Pair
12BH7A
Sylvania
NOS
same code = 7526
Vacuum Tubes
Smooth Gray Plates
Halo Getters
Copper Grid Posts
GM Tested at 4250/4350 & 4300/4600 micromhos

on a calibrated Westmore 501 (Triplett 3444) tube tester

Min. & Avg. New Triplett chart = 2000/2000 & 3100/3100 micromhos

All tubes are fully guaranteed for 30 days. Each is tested for emission, dynamic mutual conductance, shorts, & gas as applicable.

*We use the following testers:

*Dan Nelson calibrated TV-7D/U with sweep tube adapters, & digital meter with plate current test at 150V.

*Paul Hart calibrated/modified Westmore 501 (Triplett 3444)

* B&K 747B calibrated

Test results will differ between various testers for many reasons such as technical design, aging components, etc. So while test results are a good indication of quality there can be some difference between the many differently designed & maintained testers.

The following definitions are mine as I use them.
'Balanced' refers to comparing the gm test results between the lowest to the highest identical
        sections of a single tube. Within 3% I consider to be 'Balanced'

'Matched' refers to comparing the gm test results between the lowest to the highest of the identical sections of a set of tubes.
     'Matched' I consider to be within 10%. Some call similar 'Gold Matched'
     'Closely Matched'  I consider to be within about 5%. Some call similar 'Platinum Matched'
     'Tightly Matched' I consider to be within 2%.
*For Multiple item purchases click the "Add to Cart" selection for each item
*After all items have been added to your cart click on "Request Total From Seller"
*An invoice will be returned with the correct 'combined shipping' & total due when I next check my ebay account

*If your purchase is not fully satisfactory please contact me .

  • International customers welcome: Please do not ask for false value on the customs form
  • For combined international shipping you need to send an email listing the items you want to buy and I will create a single listing for all the items that you can buy with the corrected shipping charge

*Tubes will be shipped in a cardboard box with packing, usually bubble wrap or sheet foam

       Packed for protection

       Packed for ease in unpacking

*Tubes will generally be cleaned

       Clean tubes will radiate heat better & operate cooler

*Pins will generally be straightened/cleaned as needed

       Cleaned pins make better electronic connection

*Most tubes are shipped in their boxes (or replacement boxes)

       I often repair a box so it will function properly

*I try to get your package in the next mail after receiving your order.