Marstan Jmp 1202 118 Volatge?

Discussion in 'Building the Classics' started by stickyfinger, May 26, 2018.

  1. stickyfinger

    stickyfinger Active Member

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    Any one know what these typically put out on the plates? Bias will affect the plate voltage but I typically get 425-428 with Merren at 120v 60%. Ive heard 440v but hoping its lower.

    I'm thinking about switching to his power transformers. Every Merren Ive used the solder lugs are always sticking way to far off the transformer that I have to rout the chassis just to install it.

    Heyboer lugs are closer to the width of the transformer from what I remember.
    Anyone confirm and did it drop straight in a Valestorm chassis with out any elbow grease?
     
  2. neikeel

    neikeel Well-Known Member

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    The Marstran drops straight in. I always use the aluminium ring too (they need a wriggle to put on) as they finish the installation nicely.
    Voltages on the hi pairing will be 420-430v so close to stock and Merren values. IIRC his LV option is 370v once rectified.
    Doesn't the Merren come with LV option too?
     
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  3. stickyfinger

    stickyfinger Active Member

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    Don't think so Neil. His are supposed to be accurate to originals but he also does not supply wiring diagrams for his transformers.

    Looking closely at the Merren power im surprised the Lugs cant be arranged like the originals with two soldertabs per lug moved in closer like the originals. Looks like he cuts half the lug off and puts on the final wrap over it if that makes any sense. But in my case make installation a PITA
     
  4. stickyfinger

    stickyfinger Active Member

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    Just a FYI the low volt puts out 450v. The high goes over 500v.. forget exact number .
     
  5. neikeel

    neikeel Well-Known Member

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    That is interesting as Brian Wallace says that his 118 would be 420-430 or so on high taps and 370-380 on low taps (at least as I understood it) he aims for plexi era voltages on high and mid 70s metal panel for LV taps
     
  6. TAZIN

    TAZIN Active Member

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    I agree with neikeel that the Marstran 118 should be around 420Vdc - 430Vdc for the high taps after solid state rectification.
     
  7. neikeel

    neikeel Well-Known Member

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    What are your heaters - are you running a high input voltage for your selected tap to get 450v?
     
  8. stickyfinger

    stickyfinger Active Member

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    Heater are high at 3.4. Wall volt is higher usually. 123-4v.

    The Black and Brown 100v and 120v respectively on the diagram are switched on my unit. Meaning the order they come out the power transformer. I believe the wiring color to be a err at the factory.

    What would happen if I'm dropping 120v into the 100v tap??
     
  9. maxwedge

    maxwedge New Member

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    I have one of those in a JTM50 build and I get 425 at the plates biased approx 60% and 118vac at the wall. This is using the high voltage taps.
     
  10. stickyfinger

    stickyfinger Active Member

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    Ok thanks fellas,

    3.4 didn't look off initially but I looked into the voltages and the tap wires are not in order. I'm getting 430V plates with 3.2v now.

    120v tap is first
    110v next
    then the 3 EU taps

    Heyboer got the wire codes wrong!
     
    Last edited: Sep 21, 2018
  11. neikeel

    neikeel Well-Known Member

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  12. maxwedge

    maxwedge New Member

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    They didn't get the colors wrong, there different! Did you look at the spec sheet 1st for that transformer? Thought that you had a Marstran but glad that you got it working right.
     
  13. stickyfinger

    stickyfinger Active Member

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    Correct, the wiring diagram shows the voltage taps go in order from lowest to highest. The colors were correct but who ever assembled the power made a err.

    This power did solve my problem. Very thin and fit a 2.5" hole. No elbow grease what so ever.

    Will use again for some dual volt ideas.
     
    Last edited: Sep 22, 2018
  14. neikeel

    neikeel Well-Known Member

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    I like the Marstran product a lot and need two -118 clones for projects.
    However since the Brexit debacle and subsequent crash of pound they are $155each plus approx $75 shipping, 20% tax and a flat handling charge we are looking on around $300 that translates to £230, so I'll keep trawling fleabay UK!
     
  15. stickyfinger

    stickyfinger Active Member

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    That's crazy Neil, here in the USA I've never paid anything extra. Bought 100 times international Ebay, Modulous ect. The shipping from Europe to USA is unbelievably cheep too. For me to ship cheapest international its 14.25USD under 3 pounds.
     

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