HRO-60 Serial Numbers

[ashart]

My new HRO-60 wireless receiving apparatus bears serial 366 0616.

Anybody have reference material that reveals the date of manufacture?

Thank you.

-al hart, w8vr

[KM1H]

The manual for ER 366 will show month and year on the back cover. Since the 60 was built from 1952-68 and only a few manuals are on BAMA the next best thing to do is look at the caps used. The early ones used paper, then went to a mix of paper and mylar, and then to mylar and disc ceramic. The final run used all discs except for the one mylar at the transformer secondary

ER 459 is 1/56 so yours is obviously quite early. National used sequential ER numbers across all the product line. Mine is ER 345.

Carl