[Hallicrafters] SX-42 problem

[Robert Byrnes]

I have been working on restoring an SX-42 that had been worked on by 
someone else. I have got it working but I am having a problem with the 
RF alignment.
The low end of all of the bands will fall in very close but the high end 
of all bands is way off. For example, on the BC band 600 khz falls in 
nicely but at 1500 khz  I will pick up a station transmitting at 1320 khz.
The high frequency trimmer will adjust the upper end but only about 10% 
of what is needed. If I move the bandspread off of zero the high end 
starts to come down. When the bandspread gets to 70 on the dial all 
bands seem very close at the high end.
At this point I have stopped.
I don't know if the problem is a bad componet, an alignment problem of 
the bandspread assembly, or something the previous owner did.
I could not find a production run number to use the correct schematic. I 
was told that it was stamped "inside the chassis" but I did not find it.
I would appreciate any comments or information.
Bob ke6mtt