Epson manual MFJ-1278B MULTI-MODE Appendix B Modem Calibration, Calibration Method

MFJ-1278B MULTI-MODE APPENDIX B MODEM CALIBRATION

MODEM CALIBRATION

The MFJ-1278B Modem is factory calibrated to operate all the operational modes it is capable of. If it becomes necessary to re-calibrate the MFJ-1278B modem, please follow the following procedure:

MODULATOR/DEMODULATOR FREQUENCY CALIBRATION

Here we present you with two (2) Modulator and Demodulator Calibration. Calibration Method I requires test equipment as noted, and is the most accurate. Calibration Method II does not require test equipment, and is meant for those who do not have test equipment.

Calibration Method I

Calibration Method I below, as mentioned previously is the most accurate method. In order to do the best job possible. please follow the procedure as closely as possible. Following the procedure closely will ensure that you will calibrate the MFJ-1278B accurately. If any step is missed or not performed properly, then the performance of the MFJ-1278B becomes questionable.

Test equipment needed:

a.Calibrated Frequency Counter with 10:1 probe

b.Computer with terminal software or terminal

c.RS-232 Serial Cable

d.MFJ-1315 Power Supply/ or 12 VDC supply

Calibration Proedure:

1.Install jumpers on JMP4 and JMP7.

2.Place frequency counter at Pin 1 of JMP 9. Pin 1 is the top pin of JMP 9.

3.In the following procedure all frequencies must be calibrated to within +/- 2 Hz.

4.Type: TUNEPROC <CR>

The MFJ-1278B will respond with:

Calibration

Install loopback for TX alignment R139 For 700Hz..

Adjust R139 for 700Hz +/- 2Hz. Press the SPACE BAR on the computer keyboard.