Below each frame there is a bit of rhyme in German telling the tale.
Even the German Schnauzer in the last frame knows the man should have bought a Telefunken rohren!!!!!
PQ6689/E83F PQ (Premium Quality) logo is on other side of tube.
Evidently this tube sat for 4 years before being boxed. Note that this box has North American Philips written on it.
Month=third and fifth digits=08=August Year=fourth digit is the year, 8=1968. Genuine Telefunken Germany (Berlin and Ulm) made tubes have a diamond mark molded into the glass between the pins.