Looking for DEC DZ11 20ma dist panel and LA34 tractor feed assy.

On Mon, Jun 17, 2013 at 08:07:25PM +0100, Tony Duell wrote: Oh good point! My recollection is A + B => E (EIA) and C + D => F (20 mA), but could be wrong (in each case the first one is a Unibus board and half-populated dist panel, the second is a second Unibus board as an upgrade to fill out the other half, and the third is both for all 16 lines at once). And is the DZ11M the 8-line EIA FCC version? Is there a FCC cab kit for 20 mA? Definitely agree that the level conversion should have been done in the dist panel. Does anyone know what's inside the hash filter that mounts in the sheet metal on the back of the 20 mA bulkhead (I forget whether the EIA version has something similar -- probably)? It just looks like a straight-through Berg connector, but evidently it's not. I'm figuring it's probably just feedthrough caps or something, but can't figure out how to check that or find the value (my DMM's "capacitance" mode makes a nice random-number generator). I'd like to make sure my multiport RS232/20mA thingy solves whatever problem the filters are there for (in cases where it's not plugged directly into a real H317F which has the filter). John Wilson D Bit