phase linear 400

[gene french]

Why were you dreading it and why are the OFP plugs out of the sockets?

i dont understand....
did i do something wrong???
what are ofp plugs??
which sockets??
enlighten me....please

 

[Gepetto]

well, thats about it for today....
i got the back planes populated....
tomorrow print out the diagram and scour over the boards....
if anyone sees anything....please let me know....

View attachment 66254

View attachment 66255

Missing P-strap on the 2N5088 transistors. Hope you left enough lead length on the transistors.

 

[Gepetto]

i dont understand....
did i do something wrong???
what are ofp plugs??
which sockets??
enlighten me....please

Organic Fiber Plugs which plug the end of the socket holes to prevent solder from entering the sockets during installation. They usually stay in place until the output transistors are installed and then push them out.

 

[gene french]

i did not...you can plainly see...
i dont have any p straps....
if i am supposed to use the existing ones....they aint here yet...
i have 2 new 1305s in the p-strap....

 

[George S.]

I think OFP means Organic Filler Plugs. The fiber plugs that are in the gold cups. They get pushed out when a output is pushed in .
I see two things. More penetration of the solder on the PEM nuts would be desirable. Really shouldn't be seeing that gap on the Secondly, you've installed your bias transistors. Hopefully you've left the legs long as the body fits in the original P straps. (Joe just posted about this as I was typing this).

 

[gene french]

Organic Fiber Plugs which plug the end of the socket holes to prevent solder from entering the sockets during installation. They usually stay in place until the output transistors are installed and then push them out.

i soldered them with some old to3s i have around...
i did not get solder in there....

 

[Gepetto]

i soldered them with some old to3s i have around...
i did not get solder in there....

You are lucky if you did that...not a good practice. That is why Mill Max puts the plugs in there...

 

[gene french]

You are lucky if you did that...not a good practice. That is why Mill Max puts the plugs in there...

i was worried more about alignment than getting solder in there....they do plug in snugly.....i think a good fit...

 

[gene french]

I think OFP means Organic Filler Plugs. The fiber plugs that are in the gold cups. They get pushed out when a output is pushed in .
I see two things. More penetration of the solder on the PEM nuts would be desirable. Really shouldn't be seeing that gap on the Secondly, you've installed your bias transistors. Hopefully you've left the legs long as the body fits in the original P straps. (Joe just posted about this as I was typing this).

are you talking about the gap on the opposite side of the board??

 

[Gepetto]

 

[Gepetto]

 

[George S.]

The P strap in the photo is original to the amp and gets reused. There is a PDF that explains this. Also on my 700 Pro build thread I discussed bending the leads to 90 deg versus just bending the transistor over, Mark L's method

 

[gene french]

i have 2 new straps around a 2n1305 transistor....as i dont have an old 400 here yet to take it out of....
i guess i missed that...

 

[Gepetto]

 

[gene french]

3405....sorry

 

[Gepetto]

Bias transistor replacement instructions

 

[George S.]

Your still in good shape. Nothing you can't recover from.

 

[gene french]

yes, i am ok....just another obstacle to over come...
should i use these new clamps and extend the legs on the transistor??
or wait and use one of the older ones??
i dont see why i just dont use these new ones...
these are just spares for the 400c board with original backplane on my original 400 that i am not going to modify...
if i need these in the future, i can use the old clamps of the bias transistor that i am changing out????
what u think??

 

[George S.]

Gene, I sit the backplane into the chassis and secure it with two Assembly Aid Bolts after installing the screw and spacer the P strap is secured to. This is a "mock up". When all looks good I tack solder the legs, disassemble it, and finish soldering. I make sure the leads protrude the correct length on the backside of the board. Probably easier to just solder them in and bend them over, but I'd rather take extra time and mock them up
Installing the bias transistor is the last thing I do to the backplanes before installing them onto the chassis and securing them with the Assembly Aid Hardware.

 

[George S.]

Linda, a 400 S1, note the bias transistors and PEM nuts.