, and the old 38-1 was picking up every last electrical noise in the entire building, including the thermostats on the electric stove, the refrigerator door light and compressor coming on would make a loud crack over the speaker. The person down the hall opening their metal door, creating a static spark, would "make her snap" audibly over the speaker. Interference was almost unbearable (over ALL radios in the house). I'm running a maybe 25' antenna wire on the 38-1, loop it over the backs of the chairs, bringing the end back and grounding directly to the chassis. THAT eliminated about 99% of all nasty noise (although sensitivity suffers a slight amount on the upper end of the dial, I disconnect it from the chassis then, as the interference seems to diminish to nill in the daytime. If I move the wire even a few inches in any direction, I can lose the signal completely, or bring in some awful noise. When that antenna is set to the right position, the signal is as strong as can be, with almost zero noise. So, yeah. I would re-visit your antenna set up, perhaps moving it to orient at a different angle. I would also check your GROUND connection, if you have one... Drive a 10' copper pole in the ground and connect her up, if ya gotta!!!
I have been getting a solid 120 hz buzz or hum on all AM radios around here when listening to 1120 kHz, our local 50 kw blow torch. I have been suspecting the compact fluorescents for years, and have been replacing them with the new LED lamps. But even those are causing noise. This evening, while experimenting, I find that some LEDs are worse than others. The cheap “no name” brands are much worse than the more expensive GE brand. But the GEs are still noisy. I am sure this is not surprising to many of you.
On radios that I use regularly, I have been using these small tunable loops, sold by Grundig and others. They have been very effective at nulling out much of the noise when rotated properly.
As far as wall warts and some other electronic devices go, I wonder how well some of them meet the FCC requirements that regulate against interference to other devices?
ok,,right now 11:28est i have had my radio powered on for a few hours but volume down
I go out to the garage and turn up the volume and noise noise noise.
it is very sunny today and i will observe but i am betting that this noise will stay with me through most of the day until the sun starts dropping.
this is an AA5 radio, exterior chassis is isolated from interior chassis.
i have not tried to do the ground jumper from the antenna yet.
I am running a random wire with the largest lenght being horizontal for about 80'.
I dont have the beverage antenna connected up, just a random wire.
this has to have something to do with the angle of the sun in relation to my antenna design.
since a long horizontal run of my antenna passes over my house approx 12' avg height or more, i have to wonder if the metal roof has something to do with this issue combined with the suns angle with respect to my roof angle/pitch.
see pic
(This post was last modified: 04-20-2018, 11:52 AM by jcassity.)
Yeah, kinda tough to re-orient that wire. Maybe the metal roof IS causing interference, but seems unlikely. If the signal just isn't there in that location (due to the terrain- a good hill or mountain will kill a signal) , you need to move the wire to "catch" that signal. (I grew up in the mountains myself. Sometimes you just can't get a good signal unless you get creative with the antenna). Is there a ground connection on that AA5? (Never fooled with any of those) If so, you may want to drive a ground rod. The solar anomalies probably have some affect overall, but would be pretty much regional, and it seems like others in that swath would be complaining too. I would DEFINITELY play with that beverage antenna, as that might just be your "ace in the hole". I am so intrigued with that, I told my buddy who also lives in the mountains to look at the info about it- he is thinking about trying that . It may be a fun and informative and project! Good Luck!
Interesting (but annoying) problem. When the noise changes during the day, how rapid is the change? Does it fade out over 1/2 hour, change pitch or tone, or drop out suddenly?
One last thing I should reiterate: There is ALWAYS noise on the 38-1 (and on ALL of the other radios here in the apartment. Perhaps this is the type of noise of which you speak?) UNTIL I brought the end of the antenna wire back around on the 38-1 and grounded it to chassis. This eliminates 99% of all noise, and the signal is solid. I can adjust the ant. as normal. When I disconnect the wire, The background noise gets pretty strong. (I would have to open the cases of the modern radios to do that grounding trick-NOT happening). The noise is very prevalent from about 550-1100 khz, then tapers off the further up in frequency you go. At that point, the ant. can be disconnect from the chassis, enhancing sensitivity, but the noise is still there, though diminished considerably. Sometimes the noise is altogether gone around 1100-1400 during the day. Should be able to devise something to compensate for the noise. Like I said before... Ya gotta get creative. Employ the Beverage, if need be!!!
(04-20-2018, 02:18 PM)EdHolland Wrote: Interesting (but annoying) problem. When the noise changes during the day, how rapid is the change? Does it fade out over 1/2 hour, change pitch or tone, or drop out suddenly?
That might provide another clue.
Ed
i think i know where you are going, thought about that also
update,,, the noise slowly faded out at around 8pm, then around 8:30 hardly any noise then just now leaving the garage (doing an 87 cougar resto), the noise was barely noticeable.
never had this issue during the winter,,, i think i noticed it last summer but was very new to tube radio tech and resto then. this is only my second summer running tube radios. my 46-1226 & my AA5 S38-d hallicrafters both do the same thing.
I can easily move the antenna, thinking of not using the pole on my chimney, just omitt that and continue the wire up into the tall maple with a weight, its another 30ft higher.
the reasons i think its sun related is that my upper story dormer roof line is darn 'near' optiimal for my location at 17deg for solar panels.
(This post was last modified: 04-20-2018, 09:29 PM by jcassity.)
got side tracked but i will try that tomorrow, will make time for it
for some reason i think i recall a somewhat annoying period of time last year when this same thing happened, tried a ground rod set and had it at about 35ohms, grounded the radio and no fix.
on my aa5, there is antenna terminals 1,2,3. i think 1 is the random wire, then there is a jumper bar bonding 2 and 3 togther.
inside the radio i think 3 is physcially soldered to the chassis, thus this means i have by default a jumper already done.
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