What you see here are NOS tubes, that I purchased when I was their main distributer. 

Attention: All tubes ending on "M" are mesh plate tubes

 
 
Replace by EML Tube: 
AV300B
EML 300B
AV302B
EML 300B-XLS
AV32B
EML 300B-XLS
AV320B
EML 320B-XLS
AV2A3
EML 2A3
AV2A3M
EML 2A3-Mesh
AV5 / AV5M
-
AV8 / AV8M
-
AV20 / AV20M
EML 20B
AV30 no datasheet existed
EML 30A
 
PX25M
AD1M
Only for sale with Yamamoto AD1 amplifier
AD100
-
AV520B
EML 520B-V2 or V3
Zipped file
Datasheets of obsolete AVVT radio receiver tubes, like Marconi_R etc.
With AVVT tubes you need to know where you buy.  They really made some good stuff. 

I have kept track of the reliability of all tubes I sold, be registering the series numbers.  From this I can conclude, that the AVVT tubes from 1999-2001 were generally of very good quality.  For me, these are the only years from wich you can buy them without risk.  Specially in 2000 and 2001,  tubes were made of almost near-perfect quality with respect to reliability and lifetime.     Tubes from before 1999 can be good,  as long as they are not private branded.  So there must be only "AVVT" on those, and you're ok. 

Tubes from the older "VAIC-VALVE" brand (1997 and older)  are generally good quality. 
Tubes from 2002 or later, and so called "REF"  series I do not sell or buy. 
A factory test report is with each mathed pair. 

** Report **
The history of AVVT 2A3 tubes,  and 2A3-MESH tubes


 
TUBE TEST REPORT
Click   here    for a test  report on the AV300B by Enjoythemusic.com 
    .
TWEAK REPORT
Click   here   for a tweak report on a pair of Bottlehead parafeed 2A3 amps by Enjoythemusic.com 



Note about storage of AVVT tubes: It seems the maximum storage time of those  tubes is 5...7  years.  We do not really know yet, but this is what is seems like.

Does that mean older tubes are bad?   Probably not!  But... you need to take care of the following:

If the tubes must be stored longer,  they need to be run at full power for 20 minutes,  and two hours at normal power afterwards.  Then they can be safely stored again for another period.  In case a tube was stored longer than 8 years,  you may find the transconductance is 30% reduced or more.  So you must verify the original old DC test data, if they are still with the tubes.  In case you observe 20...50%  lower DC current, you will also have lower transconductance.  When this has happened,  do not use the tube, or your attemps may damage it permanently.    Such a tube can be brought back into good condition, when you have the equipment for it.  You can send it, and we can do that for you.   So far,  this seemed only necesairy with the Vaic-Valve 52B's  from around 1996, but it will probably also be necesairy with other tubes when the years pass by,  and older NOS tubes are found.

Remember,  this is only the case when the tubes were stored from the beginning, and never used ever since.   This is nothing unuseual, and it is almost normal with NOS tubes,  like 6SN7.  I bought a NOS pair WE-205D, that was only testing "fair".  After re-activation, it was exactly like on the datasheet again.  When the tubes are used every now and then,  they will just stay in good condition.    So here comes my old saying again,  that good "used" tubes can be better condition than random NOS tubes that were stored ever since.