OK... I'll play... First, I'm also a fan of Marcin's testers and have been very appreciative of his excellent customer support!
The design below came about following a conversation with Jeff W... My thanks to him for the impetus to do (overdo?) the project! I also find built-in meters to be very handy. Current meter below is a 0-999 mA ebay part with the stock 0.050 ohm current shunt replaced by a 0.50 ohm part. Scale is now 0-99.9 mA. Decimal point is left to the user's imagination. Volt meter is downstream of the re-purposed current test toggle switch. Meter now reads the HV supply output voltage or the tube anode voltage depending on the position of the switch. Current control is by an active current limiter... Current will stay constant (or be limited) if a tube heals while running. First image below shows the meters reading 2.8 mA tube current with the HV supply at 170 VDC. The tube below sustains glow at 139 VDC downstream of the limiter circuit as shown on the second photo... button caps were put back on switches after these photos were taken. Meter holes cut with the vertical mill at work, squared off with a small file. PCB SMD reflow was lead free with a Whizoo reflow toaster oven. Power supply needs addressed with a +12 VDC to +/- 5 VDC floating output switching supply module at the lower right of the pcb. <https://lh3.googleusercontent.com/-RIGuyXOu12g/WZoDwMLI7eI/AAAAAAAAATc/LqhX9U0yWUodA4sq_efrO8Si4zA1ccqGACLcBGAs/s1600/IMG_20170519_184558178%2B%2528Large%2529a.jpg> <https://lh3.googleusercontent.com/-dWmbfwjYxIg/WZoDrnqTgNI/AAAAAAAAATY/LAnbn-zrXTMGdXpHfEFb6mK94pGv0SUrQCLcBGAs/s1600/IMG_20170519_183427767%2B%2528Large%2529a.jpg> <https://lh3.googleusercontent.com/-hk-j0is7wWI/WZoELtOUVKI/AAAAAAAAATo/Q_i3nkI-imw_HgZugIMuK_sn0LoAPiJWwCLcBGAs/s1600/IMG_20170519_143127830%2B%2528Large%2529.jpg> <https://lh3.googleusercontent.com/-sIaREJPc-cs/WZoECmp4ENI/AAAAAAAAATk/1_ocL9fnHRUCusIYDm6EVgL-QJtLtRosQCLcBGAs/s1600/IMG_20170521_103736930%2B%2528Large%2529.jpg> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/eae83387-aedd-45dc-9050-c32ba970f1f5%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
