I pre-tinned the six pads and tinned each wire end. Bring the end in at an angle and the 12 watt soldering gun on top of the wire. The solder takes a second or two to melt. Hold the wire (tweezers) in the solder and lift the soldering gun tip. Let the solder solidify and release. Check solder job with magnifier (no shorts). Move to next wire. I actually put the chip under the long light leads with the PCB installed on the frame. If I had had some tape, I would of taped the chip to the frame. Then I ran each wire over to the correct pad and cut it just past the pad. I used my fingernails to pinch off just the end of the plastic. Oh yes. Start with the pad closest to the chip first and do the three wires. The soldering gun tip is less likely to accidentally melt the insulation off of the next wire. Then turn the entire frame 180 degrees and do the other side. I turned the printout upside down to keep the wire colors matching. The blue wire is not used and is just cut short. Print out the GP7 instructions and do it exactly the same. And the pad problem on the GP7 is not there on the SD70i PCB, so ignore that part.
David; My wife and i were just down in San Diego last week, and left early due to the bad weather both there, and here at home in Utah. Sounds like you were setup at the GTE show in Del Mar, which i planned on visiting on sunday. Sucks.... Anyway, way to go with the new decoder, i have a few on order as well, and look forward to getting them in my SD locos soon. Tony B... Wasatch Z Club
Make sure that you solder all the wires ONLY on the top of the AZL board, not through the holes (unless you are a 'professional'). The reason is: you could short if the wire is too long as it goes thru the hole and you don't need a military secure connection. Just do the easy job. Thanks Dave for the added pictures. I only mention this as John Forsythe (TCS) and I discussed this to make sure he doesn't have a lot of techincal support issues with shorts. Oh, and the color sequence is easy to remember: the black grey and white on one side, red orange and yellow on the other !! (notice the shading ?) Thought you would like that. Thanks Rob for updating the site. This was mentioned before in Z track but the loco package instructions have not been updated for more than a year since it was noticed. Jeff SF Bay Area Z .
My Z2 decoders from Norm's arrived in the mail yesterday. For those of you who have already installed them, how do they work? Any problems with BEMF? John
I only ran the engine for less than five minutes. What are bad Back EMF symptoms like? I ran the engine by itself on a level layout.
I just got mine a few minutes ago. Here is the comparison photo, with the smallest known DCC decoders to date: Most are 2 function decoders except as noted.
Robert, I got mine today also. Now I have decoders for my SD70s. David, BEMF causes the motors to overheat.
Robert, The Z2 is certainly the ticket for installation in SD70/75s. I have a CT 75 installed in a SD75 and fiddled with the lights - Mars light, blinking, etc. Fun stuff. That will come in handy for older units, such as E units. John
John, BEMF doesn't necessarily make a motor hotter. Yes, it is supposed to compensate for loading so if there is a grade or heavy load on the loco, it will effectively increase the "speed steps" by increasing the duty cycle. But if your locos run properly at the full 28 speed steps then that would be the absolute worst that the BEMF could even put into the motor. But the function doesn't allow it go that far. It only has a reasonable range above the target speed step. If the loco runs properly at any speed and load, BEMF should not cause heating. The PWM frequency e.g. 30, 60, 120 Hz or the more typical 12, 15 or 19KHz cause more heating issues with some types of motors. Did you have an experience you can relate ? Dave, BEMF can some times cause lurching and certain speeds as it trys to over compensate for some random friction, binding, etc. The theory is that the lower current Z scale motors do not produce enough feedback to make it work properly, compared to higher current N or HO. But each manufacturer has it's own electronic design and software. It is however not recommended in consists as each loco then has to counteract or interact with the other(s). Run your single loco under all conditions. Watch it closely say when it goes into a turn where it will get more friction and naturally slow down or, as it transistions onto a grade where it will need more power to maintain the same speed (what BEMF is supposed to do). Same coming out of a turn or out of a grade. Also, observe runnning at the slowest speed steps. It should make it start easier. Sorta like kick starting it but once it begins to move, reducing the effect as little as needed. Compare running just a loco and with a string of cars. You may also hear, feel or see the effect by lightly placing your finger on the running loco. Leave it on (default) or you can toggle it off / on with F6 on your Cab. Program: CV61 from 1 to 4 (1 for BEMF [default] + 3 for F6 control). If you find that it does not work with your loco, you are scared or just have that preference, you can turn it off all the time by programming CV61 to 0. You must also change: CV56 from 3 to 0 CV57 from 10 to 0 to keep the PWM frequency from bouncing around too (these two CV's do not work when BEMF is on). .
