Hi!
I'm wiring in feeders on the outside main line of my HO 11x15 layout. Buss wires are #14, feeders are #20, and spaced 3 feet apart. Testing is going just fine, but I do have a couple of questions.......
- When a power buss wire is terminated (the far end, not the end going into the circuit breakers), how do you terminate it physically? I figured I would just staple each wire to the benchwork, but wondered if there was a better way.
- Obviously I can tell if a loco responds properly on a given portion of track. But (without buying a specialized DCC meter), can I tell how strong the signal is using the functionality of a typical electrical multimeter? If so, what measurement do I use? If not, what specialized meter do you recommend?
Thanks,
Mobilman44
ENJOY !
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
A small electrical style plastic cross-braced, twin nailed, staple would be fine. Anything, really, that won't pinch the insulation, and that will securely hold the ends apart and up out of the way. That's all you need.
You could even use brass or steel eyelet screws, thread the ends through the eyes and wrap the ends three or four times around the wire to keep them tucked up.
-Crandell
I terminate my buss wires at a terminal strip. I fasten wires to the underside of the layout with staples, but I do not staple the wire. I put in ceiling tile staples with a stand off stapler like you would use on the wire, but I then use a cable strap (some people call them tie wraps or zip ties) to hold the bundle of wires to the staple. That way there is no way it can damage the wire.
I'm not sure why you want to measure the voltage at the far end of your buss, but you can use a cheap multimeter. Because AC meters are calibrated for measuring a sine wave and DCC is a square wave the reading will not be exact, but it will be close enough for what you want to do. Just take an AC reading from rail to rail at the beginning of the buss and another at the far end. They should be pretty much identical.
Dave
Lackawanna Route of the Phoebe Snow
If you are using a Digitrax system than no terminators are required. Digitrax boosters have caps and resistors internally to clean such noise. Any other system may or may not benefit with a terminator. The size of your layout should be fine for noise and interference problems. I would put a wiring connector on the end so I can plug in an extension later.
Here is a good link for you.
http://www.members.optusnet.com.au/nswmn2/DCC.htm#Terminators
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
No need to terminate, other than to physically clean things up.
As far as measurements, static measurements won't mean much. Without a load, the voltage could look good even if the wiring is horrid. The quarter test is all you should need. The standard you are wiring should ensure things work well if they pass the quarter test.
Jeff But it's a dry heat!
I hope no one misinterpreted my post. I terminate my buss wire at a terminal strip (plastic strip with screws), not a terminator. If it needs to go on later I can just start at that terminal strip.
I agree that the quarter test or something similar is all you need.
Hi again!
Thanks all, you have answered my questions. I'll certainly do the quarter test and will tape the ends of the bus wires and then staple to the benchwork.
Phoebe Vet I hope no one misinterpreted my post. I terminate my buss wire at a terminal strip (plastic strip with screws), not a terminator. If it needs to go on later I can just start at that terminal strip. I agree that the quarter test or something similar is all you need.
I too use a terminal strip. You never know when you will find the need to expand.
Engineer Jeff NS Nut Visit my layout at: http://www.thebinks.com/trains/
Quarter test will verify the wiring is solid back to the booster or circuit breaker. That's a quarter WITHOUT pushing down on it - to better simulate a derail car or loco with metal wheels where one is touching each rail in a way to short things out. A loco could put a good bit of pressure against the rails, but even an NMRA weighted car isn't goign t push down that hard - if it shorts and shuts down with just the weight of a quarter, the wiring is solid.
You can't test the signal without an oscilloscope, you can only measure track voltage which, if the bus wiring is heavy enough, should be exactly the same at the furthest point as it is right next to the booster. A scope would show you the waveform of the DCC signal and see if it's still nice and square or if it is distorted, but is really overkill unless you're heavily into electronics - if the quarter test works and the trains run fine and respond to commands, it's fine.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I crimp a straight crimp connector on the end of each wire. Then I pass them through plastic cable clamp. That holds them in place and insulates them. Then if I need to extend them I just crimp in the next piece of wire.
Jack D