Preliminary Tests; Listening Tests; Functional Test; Rf Tests - Shure T2 Service Manual

Preliminary Tests

Listening Tests

Functional Test

Tests
RF
25C1018 (CC)
Shure T2 Vocal Artist Microphone Transmitter
Before disassembling the unit, operate it to determine whether it is
functioning normally.
Focused Testing: First and most important: Review any customer
complaint or request and focus your tests on any reported problem for
both listening and functional tests. For example, many complaints are for
"short range" and "drop-outs." In such cases, perform only the
this section to verify the problem. If the unit passes these, there is a
strong indication that the customer is using the product incorrectly (e.g.,
not keeping the transmitter in the receiver's line of sight, not avoiding
metal enclosures or TV interference). Return the unit to the customer
together with an explanation of the proper set-up procedures.
For complaints of distortion or other audio problems, try a "standard"
microphone cartridge (you should have one of each cartridge on-hand
for testing) and perform the audio tests in this section.
Note: Most of the following tests can be performed without disas-
sembling the unit.
1. Install a fresh 9 V battery in the T2, mute its audio, and turn it on.
2. Measure current drain: it should not exceed 35 mA.
3. Maximize the signal received on the spectrum analyzer by at-
taching a telescoping whip antenna to it. Then measure the
near-field output power: it should be 7 dBm (
model) or 3 dBm (
(If you are unsure of the results you obtained here, measure the
output power conductively by soldering a 50 Ω cable to the out-
put of the transmitter. Verify that the output power is 15 dBm,
2 dBm [ -approved model] or 10 dBm, 2 dBm [
FCC
proved model].)
4. Verify that the carrier frequency of the transmitter varies from its
nominal value by no more than "6 kHz.
5. Check for an intermittent problem by shaking the transmitter and
tapping on it. As you do so, try to keep it at a constant distance
from the spectrum analyzer. Verify that the output power on the
spectrum analyzer shows no large and sudden drops in power
level (it will, however, vary a few dB with hand position).
6. Turn off the T2.
If the transmitter passes the above tests, its
working as designed.
-approved model).
ETSI
7
tests in
RF
-approved
FCC
-ap-
ETSI
circuits are
RF
Preliminary Tests