I'm looking for a way to replace the broken meter in my Hickok 752A. I've used it to test tubes for my R390/URR so I hope this is enough on-topic.
The schematic calls for a full-scale of 280 uA and a resistance of 645 ohms. Since finding one like that is not very likely, I'm wondering if I can adapt a different meter and am considering a 200 uA meter with an appropriate shunt and a new printed scale.. I've found a Simpson Model 29 - specifically a part number: 03980. That meter has an "AC Impedance" of 1100 ohms (not sure why they spec a DC meter with AC Impedance...). I presume that shunting the meter will drop the internal resistance but it likely won't be the specified 645 ohms so not sure how much that will affect the way it would work in the circuit. Am I asking for trouble trying to do this? The original meter is dead so I really don't have anything to lose. Thanks, Barry - N4BUQ ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:R-390@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
