Synthesiser Alignment - Tait T880 II Series Adjustment Manual

M880-00
3.6

Synthesiser Alignment

• Ensure that the T881 has been programmed with the required frequencies using
PGM800Win software.
• Single Channel
Multichannel
• 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
Measure the transmitter output frequency and adjust the TCXO (=IC700) trimmer
if required.
Caution:
This trimmer is susceptible to physical damage. Do not exert a down-
ward force of more than 500g (1lb) when adjusting.
Copyright TEL
T881 Initial Tuning & Adjustment
Select a channel using PGM800Win.
Select the middle channel via PGM800Win.
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
(8MHz).
C3.9
10/07/00