R4LC Reception Problem

That's a new one on me, first time I've see reverse logic on the TMCC reception.   I know of no fix other than a new board.

John has forgotten more than I'll ever know.  But spitballing, perhaps the antenna mount is loose on the board, and the act of attaching an antenna to it causes continuity to be lost, leading to a no signal condition?  If you look at where the antenna mount is soldered to the board with a jeweller's loupe, do you see any cracks?

@gunrunnerjohn posted:

That's a new one on me, first time I've see reverse logic on the TMCC reception.   I know of no fix other than a new board.

Yup, it's a head-scratcher here as well. Doesn't make a lot of sense.

@Ted S posted:

John has forgotten more than I'll ever know.  But spitballing, perhaps the antenna mount is loose on the board, and the act of attaching an antenna to it causes continuity to be lost, leading to a no signal condition?  If you look at where the antenna mount is soldered to the board with a jeweller's loupe, do you see any cracks?

Your hypothesis is a good one, and I reflowed the solder on the antenna connector to be certain. Unfortunately, no change.

Everyone's thoughts are appreciated!

TRW

I have a similar but slightly different problem on my Lionel VL Genset switcher that has a diecast shell.   With the shell removed I get perfect reception to the radio board (RCDR).  When I set the shell back on it still works but when I install some screws holding the body to the frame I lose reception.  I have checked continuity between antenna lead and shell  (infinite Mohms).  Insulators are all in place where the handrails penetrate the shell. When checking continuity of the handrail antennas themselves it’s good from the antenna wire lug out of the shell adjacent to first handrail stanchion (bare spot on handrail).  However I can’t get continuity to the end of the handrail tip where I sanded it with a Dremel.   Seems like my one piece handrail has an open along the path.   But how can that occur on both of the handrails?