Creating a 7.5 volt DC battery to power my tube tester

[Jeffhuey1n]

When it comes to electronics, I’m the guy that sticks the paper clip in to the plug in just to see what happens. I found out and have a neat little paper clip scar for my trouble.
I’ve got an Accurate Instruments model 161 tester. It’s complete except for the 7.5 volt battery. I have an untested power supply that’s about 60+/- years old. I’m pretty sure I can get that to work but I am no electrician. I’m a helicopter mechanic by trade. Electrical stuff is fixed by the brainy guys. I swing hammers, turn wrenches and ratchet my way to a perfect flying machine. There are batteries that can work but will they work on a very old and low tech tube tester? Or, do I need to create one from AA or AAA batteries?
I appreciate any help that will help me out.
Ultimately, I’m going to get an old FM radio running that’s all tubes and dials.

 

[kellys_eye]

Do you know the load on the 7.5V supply? Batteries could easily handle it if it was for intermittent operation at under 1A. Series connected D-cells (5 off @1.5V) would do it. Get the right chemistry cells though.

A more modern approach would be to use a lithium cell(s) with suitable boost or buck converter but then you'd have to go to the expense of getting (or building) a lithium charger.

Having said all that and then searching for that device on t'internet I found a forum that doesn't speak too highly of that instrument - see post #3 on this link https://www.antiqueradios.com/forums/viewtopic.php?t=91152

 

[Jeffhuey1n]

Do you know the load on the 7.5V supply? Batteries could easily handle it if it was for intermittent operation at under 1A. Series connected D-cells (5 off @1.5V) would do it. Get the right chemistry cells though.

A more modern approach would be to use a lithium cell(s) with suitable boost or buck converter but then you'd have to go to the expense of getting (or building) a lithium charger.

Having said all that and then searching for that device on t'internet I found a forum that doesn't speak too highly of that instrument - see post #3 on this link https://www.antiqueradios.com/forums/viewtopic.php?t=91152

Thank you for the advice, I will look into the Li cell(s).
I’ve seen lots of reviews on this model. Not sure which to believe. Since I have it, I’ll get it functional and see how it looks from my perspective.
Again, thanks!