[Collins] R-388 issues

[Howard Holden]

Working on an R-388, and there are some tuning issues. 

First, I made sure all the slugs travel freely within their respective cores before turning ANYTHING. And I’ve adjusted nothing, powered up nothing. AC cable has to be replaced, and I’ve restuffed the power supply cap. 

No gears appear broken, nothing loose that I can see. The drive cable/spring assembly is in place, and detent balls are there.  

Two problems: 

1. on band changing the dial drum stops rotation upward at the 26.5 Mc band, and downward goes past the .5 Mc band to the 27.5 Mc band. 

2. On tuning the shaft driving the IF slug cams starts rotation at the low end of the tuning dial, and stops about 3/4 of the way up. The front cam at that point is hitting the bar supporting the coil slugs. The two cams are not in an opposite alignment which I think they should be, but from the dust/crud on everything it appears that neither have rotated out of position on the shaft. Should they be 180 degrees apart? I could not find any info in the TM 11-354 (?) on the tuning mechanism showing that detail. 

One more minor thing – is the neon lamp at the antenna input necessary for operation in the average shack with 100 watt class transmitters? The one on this RX is broken. 

Any pointers gladly accepted!

Thanks, Howie WB2AWQ/7