So, I have an Atlas S2 with a somewhat older S6070 sound decoder which I installed. I would like to add a Keep Alive (or similar) component to it but have no idea (even after some fairly extensive searching) as to what model number to go with. Several model numbers come up as recommended so am I to assume it is mainly a function of size to determine which will work best? Anyone who’s had experience with doing this and could give some advice would be greatly appreciated.
Or, should I just get a completely new decoder with the Keep Alive upgrade built in?
Thanks,
Dan
So doing some searching, it appears MRC puts a sticker on a lot of their decoders that says S6070. Doesn;t tell you anythign about which decoder it is, that sticker probably means soemthign else. So what you have is some MRC decoder. You can generally add keep alive to anything, the positive side goes to the blue function common, it's the negative side that is hard to find. The track wires will go directly to either 4 diodes or a bridge rectifier - this is where you pick up the negative side for the keep alive.
Other decoders have both better motor drive and better sound, so swapping entirely isn't a bad idea. Bt do you really NEED a keep alive? Short of the fancier, more expensive 3 wire types from ESU and Lenz, which need one of their decoders to support it, I feel the "run until they are out of power" basic 2 wire ones run far too long.
--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 agree with Randy. Clean track, more feeders and powered frogs may take away the need for a keep-alive. You should probably not need a keep-alive on a 4 axle engine under normal circumstances.
I powered my frogs to help with a couple of trolleys, and discovered that a lot of other engines ran better, too.
It takes an iron man to play with a toy iron horse.
Thanks for the replies guys!
Okay, looking through my paperwork, turns out the decoder is an MRC Brilliance Atlas S2/4 Sound Decoder, installed back in 09. Can’t seem to find it listed any longer. The nearest to it now seems to be their MRC platinum Series HO Sound Decoder for Atlas S2/S4 (16 bit).
The current board does not have any blue wire positive feed. There are two feeder wires from the board (marked pickup) going to the front wheels and two more (also marked pickup) going from another place on the board to the rear wheels. All four are black. There is also a red wire attached to a capacitor, and a black wire attached to another (smaller) capacitor which are then each attached to the speaker.
Tracks are kept pretty clean and they are feeder wires up the wazoo. Powered frogs are non-existent.
it's easy to find the common positive, just tie in to the blue ... it's harder to find the negative that will work, often it's on the diodes that rectify the incoming AC ...
in some cases it's just easier to replace the decoder, not only with something newer, but already incorporating the two keep alive wires properly ..
i done this on both DC and DCC systems ..
The bigger capacitor may already be a keep alive of sorts, but possibly only for the sounds. The smaller on on the speaker is a filter.
With no blue wire, there still should be the common side of the lights - that's the blue wire, even if it's just a solder pad on the board. One side of each light should connect together on the board, the other side will lead to a distinct component, or at least two different pins of the same component, those are the actual function 'wires', the one that is common betwwn the two is the common, or what would be blue on a wired decoder.
Where does the engine in question stall? Is there a region of track that causes the problem? How long since you cleaned the wheels and checked the pick up wiring inside the engine?
It seems to be an intermittent issue. Wheels get cleaned as needed. Has been awhile since pick up wires were checked. Good tip.
So, there seems to be a bit of reluctance for anyone to say that the “Keep Alive“ components are a good idea. May I ask what it is about them that seems to be an issue, other than cost and the possible hassle of installation?
I would post a pic of my loco with decoder installed assuming that might help someone determine the positive and negative access points, but I can’t seem to figure out how to post a pic. I’m not really a dummy when it comes to navigating forums, in fact, I‘m a moderator on a different one. But posting an attachment is a piece of cake there - on this site I have not been able to work out the process. Any info would be helpful and appreciated.
reasearchhound So, there seems to be a bit of reluctance for anyone to say that the “Keep Alive“ components are a good idea. May I ask what it is about them that seems to be an issue, other than cost and the possible hassle of installation?
Space may be an issue in an S2.
