For sale four rare 6550 tubes , Tung-Sol brand , made in USA.
The tubes are 100% pristine , NOS, the original boxes opened first time by me just for checking, and testing.
These are the early version , with dark plates , no holes , and triple getter.
All have similar factory codes 3226023-3,(1960 year).
Visible are near mint ..Perfect logos , shiny getters on the glass , clean pins.
Tested on my HICKOK tester and all four tubes measure between 485-500 1% (min. recommended value on this rester is 225)
Please see carefully the photos are the actual items that will be sent
I ship the items between 1-2 working days after payment via paypal, as registered parcel, (with tracking number) .
Thanks for looking, Giannis..