I'd like to install a decoder in an older Athearn Pa-1, but I don't have a programmer. If I install the "Bachmann�44913 EZ Command Decoder/Harness", can I program it with just my Bachmann EZ command controller? Here is a link to a place that sells them.
http://www.modeltrainstuff.com/Bachmann_DCC_Decoders_s/2209.htm
Thanks
Hi Buzz
The Bachmann 44913 decoder is fully compatible with the EZ Command controller, so the simplest answer is; if you can correctly install the decoder in your locomotive, your EZ Command will control the decoder within the limits of EZ Command's programming capabilities.
Please refer to the EZ Command FAQ for more information.
http://www.bachmanntrains.com/home-usa/ezcommand.php?ezpage=4
Regards
Thanks for the quick response! I'm new to the hobby, but I am pretty good with a soldering iron and know some electronics basics. The trick with the Athearns is the frame is part of the circuit so you have to isolate the motor from the frame if you install an encoder. Should be an easy install.
One more question about the Bachmann decoder, if I get more involved in the hobby (which is looking likely as it has been a great stress reliever!), and if I buy an NMRA compliant programmer, will I be able to change the CVs on this decoder? At some point I'd like to run my Athearns in consist with my Bachmanns, but I have a feeling that at the same speed step they will be running at different speeds. I'm guessing you shouldn't put trains in consist if they are not matched as far as speed. If I can change the various CVs with a programmer I would be able to get the speeds to match a little better, right?
Thanks!
I don't know if JMRI will work with the Bachmann EZ-Command. If it does, that's probably what you want. Hardwiring an Athearn diesel will take at least an hour. Make sure the motor is isolated. There are some nasty springs. Watch for the suckers. Dissassembly is easier than assembly.
Gene
My Athearns is the older style (pre '89 I think) PA-1. It doesn't have any springs....or wires for that matter. It's a very simple design, so I figured it would be a good candidate for my first decoder install. Yep - I understand that a decoder is supposed to isolate the motor from the power, and since the Athearn PA-1 get's power through the trucks and into the frame, I will have to make sure to isolate it. Thanks for the reply.
Buzzard975
The springs Gene is talking about are the motor brush springs
that are retained by the copper strips on the top and bottom of the motor.
You will need to remove the bottom one and modify it to isolate the motor electrically.
The bottom retainer has two projections that make contact with the frame, they need
to be removed to isolate the motor. Just putting tape under them is not sufficient.
They will in time penetrate the tape, good-by decoder.
The orange and gray motor leads will be connected to these copper strips.
The easy command can program a number from 0 - 9 to any decoder but cannot program "CV's".
Tim Anders
Souderton, PA
Awwww, I see. Ok, that makes sense. Yep - you're exactly right - I see those 2 prongs and the look like they would eat through tape in time. I will Dremel them away.
I know the EZ command can't progam the CVs, what I meant is if I bought a programmer, would it be able to program the Bachmann decoder I mentioned.
Thanks a lot for the help!
BTW, I found that just switching the lower and upper copper strips on the motor works great. that way I get a perfectly smooth one on the bottom what I can easily isolate, and the metal prongs on the top should easy to solder wires to.
Buzzard975
The Digitrax PR-3 will connect to your computer and with JMRI decoderPro
software you can program any CV you want and print out a hard copy
for future reference.
PR-3: http://www.digitrax.com/menu_computercontrol.php
DecoderPro : http://jmri.sourceforge.net/
Have fun
Tim Anders
Souderton, PA
Cool! This stuff looks fun. I'm total computer nerd (IT analyst) and this DCC stuff is a great way to combine my love of trains with my love of 1s and 0s. 8)
Thanks everybody for the info!
The Bachmann 44913 decoder does not have the necessary CVs for speed matching. CV2 (start voltage) is implemented but CV5 (maximum voltage) and CV6 (midpoint voltage) are not. Nor does it support a speed table.
Depending on the age of your Athearn PA-1, the decoder's current rating may be inadequate unless you install a later motor. The PA-1 with a gun metal coloured, oval motor has a stall current approaching 2 amps. The PA-1 with a gold coloured, flat sided motor is probably okay but be sure to check the stall current (as you should with all decoder installations.)
