[R-390] R-390 Mechanical Alignment

Thomas Hoyer thoyer1 at verizon.net
Mon Feb 22 11:30:42 EST 2021


Working my first R-390 (Been through a few 390A's) and I have a question about the cam alignment statement in the manual (different sections and fig numbers depending on version you are looking at).
I'm looking at the TM 357-35, 1962 version and in section 73 a.1 it states that the image in figure 44 shows the cam position of the 1-2mc cam bisecting the alignment line and states this is for the "low" end of the band. I can agree with this as the slugs are fully engaged in the RF modules for low end adjustment.
It then goes on to say that the second IF cam shown in that image is shown at the high end of the band (indicator reading 999). When I tune to the high end of the band, my second IF cam is not in this position. It is almost in the opposite position where the slugs are fully engaged in the RF modules. I would expect the slugs to be out of the modules at the high end of the band so the trimmers could be adjusted. 
Is the text wrong and the image of the cam position for the second IF is really at the low end of the band - not the high?
There is another section in the manual where it references the same image and says that it shows the cam positions at 0200 - which all my cams seem very close to aligning with.
TomW3TA


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