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Tube tester precision 612

jFF_Bulbo

jFF_Bulbo

Active Member
Hello. I recently bought my first tube tester, a Presicion 612. It seems complete, but i am expectant about doing it work. Well, as i read in other site, first is calibration, in order to that, resistors must be replaced. I have got the user manual and calibration procedure via
http://oldradios.50webs.com/precision/600/612cal.html
With this info i am almost ready to start to use the tester. In the manual is the list of parts. The resistor are detailed there, but i can´t find info about the watts the resistor must be. can anyone help me with a complete specification of the resistors? Thank you.
 
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I would suggest testing the resistors in place for values and not replace anything that falls within specifications.
Otherwise, there's 1-0.1uf/600v paper cap in there that could be replaced.
 
mibag6 said:
I would suggest testing the resistors in place for values and not replace anything that falls within specifications.
Otherwise, there's 1-0.1uf/600v paper cap in there that could be replaced.
Click to expand...
yeap. i know about the capacitor. I think i will be hard to find. I am in Mexico, so, i will start the search today. Do you know the watts for teh resistors? 1/4w, 1/2w,1 w? How much power could the resistor dissipate in 60´s? or i buy focusing me only in the ohms and let for last the watts?
 
Most tube gear used 1/2 watt resistors. Anything bigger than the rest will be some larger size. I would only worry about replacing them if they are off value though. Some aged better than others.

Should be no problem finding that cap. If the original value is 0.1mfd 600v, then a modern 0.1uf 630v cap will serve. Should be able to get those for very small money from anywhere that sells parts for guitar amps or antique radios. The type won't really matter, I'd honestly just find the best deal on a basic yellow film cap and stuff it in there. Anything you can buy now will be better than the paper cap it came with new.
 
Ok, I opened up mine for a peek and it looks like most of the resistors are 1/2W carbon comp of various tolerances. If you must replace any, I'll suggest getting 1%- 1W resistors, either carbon film or metal film as they'll be easier to find than comparable carbon comp.
One other thing to consider is that not all the resistors are associated with the tube testing functions ;and any that aren't can largely be ignored since you'll probably never use them.
 
mibag6 said:
Ok, I opened up mine for a peek and it looks like most of the resistors are 1/2W carbon comp of various tolerances. If you must replace any, I'll suggest getting 1%- 1W resistors, either carbon film or metal film as they'll be easier to find than comparable carbon comp.
One other thing to consider is that not all the resistors are associated with the tube testing functions ;and any that aren't can largely be ignored since you'll probably never use them.
Click to expand...
Thank you!!!!
 
gadget73 said:
Most tube gear used 1/2 watt resistors. Anything bigger than the rest will be some larger size. I would only worry about replacing them if they are off value though. Some aged better than others.

Should be no problem finding that cap. If the original value is 0.1mfd 600v, then a modern 0.1uf 630v cap will serve. Should be able to get those for very small money from anywhere that sells parts for guitar amps or antique radios. The type won't really matter, I'd honestly just find the best deal on a basic yellow film cap and stuff it in there. Anything you can buy now will be better than the paper cap it came with new.
Click to expand...
Well, thank you a lot!!!
 
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