You can view the 1 amp decoder specs by clicking on the link below:
http://www.bachmanntrains.com/home-usa/ez_content/1_Amp_Decoder_Instr.pdf (http://www.bachmanntrains.com/home-usa/ez_content/1_Amp_Decoder_Instr.pdf)
Unfortunately, you cannot program anything except address and normal direction of travel with the E-Z Command. Fortunately, your E-Z Command's range of controls is not limited by its programming capabilities.
JMRI (Java Model Railroad Interface) will NOT work with your E-Z Command but the PR-3 programmer will work with Bachmann and many other brands of decoder in addition to Digitrax. As far as Decoder Pro goes, I am not sure if the definitions for the Bachmann decoders have been written yet.
It has just been pointed out to me that in fact the defintions are available at :
http://jmri.sourceforge.net/xml/XSLT/pages/decoderIndex.html (http://jmri.sourceforge.net/xml/XSLT/pages/decoderIndex.html)
Glad you mentioned the stall amps Jim. Again, being a newbie I assumed they were a bit overbuilt and would handle any loco. Mine is the gold, flat-sided motor, so hopefully 1 amp will be enough. I got one for $17 including shipping, so I won't have a lot at stake, which is good because I don't have a way to measure the stall amperage. I guess if I hold the loco back and hit the throttle, and the decoder starts to sizzle and smoke, it's drawing more than 1 amp. :)
I'm learning as I go, and these posts have been really helpful.
The Bachmann 44913 decoder does not have the necessary CVs for speed matching. CV2 (start voltage) is implemented but CV5 (maximum voltage) and CV6 (midpoint voltage) are not. Nor does it support a speed table.
I received my Digitrax PR3 and I am using it with JMRI Decoder Pro and finding out that there are not many cv's changes you can make with the cheaper Bachmann decoders. More for the Spectrum though, am I doing something wrong or is that the way it is.
The more expensive loco's like Atlas, Athern, Broadway Limited, Proto and Stewart and especially those with sound seem to have many more cv's.
I did install a digitrax decoder in a 70 ton Bachmann Switcher and that seem to have most of the cv's the more expensive loco's have excluding of course those with sound.
Funny I just got into this more out of curiosity about cv adjustments, but I love it. I feel a little disappointed with not being able to do anything more with Bachmann, but after considering the cost of a DCC Bachmann engine for under $50.00, it's still a bargain. Bachmann, because of the price of an operating DCC simple system, started me in DCC.
I would think I could replace some decoders in a few of my Bachmann Loco's with better decoders, some are great runners and I may try sound decoder in a few of them.
buzzard,
some notes from my experience with older (1975-1995) athearns......
first, it is unnecessary to remove the prongs on the bottom motor clip if you switch the clips. use the top motor clip on the bottom and vice versa. then all you will need to do is cover the bottom clip with electrical tape. i had many athearns so i had a spare clip to keep everything together.
about the motor brushes and springs.... the motor brush is shaped to fit around the spinning part of the motor. getting the brush out of this alignment will detract from the performance of the locomotive, so be very careful of the alignment of the brushes. on some athearns, the top of the brush has a little slot in it so that you can align it with a screwdriver. the slot should be in line with the motor shaft.
athearn wheels are sintered metal. as with the rest of the athearn pickup system, it works well on dc bot is finicky on dcc. you may want to replace the wheels with nickel silver ones from nwsl or jaybee. the pickup from the trucks to the motor uses a metal clip from the top of the motor to the tops of the trucks. don't try to modify the clip. solder directly to the contact bars on the top of the trucks. the trucks also use the pivot point on the frame and a hole in the truck bolster for the other side of the circuit. this pivot point is another weak link in the circuit when using dcc. you may want to bypass it by soldering directly to the metal plate in the truck that picks up power off the wheel bearings.
note that athearn's electrical contacts in the trucks are of a metal which is not easy to solder to. before attempting to do this, completely disassemble the trucks and use a couple of alligator clips as heat sinks so that you don't melt the plastic parts of the truck. an alternate method would be to drill and tap those contact plates to accept a small brass screw, and solder your wires directly to the screw.
as far as adjusting cv's goes. if your decoder supports speed tables, you can tweak those to get your locomotives to run together. i did mine by timing the locomotives over a 6 foot (2 lengths of flex track) section with a stop watch, calculating the speed difference as a percentage, then adjusting the speed table of the faster locomotive by that percentage. you always want to match your locomotives to the slowest one that you intend to use in a consist.
the athearn dcc conversion isn't the easiest if you want good reliable performance. but if you have the time and patience, you can make a decent dcc locomotive out of them.
jward, may I add a few comments to your excellent advice to buzzard.