I only have one loco with a keep alive, it came that way from the factory. It runs so long off the track that is could easily run 5 feet right off the edge of the benchwork. The fancier ones on Loksound decoders, you can set a CV that limits how long the keep alive works, even if the capacitor still has charge. The cheaper 2 wire ones go until the cap is discharged.
Posting a picture here is easy, you just have to have it hosted on a web site that allows sharing. There is no uploading or local storage here. Most people use Photobucket or a similar service, I have a personal web site anyway so I just put my pictures there and link them.
rrinkerSpace may be an issue in an S2.
I was going to mention the same thing about the space required. Even "supercaps" which are smaller, TCS just introduced a recent line of smaller sized stay alives, you may need to remove weight in order to fit anything into a switcher. Then, with less weight on the wheels, you can't pull as much and conductivity is reduced between the rail and wheel.
Member Tom Stage here tucked a capacitor into the cab of his Stewart VO-660 switcher but it does occupy quite a bit of room.
There is lots of information here:
https://sites.google.com/site/markgurries/home/decoders/keep-alive-compatibility
Although MRC decoders aren't specifically mentioned there is some good background info on keep alive wiring.
Good luck, Ed
I only use keep alives in my two axle critters. Nothing else seems to need them as long as the track and wheels are clean.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Thanks for the replies everyone. Will take the time to go back and double clean everything. I also have the CMX cleaner which helps a lot.
For now will hold off on any plans to order and add anything to my S2 until I try to eliminate the gremlins in a more traditional manner.
Still, anyone wanting to weigh in with further info will be more than welcome.
Hi Dan,
If you are having constant stalling problems, remember to check for things like power pick up on all wheels. Having a broken wire or dirty contacts will definitely affect performance. I would take the locomotive apart so that you can clean all the contact surfaces and relubricate them, and I would trace each wire to make sure that they are still attached properly at both ends.
Also, look for unusual things. For example, a fellow club member was having constant problems with a brand new Bowser SD40. It would stall at most of the turnouts on our portable layout where the frogs are not powered. We discovered that a wire from one of the trucks had broken off, so we fixed it. The locomotive ran fine for a little while and then started stalling again. The same wire had broken off again. We soldered it back on and it broke again two or three more times. Finally it dawned on us that the wire was too short. Every time the locomotive was being lifted off the track the wire was being pulled tight.
Another place to check is where the wires attach to the decoder - a lot of times they will simply be held on by little plastic caps, not actually soldered to the holes in the decoder.
If a loco stalls on notoriously 'bad' places on turnouts, that can usually be fixed by tuning the turnout and making sure there is good feed to all parts. If the loco stalls and the headlight flickers on otherwise plain straight (or curved) track, there very likely is a pickup or power issue in the loco itself, especially if it's the only one that does it. A keep alive only masks the symptoms, it doesn't fix anything.
When I looked to add keep-alive to my engines I just checked the cost. Adding keep-alive to 20 engines would get very expensive. Instead, I fixed my track. I replaced some switches, soldered a few rail joiners, and added a couple of feeders. Then I cleaned all the track and put graphite on the rails. I used CRC QD Electronic cleaner to clean the wheels and pickups of my engines. Now every engine runs great. I can leave my layout unused for months and everything runs fine when I get back to it.
If you are adventurous, here is how to find the positive and negative on a decoder. It's dated.\
By the way, there is no ground on a decoder as a few will mention. They realty mean minus.
http://www.members.optusnet.com.au/mainnorth/alive.htm
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Dated, but accurate, the basic circuit design of a decoder hasn;t changed much if at all from even the earliest days. The details of what microcontroller it uses, and what features are implemented in the code thereof may have changed over the years, but that has no bearing on where the two points that a keep alive needs to connect to are. There really are only two basic circuits, some use a single component bridge rectifier, and others use 4 individual diodes wired as a bridge rectifier. The information on the linked web side will help you know what to look for, even if the specific decoder in question is not listed. Trickiest part will be soldering on the wire for the negative side for most decoders, since all lights have to connect to the positive side, if there's not a blue wire, it will be a relatively large terminal to solder to.