1 pc of very rare and sought-after genuine ECC801S premium audio tube with ring-getter made by Telefunken Ulm with <> diamond mark at the bottom of the glass base and code U2106403t. Presumably unused from the laboratory of a developer of measuring instruments (slightly bent contacts, etc.), tested as a precaution on my Funke W19S with good values at minimum 8.0/10.5 mA (where "good" starts at 7.0 mA). Shipping worldwide air mail, PayPal welcome. Please have a look also to my other items for more tubes and radio parts.

ID: Box 133 (schwarze Box)