RESOLDER this RED WIRE to pin 3 of regulator IC MB3756.Ħ. Follow the RED WIRE from the clarifier control to the PC board and UNSOLDER it.ĥ. Re-tune coils 元6,元7 for maximum forward AM power.Ĥ. With any luck, you should slide about 5Kz down and 1Kz up.ĬOBRA 140,142 GTL, PRESIDENT P-400, UNIDEN WASHINGTON-(8719 PLL)Ĥ. Resolder this ORANGE WIRE to pin 3 of the MB3756 regulator. Follow the ORANGE WIRE from the clarifier control to where it connects to the PC board and UNSOLDER it.ĥ. NOTE: Some radios have a YELLOW WIRE instead of the RED WIRE.Ĥ. Solder this RED WIRE to the circuit board ground. Follow the RED WIRE from the clarifier control to where it connects to the PC board and cut it loose.ģ.
Remove R174 and solder a jumper wire in its place.Ģ.
This way you don't have to fumble around trying to remember which switch goes where, etc.ġ. This is an excellent kit and installs quickly with very little tools.
COBRA 25 RFX 150 INSTALL
I have found that the easiest way to do this without hacking your radio with a lot of switches is to install the EXPO 100 kit "L" expander kit. Re-tune 元7 and 元8 for maximum AM forward power. L14 peak is about a turn or two up from factory original setting.Ĥ. DO NOT adjust!!! Stretching L12 gets moe output. Internittent audio/modulation: Bad solder joints on pins 1&2 or 2&3 of audio ic.ģ. No TX/RX with Channel LED lit on RX and then goes out when keyed: Bad /shorted C119.Ģ. Receive on adjacent channel: Bad solder joint to C131 (next to 10.240 crystal).ģ. Weak mic gain: Some raios have a 2SC372 mic amp. "Motorboating": Locate C242(.001)on pin 5 of TA7222 audio ic and move to pin 4 of ic.Ģ. The instructions are the same as the Cobra 25 above,EXCEPT the following:ġ.
COBRA 25 RFX 150 MODS
Remove R123 and replace with a jumper.ĬAUTION!!! I do not know if both of these power mods can be done at the same time!!! Remove final and replace with a 2SC1969 transistor.Ģ. Re-tune L14,L13,L12 for maximum forward power.ġ. OVERMOD: Check for missing or cut D9, missaligned VR5.ģ. Burned R89(15 Ohm 1/2 watt): Replace with a 1 watt.Ģ. LED goes out and NO TX when keyed up: Check C118ġ. NO TX: Check for shorted 33uF(10v) capacitor across C87.Ģ. Channel display reads all 7's or 8's: Leaky/shorted C104(470uF 10v).
COBRA 25 RFX 150 MOD
Place the two wires from the RF gain control in your mod kit by soldering one wire to each of the 220uF capacitors leads.ġ. Solder in a jumper wire from where you removed the wires on the board. Find the two wires that are attached to the RF gain control, follow them to the PC board and UNSOLDER them.Ģ. You can use different resistor values to get the desired dead-key.ġ. On the solder side of the board, solder the resistor across the 220uF capacitor. In JP6 holes, solder the 220uF capacitor. PARTS NEEDED: 1- 220uF (16 to 25 volt) electrolytic capacitor.ġ- 100 to 200 Ohm resistor. Re-tune coils L10,L9,L8 for maximum forward power. Replace stock final with a 2SC1969 transistor.ĥ. Change R76 (3.3k) to a 1k (located near mike socket)Ĥ.
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