I'll be a contrarian and ask, Do you really need a tester?

I have restored many tube radios, including some boatanchors. I own a couple
of testers, but don't use them often. Usually, the tester only tells me
something I could find out another way ("That's a dud -- duh").

As Colin mentioned in another post, marginal differences between tubes may
not make any noticeable difference in how the radio performs. Many times, I
have replaced a "weak" tube with a new one, only to find that the radio
performs exactly the same.

There are exceptions, of course. The horizontal and vertical circuits in a
TV may be fussier about tube condition than the circuits in a simple,
consumer-grade radio.

One case where a tester is very useful is if someone gives you hundreds of
loose tubes. It can quickly sort out the duds from the keepers.

The best test of all is in a working circuit for which that tube was
designed.

You can test tubes without a tester if you have some working radios and
known-good tubes in the house.

For example, you can test a suspect tube by putting it in the same type
application in a working radio. If the radio still works, the tube is
"good."

You can also do the reverse. That is, substitute a known-good tube in your
subject radio and see whether the radio works better. If so, the suspect
tube was "bad." If not, it was "good" (or at least you have ruled out that
tube as the *sole* problem -- many unrestored tube radios have multiple
problems such as leaky capacitors.)

So, ask yourself, Is this something that I really need and will use often?
Or will it just be another Thing cluttering up my life?

If you're determined to get one, I'd buy a cheap emission type tester and
try it out for a while. You can always buy a fancy tester later, if that
seems necessary.

Just my $0.02 :-)

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html