[hpsdr] Fitting Alex

[Chris Smith]

OK, I'm going to expose my stupidity again here, but has anyone else had mechanical problems fitting the ribbon and 3-wire cables supplied with Alex?

After studying the logistics of the problem for a while my assumption was that the ribbon cable should be routed under Mercury i.e. between Mercury & Penny(lane) and into the socket on the front of Mercury. Then fold the ribbon back along the underside of Mercury so that the ribbon was exposed in front of Roger Rehr's great back-plate for only a few millimetres. Likewise the 3-wire cable.

First problem: the keyway pip on the IDC connector at the Mercury end of the ribbon cable was too proud and fouled the left-hand side of the aperture in the back-plate. A little light filing with a fine (now clogged with plastic) file cured that problem.

Next problem: the 8-way connector, of which only 3 poles are used, is so long it forces the ribbon cable onto some very sharp protruding wire and pin ends on the underside of Mercury. A couple of right-angle folds in the ribbon immediately behind the back-plate cured that problem.

Next & related problem: the bend in the 3 conductors of the other cable is very sharp and there is a danger of the insulation being damaged and contact made with the aforementioned sharp bits. No obvious solution apart from judicious application of insulating tape but that is in danger of being pierced. The problem here is that the 8-way connector forces the gap between Mercury and Penny(lane) to be just greater than will allow the BNC socket on Penny(lane) to slide easily into its aperture in the back-plate. I looked at the possibility of cutting small slots in the top of the 8-way shell to allow the conductors to pass out at right-angles without fouling on Mercury's under side. I haven't done this yet but may do so next time I break the installation down for any reason. 

So, how have others fared in this respect? I guess if you don't use the back plate there isn't any problem. I do like to use it and would welcome any tips on obviating the problems I've outlined.

Cheers & 73

Chris G4NUX 
 1315559810.0