I have a Conar ( Division of National Radio Institute) Tube tester model 224
for sale for $15 plus 15 pounds shipping from my Zip.This is an Emissions
tester that will test the older 4,5,6,7 pin tubes and
Octals,Loctals,Nuvistors,Decal*,Magnoval,Novar and Compactrons.This tester
will
test for Emissions,shorts and leakage.The inside of the tester looks nice, the

outside is banged up with lots of scuffs and one of the lid`s hindges is
broken.I was able to figure out how the tester works and i tested a few tubes
and it worked OK . There are no operating instructions and only a few pages of

tube setting data.You will have to find instructions and tube test data on the
Web.

Rick Yerke
101 William St
PO Box 392
Moscow Pa. 18444
USA

Emissions testers are not all that useful. A transconductance tester
is what you want.

If you are only interested in audio types and if you have a reasonable
bench to begin with, it is often better to build a simple test fixture
so you can test the types you need with minimum ado. Most of the
complexity of any tube tester is the need to be able to test thousands
of types when most modern audio hobbyists will be testing only four or
five classes of tube-basic types sharing a similar pinout and base.

Tube testers are more of a hindrance than an asset to troubleshooting
until and unless you know what you are doing.