671U-10 Rear Connector Interface Assembly
to ARINC 404, 32W4M and A106

To connect to the radio without the original „unobtainium“ ARINC 404 connector, an interface board was constructed that allows the use of two 50p flat cables (SCSI) as „backpanel wiring“ to the 635U-4 and the control box (to be built, not original). The connector pins are directly soldered to the A15 multilayer board and cannot be removed.

The possibility to remove the A15 RFI Card from the radio chassis makes it practical to construct an piggy-back interface on the bench rather than on the set itself. Later other radios can also be tested by moving this card into the new set. Nothing is soldered to the card or the unit though!

The 32W4M (top) is wired using original female pins and male coaxi­al inserts obtained from ARINC connectors removed from various odd avionics mounts.

The A106 (bottom) male pin size was a more difficult issue, as I did not have anything suitable. An easy solution was found in the pins of high-density D-Sub connectors which were bought new and dis­mantled.

<<< Perf board interface on A15

2 Rows 50p IDC, 11p Test Points, 4p Power >>>

The interface is mounted on top of the original connector using 4 threaded M4 bolts. For this the connector shell needed to be modified (holes). All wire pins and the coax inserts are safely held down by the mass of teflon wires.

<<< Interface installed on top of connector

IDC „SCSI“ cables connected to 50p rows >>>

Admittedly not a very pretty sight...

The A15 card is inserted into the radio, the wires clear the box containing the noise generator A16 and the lower edge of the radio easily.

While at left the rear cover is not installed this is shown completed at right. The metal had to be modified and the cutout enlarged vertically to a slot to allow the part to be slid down under the wires.

Now it is reeady for a test – if only the control box would be already completed.

hb9aik - vk6bqd/05-2011/A