Hp server power supply mod.

[Eldorado828]

After a couple of weeks doing some research and watching videos I ordered an hp dps-1200sb to modify for high amperage gear (kl-503, 2970N2).

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Cheap, easy to modify and work well according to sources. A couple of resistors and voila, so I hope! I'll photograph and document to share with others.
Hoping to zero in a variable 13.8 to 14.8 volts with about 70 +/- amps.

Credit to Mr bbi, Rainmaker Customs and 767 CB for doing the work and making it available to us Radio heads!

Above link is the one I bought that should be here Saturday.
More to come

 

[Brother DXer]

That's great! I hope it works out.
I'm curious to see how loud, or quiet it is.

 

[brandon7861]

The DPS-800GB's run really quiet. I put this one together (in a hurry lol) for a friend, still have the other one it was paired with in the shed with the power combiner board they plugged into.

DO NOT DRILL INTO THE FINGER BOARD TO ATTACH POWER POSTS, supposedly, there are buried traces inside them and drilling can screw them up!!! I folded the copper strap over the finger board and soldered it to both sides.

 

[dave457]

Breakout boards work better than soldering or drilling

 

[Eldorado828]

The sources named above have done some really good reviews and given really good suggestions so I'm hoping for good results. I'm going without the breakout board and will share the results.

That's great! I hope it works out.
I'm curious to see how loud, or quiet it is.

Brother, all sources also claim noise isn't an issue with this specific supply unless you try to squeeze every drop of juice out of it.

For the money if it does what they say then it's a heck of a bargain.

 

[FlatlandBusa]

I'm running a dps-1200sb as my station power supply and it has no noise from 160meters up to 70cm. Bought a pile of these on ebay for $19ea. 15 minutes of work and its at 14.7volts.

 

[Eldorado828]

It arrived yesterday and these things are tiny compared to supplies I'm used to. Pretty wild how much powa comes out of these little guys. Mod and testing soon to come.

Compared to a cell phone

 

[999]

I have a couple on the way that I'm coin to put into an old Pyramid PS-52 power supply that died on me. They should be here tomorrow so I will have a project on my plate.

 

[jtrouter]

They do work well. HOWEVER make sure that you are using very good tight tolerance resistors that has caused a few problems from the get go. My friend and i bought and converted a half dozen back in April and for the most part they have worked well. If you do not seem to get what you think you should go back thru BBI's
facebook for people whom have had problems and how they fixed them.

 

[Eldorado828]

They do work well. HOWEVER make sure that you are using very good tight tolerance resistors that has caused a few problems from the get go. My friend and i bought and converted a half dozen back in April and for the most part they have worked well. If you do not seem to get what you think you should go back thru BBI's
facebook for people whom have had problems and how they fixed them.

Will definitely keep that in mind, thanks for the tip.

I've got a good assortment of 5% but might need to get some 1%. I'll see how this works out.

I'm guesstimating 15k ohm and 15k ohm should work at a range of 13.8 to about 14.5 volts with about a 60 amp draw. Hopefully

 

[jtrouter]

You WILL want 1% if you are trying to hit the voltage range from the BBi videos.
You may have better luck than many of them but the 1 % gave the best stable voltages which was important if you want to parallel them.

 

[jtrouter]

Will definitely keep that in mind, thanks for the tip.

I've got a good assortment of 5% but might need to get some 1%. I'll see how this works out.

I'm guesstimating 15k ohm and 15k ohm should work at a range of 13.8 to about 14.5 volts with about a 60 amp draw. Hopefully

I would have to go back thru my notes but we did use the values that came from the first video.

 

[Eldorado828]

I would have to go back thru my notes but we did use the values that came from the first video.

I'm guesstimating why I might use. Bbi wanted higher voltages than I'm after. If I can achieve a variable of 13.8 to 14.5 and get about a 60 amp draw then it's all I need. I just want it to have headroom for when I want to run the 2970n2 or the kl-503 with something.
Everything I've read has seemed to be positive but your language makes me believe you've had more bad then good with them. You obviously know more about these than me, should I be worried about achieving those numbers?

 

[jtrouter]

I'm guesstimating why I might use. Bbi wanted higher voltages than I'm after. If I can achieve a variable of 13.8 to 14.5 and get about a 60 amp draw then it's all I need. I just want it to have headroom for when I want to run the 2970n2 or the kl-503 with something.
Everything I've read has seemed to be positive but your language makes me believe you've had more bad then good with them. You obviously know more about these than me, should I be worried about achieving those numbers?

The voltages were easy to hit, However the current was hit or miss as the crowbar seemed to not be as stable unless the values were tight. As you are not using more than one at a time you should be ok. We did find that 1% worked better for the crowbar. Good luck let me know if I can be of anymore help.

 

[Eldorado828]

I'm back to this one again so that it can power the amplifiers that will join the station soon.

So, I've done quite a bit of research since i started this endeavor and I found many suggesting 15k and 15k so that's where I started. I didn't achieve the 13.8 to 14.? but instead got 14.3-14.8. I'm contemplating whether to leave it or try some changes.

The amperage testing is still to come.

This stuff is super small so it isn't for the faint of heart.

I'll post pictures for others that might be venturing into this same territory.

More to come