Marti STL-10 regulator

Gotta watch those Fresnel zones!
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TPT
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Marti STL-10 regulator

Post by TPT »

This is the power supply regulator mounted on the back side of the heat sink. Part only described as "IC-1," not otherwise described in manual. I can see "LM" but rest of number is scrapped off.
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Deep Thought
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Re: Marti STL-10 regulator

Post by Deep Thought »

If someone else doesn't fill in the blank before then I'll take a peek at the STL-10 I have at the office and either get the number or measure the output voltage for you.
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Re: Marti STL-10 regulator

Post by kkiddkkidd »

The STL10a has a LM-338 adjustable regulator. LM-338 is a 5a adjustable regulator in a TO3 case. That description looks like the same thing as the lame description in the STL10 manual but who knows.



Marti STL10a Regulator.JPG
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Re: Marti STL-10 regulator

Post by grich »

My STL-10A book shows the same thing. LM338T on that schematic, but no parts list for that board.
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Re: Marti STL-10 regulator

Post by ChuckG »

I don't even bother fixing that supply anymore, you can drop a 15V 4a switching supply in there for about $25 and have a lighter, cooler, quieter unit. It also eliminates that nylon header connector that fails over time.
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Re: Marti STL-10 regulator

Post by kkiddkkidd »

ChuckG wrote: Wed Jul 15, 2020 7:46 pm I don't even bother fixing that supply anymore, you can drop a 15V 4a switching supply in there for about $25 and have a lighter, cooler, quieter unit. It also eliminates that nylon header connector that fails over time.
What supply are you using?
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Re: Marti STL-10 regulator

Post by W9PXZ »

ChuckG wrote: Wed Jul 15, 2020 7:46 pm I don't even bother fixing that supply anymore, you can drop a 15V 4a switching supply in there for about $25 and have a lighter, cooler, quieter unit. It also eliminates that nylon header connector that fails over time.
This is the advice that the late gentleman that did Marti repairs out of the old Marti factory (my apologies, but I can't remember his name) advised for all Marti power supply repairs. Just junk the original supply setup and retrofit a standard switching supply from Mouser, DigiKey, and the like, and it will be fine for many years to come. All you need to figure out is the voltage and current needed. I have done it on several RPU units.

Remove the bulky power transformer and you have plenty of room.
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Re: Marti STL-10 regulator

Post by ChuckG »

kkiddkkidd wrote: Thu Jul 16, 2020 5:46 am What supply are you using?
Meanwell RPS-60-15 about $15.
It's rated 15V 60W (4 amps). The STL-10 uses just under 3 amps at 13.5V running full throttle so it's got a bit of headroom and runs fairly cool. There is a voltage adjust pot that I turn down to 14v. Move the red wire and the AC connector. It's a 10 minute swap.
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Re: Marti STL-10 regulator

Post by ChuckG »

W9PXZ wrote: Thu Jul 16, 2020 5:18 pm This is the advice that the late gentleman that did Marti repairs out of the old Marti factory (my apologies, but I can't remember his name)
Rick Neace. Super guy, had several tricks for improving old marti gear. His passing was a loss to the industry.
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Re: Marti STL-10 regulator

Post by kkiddkkidd »

ChuckG wrote: Fri Jul 17, 2020 2:22 am

Meanwell RPS-60-15 about $15.
It's rated 15V 60W (4 amps). The STL-10 uses just under 3 amps at 13.5V running full throttle so it's got a bit of headroom and runs fairly cool. There is a voltage adjust pot that I turn down to 14v. Move the red wire and the AC connector. It's a 10 minute swap.
Thanks. I will store that back in my data bank... I have picked up a couple of clients that have multiple sets of STL10's.
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Re: Marti STL-10 regulator

Post by TPT »

Apart from some blue language based on the way that regulator is mounted (the screw for the 3 pin goes through the back heatsink, fun getting it lind up)--this unit back among the living.

I bought a Meanwell supply from Jameco, going to try 12 volts on another STL 10 with a burned out power transformer. There are several wires to be moved, the red wire is the main DC feed, but there are two others that go to the front panel. Looks like meter light for one, have to trace out the other one.
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Re: Marti STL-10 regulator

Post by RGORJANCE »

Chuck:

Thanks for the detail on the power supply.

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Re: Marti STL-10 regulator

Post by kcbooboo »

The STL-10 manual has a block/wiring diagram. They use 13VAC for the meter illumination but there's no reason it can't be 12VDC or even less if you want longer bulb life.

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Re: Marti STL-10 regulator

Post by ChuckG »

TPT wrote: Fri Jul 17, 2020 6:26 am There are several wires to be moved, the red wire is the main DC feed, but there are two others that go to the front panel. Looks like meter light for one, have to trace out the other one.
The meter lights are AC so there are 2 wires back to the supply.
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