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TV Interference from a Bachmann Engine

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  • Member since
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  • From: AU
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TV Interference from a Bachmann Engine
Posted by xdford on Monday, September 24, 2007 5:21 PM

Hi all, 

 

I was at a friends place yesterday who has just got into the hobby with a Bachmann N scale McKinley set. He is having problems with TV Interference and so does his neighbour. I tried installing  capacitors on the track, making sure the connections were clean etc and while we reduced it a bit, it was not as it should be.  I also tried to solder a capacitor to the sides of the frame (I'm in HO so not quite used to the Bachmann system in N) but the solder would not flow readily.

Are these locos notorious for this or is there a more readily available means of correcting this?

 

Thanks in Anticipation from Down Under

 

Trevor   www.xdford.digitalzones.com FYI

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Posted by ndbprr on Monday, September 24, 2007 5:28 PM

Last time I heard of this was many years ago and I think the answer was to put the capacitor accross the antenna leads on the TV.  I'd also try putting one accross the power to the track if using a power pack (DC not DCC)

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Posted by NeO6874 on Monday, September 24, 2007 5:28 PM

While it *MIGHT* be the loco, it could also be the power pack he's using.  THe Bachmann ones are OK, but they're not teh best.

 

I'm not too sure about how things are in Australia, but here in the states, everything electronic has an FCC label saying something to the effect of "This shouldn't cause interference, but if something else interferes with its operation - deal with it."

If the TV's are using a common feed for cable TV or the antenna, the interference could be causd by the fact that teh signal isn't strong enough in its own right to give you a clear picture...

-Dan

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Posted by jeffrey-wimberly on Monday, September 24, 2007 6:12 PM
Back when I had to get my TV programs on an antenna, my trains would tear up the TV signal all the time. It wasn't because of a cheap power pack either. I was using a two amp MRC to power Athearn locos. I put a signal booster on the TV. Problem solved. Now I have cable and it's no longer an issue.

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Posted by loathar on Monday, September 24, 2007 6:45 PM
I've got to jump in on this one. (sorry xdford) I get bad interferiance on my stereo when I run my trains. (DC and DCC, AM and FM) What is this capacitor idea you folks have mentioned? What kind of capacitor and how do you do it?
I get a lot of radio static when I turn my computer on too.
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Posted by xdford on Monday, September 24, 2007 6:58 PM

 loathar wrote:
I've got to jump in on this one. (sorry xdford) ...

 

No need to apologise... thats what these places are for and hope you get your answer too!

Cheers from down under!

 

Trevor  www.xdford.digitalzones.com FYI 

 

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Posted by modelmaker51 on Monday, September 24, 2007 9:23 PM

I seem to remember that my European loco from way back had small disc capcitors across the motor leads.

You might try a filtered & surge protected power strip (from a computer store).

Jay 

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Other builds: https://imageshack.com/my/albums 

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Posted by modelmaker51 on Monday, September 24, 2007 9:42 PM

I seem to remember that my European loco from way back had small disc capcitors across the motor leads.

You might try a filtered & surge protected power strip (from a computer store).

Jay 

C-415 Build: https://imageshack.com/a/tShC/1 

Other builds: https://imageshack.com/my/albums 

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Posted by ndbprr on Tuesday, September 25, 2007 5:55 PM
The interference comes from leaking AC onto the rails.  Every time the brush in the motor touchs a new pole of the comutator it acts like a capitance discharge or for lack of a better description a PFFT is generated that travels back the Ac line and can cause havoc with electronics as described.  A large enough capacitor across the DC poles of the power pack should help resolve the problem.
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Posted by tstage on Tuesday, September 25, 2007 6:10 PM

I get a little interference when I turn on my DCC system.  It gets worse when actually running a train.  However, since TV is pretty much worthless anyhow, I consider it an improvement in the programming.

Tom

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Posted by loathar on Tuesday, September 25, 2007 7:57 PM
ndbprr-Are you talking about those ceramic disk capacitors or the larger barrel type?
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Posted by Don Gibson on Tuesday, September 25, 2007 8:52 PM

 (TVI) RF interference comes from arcing -most generally from the DC motor, and can be reduced by a simple small capacitor across the motor brushes.

DCC puts a decoder module between the wheels and the motor, and I do not know how that affects the DCC commands.

SOUNDTRAXX also used to offer a choke as a 'hash' filter.

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Posted by larak on Tuesday, September 25, 2007 9:28 PM

 loathar wrote:
ndbprr-Are you talking about those ceramic disk capacitors or the larger barrel type?

I would suspect that a disk type on the order of 0.01 to 0.1 uF would work. Large electrolytics have too much inductance to properly filter higher frequencys. If you need to go larger perhaps a tantalum mini would work. 

Unfortunately, its going to depend on the wear level of the brushes, the speed of rotation, the current drawn, the number of insects in the tunnels, etc so a bit of experimentation will likely be in order. My 2 cents [2c]

Karl 

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Posted by modelmaker51 on Tuesday, September 25, 2007 9:32 PM

 loathar wrote:
ndbprr-Are you talking about those ceramic disk capacitors or the larger barrel type?

Yes, the former.

Jay 

C-415 Build: https://imageshack.com/a/tShC/1 

Other builds: https://imageshack.com/my/albums 

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Posted by Pathfinder on Tuesday, September 25, 2007 11:06 PM
 xdford wrote:

Hi all,

I was at a friends place yesterday who has just got into the hobby with a Bachmann N scale McKinley set. He is having problems with TV Interference and so does his neighbour. I tried installing  capacitors on the track, making sure the connections were clean etc and while we reduced it a bit, it was not as it should be.  I also tried to solder a capacitor to the sides of the frame (I'm in HO so not quite used to the Bachmann system in N) but the solder would not flow readily.

Are these locos notorious for this or is there a more readily available means of correcting this?

 

Thanks in Anticipation from Down Under

 

Trevor   www.xdford.digitalzones.com FYI

How far away is he neighbour?  I find it strange that an N scale locomotive could cause that level of interference.  Maybe look to something else with a bigger output (unless of course the neighbour is in an adjacent room, like an apartment). 

Keep on Trucking, By Train! Where I Live: BC Hobbies: Model Railroading (HO): CP in the 70's in BC and logging in BC
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Posted by xdford on Wednesday, September 26, 2007 7:56 AM

Hi, To be truthful I don't know where the neighbours TV would be. Looking out the window, there was the standard distance between the wall/eave and fence and the same for the neighbours place so 6 ft wall to wall.

Jim tried a cap on the frame and he reports that it was considerably cut the interference on his TV so hopefully it has helped with the neighbours reception.  Following a friends suggestion he put the capacitor using the headlight  cavity and the headlight to hold it in as we couldn't solder it despite our best efforts!

So if there is anything else to be done,,, and I will check out the power pack next time I'm there, please keep em coming....

 

Regards from Down Under 

Trevor 

 

 

 

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