There were at least 3 or 4 iterations of the HQ-180 Series of manuals plus several addendums issued.
Through the 60's as costs became important, part changes and/or circuitry changes initiated by the product manager were often brought to the manufacturing floor to be implemented, but updates to the printed manual were often never done.
Let me also point out that initially, when introduced, there were separate manuals for the HQ-180, HQ-180A, etc. It was later that they came out with the "HQ-180 Series" which included the HQ-180, HQ-180A, HQ-180AX, and the HQ-180XE.
The first "Series" manual is the one shown in the previous post with Part # 52787-1.
The last "Series" manual, I believe, was generated in ~1968/69 when Hammarlund was now owned by EAC. Part # of the manual I have is 9001-06-00001 Issue 3. A 2 page addendum was also issued for this manual.
Finding the 100% correct documentation for your receiver probably would be very difficult. Even the manual that was included in the box with the receiver may not have had a 100% schematic that agreed with the physical receiver. When initially purchased and for some time thereafter, the customer was more interested in features and performance rather then a dissection analysis between receiver circuitry and schematic. 50 to 60 years later, that scenario may sometimes be flipped around
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