OSCOR OSC 5000 - Testing the Telephone Lines for Carrier Current; Testing Telephones for RF Transmitters

SECTION 6: CONDUCTING A SWEEP
105 REI OSC-5000E
With the phone off the hook and the audio coupler connected to the tip and ring
conductors, you should hear the dial tone and any audio from the telephone
mouthpiece. (For analog or hybrid systems -- a hybrid system uses analog for the normal
tip and ring signals, but power and digital controls on the remaining 2 to 6 conductors.)
Test ing th e Te lephone Li nes for Carrier Current
Using the AC VLF cord (the power cord) and the VLF probe attachment, the telephone
lines can be tested for carrier current transmitters. All conductor combinations should be
tested using a procedure outlined on page 97 Checking For Carrier Current Threats. All
phone lines in the target environment should be tested.
To test telephone lines for carrier current:
1. Connect the VLF adapter (see page 9) to the AC power cord.
2. Connect the blue Modular Phone Adapter in line with the telephone.
3. Select the AC VLF input with the OSCOR the Sweep Mode.
4. Tune to each signal that occurs and analyze it for threat potential.
5. Test each combination of conductors for carrier current signals.
Test ing Tel eph one s f or RF Transmi tte rs
There are types of RF transmitting telephone bugs that are only activated when the
telephone is off the hook. Therefore, it is necessary to test the telephone for this type of
RF transmitter when the phone is both on and off the hook.
To test the telephone for an RF transmitter:
1. Place the telephone very near the OSCOR unit; it also works well to wrap the
telephone cord that connects the handset and the base unit around the OSCOR
whip antenna.
2. Put the OSCOR in the Sweep Mode (see page 27 Sweep Mode (Spectrum
Analyzer Functions)).
3. Compare the Frequency Spectrum with the phone in the off-hook position to the
Frequency Spectrum in the on-hook position. It may be useful to generate plots of
these two configurations and compare the plots or utilize the OSCOR Friendly
and Peak Display modes.
4. Any signal that appears only in the off-hook position should be further analyzed
using the Analyze Mode.