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This TIU Tester is the best thing that's happened this year.  When I decided to install the DCS Wifi capability to all tracks with new TIUs with the USB ports, a series of gremlins appeared that would have precipitated the implosion of my Run Room.  Fortunately with all the TIU signal discussion in the forum topic, "Weak DCS signals, Failed TIU Output Drivers, and Design Solutions developed under collaboration between AGHR and MTH", and the TIU Signal Tester Design I have reached the stage where I can make do with what I have until I can improve my TIUs.

I am also looking forward to playing trains with my tablet and "quilling" whistles.

A pdf of my novice Tester Build is attached.

TesterComplete

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Last edited by Susan Deats

Cool, I'm glad that I was a small part of bringing this to the masses.  Adrian probably deserves a major part of the credit, and of course Stan for suggesting the multi-level aspect of the design.  And we can't forget Tom for coming up with the great and detailed instruction set and parts set.

I like your little box, makes a nice unit and it won't get knocked around.

Susan Deats posted:

This TIU Tester is the best thing that's happened this year.  When I decided to install the DCS Wifi capability to all tracks with new TIUs with the USB ports, a series of gremlins appeared that would have precipitated the implosion of my Run Room.  Fortunately with all the TIU signal discussion in the forum topic, "Weak DCS signals, Failed TIU Output Drivers, and Design Solutions developed under collaboration between AGHR and MTH", and the TIU Signal Tester Design I have reached the stage where I can make do with what I have until I can improve my TIUs.

I am also looking forward to playing trains with my tablet and "quilling" whistles.

A pdf of my novice Tester Build is attached.

 

I'm glad it was helpful. When everyone jumps in to help and refine the design, neat stuff comes out!

Those are very nice instructions Susan. Glad you got everything up and going and it sounds like trains are running again, the best part! Along with GRJ, I like the box you installed it in as well. I might try that myself, I have a few old Radio Shack boxes around here somewhere.

And as Adrian (who got this going) said above, "When everyone jumps in to help and refine the design, neat stuff comes out!" GRJ and Stan refined everything to make it what it is today, then GRJ did the PCB designs and layouts. And I think it has been a great learning thread as well. Although I can't always keep up, I really enjoy following these folks when they are preparing to make the "neat stuff come out"! 

I am honored to have been allowed by these folks to act as 'ordering and shipping clerk', which I do find to be enjoyable (they helped me with that too!). Makes me feel like I am contributing here in some small way.

Also, for everyone else here on the forum or elsewhere, I plan to keep the kits available for anyone that wants one.  

I ordered a kit from Tom and just finished putting it together. Calibrated it with the "shorting screwdriver method" and it appears to be working correctly. First I ran a couple of engines on the layout to check signal strength and pretty much got 10's all around. Then I checked each TIU channel with the checker, first with the TIU hooked to the layout and then with the TIU disconnected from the layout. In all cases the green light flashed, never got the red light to flash.

So is this telling me my signal strength is somewhere between 5 and 10 volts? I understand calibrating the tester with a known good TIU so the pot can be adjusted to just make both leds flash, but how do you know if you have a "good" TIU? Will a new, just out of the box TIU always have a 10 to 12 volt signal? Is there any other way to calibrate it to 10 volts?

I would also like to thank Adrian, Gunrunner, and Tom for researching, designing, and putting the tester kits together.

Ken

kanawha posted:

... In all cases the green light flashed, never got the red light to flash.

When you say "the green light flashed," you do mean both green & red simultaneously?  You should never be able to make JUST the green light to flash (by itself).

OTOH, if the signal is in the "maybe" zone (5-10V) then you can get JUST the red to flash.

There is no published info from MTH that specifies the minimum DCS signal level fresh out of the box.  Anecdotally, based on Adrian's extensive study (refer to other OGR threads where he shows tables, oscilloscope photos, etc.), new TIUs indeed put out more than 10V.  So, in practice, if you have a "known good" TIU and adjust the trimpot to flash green (and red) when there is DCS activity, then you will be setting the threshold higher than 10V.  My guess is the change in trimpot "angle" between 10V and, say, 12V will be small...maybe only 10-20 degrees?

