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Phase Linear 400

ok . I'll put the rest of the outputs in one row at time and check it as I go . It will have to wait until tomorrow , I'm done for now. Thanks
 
laatsch55 said:
Also Dean and Ed Blackwood set the bias with a scope and watch until the "notch" disappears at around 360-375. And that's where they leave it.
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That's so cool, I'm not deaf afterall! That's where it starts to sound OK. After around .42, I can hear no further sonic benefits....
 
Yep, if you have a scope it's pretty easy to see. There'll be a notch at the crossover point until enough bias is present to make it disappear. I'll see if I can post a pic. Have to generate one on the scope first.
 
I have a scope. I'm concerned why the left side bias reading was so high,this is with the DLT and the pot fully CCW when right was 0. Granted the not all outputs are in yet.
 
Ok all the output trans. are in . The DLT is connected(the bulb dims way down to just about dark) the trim pots are fully CCW. I'm getting 289mV across R38 on left and 0mV across R38 on the right. I don't want to take the unit off the DLT, fearing the left side is going to burn . The board voltages I checked are close to spec.
 
I can adjust the left as in turn it up but its almost at spec now.
I'm getting nothing on the right,turning the pot does nothing the meter shows a little voltage on start up but then goes to zero. I'll check the board connections
 
The original 3403's with the flat facing away fom you , and from left to right it was BCE. Also , did you drill out any holes to accomodate larger wires?
 
No holes drilled . I was getting a C>E connection on the left 2n5088 in circuit so pulled it but it test good out of circuit. The pin outs are not a big problem I just match them to the board . The TO-3 sockets look good ,the transistors fit tight. I'll check the regulated voltage again.
 
With Q6 in circuit I get a C>E neg on C. I check Diodes 6,7,8 all good in match board symbol. what up ?
 
B-E is conducting both ways B-C is good(in circuit) . The offset way high and moving up and down. I'm going to check the TO-92 transistors
 
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