Jeff is all for it... I am all against it! I played with BEMF and while IT DOES make your locomotive RUN BETTER, no doubt there! I believe it does it at the cost of wear and tear on the motor. Without BEMF, your loco will run much like it does with a Marklin power pack... Quiet and smooth. With BEMF on, the locos start making sounds. Buzzes and chugs. Me and Kim spent several weekends experimenting with it, and the running characteristics were enhanced for sure, but having spent 30+ years repairing equipment, I feel I have developed a sixth sense towards machines, and I can feel when something is wrong. One of those feeling is when I hear sounds that should not be there. Sounds are vibrations, and vibrations are when something moves back and forth. Over the years I have seen systems using little motors like these for pre-aligners that make sounds, and other machines do not make sounds. I have seen these quiet motors last 5-10 years, and I have seen the noisy ones last a few months. Next issue is heat. The quiet motors always run cooler that the noisy motors. I ran a Marklin steamer with a TCS M2 decoder for about an hour or 2, while Kim was taking measurements, and we were doing all kinds of capacitor tests. The Steamer made a great chugging sound while the BEMF was turned up to it's maximum settings. We ran over 2" wide pieces of tissue paper to simulate running over dirty track, using caps as electronic flywheels to carry us over. Boy was that loco hot! I mean smoldering! We turned off BEMF, and found that the loco could run longer with caps if it had BEMF turned off. Also after a half hour we noticed the loco was running much cooler. It was also running very quiet. Our conclusions were, BEMF causes vibrations, sounds, friction, increased current use, excessive heat, and therefore must be wearing out our motor in favor of great running characteristics. I just turn it off now.
I only have one engine with BEMF. With it on, it runs hot, and when I turn it off, it was cool. The F59PHI actually ran pretty smoothly with it, but I dont want to take a chance with the motor.
I just finished installing Z2s in some SD75s. All went well with two and they run fine. On a third, everything looked fine, but when I went to program it, smoke came from the decoder, so it is fried. I checked everything and it looked fine, so no idea what happened. John
Probably the gray and orange wires have continuity, in other words there was a short. It's safest if you use a multimeter set to the ohms scale, and measure across the orange and gray wires. 1.4K ohms or higher is good. 0 ohms means a short is present, so re-check everything, including frame touching anything.
Or either one of the grey/orange to the chassis (DCC track volts). You are not using the blue function power, are you ? tied off, cut off and/or taped to make sure it is not shorted ? .
My little multi-meter is on the fritz, so I should get another one. I clipped off the blue lead so it is inside the clear covering and not touching anything. I really like that Z2s will run either DCC or DC without having to program them either or. That's great for shows where the modules are DC. John
All DC decoders will run in DC mode but most are nowadays defaulted off (see Note below as one major reason). CV29 controls this on all decoders (it is one of the NMRA standard CV's). Default values are 2 for 2 digit addressing, 28 speed steps, no DC mode. Add 4 to the value if it does not run in DC mode. If you have a long address, CV29 will be 34 for no DC mode and 38 with DC mode on. If you want to run the loco 'backwards' by defualt (like the last in a consist), then you cannot add 1 to any of the values for NDOT (Normal Direction Of Travel) = reverse. When it is placed on a DC track, it will still run in the same direction as it was wired for, forward. You have to reverse the motor leads in this case (or turn the Digitrax decoder board upside down). If you try and run with NDOT=reverse, it will short out when you hit a DC spot. Note: in DC mode, the power to the motor still passes through the DCC 'power supply' which is a 4 diode rectifier. The loss here is about 1.5 - 2 v. This voltage is still passed on to the motor thru the same drivers that the DCC functions due which results in a little more losses. So expect the loco to either run slower than other DC only locos or, take a few more volts to run the same speed as before. .
Thanks for the info Jeff. As always, you are the source for DCC details. I plan to replace the Digitrax decoders in my MTL locos with the new TCS ones as soon as I can afford to buy a bunch. With the TCS decoders I have no problems with consists or clearing them, those functions work like a charm. John
Here' s a question for Jeff or anyone else who could provide some input. Currently I run Digitrax DZ123MO decoders in all my MTL locos. All were "broken in" as DC locomotives prior to converting to DCC. All run pretty much the same speed (when trying to speed match in DCC) except one which acts like it's on steroids (runs super fast, and motor doesn't get hot). This isn't too big of an issue, I'm just wondering why only 1 loco is running a lot faster as the same speed setting as the other locos I have. I've taken all locos apart to see if there was any binding, etc, and nothing. Has anyone else had this issue with any of the Digitax decoders and if so is there any fix?
Joe, you can always speed match them. I use cv5, 4, and 2. Cv 4 for top speed, cv5 for the mid speed, and cv2 for initial speed. This is how speed match my SD70 to a GP35. I speed up the speed table of the SD70 compare to the GP35. Sort like giving a SD70 a head start, and its different for each engine, so you just have to play with the numbers. Also, its not unusual for the speed difference. Half of my geeps runs slow, and half of them run fast. I also try to match the engines that run the same speed when I double head them.
