RayL posted:...That's only part of it -- I have 2 of the 40-1028 ITADs that I can't get to activate unless I cover the window completely.
Regardless of how I adjust the range control, the relay will only 'click' when the window is completely covered.
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Could the relay "click" be from it de-activating? If you do an OGR search on "MTH ITAD" you will find threads decrying over-sensitivity to ambient light. So if you are testing this on a bench with a desk lamp nearby or near a window during the day, ambient light can activate the ITAD...and only when you block the sensor window does it de-activate. This would explain the backwards behavior. If this applies, as you can read about in more detail in the other threads, some ideas include re-positioning (not always practical with the lock-on design) or fabricating a shade/awning or similar shielding to give the sensor what amounts to tunnel-vision.
I have not seen the guts of the MTH ITAD, but for similar devices like the Lionel 153IR, the range control knob only adjusts the brightness of the transmitted IR beam. This IR beam bounces off the passing train back to the IR sensor which activates the relay. So if it is indeed ambient extraneous light activating the ITAD, messing with the range/sensitivity control is ineffective which can be confusing.
Of course you may simply have defective units. If this is the case and out-of-warranty, are you considering DIY troubleshooting/repair? I will assist if you can post photos and are handy with a meter and soldering iron. Or if you are just going to toss them, consider sending one to me as I've been curious to see the MTH ITAD design and I can post a teardown report here for future reference. Previous threads have given confusing/conflicting statements on the functioning and wiring of the MTH ITAD. Here's a teardown I did for the 153IR which another member sent me.
