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,

• Tube 1 ('Δ2L2'):    97.0 / 99.2 = 12,125 / 12,400 uMhos @ 18.2/18.2 mA Anode Plate Current 

• Tube 2 ('Δ3B2'):    102.5 / 104.7 = 12,812.5 / 13,087.5 uMhos @ 20.0/20.8 mA Anode Plate Current 

'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!".

• Thank you for looking!