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Radio Modification Information

HTX100 Alignment of P.L.L. and Carrier Oscillator Portion
 
PLL & Carrier Oscillator Alignment Procedure
Step
Preset to
Adjustment
Remarks
1
Mode: RX, CW
S.S.G.:29MHz
L302
Connect a DC voltmeter to TP 301.
Adjust L302 for 4V +/-0.1V reading on the DC voltmeter.
2
Same
L303
Connect an oscilloscope to TP302
Adjust L303 for maximum reading on the oscilloscope.
3
Same
L313
Connect a frequency counter and the oscilloscope to TP303.
Adjust L313 for 10.695 MHz +/-10Hz reading on the frequency counter.
4
Mode: RX, CW
S.S.G.:29.699MHz
L312
Connect an oscilloscope to TP307.
Adjust L312 for maximum reading on the oscilloscope.
5
Same 
L321
Connect a frequency counter and the oscilloscope to TP307.
Adjust L321 for 22.0009 MHz +/-10Hz reading on the frequency counter.
6
Same as step 1.
VR303
Adjust VR303 for 22.0000 MHz +/-10Hz reading on the frequency counter
7
Same as step 1.
VR302
Connect the oscilloscope to TP305
Adjust VR302 to obtain the waveform as shown on the Fig 1.
8
Same as step 1.
VR301
Connect the oscilloscope to TP306
Adjust VR301 to obtain the waveform as shown on the Fig 1.
9
Same as step 4.
L317 
Connect a DC voltmeter to TP 303.
Adjust L317 for 5.5V +/-0.1V reading on the DC voltmeter.
10
Same as step 7.
No Alignment
Connect a DC voltmeter to TP 303.
Check if voltage is more than 3V at TP303.
11
Same as step 1.
L321
Connect a frequency counter and the oscilloscope to TP304.
Adjust L321 for 38.695 MHz +/-20Hz reading on the frequency counter
12
Mode: TX, CW
S.S.G.:29MHz
VR304
Connect a frequency counter and the oscilloscope to TP304.
Adjust VR304 for 38.695 MHz +/-20Hz reading on the frequency counter
13
Mode: RX, CW
S.S.G.:29MHz
No Alignment Connect a frequency counter and the oscilloscope to TP301.
Check if the frequency is 38.695 MHz +/-1.0 - 2.0 kHz when turn the RIT volume to 
fully clockwise to counterclockwise.Taken from the RS Service Manual # 19-1101 by Rogerbird

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HTX100 Alignment of Transmitter Portion Taken from the RS Service Manual #19-1101 By Rogerbird
 
Transmitter Alignment Procedure
Step
Preset to
Adjustment
Remarks
1
Mode: SSB
No Modulation
VR12
Remove the B001 (PB-100) from the Main PCB. 
Connect a DC Ammeter (+) to TP6 (-) to TP5. 
Adjust VR11 for 50mA reading on the DC Ammeter. 
2
Same
VR11
Connect a DC Ammeter (+) to TP6, (-) to TP4. 
Adjust VR12 for 50 mA reading on DC Ammeter. 
3
OSC 1: 500 Hz
OSC 2: 2400Hz
S1,S2: ON
Mode: SSB
L26
Disconnect the DC Ammeter. Reinstall the B001 to the Main PCB.
Connect a RF Power meter to the antenna jack and then, connect a RF SSVM, and oscilloscope across a RF dummy load to the RF power meter.
Adjust L26 for maximum reading on the RF SSVM.
During this step, set the AF S.G. so that the output is less than 20Vp-p. Repeat this step two times.
4
Same
VR5
Adjust level of OSC1 and OSC2 for 30 mV reading on the AF SSVM, then  adjust VR5 for 36Vp-p reading on the oscilloscope.
5
Pull  RF Gain
Control
(Low Power)
VR6
Adjust level of OSC1 and OSC2 for 30 mV reading on the AF SSVM, then  adjust VR6 for 16Vp-p reading on the oscilloscope.
6
OSC1, OSC2:Off.
VR4
Adjust VR4 so that the carrier leakage at SSB and CW becomes minimum and almost equal.
7
Same as step 3.
VR9
Adjust level of OSC1 and OSC2 for 30 mV reading on the AF SSVM, then  adjust VR9 so that the "9" LED just lights on.
8
Mode:CW
No Modulation
VR13
Connect a AF SSVM across a dummy load (8 Ohm) to EXT jack.Connect a key switch to the Key jack. With Key switch ON, adjust VR13 for 0.2V reading on the AF SSVM. 
9
Mode:CW
KEY SW: ON
No Alignment
Check if the RF power level is 23 ~ 29W reading on the RF power meter.
10
Mode:CW
(Low Power)
Pull RF Gain Control
No Alignment
Check if the RF power level is 3 ~ 7W reading on the RF power meter. 
Copied By Rogerbird from the RS Service Manual #19-1101

Click Here to see Alignment layout

HTX100 Alignment of Receiver Portion Taken from the RS Service Manual #19-1101 By Rogerbird
 
Receiver Alignment Procedure
Step
Preset to
Adjustment
Remarks
1
 
L2 ~ L5
L7 and L8
Alignment for Sensitivity
Adjust coils for maximum reading of the AF SSVM. (During this step, set the Standard Signal Generator attenuator so that the standard output is less than 0.5W (2v/8ohm)). 
2
Squelch: Fully clockwise
VR2
Alignment for Squelch
Set the output of the Standard Signal Generator attenuator to 1mV and squelch to maximum. Adjust VR2 so that squelch just breaks. 
3
 
VR1
Alignment of S-Meter
Set the output of the Standard Signal Generator to 100uV, no modulation. 
Adjust VR1 so that "9" LCD just lights on. 
4
NB: ON
L1
Set the level of the Standard Signal Generator to 2uV, then adjust L1 for maximum reading on the oscilloscope. Connect the oscilloscope to TP1. Copied from the RS Service Manual #19-1101 By Rogerbird

Click Here to see Alignment layout