Cobra 146 GTL

Realistic TRC-453

Uniden AR-144

Uniden PC-122 & AR-144

Uniden Pro -810e Base

...and similiar SSB radios.

How to make Cobra 29gtls slide on transmit

1)Remove D-18 , R-110 , C131 and R-112.
2)Put jumper were R-110 was.
3)Take orange wire from delta tune and unsolder it from board then resolder it to Tr-23
(Solder to the pin closest to front of board.
It should have around 8 VDC on this pin.)
4)Put radio back together and if all is done right you should
slide transmit 5-6 KCs up and down.
For more slide change D-16 to a 1N-4007

Clarifier modification: President p-300

1)Find the Brown Wire and White Wires from Clarifer.
2)Cut the White Wire from the PC Board and solder it to Ground.
3)The Brown wire which is located on the board behind the meter where all the buttons are goes to 8v this is found on the left side front 2nd trace use a Volt meter to find this.
4)Cut D30.
5)Put the covers back on and power radio.

When this mod is finished you should have 2.5 Kc to 4 Kc slide up and down. not all radios of the P-300 series is the same on slide.

Clarifier modification: Cobra 146 & AR-144

1) Lift anode of D-30 and connect a 5.6 uH choke in series.
2) Cut D-32.
3) Cut both traces on the PCB going to the clarifier .
4) Solder one wire to PCB ground.
5) Solder a wire from the other cut trace to an 8 VDC source
(note: 8 volts can be found on the cathode of D-50)
6)This should give you 5 kc of slide.If more slide is wanted then change D-30 to a super slide doide.

Clarifier modification: TRC-453 and Uniden PC-122

1)Find the backside of the clarifier knob.
2)Solder the bottom pin to GROUND. 3)Solder a wire to the top pin of the PCB.
This pin should be cut loose from any traces going to it!)
4)Solder that wire to an 8VDC source.This can be found on the second jumper behind the PLL chip(IC-2).
5)Cut D-25.

Clarifier modification: Uniden Pro-810e

1) Cut D-25.
2) Cut D-32.
3) Cut both traces on the PCB going to the clarifier .
4) Solder one wire to PCB ground.
5) Solder a wire from the other cut trace to an 8 VDC source
(note: 8 volts can be found on the trace that connects R-107 & R-106
6)This should give you 3 kc of slide.If more slide is wanted then jump D-24 with a piece of wire.(Sometimes it works)

Channel Expansion:

1)Unsolder the PLL chip.UPD2824 or D2824.
2)Throw it away.It can't be modified.
3)Solder in a new PLL UPD2816.
4)Connect pin #20 to pin #21 GROUND.
5)Solder a wire from pin #9 to one side of a SPST switch.
6)Solder a wire from PCB GROUND to the other side of the switch.
7)If all goes well this should give you 27.420 - 27.860 Mhz.
Yes, i know 27.420 in between the channel SO use the clarifier for the 5 kc offset.
8)If you can't get all the frequency coverage then adjust L-14 the VCO coil.

"Peaks and Tweaks"