开云体育

I have just recently started collecting old Hewlett Packard test equipment, though I have been actively collecting and restoring Tektronix equipment for over a year. I started my HP collection with several of Nixie display counter-timers (5245L, 5246L, and a 5326B), a function generator (8116A) and a bunch of bench power supplies (6211A, 6212A, 6216A, 6217A and 6218A) and have been really happy with everything. My most recent acquisition is an 8660C synthesized signal generator, and while searching for a service manual I ran into a confusing situation that I have seen before with HP equipment: the model number appears to have been reused for at least one other instrument (in the case of the 8660C it is also the model of a phase modulation test set).

Unlike other model number collisions I have seen, these two instruments are not separated by decades: the 8660C test set is from 1975, while the 8660C signal generator is from 1981. Is there some explanation for why HP would reuse instrument model numbers like this?

-- Jeff Dutky

First of HP used to build instruments sometimes for decades, the 8660 for example was built for almost 20 years starting with the A and ending with the D model , the changes mostly were applied to the front panel.
As far as the testset concerns HP sometimes designed, build and sold accessories that were meant to support the service and/or calibration of a certain instrument, in this case the accessory was branded with the model number of the unit it was supposed to support followed by a letter and 2 digits, for example 8660C-K10 .
Altough this systematic can be a bit confusing it was quite common with HP back in the pre Agilent days!