- after soldering the decoder wire to the top clip on the motor, do not reinstall the long bar that went from the front truck to the top of the motor to the rear truck. Seems obvious, but an earlier poster burned up several decoders just this way.
- do not connect the blue wire to the headlight bracket. This is another sure way to burn up a decoder. If you want to reuse the existing headlight, shorten the bronze leaf spring that touches the tip of the bulb so that it is well clear of the contact on the front truck, then solder the white decoder wire to the stub of the bronze spring. Alternately, remove the bronze leaf spring and solder the white decoder wire to the tip of the bulb. The return from the bulb is to the chassis of the locomotive and thence to the wheels. This is called half wave lighting and is not only easy, it will prolong the life of the bulb. Alternately, remove the headlight lens, ream the hole to 3/16" and install a 12 volt, 15 mA T-1.5 lamp in the original headlight hole. No more lit up cab and a very realistic looking headlight.
- If you upgrade the wheels to NWSL, keep the old ones. Sooner or later you will run into a Proto 2000 locomotive with split gears and you will have spares on hand.
Jeff and Jim - thanks for the latest posts. Very informative. I believe I understand everything you're both saying. In one of my earlier posts I mentioned I was just going to switch the contacts on the top and bottom of the motor - so I got that covered. Understood also on that metal strap across the top - it would dump the current straight to the motor which is the decoder's job. I know that decoders need a good consistent current so I was already planning on powering the decoder straight off the trucks. I've already had one truck completely apart (with the plastic removed and everything) so melting them won't be an issue. I figure I might use a dremel to scratch up a small area to better accept the solder. So should I run wires from the left side of both trucks together, then to one of the power inputs on the decoder, and do the same on the right? That way each input will have 2 sources?
Thanks a lot for the tip on the wheels! I've spent hours "googling" this stuff and never saw that mentioned. That's the great thing about these boards - you get answers straight from people who know what they are doing. So both of those companies make replacements for these Athearns with the proper gear and everything?
Jim - good advice on the bulb - I was already thinking about an alternative. I will look much better when stationary and not emitting light out the bottom. Thanks for the specs on the replacement bulb - I wouldn't have had a clue. I know LEDs are popular too, and I think you just have to put a resistor in series with it?
Again, I really appreciate you guys taking the time to help.
on the pickups from the trucks. YES!! most locomotives on the market to-day pick up power off both trucks. dcc is alot more sensitive to disruptions of track power, whatever the cause. the power pickups on both trucks was always a good idea, with dcc it is a must!!! while in theory it is possible to run dcc off one truck, in practice one truck pickup will cause you problems eventually.
as for the replacement wheels, they are just that-wheels. athearn wheels have stub axles that the axle gears press fit on. you reuse the athearn axles and simply replace the wheels. it is very simple, twist off the wheels from the axles, twist the new ones back on. the only tool you need is an nmra guage, something you probably already have, and should get if you don't have one.
please note: some older proto2000 and stewart, and walthers diesels use athearn copycat drives, and athearn parts can be used on these engines.
Yes, an LED is also a good choice for headlight. A 5 mm warm white looks good in these locomotives, and yes, you have to use a resistor. 1000 ohms, 1/4 watt is a good place to start. The resistor can be in series with either LED lead. If you look closely at the rim around the LED, it has a flat side. The lead next to the flat connects to the white (negative) decoder lead. Your LED may also have one lead longer than the other. This lead connects to the decoder blue (positive) lead. The resistor can be connected between one of the LED leads and its decoder wire or it can be cut into the wire closer to the decoder if you prefer. Use shrink tubing to insulate the joints. I often slip a piece of shrink tubing right over the resistor, insulating both ends and protecting the resistor, all at once. If the tubing is clear, so much the better - you can see and read the resistor value. But coloured shrink tubing will work too - enough of the shape of the resistor shows through for you to tell where the resistor is.
