Today I hooked up a pair of feeders in order to test out an auto reverse loop module. Since the return loop will be located in a hidden section of track, I wanted to test out this section prior to installing the upper level. The loop and relay worked fine. But then something really strange happen. 350 feet down the mainline (code 83), I had placed a sound loco on the track and had forgot all about it. To my surprise, the loco came alive with full sound. Now from all I have read from the so-called DCC experts, a feeder is needed every 9 feet or less in order for the digital signal to be recieved. So as I scratched my head thinking "that's not suppose to happen" the loco is too far down the mainline to recieve a clear signal. So as you can guess, I entered the loco's address, and to my surprise it started to move, and I had complete control (speed, sound, etc) The loco went completly around the layout (400 feet of it) off a single pair of feeders.
So my question is this....
Are feeders really required every 6-9 feet as i've have read? or is this just a MR urban legend? .
Have Fun.... Bob.
It depends, Bob. If your feeders are new, and they have a good purchase on both their ends, and your tracks are firmly in place (no highs, lows, wobbles), then I don't see why sufficient current can't run a long distance. When the question of feeders arises on this forum, I always provide an answer dealing with my own off-layout yard. If is fed at the layout end of a long bridge of about 5', and that bridge connects another shelf full of a mix of unused EZ-Track and flex sections to form four classification tracks connected by a mix of EZ-Track and Atlas...and I think there is one Peco Code 83 in the mix for good measure. In total, from one end, there are about 30' of rails fed. I have yet to have to go over and kick a loco in the pants to get it to start up and move off that shelf, cross the bridge, and join the layout.
The long-timers will say, "Give it time. It'll change." At some point things weaken, corrode, whatever, and you find yourself adding feeders. So far, though, now two years into my off-layout yard, and having removed that bridge a dozen times in order to service the hot wood stove behind which it runs, I still have a perfect record.
So, no, I'm not surprised at all.
-Crandell
Bob
A clear signal is secondary to having good flow of electricity. You just happened to have five amps or more flowing through 28 g wire. Don't put more feeders on and tax the booster and see what catches fire and let us know. The biggest point we can make is to have reliable source to the boosters breaker or some sort of fuse. One day a loco will run a closed switch while you are at the other end and something will cook.
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!
I ran around my whole 8x12 loops with one pair of feeders. But that was built with flex track, and new joiners. A simple 4x8 I set up with some Bachmann EZTrack with FOUR feeders equally spaced had issues with slowing down.
Once you run for a while, and you paint and ballast the track, those joiners aren't going to be so reliable anymore. Put the feeders in.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Things change over the years. My current layout was started in the mid 80's, and was run with a command system called Dynatrol, which had receivers in locos, power buss just like DCC, etc. I wired it to be bullet proof, using 12 gauge for the power buss and drops every few feet. As the railroad grew, I maintained wiring standards to the nth degree. When DCC came along I jumped from Dynatrol to NCE and didn't have to make any changes to the wiring. In the meantime, the railroad grew and expanded and I maintained wiring standards using DCC standards. Note: some of the 80's wiring is still intact and working.
The layout today is three decks, is broken into 4 power districts, each with its own booster, and I verrrrrrrry seldom have to replace or add any wiring. IN short, build it to last to begin with and it will. If you want to take short cuts now, you will pay later.
Bob,
Having feeders every few feet or so (3 feet is recommended) helps the following:
1. The burden of carrying current through the rail via the rail joiner is reduced. Intermittent current flow is bad as the on/off on/off behavior of a bad connection can scramble a decoder's programming or cause erratic locomotive behavior.
2. Without feeders, as you get farther from the source point (booster or circuit breaker), the resistance increases through the rails. For example, at 350 feet out, place a quarter on the track; does it trip the protection circuit, or does it buzz? if it buzzes, then there is too much resistance in the rails to trigger the protection as the total current seen by the booster is reduced. If a locomotive or other mobile decoder device is placed in this situation (running up against a turnout is a common situation) for a long period of time, this can cause damage to the decoder, loco, etc. because all the available current tries to pass through the unit.
We have found at our RR club, some of our members cannot hear the short circuit high frequency buzz. Many men over a certain age loose their high frequency hearing. One member's loco was on a section of track where the quarter test failed (we are rewiring the entire layout now to eliminate this and other issues) and the locomotive was against a turnout. Once someone smelled something burning, it was too late; the plastic cab had melted!
Carl in Florida - - - - - - - - - - We need an HO Amtrak SDP40F and GE U36B oh wait- We GOT THEM!
So in short Yes your trains will run. But you won't have the protection if something goes wrong, and in time it will and the reason won't be apparent. You'll be here swearing against the decoders or the part that fried.
Springfield PA