This page shows the alignment instuctions for
the Cybernet UK 27/81 radio's
Using the PTBM 134 AOX PCB
Make sure that the delta tune is set to "0".
Connect a frequency counter to the base of Q-10.
Adjust CT-2 for a reading of 10.24046 +/-50Hz.
Ensure that the set is in RX,on CH 40.
Attach a DC voltmeter to TP-1.
Adjust T-1 for a reading of 4.0 V +/- 0.1 V.
Change to TX ,then adjust CT-1 for a reading of 4.0 V +/- 0.1 V.
Change to CH 1,TX,and make sure that a reading of between 1.8-2.5 V is obtained.
Change to RX,make sure that a reading of between 1.9-2.5 V is obtained.
Set the power supply voltage to 9 Vdc.
Attach a oscilloscope to the ant socket.
Put the set on CH 20.
Adjust T-2,T-3,T-4 for the maximum wave form on scope.
Turn the power supply voltage up to 13.2 Vdc, and make sure the radio is set to high power.
Adjust L-4,L-8,L-9 for maximum reading on watt meter.
Rotate L-4 clockwise to obtain 4.4 W.
Rotate L-9 counterclockwise to obtain 3.8 W.
Ensure that the power output difference on CH 1 and CH 40 is within 0.3 W.
Put the set to lo power,and change the power supply voltage to 15.6 Vdc.
Adjust RV-5 for a reading of 0.5 W.
Change to CH 40,TX.
Apply 20 mV/1.25kHz audio to mic input jack.
Adjust RV-6 for maximum deviation.
Adjust RV-2 to exactly 2.15 kHz deviation.
Adjust RV-6 to exactly 1.6 kHz deviation.
Remove audio from audio input jack.
Adjust RV-4 that the set's RF meter reads the same as the external RF meter.
Attach signal generator to ant socket and set its output for 27.79125 MHz without modulation.
Attach a DC Volt meter to TP-2.
Adjust T-5,T-7,T-8,T-9,T-10,T-11 for maximum voltage, then rotate T-5 1/2 a turn clockwise.
Add a 1 kHz audio signal with +/-0.8 kHz deviation.
Attach an oscilloscope to the speaker.
Adjust T-12 for maximum reading on oscilloscope.
Set the RF signal generator to provide 100 āV (40dB).
Adjust RV-3 so that the signal meter reads "S-9"
If you have not checked out my modifications page for this radio Go And Take A Look
This counter shows the number of hits since the 19th September 1998
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