Calibration Signal Pigtails - MJL - 10/18/01
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The muon tracking calibration signal pigtails are short cables
(4 feet long for North) that attach to the anode pulser pins on
one end and have a round Amp connector on the other. The round Amp
connector mates with a long calibration cable that carries the
calibration pulse from the calibration system in rack 3. The cables
have four twisted pair; each pair with a drain wire and shield and
there is an overall shield for the whole bundle.

At the chambers the connections are to the anode pulse or "calibration"
post and to the sigHV-return post on the anode card near the outer (in
theta) edge of the chambers. On stations-2 & 3 the "calibration" post
is the one farthest from the outer theta edge of the chamber and the
sigHV-return is the one next to it. I don't remember how the posts are
arranged on station-1.

Connections are as follows:

red          - gap1 "calibration" post
black(red)   - gap1 sigHV-return

green        - gap2 "calibration" post
black(green) - gap2 sigHV-return

blue         - gap3 "calibration" post (spare in the case of station-3)
black(blue)  - gap3 sigHV-return       (spare in the case of station-3)

white        - spare  (pull back and tape down)
black(white) - spare

A 1/4 watt 100 ohm resister was placed across the "calibration" and
sigHV-return posts for the South arm; except for station-1 which already had surface mount
resistors installed. The North arm anode cards already have a 51 ohm surface
mount resister on the boards so NO resister needs to be added across the posts
on any of the North chambers.

All of the shields and drain wires should be tied together to a wire with
a lug at the end of it and the lug should be connected to frame ground on
the edge of the chamber via one of the grounding bolts there.

Once the pigtails are installed they should be tested with a pulser. The
exact procedure for this will need to be worked out, but I will be something
like this:
* use a modified version of a long calibration cable connected to a Phillips
pulser to apply a 10 volt by 10 microsecond pulse to the pigtail
* connect a special connector to a cathode card edge connector that brings the
signals onto lemo cables that can be connected to a scope
* pulse the cable and check to see that an induced signal on the cathodes is
seen on the scope