Contemporary Research
6
2
32-MTA Mono TV Tuner
Troubleshooting
Symptom: Front-Panel Channel Up does not operate, advances one channel when powered
The RS-232 port has contact closures for Channel Up and Down on pins 4 and 9. Off-the shelf RS-232 control cables (such
as consumer null modem cables) that include those wires can lock up channel operation. If the problem clears up when you
unplug the RS-232 cable, use a cable with only 3 wires for GND, Transmit, and Receive.
Symptom: Problems with Cable Channels
There are three types cable channel systems, Cable, IRC, and HRC. While the Cable setting works for over 90% of
installations, there are a few cable systems set for IRC and HRC channel frequencies. Here’s how to tell which is which:
•
IRC
– Channels 5 and 6 are missing. Change to IRC and they should appear.
•
HRC
– None of the channels tune in. Change to HRC.
Front Panel Programming
To Enter
a Front Panel Programming Mode:
1.
Press
and hold
the Mute A/V button such that the red LED light above is lit (indicating Mute On).
2.
Press Select Up.
3.
Release all buttons, the 232-MTA will now be in the front panel programming mode.
4.
The front panel display is dedicated to programming information display while in this mode.
5.
Changes are saved in non-volatile memory as they are entered.
6.
The Select up/down buttons scroll through programming modes 0 through 9 and 10+.
7.
The Channel up/down buttons scroll through possible parameters for each mode.
To Exit
the Front Panel Mode
Push and release the Mute All A/V button.
Modes 10 and above
When you select programming mode 10 and above, the Mode digit and decimal point will flash. For example, if
Mode 14 is selected, the display will show a flashing
4.
- followed by the current parameter setting.
Modes 10 – 14 are identical to RS-232 Commands Q0 – Q4, included for RS-232 programming compatibility
with the 232-STS. In the 232-MTA all 10+ functions are fixed.
