[R-390] URM-90 LCR bridge (Bill Smith) ZM-11 Manual (OT)

[K2CBY@aol.com]

The ZM-11/U manual posted on BAMA leaves a lot to be desired. Apparently it is a preliminary draft based on the prototype, rather than the production unit.

A lot of the component values shown on the BAMA parts list and schematic are high precision specialty parts while the box itself uses garden variety 5% and 10% parts for most everything except the bridge standards and the meter multipliers & shunts.

The biggest problem is that the BAMA voltage/resistance diagram and chart are incomplete. A lot of the values are shown just as lettered footnotes, but the footnotes table is not present.

To further complicate matters, there is also a ZM-11B/U model which, I am told, uses a slightly different tube lineup.

I posted a query similar to yours to the "Milsurplus digest" page a week or two ago and was referred to "http://www.pacificsites.com/~brooke/CDW.shtml". Fair Radio also advertises a reproduction of a ZM-11/U manual. I have been trying to find out (without success) which version of the ZM-11 these offerings describe before I shell out hard money for either. Any help? Clues?