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  1. gregc

    One Loco out of 6 stops on same spot ???

    dcc has a checksum so that it can detect corrupted packets and ignore them. see top of 2nd page of NMRA standard 9.2
  2. gregc

    One Loco out of 6 stops on same spot ???

    i've wondered how locomotives with multiple contact points can fail to get power. By multiple contact points, I mean multiple wheels, metal on metal contact between tender trucks and metal frame, and a metal draw-bar. Of course there's a problem if the drawbar looses contact, but I also...
  3. gregc

    Low-Tech methods of powering a frog?

    here's a reliable approach to consider from the Pacific Southern. there's a yellow dowel protruding from the block on the left that extends thru the facia. It is moved left/right (vertically in the photo). The block pivots on the screw near the top. The advantage of a toggle over the...
  4. gregc

    Low-Tech methods of powering a frog?

    and there's always using the point contact with the main rail
  5. gregc

    Radio cab interference

    microwave ovens operate at 2450MHz, resonant freq of water molecules. NCE wireless operates at 916 MHz. some wireless phones. anything that says 900 MHz
  6. gregc

    Radio cab interference

    The Pacific Southern was using the NCE wireless cab until there were reliability problems. I borrowed a spectrum analyzer from work and we were able to see an intermittent signal at the frequency the NCE system operates (916 MHz ?), which is in the unlicensed and shared ISM band. There...
  7. gregc

    Calculating Ohms

    it's one thing to limit the current thru an LED with a resistor, but not typically done with a motor which has a dynamic load. why not find a supply, a wall wart, that is closer to the operating voltage of the motor and equal or greater current?
  8. gregc

    Wireless DC transformer for G scale ?

    have you consider RC car controllers?
  9. gregc

    Reversing Loops

    why would mechanical relays matter? curious
  10. gregc

    Reversing Loops

    i don't think you necessarily need 2 separate reversers unless you expect to have two trains enter/exit both loops at the same which may not be possible with the crossovers. both reverse sections would be wired together and a train straddling any of the 4 ends would cause both reverse section...
  11. gregc

    Different way to do detection/occupancy

    is there a diagram showing a schematic, as well as a diagram that shows the geometry of the sensor and the track?
  12. gregc

    Power Supply for "far-away" UTPs

    presumably in the middle, so that no UTP is more than 15 ft from the supply?
  13. gregc

    NCE control question

    if the other operators also have NCE cabs, they can bring them to your session, as well as you bringing yours to their session
  14. gregc

    NCE layout needs lots of help

    First, I'm not talking about JMRI. I suggesting what PC control software can do. (i'm an electrical/firmware engineer. this is why the Pacific Southern uses custom software) no, everything goes thru the computers. If the computer is off, the railroad is dead. i'm trying to say that the...
  15. gregc

    NCE layout needs lots of help

    I found the JMRI wiki pages difficult to understand. I understand it to be collection of programs. It's not clear to me how well is scales and what it does and doesn't do. Before converting to DCC my understanding is that on the Pacific Southern, you moved from tower to tower to both route...
  16. gregc

    NCE layout needs lots of help

    as i tried to explain, toggles can be used now, but with full computer control, the toggle switch will need to be disconnected from the switch machine and routed to the computer that is now controlling the switch machine. The control software can then either control the switch machine based on...
  17. gregc

    NCE layout needs lots of help

    presumably your looking for a migration path from something that will allow you to operate solo on a partially completed layout to at least something that allow a number of people to operate the layout. The Pacific Southern that has existed for over 50 years, has gone thru several evolutions...
  18. gregc

    Toggle switches

    switches can get expensive. Here's a bunch on ebay. 35 cents per
  19. gregc

    DDC engine polarity question

    a DCC locomotive moves in the direction it is commanded. The decoder rectifies track voltage and applies the appropriate voltage polarity to the motor so that it moves in the commanded direction. DCC track voltage is constantly alternating. The time between changes in polarity represents...

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