Asymod IIIs Installation Manual page 42

Cobra 2000GTL and Asymod IIIs Installation Instructions
1- Replace C183, C187 & C76 with a 2.2uF ceramic non-polarized capacitor.
2- Replace C175 with a 1000uF 25V electrolytic capacitor.
3- Replace FT1 filter with a 6 kHz - 7.5 kHz wide, 455 kHz - LT455EW.
4- Earth all floating PCB grounds to chassis (Y).
5- Connect dedicated ground wire from PCB to Asymod power in (-) (X).
6- Connect +12 V power wire at JP1 to Asymod power in (+).
7- Install ¼" Line-In connector at rear panel with 22uH inductor and a .001uF ceramic non-
polarized capacitor and coax wire RG-174.
8- Remove TR-24 (A)
9- Solder a 1kΩ from (+) lead of C108 to (-) lead of C104. (V)
10- Replace R123 with 4.7kΩ (B).
11- Replace R125 with 10kΩ (C).
12- Verify TR23 base is at 1.64V.
13- Replace C105 with a .01uF ceramic non-polarized capacitor (D).
14- Replace C101 with a 2.2uF ceramic non-polarized capacitor in series with a 1kΩ, put
capacitor in the + lead of C101 (E).
15- Remove R119 (F) and R118 (G).
16- Replace TR22 (H) with a 2N3904, invert two the right leads, EBC-to-ECB.
17- Insert one side of a 8.3kΩ resistor in R118 (G) lead that goes to Vcc 6V.
18- Insert one side of a 10kΩ resistor in R119 (F) lead that goes to ground.
19- Insert one side of a 100kΩ resistor in R119 lead that goes to the base of TR22 (I).
20- Tie together and solder together the top 3 leads of the 8.2kΩ resistor @ R118, 10kΩ
resistor @ R119, 100kΩ resistor @ the base of TR22 (J).
21- Verify TR22 base is at 1.9V.
22- Solder a .1uF ceramic non-polarized capacitor (U) from the base of TR22 to ground.
23- Replace R116 with a 1kΩ resistor (K).
24- Remove C99.
25- Cut trace that goes from the collector of TR22 to the (+) lead of C99 (L).
26- Solder a 2.2uF ceramic non-polarized capacitor (M) from collector of TR22 to (+) lead of
C99 at bottom side of PCB and connect the audio preamp out coax (+) lead (N) that goes
to Line-In connector at the (+) lead of C99 and ground shield to nearby available hole.
27- Connect procced audio from Asymod to (-) lead of C99 (O) for SSB to balanced
modulator via a 2.2uF ceramic non-polarized capacitor (U).
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