Search found 27 matches

by 1096
Thursday 16th Jul 2009, 9:58
Forum: CB Radio Repair and Troubleshooting
Topic: Uniden pc 68xl
Replies: 2
Views: 2440

Re: Uniden pc 68xl

Anyone???
by 1096
Sunday 12th Jul 2009, 17:27
Forum: CB Radio Repair and Troubleshooting
Topic: Uniden pc 68xl
Replies: 2
Views: 2440

Uniden pc 68xl

Radio Make and Model: Uniden pc 68xl PCB Number: PLL Number: Test gear available: Bird 43p, O'scope, mutlimeters, freq. counter, signal generator.... Symptoms: Lost transmit.... Keyup What is working: Tx/Rx light changes color, receive works.... What has been tried: Changed Q9, Q19, final, driver, D...
by 1096
Thursday 26th Mar 2009, 8:40
Forum: CB Radio Repair and Troubleshooting
Topic: RCI 2950 sticks in PA mode
Replies: 0
Views: 1546

RCI 2950 sticks in PA mode

Radio Make and Model: RCI 2950 (non DX) PCB Number: PLL Number: Test gear available: Bird 43p, voltmeter, RF Signal Generator, other things Symptoms: Turns on in PA mode and there is no way to get out of it.... Radio will eventually allow you to use it.... What is working: Works very well when not s...
by 1096
Friday 20th Mar 2009, 10:11
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

R106, R93, and R110 have no voltage at them and I couldn't find voltages for those points.... Your schematic must different from mine.... My channel display will also read channel 48 on channel 40 when I hit the channel 9/norm switch.... I think ultimately I may have a dead PLL.... No voltage whatso...
by 1096
Friday 20th Mar 2009, 9:29
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

Replaced all of them and replaced D14 and D15 also and still only have 1.5 volts.... IC3 has 1.5 volts on pin 7 in TX mode which it is supposed to have 2 volts in TX....
by 1096
Friday 20th Mar 2009, 7:26
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

It has to be one of those.... I'll replace R98 and see what I get.... I replaced D19 but nothing....
by 1096
Friday 20th Mar 2009, 3:36
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

D19 has 1.5 volts and R98 has 8 volts on one side and 1.5 on the side that connects to the zener.... Replaced C113 and nothing.... Removed and checked R98 and it is in spec.... R124 is in spec also.... C112 has 0.42 volts at it but I replaced it and it still gives nothing.... When I check R124 and R...
by 1096
Friday 20th Mar 2009, 1:26
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

I did lift R124 after I tested it and nothing hapened so we can rule that one out but I'm going to take a look at those others and see what I get....
by 1096
Thursday 19th Mar 2009, 14:45
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

R124 had 0.42 on the leg closest to the PLL and @1.5 on the side furthest from the PLL... R70 had 8 volts....
by 1096
Thursday 19th Mar 2009, 14:43
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

Those checked out fine at Tr23 and D22.... Can't seem to find Z10
by 1096
Thursday 19th Mar 2009, 14:37
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

Another new and interesting twist, is that the channel 9/norm switch goes to channel 48 instead of channel 9.... PLL is probably dead.... No voltage at PLL....
by 1096
Thursday 19th Mar 2009, 12:38
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

D22 tests ok under a diode test but the diode it self seems to have what appears to be ink all over the inside.... I think it is blown.... R70 checks out ok.... TR23 checks out ok.... Where is the 5v regulator????
by 1096
Thursday 19th Mar 2009, 11:25
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

Let me try those and see what I come up with.... Thanks for the help, I think I'm finally getting somewhere....
by 1096
Thursday 19th Mar 2009, 10:02
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

R124 has about 1.5 volts on one side and about 0.42 volts on the other.... D8 is good but i have yet to check the diode in back near the DC input.... Appears to be good visually but looks are deceiving....
by 1096
Thursday 19th Mar 2009, 9:33
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Re: Cobra 29 No Keyup

