GAI-Tronics 12250-001 VLC Kit - Manual (Page 2)

Pub. 42003-109E
M ODEL 12250-001 V OLUME L EVEL C ONTROL R ECEIVER A SSEMBLY R EPLACEMENT K IT Page: 2 of 7
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Notes:
1. This volume level control (VLC) kit can be used on older GAI-Tronics amplifiers (not listed); however,
it is not recommended. Amplifier models not included on the list on page 1 have been obsolete since
the 1987-1989 time period, and replacement parts for them are available on a limited basis. If the VLC
is to be installed in a station with an older amplifier, replace amplifier with a listed model (possibly
switching amplifiers from a location that does not require a VLC and has a newer, listed amplifier).
2. FM and CSA approvals are nullified with the addition of VLC.
This kit includes the following components:
Qty Description
1 Volume Level Control Receiver Assembly
2 Screw, 6-32 x ¼-inch PHMS
2 Resistor, ¼ watt, 5%
1 Template (for locating drilling holes)
1 Tie Wrap
1 Label, 24 VDC Only
Note: All items contained in this kit may not be required in all installations.
Installation
Preparation of VLC Board (24 V DC Applications Only)
Models 701-103, 701-203, 701-207, 701-307, 713-102, 723-003 and 751-002
1. Remove the hardware securing Q101 (tabbed transistor) to the VLC PCBA mounting bracket. See
Figure 1. Make note of the placement of the Q101 mounting hardware pieces so that it is re-assembled
correctly later.
2. Remove the 3 screws securing the PCBA to the mounting bracket.
3. Replace R101 by de-soldering and removing the old resistor. Insert the 6,200 ohm, ¼ watt, 5%
(blue-red-red-gold) resistor provided in this kit into the PCBA, and resolder it. See Figure 2.
4. Trim the resistor leads on the solder side to avoid possible shorts after re-assembly.
5. Reinstall the VLC PCBA onto the mounting bracket with 3 screws previously removed.
6. Reinstall Q101’s mounting hardware taking extra care to ensure the correct orientation of the insulator
to avoid a possible short of the transistor collector tab to the ground. See Figure 1.
7. Place the 24 VDC ONLY label provided in this kit on the mounting plate.