Remember, the screw-driver calibration technique is just to get you a seat at the table - no oscilloscope required.

GGG posted:

Did you put the green LED in the wrong spot?  Testing TIU while still attached to the layout or even a test track with lighted lockon will effect results.  Test TIU stand alone.  G

GGG and STAN2004,

I installed the LED's in the correct place, the problem is when I wrote the post I meant to say the red light flashed and the green light wouldn't flash. My bad!

After re-reading all the posts I decided to calibrate the tester to my home layout TIU. I have one Variable channel that I never have used so I assumed that channel was good. Set that channel to fixed and re-caled  the tester so both LED's flash when sending a command. Interestingly I only had to turn the pot about 10 deg CCW from its previous position. Checked the other three channels (unhooked from layout) and everything tested good.

Now to check our club's TIU's which we have been having a number of problems with.

Ken

Back on page 6 of this thread, RTR12 mentions ordering them at DigiKey but I didn't see an actual part #.  With the Jan 2019 price hike by USPS, the minimum DigiKey shipping charge for First Class Mail is now over $4.

As mentioned in the post above his, I get them for about a dime a piece on eBay (free shipping from Asia).  Search eBay for "2.54mm screw terminal 2 poles"

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gunrunnerjohn posted:
stan2004 posted:

Tough crowd you guys are.  OK, for anyone who feels misled, I will send you 11 cents in the mail.  However, you must pay postage.   

Stan, I was going to buy 1,000, so I'll need $11.00, and I'll pay the postage.

Not so fast!  Note that the eBay listing says "OR BEST OFFER".  Does that mean if seller accepts an offer of $99 (instead of $111) for 1,000 pieces that you will SEND ME a $1? 

But a promise is a promise.  I will send you 11 cents for each of your 100 transactions.  That's 11 cents x 100 = 1,100 cents.   A penny weighs 0.088 ounces.  So package will weigh 7 pounds.  To save you postage I'll use a Priority Mail Flat Rate box.  I don't think I can fit 22 rolls pennies in a Small Flat Rate Box so I'd need to use a Medium Flat Rate box.  That's $14.35.

You know my Paypal address so as soon as I see a payment of $14.35 from you I'll send you 1100 cents. 

 

RJR posted:

RTR12.  Do you have a catalog number or location for the tiny 2-pole connector you used on these kits?

Digikey part # ED10561-ND, but it's way more than Stan's TBs. I tried a couple others (Digkey) for a little less, but these seemed better to me, wire size, screws, quality, etc. (Long story, but I tried some from ebay as well and that hasn't yet worked out, for me anyway. First time I have really ever had problems ordering parts from Asia on ebay too.)

It's also on the parts list included with the tester as: TB1 Term Block OSTVN02A150 On Shore Technology 2.54MM 2POS PCB ED10561-ND

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A bit of a kit update (for anyone interested) on the kits, since it was mentioned earlier:

Digikey has also added tariff charges to most of the parts used for the TIU Tester, I haven't checked all of them. And as mentioned the postage has increased a little too. I still have enough parts left for maybe 10-12 complete kits at the pre-tariff prices.

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Lastly... Oh-my, the crowd has gotten tougher during my absence here...  (or, I always enjoy GRJ & Stan's back and forth )

Last edited by rtr12
rad400 posted:

GRJ , RTR12

If you still have any more kits of the port tester, I will take one.  I already put one together for the club, but like to have one for home use/testing.

Let me know.

Thanks,

Bob D

FredB posted:

Hi RTR12

If you still have these test kits available I would like two, one for the club and one for my home layout . Payment through PayPal is not a problem. Thanks 

Fred B

MTH ASC

TCA MEMBER 16-71895

Bob & Fred,

Yes, I still have some kits left. Could you please email your requests to me at the email address in my profile?

I can keep track of the emails, but I seem to lose things here on the forum.

Thanks,

Tom (rtr12)

Last edited by rtr12

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