Railpower 1300 testing

[mmagliaro]

Hi folks.
My new old oscilloscope is here, and it works beautifully.   I caught a nice Tektronix 2336  off eBay quite cheap
and it is spotlessly clean.  Crisp, bright display, all the controls are clean and tight, and a quick initial test on my
throttle gives me a sharp clean trace that was easy to trigger onto and shows the pulses on top of the DC just beautifully.

So.... on the heels of the Product Discussion thread about Railpower 1300's blowing up decoders in Rapido engines,
(here: https://www.therailwire.net/forum/index.php?topic=44120.0) I had mentioned in that thread that I wanted to scope a 1300 and see what it puts out to see if I can actually see
what it is doing that might be destroying sensitive electronics.

I am asking for a volunteer "donor" 1300 that I can test here.

1. I will scope it and take pics of the pulse and DC displays to discuss here on Railwire. 
2. I will just be running a standard Kato or Atlas conventional-motored engine on it.
3. I do want to drill out the rivets and open the case to see what's inside this model and reverse-engineer the circuit
if possible (unless it has some annoying proprietary chip in it, or one of those innocuous black "blobs" that contain
un-viewable components, but I doubt that this will be the case).

I will not damage your power pack.  I'll put it back together with screws and return it in a week or so after I'm done
experimenting on it.

Anybody game to find out what makes the 1300 tick?

Thank you.

[metalworkertom]

I think I have one , will check after work.

[wcfn100]

I have one.  Let me sure I have something to run with in the meantime and you're welcome to it.

Jason

[metalworkertom]

I have two. Neither are in use .

[mmagliaro]

I have two. Neither are in use .

This sounds like my best option.  I would much rather do this on one that is not going to be missed while I am messing with it.

I'll PM you with details.  Thanks!

[Doug G.]

Other MRC packs are pretty discrete so the 1300 is unlikely to have any kind of potted or otherwise inaccessible circuitry in it.

Doug

[mmagliaro]

Other MRC packs are pretty discrete so the 1300 is unlikely to have any kind of potted or otherwise inaccessible circuitry in it.

Doug

Yep, that's what I've seen in the others I've been inside of.
Yay, discrete!

[BCR751]

Hi folks.
My new old oscilloscope is here, and it works beautifully.   I caught a nice Tektronix 2336  off eBay quite cheap
and it is spotlessly clean.  Crisp, bright display, all the controls are clean and tight, and a quick initial test on my
throttle gives me a sharp clean trace that was easy to trigger onto and shows the pulses on top of the DC just beautifully.

Hey Max, would yo please show/tell me how to hook the scope up to get those measurements?  I've got an old Tektronix Model 465 that I've never used 'cause I have no idea how to.  Any help would be greatly appreciated.

Doug

[Doug G.]

Yep, that's what I've seen in the others I've been inside of.
Yay, discrete!

Same goes for HiFi amplifiers too.

Doug

[OldEastRR]

Hopefully MRC won't get annoyed. You DO have a lawyer, Max?

[MK]

Why would he need a lawyer?  He's only scoping the output of the 1300.  He could do that without even opening the unit.

If he needs a lawyer, then so does Fluke, Tektronics, HP and a whole bunch of other test equipment manufacturers.

[Maletrain]

If he needs a lawyer, then so does Fluke, Tektronics, HP and a whole bunch of other test equipment manufacturers.

Those companies almost certainly already have lawyers.

It has become quite common for companies to try to suppress information that makes them or their products look bad by suing the person providing/publishing the info.  Even when they know it is true.  The problem is that they can bankrupt the person telling the truth before he can get through the legal system.

In this case, however, MRC would lose more customers by doing that than they would by accepting the facts, because there is already a lot of publicity involved.  So, I doubt they are going to sue somebody for providing test results on this forum.  "Nasty" is not a successful business model in the long run.

[mmagliaro]

I have no expectation of needing a lawyer.  I really think that is overreacting.   I can take apart any piece of equipment I own.
And I can say anything about it that I discover.  I'm not stealing their design or making a knock-off.  I'm not in any business that competes with them.

If MRC were to actually attempt to sue me for some sort of slander or defamation, it would end up costing me money and time, yes.  And I would do this anyway.

Ya know... there's always a possibility that I will find absolutely nothing wrong with that power pack.  MRC would thereby benefit from what I write.   Whatever is going on with this thing, I bet it's not going to be easy to find.   It could be something that only happens once in a very great while (like dozens of hours).  If that's the case, most likely I will not find it. 

[C855B]

Max, you're probably already thinking of this... but since we're talking about transients here, part of the testing regimen needs to be how it behaves with sudden changes of operating conditions. First thing comes to mind is wheels bridging a gap with reversed polarity, simulating a forgotten toggle entering a reverse loop. Second is sudden application of power - throttle at a variety of settings, loco runs into a dead block (another forgotten toggle), throw the toggle and see what happens with the inrush under load. These two scenarios are very common occurrences in DC layouts.

If it were me, I'd be using a modern digital scope with recording capability (I have a Tektronix 465 hiding in a closet). I have no real reason to have one any more, but I suggest these single-shot events are going to be elusive with a standard non-memory scope. There are relatively inexpensive USB 'scope black-boxes that use a PC for display and control which might be worth looking into.

[Doug G.]

Regardless of outcome, I still maintain it is not MRC's responsibility to assure the 1300 works with any device from the future from when it was designed. How many contemporary model locomotives has it blown up?

Sometimes, this DCC thing gets a bit ridiculous with enthusiasts almost demanding everything ever made in model railroading, comply.

However, I am not intimating that Max or anybody else here has that attitude. I know Max's scientific inquisitiveness is in action.

Doug