DréCB's CB/HAM RADIO Information Site - UNIDEN/PRESIDENT WASHINGTON BASE TRANSCEIVER -

 


Uniden-/President

WASHINGTON

(858 PLL)

    SCHEMA-WASHINGTON.ZIP   


 

MODULATION

VR7 or cut D23
AM POWER: VR8
SSB POWER: CT7
RX COILS: L3 thru L8
TX COILS: L32,L30
SAMS PHOTOS: #126,127,128,170,171,176,179,200,207

POWER TWEAKS

(Mike circuit changes:)
1. UNSOLDER banded end of diode D21 and lift up.
2. UNSOLDER banded end of diode D22 and lift up.
3. SOLDER a 4.7 k resistor across where D21 and D22 was unsoldered.
4. Replace R78 (27k) with a 56k.
5. Replace R84 (4.7k) with a 2.2k.

(Transmit circuit changes:)
1. Replace C174 (56pF NPO) with a 82pF NPO ceramic capacitor.
2. Replace C173 (180pF NPO) with a 220pF NPO ceramic capacitor.
3. Re-tune coils L32,L30,L29,L28 and VR8 for maximum forward AM power.

CLARIFIER

1. UNSOLDER and remove D30.
2. UNSOLDER and remove D29.
3. Add a jumper in the holes from where you removed D29.
4. Cut the end of R119 that is closest to D29.
5. Add a jumper wire from R119 (the cut end) to the banded end of D44.
6. Follow the PURPLE/WHITE wire form the clarifier control to the PC board and UNSOLDER IT.
7. Resolder this wire to the PC board ground.
8. If all went well, you should slide 1 kc up and 3 kc down.

KNOWN BUGS

The AM regulator 2SC1419 is WEAK. Unsolder it and toss it in the trash.
Replace it with a GE-66, ECG-152 or a NTE-152.
Relay buzzes on SSB, no am transmit, lights go dim, or the fuse pops sometimes?
Replace C179 ( a 2.2uF 25v tantalum cap located near finals) with a standard 2.2uF electrolytic capacitor.

PAY ATTENTION to the "+" and "-"!!!





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