First Time Building PL400 BP Rev B

[Phantom Lamb]

All,

New to the forums and wanted to reach out. Have recently acquired the BP to help my dad finish this project that both of us have been working on for a while. I have been provided with the attached along with the board, components, soldering iron, and multimeter.

My biggest concern is soldering the solder cups before putting on the components. Any tips/help would be much appreciated as I don't want to trash this board!

Thanks,

 

[MarkWComer]

I used an old washcloth under the board to keep them pushed up from behind to solder them in.
Solder from the edge so you don’t fill the holes, you usually get one extra in the package in case you accidentally ruin one in the process.

It’s the PEM nuts that I hate. LOTS of HEAT on those, and keep them flush with the board so your collector screws won’t go in crooked.

 

[Gepetto]

A trick for the PEM nut soldering, hang the screws in the kit below the board while soldering. Keeps tension on them and keeps them straight while soldering.

 

[MarkWComer]

WHOA! STOP!
Forget what I said about the washcloth- that’s what I did for the components.

I used a wood block and a record clamp:

 

[Gepetto]

Glad you clarified that Mark.

The masking tape shown in the instructions provided works best for the socket cups. It prevents any possibility of getting solder into the entry end of the socket cups. The exit end of the socket cups are plugged by organic plug material. DO NOT REMOVE those plugs during any board assembly steps. They will be removed automatically when you install the transistors.

 

[Phantom Lamb]

Thanks guys, this has been a huge help so far.

I am currently on the PEM soldering and these things are a bear. I soldered some crap joints last night just to adhere them to the board and will be doing clean up today or tomorrow.

I was thinking of just screwing in the screws completely to the PEM nuts to put tension on them. Aside from these screws getting really hot, is there any reason this shouldn't work?

Thanks,

 

[laatsch55]

Nope..
Nav-Linear came up with some clamps I use and they were plastic, using plastic screws. They're good for 10 solderings.
Just remember to make sure the solder gets to the other side...

 

[Mohawk]

The only issue I see with using the hex screws to hold in the PEN nuts is the screws will "wick up " some of the heat needed for a solid bonded connection !
If you have a lower wattage iron this approach might not work out .....

M

 

[Gepetto]

Doing so means you will be removing the Kapton tape on the top of each risking:

1. Solder buildup on the end face of each which is bad
2. Solder in the threads which is bad
3. Screw soldered to nut which is the combination of 1 and 2 above, also bad.

Solder joints must be nice or you will have issues. Solder joints should look like the attached when you are complete all 32 or 48 solder joints.

 

[Phantom Lamb]

So moving along in the build I made a pretty dumb mistake and accidentally added R6 to one of the boards and am now short a resistor R5 on the other board.

Thinking I should just snip it and try to solder in the best as possible or order more resistors?

Thoughts? You guys have been a huge help so far, thanks for everything.

 

[WOPL Sniffer]

Glad you clarified that Mark.

The masking tape shown in the instructions provided works best for the socket cups. It prevents any possibility of getting solder into the entry end of the socket cups. The exit end of the socket cups are plugged by organic plug material. DO NOT REMOVE those plugs during any board assembly steps. They will be removed automatically when you install the transistors.

Joe, are those solder cups really gold? After a Shit-Load of wopls, I got a baggie with a bunch in there........ Maybe I'll make me a nose ring?????

 

[WOPL Sniffer]

So moving along in the build I made a pretty dumb mistake and accidentally added R6 to one of the boards and am now short a resistor R5 on the other board.

Thinking I should just snip it and try to solder in the best as possible or order more resistors?

Thoughts? You guys have been a huge help so far, thanks for everything.

Unsolder it. This is where 2 irons work the best.

 

[WOPL Sniffer]

Pay close attention when doing a build. It will save you A LOT of headache. Mark your part off the BOM and move to the next.....

 

[Phantom Lamb]

Understood. I'm having trouble unsoldering it as the lead hole in the board is ridiculously small.

 

[MarkWComer]

Look for a vacuum desoldering tool, looks like a syringe.
It gets most of the solder, usually enough to make the job easier.
Your BOM has all the part numbers listed, it helps to order replacements for some things like the pico fuses. Sometimes Mouser may be out of stock, but the part numbers also work at Digi-Key.

 

[laatsch55]

Understood. I'm having trouble unsoldering it as the lead hole in the board is ridiculously small.

Warm up one lead and pull it. Warm up the other lead and pull it. Then desolder the remaining solder. Desoldering and pulling a resistor should not be that difficult..

 

[Wheel-right]

Nope..
Nav-Linear came up with some clamps I use and they were plastic, using plastic screws. They're good for 10 solderings.
Just remember to make sure the solder gets to the other side...

Would you happen to have a pic of those clamps? Might try making something up. Thanks

 

[laatsch55]

You bet, I'll get a pic when I get home. Or check some of my build threads, Bennett using them for years..

 

[Phantom Lamb]

Thanks all, I have a solder pump. Will try. A little later tonight.

 

[J!m]

I have had good luck desoldering by getting it molten and blowing it out with an air gun. I don’t think “canned air” (or Perriair from Spaceballs) would work.

Sometimes takes a couple tries but it works. Feels nice when it splashes on you too.