Search results

When you end up making the extra fins, I made a cardboard template of the chassis/heat-sink interface. It's easier to get the template to lay flat on the chassis first, then transfer the marks to the heat-sink. You have to cut two relief holes that you can see in one of the pictures.

I'm sorry but I only bought 12" which was just enough to make 2 heatsinks. The item number on the bay is 202031500257. It cuts pretty easy with a table saw. When you cut it be prepared for aluminum chip to go everywhere. I did use one of my junkier saw blades.

I haven't set it up yet... Still working on some cosmetic things.

Thanks for the kind words. When I first sat down I was wondering if this was a good idea. It got easier after each column was done.

In case anyone notices the un clipped leads in the lower left of the left side picture of the back wall. I clipped them off before powering up.

I'm sure glad I got the Phoenix connectors for the PL14_20. I've had that board in and out and back in about 4 times. After rebuilding the back wall I reinstalled it once again and setup for the power up procedure. I setup the variac and DBT and flipped the switches... At about 60 VAC where I...

I also got in the new recommended resistors to rebuild the back wall. When I started I thought I had bit off a little more than I could chew. Removing the old resistors wasn't too difficult but cleaning up the blobs of solder was the issue. I'm not sure where I got the solder wick I had but...

I was able to get to work on the bias transistors. I don't know if someone had worked on this unit before me or being in the 4th month of production PL was still working out the kinks. Below is what was installed in my 400. There were 2 layers of heat shrink around a MPS5172 transistor along...

Joe thank you for the clarification. New resistors and diodes on order.

I think I'm going to rebuild the back wall. A couple of questions. What I have differs slightly from the schematic included with the narrative wiring instructions. Resistors R36&37 are 150 ohm, on the schematic, but I have 100 ohm. Assuming I rebuild it should I get the 150's? **...

Joe, Thank you for the help with this. Alan

While I'm at it would it be of benefit to replace the .22 emitter resistors and the 10 and 150 resistors? What wattage would they be? Is a metal oxide the right part?

The strap, if you will, for my transistors doesn't completely enclose the Q6. Is that something anyone would have a couple of? Once I remove the heatshrink etc I don't think the bracket I have will hold a TO92 part.

Here's a close up of the bias transistors

The bias transistor IS encapsulated in heatshrink and what looks like silicon. Is there a suggested replacement if it breaks while I'm reconfiguring it?

:hello1::hello1::hello1::hello1: Cheap Chinese Tester to the rescue! Rewired the bias transistor per the results of the CCT and the 400 powered up properly. As soon as I started to increase the variac, the B+ increased as well! The relay kicked in at about 110VAC. Once at 120VAC the offset...

I thought I'd check the bias resistors since I thought the connection might be compromised. I only have a cheapie Chinese testor but it does tell me which lead is what. Good news is the Bias Xistors are still have a good connection. Bad news is based on the testor my colors do not match the...

Went through BOM item by item and found no parts mis-placement. I thought I found something but it turns out it was nothing. R53 Actual=Brown Grey Violet Brown Brown (1.87K Ohm Correct per description) vs BOM said Brown Grey Black Brown (1.8K Ohm) R35L R35R R37L R37R Actual = Red Red Black...

A couple of questions / concerns about possible cause of this overcurrent situation. *would loosing connections with one of the back wall thermal transistors be a source? When fiddling with the heatsinks there was a lot of stress put on those connections. At least once I lost my hold on the...

When you say base drives do you mean disconnect 3L&R and 9L&R? Can I assume that the WOA board is causing the problem somehow? I think I'm going to have to go through the build with a fine tooth comb. One thing that did happen when I was soldering it, I installed Q3, 4,5L backwards. I noticed...