Well, I have bad news and good news. The bad news is that I was
unable to fix my RL01 cable. I tried a few approaches to reconnect
the pins I could see were disconnected and wasn't able to get it to
work. However, the good news is that I was able to acquire another
cable and that fixed the problem entirely. In fact, the PDP-11/73
booted off the RL01 pack the first time I powered it up. I have three
packs and was able to read all of them. One contains RT-11 V5.5,
another is a TSX-Plus system disk but appears just to boot RT-11SJ.
It does have lots of files on it with ".tsx" extensions but doesn't
seem to boot TSX. The third is a blank scratch pack.
I'm now in the market for a cable and breakout panel (cab kit?) for
my RQDX3 controller so that I can connect an ST225 drive and an RX50
floppy drive to my 11/73. I know it's possible to build one of these
but from my experience with attempting to fix the RL01 cable, I don't
think I want to tackle that project. If someone has a cable and
breakout panel they'd like to sell please get in touch with me.
Anyway, thanks to everyone who has given me help with this machine. I
now have a working PDP-11/73 with 1.5mb of memory, an RX02 floppy
drive and an RL01 hard drive and it's all working!