#49: HP-410B: Initial tests

[@robertcalkjr.8325]

Nice. They are not very cheap on ebay. Can't wait to see part 3.

[@dhpbear2]

I noticed when in the 'OFF' position, the meter movement is NOT shorted! This could be remedied by running a wire from S1-f-5 to S1-g-5. :)

[@Andrewausfa]

Fine meters. I'd like to see you testing the resistors etc on video just to get a good glimpse inside! Regards - Andrew

[@dedskin1]

Hi , nice video , rare one , but not exactly explained how it works , im interested in how it works , i ordered similar one, not that good, little simpler , with just 3 tubes and input selector, just AC voltmeter , but i dont understand how those 2 tubes work or what they do , can somone explain, or point to explanation .

[@radiophysicsandelectronics6923]

I'm glad you liked the video. The following two videos describe the basic operation of VTVMs, kzbin.info/www/bejne/hoHdaHdmaZ2XjM0 and kzbin.info/www/bejne/fYOWo4VtqchmZrs. Are these helpful for your question?

[@materialsguy2002]

I am very much enjoying this series of videos and your methods of evaluation and investigation. I was curious about the square wave response of this meter and found the the answer and some good background on this family of meters here: www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1955-04.pdf

[@radiophysicsandelectronics6923]

Great find, thanks for posting it! There are continuations of the article in two additional Journal notes, www.hparchive.com/Journals/HPJ-1955-05.pdf and www.hparchive.com/Journals/HPJ-1955-06.pdf.