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DIGITRAX PM42 Question

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  • Member since
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  • From: Columbus, OH
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DIGITRAX PM42 Question
Posted by dano99a on Friday, September 30, 2011 10:52 AM

Ok, so I'm very familiar with most of the digitrax equipment and I install decoders professionally. But I'm perplexed a little by the PM42. I know it handles power districts (have the 4 set up now) but can one of the terminals ALSO handle auto-reversing at the same time as managing the 4 power districts?

Thanks for all your help!

DANO
C&O lives on!!!  
Visit my railfan community site: http://www.crtraincrew.com

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Posted by jrbernier on Friday, September 30, 2011 11:09 AM

  Each of the 4 section in the PM42 can be a power district or an auto-reverse unit - But NOT at the same time.  I have found that the AR1 makes a better auto-reverse unit as is has a 'pot' to adjust the sensitivity.  We have 16 PM42's on the club layout, and 3 AR1's - the PM42 can only adjusted in 'steps' of sensitivity.

Jim

Modeling BNSF  and Milwaukee Road in SW Wisconsin

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  • From: Clearlake, California. USA
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Posted by Lake on Friday, September 30, 2011 4:49 PM

I also use the PM42 for power districts and auto reverse and go with Jim's replay.

IT is easier to the wire a AR1 for auto reverse then a PM42.

Ken G Price   My N-Scale Layout

Digitrax Super Empire Builder Radio System. South Valley Texas Railroad. SVTRR

N-Scale out west. 1996-1998 or so! UP, SP, Missouri Pacific, C&NW.

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Posted by simon1966 on Friday, September 30, 2011 5:23 PM

I can't for the life of me remember where I read it, or was told this, but I think that Digitrax even recommends not using the PM42 for auto reverse.   So when I got my PM42 I also got an AR1

Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum

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  • From: Reading, PA
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Posted by rrinker on Friday, September 30, 2011 6:05 PM

 What they no longer recommend is using the SAME PM42 as both - where one section is configured as a breaker, feeding another section of the SAME PM42 configured as auto-reverse. This was an option shown in the original manuals, but it seems to cause issues, so that diagram has been removed from the manuals.

 Regardless, it IS much easier to just use an AR1, easier to adjust with the potentiometer instead of trying to fiddle with CVs to set trip levels.

                                --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by Aikidomaster on Friday, September 30, 2011 6:43 PM

Randy,

This is the first time I have heard of the AR1. I looked it up on the Digitrax website. Obviously, this is for auto-reverse and I assume can be used on turntables. How does it interface with LocoNet or does it in fact need to interface with LocoNet. I assume, that the AR1 acts as a separate power district. Please, explain.Bow

Craig North Carolina

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Posted by simon1966 on Friday, September 30, 2011 7:30 PM

Craig, the AR1 does not connect to the Loconet, it is just an independent auto reverse circuit    The very basic manual can be found here  http://www.digitrax.com/ftp/ar1.pdf   I suppose you could consider it a separate power district, but in reality it can be a sub unit of a power district just reversing a specific section of track within a power district.  The main thing is that the track section is isolated from the rest of the district as noted in the PDF diagram.  It is a very simple connection.

Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum

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