There is no voltage on any of the pins except for 2 on the PLL, the voltage is only 0.40 volts on those 2 pins.... Keyed or unkeyed.... I replaced the 10.240 mhz crystal and still nothing.... R88 only has 0.41 volts with no change when adjusting L19.... I'll check R124 and see what I get.... I think...
by 1096
Thursday 19th Mar 2009, 4:09
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 No Keyup
Replies: 18
Views: 9780

Cobra 29 No Keyup

Radio Make and Model: Cobra 29 LTD PCB Number: PLL Number: Test gear available: Bird 43p, Voltmeter, RF Generator, and misc other things.... Symptoms: No Keyup.... Meter light blew and then I lost keyup What is working: Final, Driver, Predriver are all good and working.... TR16 and IC3 checked out o...
by 1096
Saturday 28th Feb 2009, 10:46
Forum: CB Radio Alignments
Topic: Test Points in cobra 148gtl
Replies: 6
Views: 4597

Re: Test Points in cobra 148gtl

yes, these are the only 2 needed to bias the driver and final.... I believe there are others for PLL and noise blanker too....
by 1096
Friday 27th Feb 2009, 12:39
Forum: CB Radio Alignments
Topic: Test Points in cobra 148gtl
Replies: 6
Views: 4597

Re: Test Points in cobra 148gtl

They are just below the transformer on the right side about midway down.... A purple and I think it is a green wire are attached to them.... These are not like the test points in the 3600 and 6900 board radios, these are 2 small pegs sticking up from the board and the wires slip over the top of them...
by 1096
Thursday 26th Feb 2009, 6:56
Forum: CB Radio Modifications
Topic: Cobra 148 GTL mod confusion...
Replies: 7
Views: 9908

Re: Cobra 148 GTL mod confusion...

Do not remove TR24!!!! Your radio will sound like garbage in all modes.... If you must remove a limiter then remove TR26, this only disables it in AM mode.... If your going to do any of the mods then do the NPC-RC mod but revise it so that you remove TR26 instead of TR24.... I have done this NPC-RC ...
by 1096
Thursday 26th Feb 2009, 6:50
Forum: CB Radio Modifications
Topic: How can I increase Dynamike range on Cobra 29?
Replies: 4
Views: 3334

Re: How can I increase Dynamike range on Cobra 29?

If you are using a stock mic it will make it more sensitive and increase response but you will get a bit more noise.... If using a noise cancelling mic, this will give it a nice boost without the obvious worry of increased background noise.... You could just keep the mic gain lower with a stock mic....
by 1096
Wednesday 25th Feb 2009, 14:40
Forum: CB Radio Modifications
Topic: new magnum s-980 50 WATTS???
Replies: 5
Views: 3663

Re: new magnum s-980 50 WATTS???

Turn VR14 fully clockwise....
by 1096
Wednesday 25th Feb 2009, 14:38
Forum: CB Radio Modifications
Topic: How can I increase Dynamike range on Cobra 29?
Replies: 4
Views: 3334

Re: How can I increase Dynamike range on Cobra 29?

Change R67 from a 33 ohm to a 10 ohm.... Enjoy
by 1096
Saturday 27th Sep 2008, 11:17
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29 Display Dims When Keyed
Replies: 0
Views: 1447

Cobra 29 Display Dims When Keyed

I have an EKL blue channel display in a Cobra 29 NW and the channel indicator dims when you key it.... I have heard talks of adding a resistor to remeby this but not sure where it may go.... Anyone experience dimming of the display and know how to fix it...
by 1096
Friday 12th Sep 2008, 12:50
Forum: CB Radio Modifications
Topic: ekl mod , setting bias voltage
Replies: 1
Views: 2053

You need about 3.0 volts.... Run it from the gate which is the leg farthest to the right looking at the solder side and then run the other leg to the positive side of C116....
by 1096
Friday 12th Sep 2008, 12:36
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 29
Replies: 3
Views: 2121

I'm using a Road King 56 on it because that is what this person intends to use with it also.... I ran a 1k resistor in series with the audio line and nothing hapened and I also removed the cap at the audio chip and nothing either.... The radio did have a resistor soldered across the receive pin that...

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