Tait T800 SL2 25W, Service Manual

Page: 56 / 383

B3.12 T855 Initial Tuning and Adjustment
M8SL2-00-002-812
© Copyright Tait Electronics Limited August 2004. All rights reserved.
3.8 Gating Delay
Two solder links (SL210 and SL220) are provided on the bottom of the PCB to allow
three gate delay time options, as shown in the table below.
*Factory setting.
3.9 Noise Mute Adjustment
Connect pins 1 and 2 of PL250 to enable the noise mute.
Align the receiver as instructed in Section 3.6 and Section 3.7.
Set the RF level to –105dBm with ±3kHz deviation (±2.4kHz) [±1.5kHz] at 1kHz.
Set RV230 (front panel gating sensitivity) fully anticlockwise.
Adjust RV310 (noise mute gain) fully clockwise to close the mute (if necessary
turn off the RF signal and then turn it on again).
Rotate RV310 anticlockwise until the mute just opens.
Reset the signal generator for the required opening sinad and adjust RV230 clock-
wise until the mute just opens.
3.10 Carrier Level Mute
Connect pins 2 and 3 of PL250 to enable the carrier mute and disable the noise
mute.
Apply an on-channel signal from the RF generator at the required mute opening
level with ±3kHz deviation (±2.4kHz) [±1.5kHz] at ±1kHz.
Adjust RV235 (carrier mute) anticlockwise to close the mute (if necessary, momen-
tarily turn off the RF), then slowly adjust it clockwise until the mute just opens.
The mute should now open at this preset level.
SL210 SL220 Closing Delay
linked not linked <50ms*
not linked linked <25ms
not linked not linked <20ms