Check, Rework The Optimod-Fm Card #6 - Orban 8100A/XT2 Operating Manual

2-10
Installation
a) Remove Card #5 and check the part number etched on the solder side.
If the part number is 30741-000-03, the card you have is the correct one for use
with the XT2. Set the card aside (do not reinstall it yet) and skip to step 5. You may
return the Card #5 included with the Retrofit Kit to the factory for credit.
To do this, contact Orban Customer Service at one of the numbers at the front of this
manual to get a Return Authorization number. We will need to know the serial number
of your OPTIMOD-FM and the six-digit serial number stamped on the card itself. Only
the Card #5 included with the Retrofit Kit (not the one that was already in your unit)
will be accepted for credit. The duplicate Card #5 must be returned to us within 60 days
of the date of its shipment to you.
Upon receipt of your duplicate Card #5, we will mail a refund to the organization
represented as the owner on the Registration Card. If the Registration card is not on
file, other proof of ownership will be required.
If the part number is 30451-000-nn (where -nn is any number) or 30741-000-02
■or -01, use the Card #5 provided in the Retrofit Kit (which will have an etched number
of 30741-000-03 or higher) instead of the old card. Do not install the new card yet —
set it aside, taking care not to confuse it with the old card.
The old card is not returnable, but can serve as an emergency spare (although you may
hear more processing artifacts with it).
5) Check, rework the PTIM D-FM Card #6.
Allow about one hour for this step.
The rework in this step enables the XT2 to defeat the OPTIMOD-FM ' s high-frequency
limiters and soft clippers, and it redirects the output of Card #6 to the accessory port
installed in step 3.
a) Remove Card #6 check the part number etched on the solder side.
If the part number is 30461-000-05 or above, the card you have is the correct one
for use with the XT2. Set it aside and skip to step 6.
If the part number is 30461-000-04 or below, continue to step b.
b) Remove all the solder from both sides of the foil pad connected to the center terminal
of toggle switch S602 with a vacuum desoldering tool. Use fairly strong diagonal
cutters to gently clip the center leg of S602, leaving a stub on the switch long enough
to later solder two wires to (1/8 " will do). Remove and discard the portion of tire leg
formerly soldered to the card. Gentle wiggling with chain-nose pliers may help release
it.
c) Solder the banded (cathode) end of a glass 1N4148 diode to the pad where the center
leg of S602 was attached.
d) Desolder the non-banded (anode) end of glass diode CR603 with a vacuum desoldering
tool. Bend the diode upward so that the free end is pointing toward S602. Using the
long wire from the kit, connect the free end of CR603 to the center terminal of S602.
Also connect the free end of the 1N4148 diode installed in step c to this terminal.
Carefully solder both diodes to the terminal. Avoid excess heating and excess solder
or flux (which could creep into the switch).