Tait T850 II Series, Service Manual

Page: 157 / 370

M850-00
T856/857 Initial Tuning & Adjustment C3.3
Copyright TEL 31/09/98
3.1 Introduction
When you receive your T856 transmitter or T857 exciter it will be run up and working
on a particular frequency (the "default channel")
1
. If you want to switch to a frequency
that is within the 8MHz switching range (i.e. ±4MHz from the factory programmed fre-
quency), you should only need to reprogram the transmitter/exciter with the
PGM800Win software (refer to the PGM800Win programming kit and Section 3.2
below).
However, if you want to switch to a frequency outside the 8MHz switching range, you
will have to reprogram and re-tune the transmitter/exciter to ensure correct operation.
In this case you should carry out the short tuning procedure described in Section 3.4.
If you have carried out repairs or other major adjustments, you must carry out the full
tuning and adjustment procedure described in this section (except for Section 3.4).
3.2 Channel Programming
You can program up to 128 channel frequencies into the transmitter/exciter’s EEPROM
memory (IC820) by using the PGM800Win software package and an IBM

PC. You can
also use PGM800Win to select the transmitter/exciter’s current operating frequency (or
"default channel").
If the transmitter/exciter is installed in a rack frame, you can program it via the pro-
gramming port in the speaker panel. However, you can also program the transmitter/
exciter before it is installed in a rack frame as follows:
• by using a T800-01-0010 calibration test unit;
• via D-range 1;
• via D-range 2 (standard T800-03-0000 auxiliary D-range only);
• via SK805 (internal Micromatch connector).
If you do not use the T800-01-0010, you will have to connect the PC to the transmitter/
exciter via a module programming interface (such as the T800-01-0004).
For a full description of the channel programming procedure, refer to the PGM800Win
programming software user’s manual.
Note: When an auxiliary D-range kit (D-range 2 - T800-03-0000) is fitted, you can
also select a channel with an external switch, such as the DIP switch on the
rack frame backplane PCB. Refer to Part C in the T800 Series Ancillary
Equipment Service Manual (M800-00-101 or later issue) or consult your
nearest Tait Dealer or Customer Service Organisation for further details.
1. Use the "Read Module" function in PGM800Win to find out what the default channel is.