• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Any new Tube Charts for NRI Model 70 Tube Tester?

Hi all,

I have recently acquired and completely restored and calibrated old NRI Model 70 Tube Tester.

It works perfectly, but I miss a lot of tubes in my chat (on build-in roll).

Mine roll is indexed as NRI-70 3-53," (assuming from 1953) and the previous tester's owner included another Tube Chart Roll, indexed NRI-70 3-59" (assuming from 1959).

I know it's old model, but the latest data I found was in NRI Journal from 1962, stating the latest Tube Chart of the time is indexed as: "NRI-70 1-61".

So now I know that I am missing at least two years of Tube Chart updates for sure and possible even more (not sure what year NRI stopped updating Model 70's charts).

Does anyone have later Tube Chart for NRI Model 70 than "NRI-70 1-61"?

Or have any helpful information about this tester, especially compatible charts I can use or data how to add a new tube to it's chart, etc?

Thanks in advance!

Old Hush

P.S. I have the original manual and schematic already.
 
Thank you very much, Old Hector!
In fact I found before the Precision Data site through another forum, but the link was broken and I was not sure which model to look at all.
This time I have spent some time cross-matching the two roll charts I have with Precision ones and I found that the best and most complete match is the Precision 600 chart with few Mods (two set of columns need to be re-arranged), but after finishing that and reverse-formatting it in Excel - I am proud to say that I have up to date most complete NRI Model 70 chart available!
I have checked about 15-20 various tubes form my stock and found all of them to be testable and results completely align with the previous test I did in a lab.
Thank you once again for the good advise!
Cheers!
 
Thank you very much, Old Hector!
In fact I found before the Precision Data site through another forum, but the link was broken and I was not sure which model to look at all.
This time I have spent some time cross-matching the two roll charts I have with Precision ones and I found that the best and most complete match is the Precision 600 chart with few Mods (two set of columns need to be re-arranged), but after finishing that and reverse-formatting it in Excel - I am proud to say that I have up to date most complete NRI Model 70 chart available!
I have checked about 15-20 various tubes form my stock and found all of them to be testable and results completely align with the previous test I did in a lab.
Thank you once again for the good advise!
Cheers!
Your post is a couple of years old now so not sure if this will reach you, but would you be willing to share the chart you managed to generate. I have an NRI 70 on the way from an estate sale and trying to get resources in order before I embark on restoration.