A progress report re the wireless.
My MS156 to RP SMA connectors arrived and work allowing an external aerial. The cable provided was however very stiff and springy so any small deflection put stress on the coupling so I guessed that to be permanent mounted in the case would be difficult without a clamp stopping the strong pulls on the connector.
In the end I got the same connections with adapted U.FL Mini PCI leads so I need not have wasted my money on the MS156. If a short piece of ordinary solid copper telephone cable wire is inserted into the female socket of the U.FL Mini PCI connector and then this wire is nipped off so that about 0.9 mm protudes. Between 0.8 and 0.9mm looks like it would work, too short and it does not switch the RF and too long and the connector won't snap on and damage may be done. About 0.8-0.9 mm is as short as my snips would cut it whilst the wire was pushed into the socket. The total wire length is about 2mm with this cut. The U.FL Mini PCI leads that I have are a much more flexible cable and are easy to bend about. Both the MS156 and the adapted U.FL Mini PCI seem to need a solid push to get them to snap on with a nice click.
It all worked well enough on a bench to encourage me to drill holes to mount the RP SMA connectors on the side of the router sitting behind the PCB. i.e. the side with no components. This way round the board drops back into the case and then the leads run over the top of the board where there is a big space and the RP SMA connectors fit through a hole each side. They then hold the board in place if the hole is well positioned
I have compared the wireless with a DG834G wireless using inSSIDer and measured before and after the mod. The mod boosts the signals so that rather than being 2-3 db less than the DG it becomes 2-3 db more. A gain of about 5db in inSSIDrer and definitely 1 bar on the windows wireless display. Possibly better if your lucky with antenna orientations. It seemed very useful but after leaving it for a couple of days I have to say that signal strength does not seem to be the cause of the poor wireless behavior. Things still loose connection and there seems to be need for a wireless restart sometimes
I am sufficiently disappointed to have now removed the connectors and turned off the wireless --- I now have two extra small ventilation holes left in the side of the beast. The wireless is back where it was on inSSIDer and connection reliability is, I think, just the same with and without the antenna.
It all provided some amusement
and no harm seems to have been done apart from more ventilation!
in the router!