6
OPERATION
Circuit Description
The V-9939B Microphone Adapter has inputs for
both high impedance and balanced low
impedance microphones. It also has input for a
push to talk contact closure. When the closure is
applied, a high gain pre-amplifier is turned on
and the output relay is activated. The unit will
stay active until the contact closure is removed.
The preamplifier circuit also contains a voice
limiting circuit to limit extremely loud inputs.
TECHNICAL ASSISTANCE
When trouble is reported, verify that power is
being supplied to the unit and there are no
broken connections. Check voltages for proper
polarity on the cross connect block.
Table 1 identifies symptoms of some possible
problems with solutions. If a spare unit is
available, continue to troubleshoot by
substituting the spare unit for the suspected
defective unit.
Assistance in troubleshooting is available from
the factory. When calling, you should have a
VOM, a test set available and call from the job
site. Call (540) 563-2000 and press 1 for
Technical Support or visit our website at
http://www.valcom.com.
The V-9939B is not field repairable.
Valcom
equipment contains no user serviceable
parts inside.
Valcom, Inc. maintains service
facilities in Roanoke, VA. Should repairs be
necessary, attach a tag to the unit clearly stating
your company name, address, phone number
and contact person and the nature of the
problem.
Send the unit to:
Valcom, Inc.
Repair and Return Dept.
5614 Hollins Road
Roanoke, VA 24019-5056
TABLE 1 - TROUBLESHOOTING CHART
SYMPTOM
1. No relay operation in V-9939B
when microphone talk button is
pressed.
2. Relay operation but no output.
3. Audio from V-9939B but not from
V-1094A.
4. No output from V-2001A.
5. Output from V-9939B and
V-1094A or V-2001A but not
from speakers.
SOLUTION
Check for -24VDC at V-9939B across the PWR terminals. Verify
connection from microphone to terminals SW and GND OUT (refer to the
Installation section).
Verify connections from microphone to MC and HZ or LZ terminals. Turn
volume control up (clockwise).
Verify Tip and Ring connections from V-9939B to V-1094A. Verify proper
voltage and polarity at -24VDC and GND terminals of V-1094A. Turn up
volume at V-1094A.
Recheck all connections per Figure 4. Make sure the V-2001A passes the
power test in Figure 4, step 16.
Verify proper voltage and polarity to speakers. Verify audio connections to
speakers. Verify speakers are Valcom one-way amplified speaker
assemblies.
VALCOM LIMITED WARRANTY
Valcom, Inc. warrants its products to be free from defects in materials and workmanship under conditions of normal use and service for a period of one year from the date of
shipment. The obligation under this warranty shall be limited to the replacement, repair or refund of any such defective device within the warranty period, provided that:
1.
inspection by Valcom, Inc. indicates the validity of the claim;
2.
the defect is not the result of damage, misuse or negligence after the original shipment;
3.
the product has not been altered in any way or repaired by others and that factory sealed units are unopened (a service charge plus parts and labor will be
applied to units defaced or physically damaged);
4.
freight charges for the return of products to Valcom are prepaid;
5.
all units ‘out of warranty’ are subject to a service charge. The service charge will cover minor repairs (major repairs will be subject to additional charges for parts
and labor).
This warranty is in lieu of and excludes all other warranties, expressed or implied and in no event shall Valcom, Inc. be liable for any anticipated profits,
consequential damages, loss of time or other losses incurred by the buyer in connection with the purchase, operation, or use of the product.
This warranty specifically excludes damage incurred in shipment. In the event a product is received in damaged condition, the carrier should be notified immediately. Claims
for such damage should be filed with the carrier involved in accordance with the F.O.B. point.
Headquarters:
In Canada
Valcom, Inc.
CMX Corporation
5614 Hollins Road
35 Van Kirk Drive #11 and 12
Roanoke, VA 24019-5056
Brampton, Ontario L7A 1A5
Phone: (540) 563-2000
Phone: (905) 456-1072
FAX: (540) 362-9800
FAX: (905) 456-2269
