[Pryso]

A few months ago I bought two vintage tubes from eBay dealer west_coast_components.  Unfortunately I didn't have the chance to test them until a couple of weeks ago.  The bad news was one failed the grid emission test for gas.  So I contacted the seller, explaining the situation.  He offered to replace the tube, no questions ask.

Considering the time that passed I believe this was great service.  It is too late to provide positive feedback on eBay so thought I'd acknowledge his service here.

[FullRangeMan]

Great seller indeed, I had no such lucky with VacuumTubes.com for plain 84USD.
Iam boughing tubes since 1998 and have just this mishap, never had any prob w/sellers from China Ukraine Moldavia Bulgaria Russia Poland etc
What are the tubes you have bought?

[Pryso]

I got two 5852 Bendix (6X5GT) which is recommended as a great rectifier for my Sachs SP-14.

[sfox7076]

Not sure how that tube could fail grid emission.  It doesn't have a grid. 

[FullRangeMan]

He mean say Cathode emission failed, 5852 have two cathodes-full wave rec.

[sfox7076]

He said grid emission for gas.  It could be a gassy tube.  It could have heater cathode leakage I guess.  But if the tube was tested wrong, it could still be good.

[FullRangeMan]

Thanks for clarify.

[Pryso]

Hey guys, I know just enough to get in trouble. 

I have a B&K 707 tester.  Two of the basic tests are with buttons labeled Shorts and Grid Emission.  When a tube is good, an indicator needle remains fixed, but when bad it swings into the Reject area.  More detail is found in the manual which states "Gas, grid emission, or even obscure grid-to-cathode leakage are all disclosed by an exceptionally sensitive grid current check.  This test will reveal as little as 2 or 3 micro amperes of current in the grid circuit."

Not being an expert in electronics or vacuum tubes I simply go by what the B&K tells me.  And since the test button is labeled Grid Emission, that is what I reported when it failed, rather than the longer definition quoted above.  One of the two NOS tubes passed both Shorts and Emission button tests, the other failed the latter.  Because I don't know more about electronics I'm not inclined to use any tube that fails either test. 

[FullRangeMan]

THis 707 can test rectifiers? it have a test socket for rectifiers or 5852?

[Pryso]

FRM, since the 5852 is a substitute for the stock 6X5GT that was how I tested it.  So no, the 5852 was not itself listed in the B&K tube chart.

As reported, one of the NOS tested fine.  A few days ago when I received the replacement it too tested good.

[FullRangeMan]

OK, it would interesting test this tube again.

[Pryso]

I have no idea why it should test differently?  But no doubt you know more about tubes than I do.

So I pulled the bad one from the trash and tested again (3rd time actually).  Again the needle swung well into the Reject area. Back to the trash. 

[FullRangeMan]

I no expert really, I was think if you would activate the getter for some hours to clean the gas?
By what you said now a change already occur.

[A_shah]

A few months ago I bought two vintage tubes from eBay dealer west_coast_components.  Unfortunately I didn't have the chance to test them until a couple of weeks ago.  The bad news was one failed the grid emission test for gas.  So I contacted the seller, explaining the situation.  He offered to replace the tube, no questions ask.

Considering the time that passed I believe this was great service.  It is too late to provide positive feedback on eBay so thought I'd acknowledge his service here.

I had the same issue with this dealer on Ebay , when I requested a replacement " No questions asked he just sent me an extra pair of Bendix 5852 .

[doggie]

If we are praising good dealers then I can recommend Brent Jesse and also Viva Tubes.