Hickok 600A

so I took the plunge and bought a Hickok 600A, that has supposedly been recently calibrated, I guess I will know more when I get home.
Since this will be the first ever tube tester I bought, any comments/input/do's and don'ts would be appreciated.
I have also read that calibration tubes are used to calibrate testers, are these a good idea to get?
Also, how can one tell that the tester is still in calibration.
Once I've had a chance to play with it, I'm sure I'll have more questions.
And yes, it comes with a full set of manuals and the dial is supposed to be in very good condition as well.

so after a lot of web surfing, found a supplier of 6L6 metal tube Hickok calibration tube, of which I have ordered one, cause sure as heck, even though it states 'recently' calibrated, it will need it.
I will probably do a restore on this unit, probably will need to at least replace the few caps and check on the old resistors as well.

MontanaWay wrote:so after a lot of web surfing, found a supplier of 6L6 metal tube Hickok calibration tube, of which I have ordered one, cause sure as heck, even though it states 'recently' calibrated, it will need it.
I will probably do a restore on this unit, probably will need to at least replace the few caps and check on the old resistors as well.

Good Idea. How much did htat set you back if I may ask. Looking for one myself.

this is where I got my 6L6 from, also, http://www.audiotubes.com/testcal.htm, here is an excellent calibration 'how to', mainly written for the 600A http://userweb.windwireless.net/~jimc/hickoktest.html

well I've tried my 600A for a little while, even went through the calibration checks/tests.
It really is not too bad, but it does need some tweaking, so I will do a full calibration in the coming weeks.
All the original resistors are well within tolerances, even the capacitors are!
So all in all, not a bad purchase I reckon, I'm sure it will give me excellent service for years to come!