MTH Scale Trax ITAD

@mort1345 posted:

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All of my other accessories on the z4000 aux power work fine including a MTH Itad and a Lionel Itad and other relays

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Begs the question what else could it be aside from wiring? 

That is, you say you have a working MTH ITAD powered by the Z4000.

It would involve removing/adding ~5 connections but did you try swapping one of the "bad" ITADs into the location of the working MTH ITAD?

I have 3 of these from the secondary market.  Tested all on my workbench and were ok.  I have hooked one up on the layout using the same barrier strip and it ( works fine as does a Lionel)  I have 2 that will not work on the layout.  Even tried them direct off of the z4000 ACC output and no go.  Have not tried reversing the + and - on the relays yet.  Is that safe to do.?

I have done that swap on the layout and one of the 3 is ok and the other 2 will not work.  Take them back to the bench and work fine there.

thanks for the reply.  Will be away for a week.

Mort

@mort1345 posted:

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Have not tried reversing the + and - on the relays yet.  Is that safe to do.?

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Not sure what you mean by relays.  An ITAD does have a relay buried inside it, but none of the ITAD terminals are referred to as + or -.

When you say the signal does not operate properly on the layout, is the signal hooked up to the ITAD or to a relay? 

Specific to the ITAD.  Is your layout "quiet" enough (and your hearing good enough) that you can hear the relay buried in the ITAD "click" on and off?  If the only difference between working and not working is the physical location of the ITAD, I'm wondering if there is a bright light on the layout that interferes with correct ITAD operation.

Stan: i was referring to the itad internal relay.  When I hooked up to z4000 it is under layout so no light interference, if I change power input on the itad will that hurt the itad ??  Yes I can hear when  it clicks or not

Away all week will work on it this  weekend

Mort

If by "change the power input" you mean to swap the wires AUX+ and AUX- per photo below, then no, this will not hurt the ITAD. But  I would be stunned to find this makes a difference.  Since you can "hear" the ITAD's internal relay click on/off you don't even need to hook up a signal to the ITAD "outputs".  This ought to make any swapping/testing that much faster.

It's baffling how all 3 work on the bench but only 1 works on the layout.  The only other "user-adjustable" setting is the RANGE control knob.  Did you fiddle with the RANGE setting on the different ITADs to confirm they behave as expected?

The ITADs work by sensing reflected infrared light bounced off the passing train.  The sensitivity control allows tuning the threshold of sensed IR light to activate the relay.  These things, as you noted, work great on the bench but the ambient light conditions on the layout can fool the sensor.  Don't point it towards a window.  Try a dark background where the ITAD is aimed.  If that works, you can get creative with dark-toned scenery or buildings.

Want to have fun?  Aim two of these at each other across a double-track main line.

These MTH ITADs are terrible.  The infrared is very light sensitive.  I have a pair also that I could never get to operate consistently.  Mine would stop working when a black car went by.  If you want to do a test, turn the lights out and see how they work.  They should actually improve performance.

Truthfully if you want worry free, take them out and buy the zstuff sensors.  That is what I did with my MTH signal bridge and it has worked perfectly.

However if you are really committed to the MTH version, you could try getting some heat shrink tubing and glue it on like a hood over each infrared sensor.  I had some modest improvement but not much.

If you want my two MTH versions you can have them for the cost of shipping.  They have just been sitting on a shelf unused for a few years now.

Have Fun!

Ron

@Ron045 posted:

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If you want my two MTH versions you can have them for the cost of shipping.  They have just been sitting on a shelf unused for a few years now.

Hi Ron, did anyone take you up on this? 

If the price is right (i.e., shipping is reasonable), I'd be willing to do a tear-down of the Scaletrax ITAD (I've done this for the Realtrax ITAD and the Lionel 153IR) posting schematic information and internal construction details for the greater good as it were.  I figure I might be able to re-sell them "at cost" when I'm done with them to a fellow OGR'er.

I sent you an email (check your JUNK folder, ha ha).

Was able to get to the 2 remaining ITADS yesterday.  By turning the Range setting back and forth the ITADS responded and are now working on the layout.  For some reason they always worked on my workbench.   As per Ron045 "These MTH ITADs are terrible.  The infrared is very light sensitive.  I have a pair also that I could never get to operate consistently."  Mine do not respond to a white car however.

For now that is al the ITADS I have, and I have some Zstuff relays for my remaining signals.  And an Axatrak that using insulated rail.  Those work very good.

Thanks for all the assistance

Mort

@mort1345 posted:

Was able to get to the 2 remaining ITADS yesterday.  By turning the Range setting back and forth the ITADS responded and are now working on the layout.

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Right.  There have been OGR threads where I recall advising folks to spray some contact-cleaner into the Range adjustment knob (i.e., trimpot or potentiometer) of the Lionel 153IR occupancy detector.  AFAIK,  both manufacturers (Lionel and MTH) use so-called "unsealed" (vs. sealed) adjustment controls for the Range adjustment on their Infrared detectors.  This means the grime, grit, and similar detritus is allowed to settle on the control component which can render them ineffective.  Consider yourself lucky that simply jostling the Range control back/forth brought them back to life!