Advice on a tube tester

Super risky buying used tube testers.  Once in a while a really nice one pops up that has been freshly serviced but it’s rare.  
 

Just about every eBay ad says clearly , no returns and many say powers up , not tested.   I was fortunate to buy a mint Hickok 800 that I saw work.   When I received   It I tested several tubes that were Amplitrex tested and my results matched those numbers closely.  I consider myself one of the lucky ones.  Most need service 

Just remember, most are pretty crappy.   Nice ones cost $$$ but are worth it 

Adjust for inflation my tester was over $1600 in 1959. It cost $159 new 

If I did not see a video of mine in use, with 6 v power and 12v preamp tubes I never would have taken the chance.  Plus it looks like it belongs in a museum but that doesn’t mean anything other than someone took care of it.  It suggests a hobbiest used it and it wasn’t the shop workhorse. 
 

remember everything had tubes back then.  Most of these testers have seen heavy use and it shows.  

My system is all tube as well.   What prompted me to buy a tester was actually the fact that I sent a NOS rectifier to the guy who built my amp.   I actually sent 2.   Unfortunately one was shorted and failed during the amp's burn in.   Fortunately for me , Matt over at Toolshed Amps is a good guy and replaced the damaged parts , a cap and PS at no additional cost .   After all, I sent him the tubes.  I didn't buy his basic tube set , I went NOS and WE 300b.

So the night he reached out to tell me I had a bad tube, I said that's it !  I'm buying a tester.   It took a while to find that Hickok but it arrived right before I got the amp.   

I figured if I'm playing with 4 pin antique tubes, NOS , and rectifiers I am a fool not to buy one.  I will never plug a tube in without fully testing for shorts, filament good, and Gm.   Turns out another one of the 6 NOS 5r4gy was shorted, fortunately that tester identified it and prevented a catastrophic failure.   Thing paid for itself one week into owning it 

I have a Hickok 800 , it’s perfect for screening tubes and preventing your amp from being a “tube tester”.   It’s more than adequate and fairly accurate.   If I were buying and selling tubes I would get a 539 or military type Hickok

Smart move.  That’s the benchmark in tube testers 

I spent some money, but I quickly found what tubes were great, who to trust , who screwed me.   
 

The 800 will test my 300b ,205d , rectifiers, 12**7,  EL84 , EL34 , 6l6, 6922.   So for me it was money well spent