[MRCA] April fools day update on the PRC-47 project

[James Green]

This is a serious post no fooling around.

OK I discovered a couple things that were preventing me from getting proper data. First the O-scope probe I was using is wonky. I switched to another and am getting much better results. I am seeing signals where they should be and I am feeling more confident with the results. Second, The frequency generator I am using only goes up to 135KHz. That kind of sucks because it is supposed to go up to 13MHz.

I decided to start over with the voltage switched on testing in the manual paragraph 3-5a

I started with 3-5a-7 because everything before that was either self evident or I knew it was working. 
3-5a-7 tested within reason so OK
3-5a-8 was supposed to measure 20VDC regulated. I got 25.33VDC so my regulator is not working. No big surprise there
3-5a-9should match 3-5a-8 and did at unregulated 25.33 VDC
3-5a-10 tested within reason so OK
3-5a-11 For this one you are to see if the filaments of V1 & V2 light up. They are impossible to see without the use of extender cables.
3-5a-12 tested within reason so OK
3-5a-13 tested within reason so OK
3-5a-14 This is the bias voltage for the PL-177WA tube. It should measure -110VDC. I got -17.8VDC. In the check this section the manual said the power switch is not in HI. OK, I switched it to HI and tested again. ZAP KAPOW! something arced! Not good

Now in HI the switching transistors are working way too hard. I suspect something wonky with the Power Switch. This is not the first time I have had trouble with it.

I’m calling it a day. Perhaps tomorrow I will try to remove the switch and check it out. Probably a good idea anyway.