Short Tuning Procedure; Introduction; Synthesiser Alignment; Output Power Adjustment - Tait T880 II Series Adjustment Manual

M880-00
3.4

Short Tuning Procedure

Use this procedure only if you want to reprogram the T881 to a frequency outside the
8MHz switching range and do not intend to carry out any other major adjustments or
repairs.
3.4.1

Introduction

Reprogram the operating frequency as described in the PGM800Win program-
ming kit (refer to
Remove the top cover (nearest the handle).
Set up the test equipment as described in
Set the links in the audio processor section as required (refer to
3.4.2

Synthesiser Alignment

• Connect a high impedance voltmeter to TP300 (control voltage) in the VCO (this
measures the synthesiser loop voltage).
• Key the transmitter by earthing the Tx-Key line.
• Single Channel
Multichannel
3.4.3

Output Power Adjustment

Connect an RF power meter with suitable attenuation to the output socket and
key the transmitter.
Adjust RV502 (power control) for the required output power (between 1 and 5W).
Copyright TEL
Section 3.2).
Tune VCO trimmer CV300 for a synthesiser loop voltage
of 10V.
Tune VCO trimmer CV300 for a synthesiser loop voltage
of 10V on the middle channel.
If there is no middle channel, tune CV300 so that the chan-
nels are symmetrically placed around a loop voltage of
10V.
All channels should lie within the upper and lower limits
of 16V and 3V respectively.
Do not attempt to program channels with a greater fre-
quency separation than the specified switching range of
8MHz.
T881 Initial Tuning & Adjustment
Section 3.3.
C3.5
Section 3.5).
10/07/00