View Full Version : Battery Maintainer Noise !

06-05-2013, 11:36 AM
Back before our last trip to Ga. I picked up a "BATTERY MAINTAINER" from Northern Tool (locale store) , the purpose was to keep the battery in my pick-up topped off while we were gone for the month.
I did test the unit for several months before we left and everything was fine , tucked the unit under the hood and hooked up with the curly cord supplied with the unit.
After returning, I decided to make it a simi permanent thing since I rarely drive this truck now that I'm retired , Put the unit in a weather proof box mounted to the house and spliced in an "extension" to bring the power output overhead and down to the truck via a polarized quick connect which work's well.
One early morning , I turned the HF rig on on 160 mtrs and noticed the whole band was NOISED-UP , S-9 + noise all over the place , checked 75 and found a band of noise about 60 Kc. wide , same thing on 40 meters and 20 and 10 was a total wipe out.

Watching this noise on the "FISH FINDER" of the IC-7600 through-out the day on 40 Meters and 17 I noticed that it creaped down band as the day progressed and the temperature outside increased , took the VX-7 and put it on the AIR BAND on AM and went around the house inside looking for the noise (no Joy) out-side had a strong signal on it anywhere in the yard.
My first thought was a loose connection on the 7250 feeder line in front of the house so I took the VX-7 for a ride on the 4 wheeler the further I got from the house , the less noise , back to the house !
After going around un plugging everything I could find that was connected to power and turning off feed's to out buildings I went back to the house it's self , the only thing that was left was the "BATTERY MAINTAINER",,,,,,,,,,"BINGO" !

This thing had worked fine all winter with no noise , BUT about this time I remembered that my Son Jeff and I had tried one of these on the motor home in Ga. a year of so ago and taken it out due to the thing trashing up the two meter radio in the MH (never thought to check the HF ) this was also during warm weather .

Now , before I totally trash this thing I will try some better filtering on the output side , chokes , capacitors and beads !
Plan "B" will to build my own little maintainer from a known good clean supply and a automotive lamp to monitor the state of charging.

Just thought YA'LL might find this interesting and maybe save someone else the trouble of chasing around trying to find the noise (these thing's seem to be temperature sensitive) .

73, John

06-05-2013, 12:08 PM
Almost any nice quiet regulated 13.8v supply will work well as a maintainer, or float charger. It's not a very good charger (very slow), but it will keep a charged battery charged. I have used large and small Lambda, Icom, and Kenwood power supplies that way. Quiet as a mouse.

06-05-2013, 08:06 PM
I picked up one 700' away! I knew it had to be some thing in my house/garage because the closest house I can see is 3 miles away. I had another one that was made to power a cheap 12 volt fridge that drove me nuts because I did not know it was plugged in I kept turning off breakers it would go away and then come back after I thought I had nailed the circuit.

06-06-2013, 07:34 AM
Install it on the truck, instead of the house, and only plug it in when you are NOT HOME.

Mine is "installed" under the passanger seat in the motor home.. (Not plugged in or hooked to a battery at all since I don';t have a car)

I'll install it on the car when I get one.

06-06-2013, 12:10 PM
Dug around the junk box and found my coffee can of troids that I had "extracted" from defunked puter power supply's , pulled one that had 2 runs of what look like # 18 solid wrapped through the do-nut about 10 turns worth (glad I didn't have to do that).
4 butt splices ,8 squeeze's, and about 20 minutes later ALL is so far quiet on ALL BAND'S , everything is tucked back into the weather proof box and buttoned up again .

NOW WE WAIT AND SEE if it stay's that way !

06-06-2013, 07:25 PM
I "fixed" mine too I scraped it and use another one I had it was quiet. Power lines make pretty good antennas!

06-07-2013, 07:17 AM
I "fixed" mine too I scraped it and use another one I had it was quiet. Power lines make pretty good antennas!

Living out here in the "Sticks" where it's a 50 mile drive to the nearest real town where there are a lot of part's houses to choose from, one learns to improvise or "do what you can with what you got".
The existing maintainer worked, was just not quite right (a lot like "Cousin Eddy") , soooooo , dink with it till it doe's what I want it to do, or go to plan "B" !