On Tue, Feb 13, 2024 at 04:19 AM, Don - AC2EV wrote: "How does one tell if the scope is a low serial number or a high serial number? My unit is #107437 as indicated on the front face. There¡¯s no letter indicator."
The "high" serial numbers for the 465B are S/N B0600000 and up. That's how it is stated on the cover of the high S/N version of the 465B service manual.
The 465B high S/N manual is marked copyright 1982. The previous version was marked copyright 1979.
The leading alpha character designates the manufacturing location and I am not sure how Tek controlled the assigned numeric characters with respect to the alpha characters. Hopefully, someone can clarify that.
Note that the High/Low break point is different for the 465 Model.
Tom Phillips