This eBay sale is for 2x = TWO = A Pair of VACUUM TUBES
(aka) Lamps(RU) / Valves(UK) / Röhre(DE)
Condition: Lighly Used, Tested Strong with Balanced Plates.
Our Test Set : Recent 11/11/2021 Dan Nelson Restored, Upgraded & Calibrated
Mil-Spec TV7A/U Tube Tester with Digital Meter reading Transconductance (Gm)
in uMhos and mA Anode Plate Current.
TWO (2) 1972 & 1973 SELECTED Amperex Heerlen, Holland ECC88 6DJ8 Tubes
made for Hewlett-Packard's Professional Commercial / Military Test Equipment.
Two Vacuum Tubes TV7 TESTED Strong with Balanced sections
AMPEREX Heerlen, Holland 'Δ2L2' ' 'Δ3B2' ECC88 6DJ8 Tubes branded for HP (Hewlett Packard)
TEST RESULTS:
Both tubes tested : NO SHORTS, NO GAS, NO LEAKAGE, NO Apparent Microphonics Detected,
'Bogey' = NOS Amperex average Factory Vintage New Spec for a 6DJ8 / ECC88 Twin TRIODE = 12,500/12,500 micromhos (Gm) Transconductance( 100/100 TV7 meter reading) at 15.0 /15.0 mA (Anode) Plate Current (+/- 10%) .
Testing on any TV7 tube tester the Minimum Good value is 62/62
where 62/62 = 7,750/7,750 Gm . This represents about 62% of tube life
even though most tubes will still perform at 40% tube life such as high-quality vintage Euro tubes
(Mullard, Telefunken, Amperex, Valvo, Genelex, GEC, Mazda, RTF and other Euro tubes)..
The key is to build your high-end audio system around very efficient vintage speaker > 98 dB efficient .
Physical Characteristics ( tubes have identical internal construction, Both are closely date matched within 2 month of production)
Etched in glass : 'Δ2L2' & 'Δ3B2'= Heerlen, Holland foundry, manufactured Dec 1972 & Feb1973,
- Gray Thick "Boxed" smooth short plates
- Solid metal, "Dimple Disc" Top side Getter supported by 2 wide metal "lifts" - see pic
- Seamed tops
- Most white ink is visible : "Hewlett Packard, "Made in Holland " " 6DJ8" (see pics) vertical ink "74-16"
- These tubes were selected by Amperex and supplied to HP for use in High-End Professional Precision Commercial and Military Test equipment.
- We will ship both tubes in new Amperex tube boxes as shown in the pics including a printed page of this detailed description with test results.
Shipping:
We Pack Well and Ship Fast with many years of shipping FRAGILE Vintage Electronics and Vacuum Tubes
US: -All 50 states: Low cost USPS Advantage Ground shipping with Tracking, allow 2-6 days for delivery depending upon your delivery zone, We Ship from South Florida.
International Shipping : Insured with Tracking via Low-Cost eBay (GSP) economy small parcel consolidated Air-Freight Space Available, allow 10-40 days for delivery.
Please note some Country shipping restrictions currently apply, if your Country is in the Drop-down box under the Shipping Tab then "WE SHIP!".