My understanding about the dual voltage markings is that the lower one is continuous. The higher one is inrush. That practice was inherited from the tube era -- at power up, the rectifies tubes with direct heat cathode warmed quicker that the indirectly heated amplifier tubes, so there was lower load and lower drop at first. The inrush condition settles in about 5 seconds or so and the voltages drop to running level.
I don’t think the cap ratings are dual voltage ratings at all. They look like capacitance-voltage and this seemed to agree with measurements. For example in this supply, the 20(uF)-50(V) caps are half the volume of 40(uF)-50(V) - as expected. Back then, the capacitances were relatively tiny given the volume when compared to modern electrolytics. And there were plenty of “oddball” capacitances as well, like 30uF, 40uF, etc. Many different equipment brands of that vintage used those capacitors.
I'm not sure why, but this is so relaxing!
I use some of his videos to get to sleep
Looks like static built up on the meter face, Wipe off with some dish soap, or dryer sheet and it will probably be fine.
If you ever make it to southern CA, you have to look up Apex Electronics in Sun Valley. Plan at least two days there. lol
These are my favorite videos that you do.
On the Maximum Ratings table in the datasheet for the transistor (at 14:20), the 2N375 is listed in the centre column, so it's a 60 V VCES, etc.
My understanding about the dual voltage markings is that the lower one is continuous. The higher one is inrush. That practice was inherited from the tube era -- at power up, the rectifies tubes with direct heat cathode warmed quicker that the indirectly heated amplifier tubes, so there was lower load and lower drop at first. The inrush condition settles in about 5 seconds or so and the voltages drop to running level.
Are your viewers aware that Hewlett Packard is an anagram for "The lewd packrat"...? Thanks for the video. Appreciated muchly.
Great video. i have one of these waiting a recap.
I don’t think the cap ratings are dual voltage ratings at all. They look like capacitance-voltage and this seemed to agree with measurements. For example in this supply, the 20(uF)-50(V) caps are half the volume of 40(uF)-50(V) - as expected. Back then, the capacitances were relatively tiny given the volume when compared to modern electrolytics. And there were plenty of “oddball” capacitances as well, like 30uF, 40uF, etc. Many different equipment brands of that vintage used those capacitors.
Those hand wound resistors (shunts) are probably made of manganin rather than nichrome.
You cannot lead-solder nichrome.
Thanks, I had not heard of that alloy
And Manganin have a much lower temperature coefficient than nichrome which is used for heating elements.
This is from before they bought Harrison.
Typical old devices: luxury engineered chassis and mechanics, poor electronic. New devices: rich electronic, but poor mechanic and chassis.
Which junk store? Halted and Wirdstuff are both gone ...
Yes they are all gone. The one standing is:
www.excesssolutions.com/
Nice toy.