Introduction
Thank you for purchasing the MFJ-624DM Telepatch II. We believe this phone patch with its unique
hybrid design is one of the finest patches on the market today. This patch is designed to provide
undistorted audio and good receiver to transmitter isolation. The adjustable NULL control allows over
30 dB null in most telephones to provide smooth VOX operation.
Please take the time to completely read the instruction manual to get familiar with the MFJ-624DM
before operation, particularly if you have never operated a phone patch before.
Warning:
Only one radio should be connected to the radio at any given time. If
more than one radio is connected damage may occur to the unit or to the
transceivers.
Installation
THE MFJ-624DM can me configured for use with a radio having either a 8-pin round connector or an 8-
pin modular connector. The MFJ-624DM is designed to remain permanently installed between a
transceiver, a telephone line with a modular connector, and a telephone receivers handset. The
telephone and the radio will operate as if the phone patch were not in the circuit when the Patch
IN/BYPASS switch is in the BYPASS (out) position.
1. Connection to Telephone
a. Disconnect the modular phone from its line cord.
b. Connect the line cord from the wall jack to the modular jack on the Telepatch II labeled
Line.
c. Connect a second line cord from the modular jack on the Telepatch II PHONE to your
telephone.
2. Connection to Radio
a. Transceivers with Patch IN/OUT Connectors
i.
Connect a shielded audio cable from AUDIO IN on the Telepatch II to PATCH
OUT on the radio.
ii.
Connect a shielded audio cable from AUDIO OUT on the Telepatch II to
PATCH IN on the radio.
iii.
Connect a microphone to the 8-pin microphone jack on the front panel. Only
one microphone should be connected at any given time.
iv.
Connect a speaker to the speaker out jack of the Telepatch II.
b. Radios without PATCH IN/PATCH OUT Connectors
The MFJ-624DM has a modular connector on the rear for connection to a transceiver
microphone jack. If the transceiver has a modular connector a cat 5 patch cable can be used
to connect the transceiver with the MFJ-624DM. If the transeiver has an 8-pin round
connector a cable such as the MFJ-5398 should be used. Use the following section to
conifure the jumpers specific to the transceiver being used.
If your radio is listed in the appendix of this manual you can use the pre-tested jumper
confiuragtions shown. MFJ recommends that you check each connection before applying
power to the MFJ-624DM. If your radio is not listed use the following section to determine
the proper jumper settings.
Summary of Contents for Telepatch II
Page 6: ...Schematic ...
