[Amps] For any technicians

[Will Matney]

I received an original copy of a manual for a Conar model 282 RF signal 
generator with some other test equipment I bought. I had to tell this 
even though it doesn't concern amps in particular. The manual included 
two engineering change notices in it. Now if any has serviced test 
equipment like me, you'll know that for most old equipment there's no 
manulas for, and you replace what's bad by the part number or codes. 
First off, the generator in mention was a cross between two. It stated 
as follows;

"Your model 282 signal generator incorporates design changes that 
improve its serviceability and make it easier to adjust. The manual 
reflects these changes and is marked model 282; however, the front panel 
is labeled model 281. This is correct because no external changes have 
been made. If you have any questions or need technical assistance, 
please let us know that you have the model 282".

Now to me, this sounds like they were getting rid of any left over 
cabinets before a model change. If a serviceman didn't know this, he 
would be asking for parts and service on a 281! Next, there was a paper 
called "special instructions" which stated;

"Crystal CR30 Marking; You may find that crystal CR30 is marked 
incorrectly as 6.5546 MHz. The manufacturer made this error during the 
marking process. The actual value of the crystal is 6.5536 MHz and can 
be used in this instrument".

Now what if someone replced the crystal with the marked value and never 
could get the rf output correct? I would think any manufacturer would 
have made the crystal supplier re-do the whole lot! The reason I'm 
mentioning this is I wonder just how many other manufacturers have been 
guilty of this? Has anyone heard of anyone else doing the same on kits 
or manufactured equipment?

Will