Jim, when using the 12v light, do you have or have you noticed any excess heat? I usually do this very option in my Atherns but on a very recent venture, I installed a 12v light in a Kato body switch engine and the area around the light buld got hot and softened to a great degree! I have repaired by cutting it off and gluing on a new one then installed an LED. These were brand new bulbs from Micro Mark and were supposed to work directly off the decoder without any further modifications. Stephen
Oh wow, I had no idea the wheels came off the axles. Ok, I think I have enough info to be dangerous now! :D Thanks to everybody for the informative posts. I've learned a lot from them!
Quote from: Stephen D. Richards on March 09, 2009, 09:15:33 PM
Jim, when using the 12v light, do you have or have you noticed any excess heat?
Using the original Athearn lamp in a half wave circuit (current return to one of the rails instead of the blue wire) means power is applied only on alternate half cycles of the DCC waveform. This is turn means the light is operating at only half power so it does not get overly hot and lasts for a long time.
The 12 volt 25 milliamp bulbs are low power and do not get very warm at 12 volts. If you multiply volts times amps to get watts, they produce only 300 milliwatts or .3 watts of heat. Compare this to a grain-of-wheat bulb operating at 12 volts, 80 mA which is almost a full watt. Surface temperature of a bulb does not depend on wattage alone. It also depends on the surface area that is dissipating the heat. A T-1-3/4 bulb has about 5 times the surface area of a GOW bulb. If the heat dissipation per unit area were constant, the surface of the GOW bulb would be about 15 times hotter than the T-1-3/4 bulb (3 times the power divided by .2 times the area.) Things become a lot more complicated when part of the bulb is touching or embedded in plastic, but it is still easy to see why one bulb can be perfectly safe while another can destroy a locomotive shell or a passenger car body.
For comparison, a white LED typically operates at about 3 volts. If we use a 1000 ohm resistor, and the output of the decoder is 12 volts, the voltage across the resistor is 9 volts (12 - 3) and so the current through it is 9 milliamps (9volts/1000 ohms.) The power dissipated by the LED is 27 milliwatts (3 volts x 9 milliamps) which will cause virtually no temperature rise. The resistor, on the other hand, will dissipate 81 milliwatts (9 volts x 9 milliamps) which is still only about a quarter of what the low power bulb produced. No melted plastic here. But let's suppose someone wants the maximum light out of his LED so he uses a 180 ohm resistor. The voltages across the LED and the resistor stay the same, but now the LED is producing 150 milliwatts (no problem) while the resistor is producing 450 milliwatts (enough to melt lots of plastic.) Suppose to make matters worse the installer chooses to use a 1/4 watt resistor. At half a watt, this little resistor will almost glow in the dark. It will certainly get hot enough to not only melt plastic but also cause it to smoke (not so good.) Some times an owner wants his locomotive headlight to be as bright as possible. The trick then is to spread the resistor heat out, such as using ten 18 ohm 1/4 watt resistors or five 36 ohm 1/2 watt resistors in series. If space is really tight, a pair of 91 ohm 1/4 watt resistors epoxied to the frame can be used. The epoxy helps conduct the heat from the resistors to the frame.
I apologize if this is more than you really wanted to know about light and heat, but I though you might be interested.
Jim, just what I was looking for. Sorry I got you started but thanks for the info. I was having some problems with the different bulbs and I now understand why. I generally use a smaller resister with the LED's and vary them according to how much light output I like looking at with each locomotive. I have used some 1/2 watt but gennerally stick with 1/4 watt. Without really understanding why, they just seemed to work the best. These bulbs were a pretty good deal, I thought, so I bought a bag of them. (40). Now I know why they were such a good deal! lol Thanks again for the explanation. Stephen
Well I got my decoder installed, but I dont have the replacement wheels yet. I ran it to see what happens and it will run most of the way around the track but will occasionally stall out and my controller flashes. I am noticing lots of sparks that appear to be just inside the wheels around the axle. I suppose this is a result of the wheels? I am going to go ahead and order replacements.
On the bright side, Ive discovered how smooth these old Athearns are, even in DC mode. Either way they are nice trains. This is a bit of a tangent, but on these Athearn PA1s, some have metal trucks, some have plastic. Two of mine have metal, one has plastic. Is there any consensus one which is better, or is it just a matter of personal preference? The metal ones are a bit heavier, but I think the ones are quieter. As I look for new ones for my collection I am seeing the same road names in both configurations, and Im trying to decide which I should buy.
Thanks.