Extender card design

[johndon2000]

I need a number of extender cards for tesing & repairing telecomms system cards... they can't be bought "off the shelf" and I think it would cost about $500/£500 to have someone design one for me... is it quite straight forward to design your own extender card?? (surely it's just case of designing a PCB with connectors on each end?!). Many thanks...

[Kremmen]

Provided you know the connector types yes, creating a design for an extender is straightforward. Whether it will work as intended depends. If there are high speed signals traversing the extension then you could get issues from signal propagation delays and trace inductances/capacitances. Real high speed signals see the tracing as transmission lines that need to be correctly terminated and the trace line impedance is also supposed to be close to the original. Meaning you need to pay attention to the PCB material, thickness, trace widths and spacing. Formulas for calculation can be found in inet.

[daedalus]

if you post a photo of one of the daughter boards connectors, ideally showing the tracing up to the connector we can probably advise how much of a pain its likely to be.

[johndon2000]

Hi, I've attempted to attach a pic but it won't let me!!

If you google "NT9X35BA" it brings up a pic...

Thanks

[dfmischler]

Is this the extender card you need?  Or maybe this one?  This was from a quick search for "nortel extender card" on ebay.  There are more choices.

[daedalus]

Hi, I just came across one of your earlier posts about this card when googling. Are you refurbishing these cards commercially, or do you just have a couple of dead boards and want to get the system up and running? From your previous thread it sounded like the latter. These guys have 7 of the same module on ebay for $80 each, which have been tested as good and come with warranty. http://www.ebay.com/itm/Nortel-NT9X35BA-DMS-100-EN-NET-X-PT-CARD-/300575313492

At that price you would need to have quite a few broken modules to be worth the time/effort reverse engineering a schematic for something this complex.

The connectors may well be proprietary (cant see from picture), if so that means scrapping a backplane and a module to make your extender. Even with your breakout, you will need some serious kit to sniff the traffic across the bus, and some serious time investment to decode what is happening. This really isn't worth it for a $80 swap-out.