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SUPERSTAR 3900 alignment | Radioaficion Ham Radio

SUPERSTAR 3900 alignment


SuperStar 3900 (High Band) Line-Up Proceedure

25.615-28.305MHz Version

This is SUPER STAR 3900 alignment, re-written for the experienced technician.

Equipment Suggested: Audio Generator; RF VTVM; DC Power Supply (4A Regulated MINIMUM); Freq. Counter; Oscilloscope; RF Wattmeter & Dummy Load (25W minimum); RF Sig. Gen. (capable of 1KHz at 30< mod-AM, 1.5KHz deviation at 1KHz-FM); V0M-20K ohm/V min...

SUPERSTAR 3900 alignment


1. Fo Counter to pin terminal between C78 and C79. Should read 10,24000MHz ±200Hz; if out of tolerance change XI.

2. Fo Counter to TP-6 (R102):

  • Mode selector to CW, adjust L26 for 10.695MHz.
  • Mode selector to USB, adjust L27 for 10.6925MHz. key radio
  • Mode selector to LSB, adjust L28 for 10.6975MHz. key radio
  • (tolerance on above: +0, -100Hz.)

3. Scope to TP-4 (pin terminal between C82 and R107):

  • Mode selector to AM, Clarifier to center; Band to “D” Ch. 19.
  • Adjust L16 for max RF output.

4. Scope to TP-3 (R-74):

  • Mode selector to AM, Clarifier to center; Band to “F”, Ch. 40.
  • Adjust L18 for max RF Output.
  • DC Voltmeter to TP-2 (R-109).
  • Adjust L17 to 5.0VDC, tolerance .1VDC.
  • Check 'A* Band Ch 1, must be 2.2DC approximately.

5. Fo Counter to TP-3 (R-74):

  • Mode selector to AM, Clarifier to center; Band to “C”, Ch. 19.
  • Adjust A, for 16.040MHz, ±50Hz.
  • Mode to USB; adjust B, for 16.0425MHz; ±50Hz.
  • Mode to LSB; adjust C, for 16.0375MHz; ±50Hz.
  • Leave in LSB; transmit-no input; adjust VR15 for 16.0375MHz, ±50Hz

(NOTE: Check board layout for “A”, “B", and “C” adjustment).

6. Fo Counter to TP-3 (R-74):

  • Mode selector to AM, Clarifier to center; Band to “F”, Ch. 19.
  • Adjust L19 for 17.390MHz, ±50Hz.
  • Mode to USB; adjust L20 for 17.3925MHzt ±50Hz.
  • Mode to LSB; adjust L21 for 17.3875MHz, ±50Hz.
  • Leave in LSB; transmit with no input; check for 17.3875MHz ±50Hz.

(VR15 is the adjustment for this, which should not be needed!)


1. Driver/Final Bias adjustment:

  • Remove small plug-in PCB from TP7, TP8, and TP9.
  • Mode selector to USB; Band to “C, Ch. 19.
  • Current meter to TP9 (+) and TP8 (-). Transmit, NO INPUT.
  • Adjust VR11 for 10mA, ± 0.5mA
  • Current meter to TP9 (+) and TP7 (-). Transmit, NO INPUT.
  • Adjust VR10 to 100mA, ± 0.5mA

2. Mode selector to USB, Band to F”  Ch 40.

  • Insert 1KHz 30mV audio to mike input, and transmit.
  • Adjust VR12 and L42 for maximum RF output.
  • Adjust L40, L43, L44 and L33 for maximum RF output, then repeat
  • until no further increase can be obtained.
  • Adjust L42 for balance of RF output power between “F” band Ch 40, and “A” band Ch 1.

3. Apply 500Hz and 2.4KHz (30mV) audio tones to mike input, at same time. Use diagram below and adjust input level of 500Hz so that wave "A"

  • form as indicated below appears on scoped RF output.
  • Adjust VR12 for 12W peak-to-peak output power.

WARNING - VR12 should not be rotated clockwise beyond 2 O'clock position, or the RF power transistor will be destroyed.

4. Mode Selector to AM, Band to “D Ch 19.

  • Adjust VR13 to obtain 5W RF power output
  • Apply 1Khz at 30Mv to mike input.
  • Adjust VR14 for 90% + modulation.

5. Mode selector to FM.

  • Apply 1KHz at 30mV to mike input.
  • Adjust VR5 to obtain 2-3KHz on deviation meter on TX.

6. Mode select to USB, maximum mike pain, apply speech to microphone. Adjust VR8 for maximum indication, without pegging meter movement.

NOTE: In some units VR8 will need to be changed to higher value.

7. Mode select to CW.

  • 8 Ohm dummy load and audio VTVM to ext. Speaker jack. Connect key switch to key sw. jack.
  • Key the switch, and adjust VR16 for 200mV, ±10mV signal.


1. Set RF Sig Gen for 27.185MHz 30% modulation. Mode selector to AM, Band to “D” Ch 19

Adjust L3, L4, L6, L7, L8, L10, L11 and L12 for maximum audio output. Audio Output to be measured across dummy load with audio VTVM

NOTE: Keep Sig Gen output as low as possible to prevent AGC action. Adjust L8 for balance between “A” and “F bands.

2. Set RF Sig Gen to 27.186MHz, no modulation. Mode selector to USB, Band to “D” Ch 19

Adjust L13 and L14 for maximum audio output, with clarifier at center.

3. Set RF Sig Gen to 27.185MHz.

Apply FM signal (1 microV, 1.5KHz deviation with 1KHz audio). Mode selector to FM; Band to “D, Ch 19 READJUST L5 for maximum audio output.

4. Set RF Sig Gen to 27.185MHz.

Input 60db (1000 microV) 1KHz 30% modulation. Mode selector to AM, Band to”D” Ch 19 Squelch control fully clockwise

Scope the audio output, adjust VR4 until audio disappears. Check that the front squelch control will “cut in” between 48-70db on all modes.   *VR3 may be adjusted if need be in SSB mode.

5. Set RF Sig Gen to 27.185MHz, output level 40db (100 microV). Mode selector to AM; Band to “D Ch 19

  • Adjust VR1 for 9” indication on front meter scale.
  • Mode selector to USB
  • Adjust VR2 for “9 indication

6. Set Sig Gen to 26.045MHz; no modulation; 40db (100 microV). Mode selector to AM; Band to “A, Ch 40

  • NB/ANL Sw ON
  • Connect DC Voltmeter to TP1 (D2). Adjust L1 and L2 for 2-3VDC reading.

End of Alignment

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