iii.
Connect a speaker to the SPEAKER jack on the MFJ-624DM Telepatch II. This
speaker will allow the station operator to monitor the audio from received
stations and telephone contacts.
c. Jumper
Function
Phone Patch
Audio
Out
In
Spk
12
VDC
Line
Phn
Mic
Output
Phone
Transceiver
Phone Jack
Patch Out
Patch In
Phone Patch
Audio
Out
In
Spk
12
VDC
Line
Phn
Mic
Output
Phone
Transceiver
Phone Jack
Ext. Speaker
Mic In
Phone Patch Adjustments
1. Null
Adjustment
a. Connect a 12-volt DC power supply or adapter such as the MFJ-1312 to the 2.5mm
(3/32”) power input jack on the rear panel.
b. Turn on the receiver and monitor a QSO in progress. Adjust the receiver volume on
the radio ofr a comfortable listening level.
c. Turn the Power switch on the Telepatch II to ON.
d. Push the NULL switch to NULL (IN).
e. Push the PATCH IN /BYPASS to IN.
f. Turn the RECEIVER GAIN control on the Telepatch II until the VU meter reads
about 100%.
g. Place a call on the telephone to a third party.
h. Adjust the NULL control on the TELEPATCH II for a null reading (lowest reading
on the VU meter).
i. Set the NULL switch to the NORMAL position.
2. Receiver
Gain
a. Adjust the RECEIVER GAIN control on the Telepatch II until the audio level into the
telephone sounds about normal according to the third party to whom you placed the call.
This should occur ON VOICE PEAKS at a level around –10dBm. The meter is
calibrated to read 100% (zero VU) when the actual signal level is –10dBm.
3. Transmitter
Gain
a. Set the PATCH IN/BYPASS switch to IN.
b. While the person on the phone speaks, adjust the TRANSMITTER GAIN control on
the Telepatch II for full modulation of the transmitter’s mic audio circuit.Adjust the
VOX gain on your radio so the VOX keys the PTT when the person speaks and
unkeys your radio when he does not speak. This adjustment is critical (translated
difficult to make) sometimes.
Summary of Contents for Telepatch II
Page 6: ...Schematic ...
