2 STRONG MATCH SYLVANIA 1276 TUBES NOS NIB COLLECT/REPLACE WESTERN ELECTRIC 205D

Description

TWO (2) early Vintage (as they are from the 1930s) Tubes/Valves. Both same codes (352). These tubes are in their original boxes which still have retained their structure and printed text/colors fairly well. More important, the tubes are in very good condition, including the Bakelite bases, pins and the silk screen prints. The etched tube identifications on the glass are legible, on one tube somewhat less easily. Impressive looks, large traditional ST ‘Coke’ bottle style, shiny black ribbed plates, top and bottom mica, bottom silvery clean 'angular D shaped' pan getters. No debris, no fog, no rattle.
Tested on my recently rejuvenated, enhanced and calibrated Hickok 600A with a socket
adapter
.Although these tubes fit loosely into the conventional 4 openings socket, there is a side pin which is aligned with the Grid pin and
should go into opening #3
; but even then without an adapter, the filament pins won't make electrical contact because all pins are somewhat shorter and equally slender compared to conventional 4 pins of a later period of tube history. Most testers in use, even vintage but still of a ‘younger age’ may not have test data entry for 1276 tube but it is the same as for 2A3 or 6A3, except for filament voltages.
1276 filament voltage is 4.5 Volts!
Typical Mutual conductance with Hickok 600A for a new tube is 3000 microMhos, the Minimum acceptable being 2100 (70%).
Both tubes
test STRONG, Mutual conductance
2800
, No shorts, No gas/Grid emission, Longevity (not immortality) very good. (for the Hickok 600A, the nearest Filament voltage is 4.3 Volts. My educated guess is that with the optimal voltage, the mutual conductance would have read the nominal 3000! (Just a thought, unless the smart Hickok engineers had compensated with the tube data settings.)
All these characteristics make them desirable for Collectors, for Replacement in compatible Movie Theater epoch sound equipment or in a New design.
These tubes are scarce to rare especially unused, in their original boxes and well preserved. I believe they were manufactured by SYLVANIA exclusively for the  Altec Service Company*, most likely with involvement and 'blessing' of Western Electric, as a replacement  (electrical and socket compatibility, quality and extensive longevity) worthy  of their  famous and lasting several thousand hours almost ‘immortal’
WE 205D
tubes used in Western Electric Amps/ Sounds Systems/ Broadcast Equipment in Movie Theaters etc. at home and abroad of a bygone nostalgic era.
*please see last picture of the box.
NOT TESTED IN AN ACTUAL APPLICATION CIRCUIT.
At the end of the day, regardless how sophisticated the tester or impressive the numbers:
"The PROOF of the TUBE-ing
Is in-circuit PERFORM-ing"
Make sure of their suitability for your specific needs.
Make sure when working with tube/valve electronics that you are Cognizant, Comfortable, Cautious and with Company.
Please look at all the pictures (actual, NOT stock, as they are part of the description) and ask your questions to avoid buyer's remorse. But be aware that someone else might grab it in the meantime and you are left with procrastinator's remorse!
Payment within 3 days would be appreciated.
No returns. Sold AS IS.
Smoke free environment.
PS
: I came across a very interesting Japanese site full of technical information about  the Sylvania 1276 tube and details of replacement for WD 205 fitted equipment. Interestingly, this is no other than the Altec Service Corporation Bulletin dated 1938.
In compliance with a recently introduced eBay restriction I cannot include the web address in the listing. If you are interested, I believe I may be able to forward it through a message question without making it part of the listing!
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