Search found 140 matches

by RedEye
Thursday 25th Dec 2008, 16:11
Forum: CB Radio Modifications
Topic: Magnum Alpha Force Mod needed
Replies: 4
Views: 3116

Magnum Alpha Force Mod needed

I agree with timrim, I would have a lot of broken radios if it weren't from some of the great help I've gotten here....A lot of people simply come here to get answers, then leave. On the other hand people like Defpom, Rick, Ramblingman and so on are a great asset to this board. As far as bad info, w...
by RedEye
Thursday 25th Dec 2008, 16:04
Forum: CB Radio Modifications
Topic: m58473p PLL channel mods
Replies: 2
Views: 2902

m58473p PLL channel mods

The owner is hoping to get 27.555, his 2000 bit the dust in a thunderstorm. Just trying to get his very old backup going for him. Does anyone have the mod to do it? Thanks again Timrim!
by RedEye
Thursday 25th Dec 2008, 2:56
Forum: CB Radio Modifications
Topic: m58473p PLL channel mods
Replies: 2
Views: 2902

m58473p PLL channel mods

Royce 1-619 Base 40 channel
M58473 PLL in the Royce "Sardine can" setup


Does anyone know if you can do a "switch mod" to this pll or does it need a different xtal?

Can't find any good pages on this pll chip

Thanks in advance and Merry Christmas to everyone here!
by RedEye
Sunday 21st Dec 2008, 1:31
Forum: CB Radio Repair and Troubleshooting
Topic: 148 GTL post clarifier mod alignment
Replies: 3
Views: 3049

148 GTL post clarifier mod alignment

I may be wrong, but when you remove R44 the unit will adjust RX/TX together. VR5 or VR7 is not in the circuit anymore.

I had the same prob a long time ago, Rick corrected the procedure for me, look here in this forum...

http://www.radiomods.co.nz/forum/viewto ... =5274#5274
by RedEye
Saturday 20th Dec 2008, 18:27
Forum: CB Radio General
Topic: AVOID CLAYS RADIO!
Replies: 14
Views: 13074

AVOID CLAYS RADIO!

Early model 200's had some issues I've heard, but mine was the last board number made, bought it off the shelf (229.00 on sale)and sent it to cobra for the free tech updates. (No Cost but shipping) I was unfamiliar with the design so when I got it back, (I used it with good reports for about 6 month...
by RedEye
Saturday 20th Dec 2008, 17:34
Forum: CB Radio Repair and Troubleshooting
Topic: Power Mic Problems
Replies: 8
Views: 7372

Power Mic Problems

Have you checked to see if the mod limiter is intact, many times these are removed or "hacked" by less than skilled techs. You may simply be overdriving it without the limiter in place. Let us know what you find!
by RedEye
Saturday 20th Dec 2008, 17:16
Forum: CB Radio Repair and Troubleshooting
Topic: 148 final gets hot?
Replies: 2
Views: 2301

148 final gets hot?

Sounds like a problem exsisted prior to the mosfet install. If someone replaced the final before, it most likely was frying them out prior to anything you did. Check for any other "hack" mods that might be causing the problem. jumped diodes, solder bypasses or even a bad solder joint or solder blob ...
by RedEye
Saturday 20th Dec 2008, 17:10
Forum: CB Radio Repair and Troubleshooting
Topic: SuperStar 121
Replies: 1
Views: 2091

SuperStar 121

Start simple, check the mic, is it working properly? Switch to PA and see if mic/audio is working, Let us know how it does....
by RedEye
Saturday 29th Nov 2008, 3:21
Forum: CB Radio Modifications
Topic: Cobra 29LTD CLASSIC with ERF- 2030 after modification
Replies: 20
Views: 23586

Cobra 29LTD CLASSIC with ERF- 2030 after modification

You are right, I never meant everyone needs a linear, But a properly tuned radio can key 1~2watts and have forward swing to the proper limit of the final without the poor effect of a swing kit. It's like a kid with his first car, cutting off the muffler and believing it's a hot rod, it may be noisey...
by RedEye
Saturday 29th Nov 2008, 2:29
Forum: CB Radio Modifications
Topic: Cobra 29LTD CLASSIC with ERF- 2030 after modification
Replies: 20
Views: 23586

Cobra 29LTD CLASSIC with ERF- 2030 after modification

With all the respect I can muster for a fellow radio tech, a swing kit is the poor man's way to create false watts. You may show wattage on an external meter but it is not viable wattage when you have created a radio that now spatters all over 6 channels. It is insane how some people think that a ra...
by RedEye
Saturday 29th Nov 2008, 1:47
Forum: CB Radio Modifications
Topic: Talkback on radio without PA?
Replies: 10
Views: 9494

Talkback on radio without PA?

In the TR 467, The speaker is already grounded, it isn't a floating ground. running a resisitor to chassis ground will do nothing in this specific radio.
by RedEye
Saturday 29th Nov 2008, 1:41
Forum: CB Radio Repair and Troubleshooting
Topic: tx meter hardly oves
Replies: 13
Views: 8373

tx meter hardly oves

Dodge, That radio dosen't use a "needle" meter. 30 years didn't help this time!!!! Heh Heh.....
by RedEye
Friday 28th Nov 2008, 17:01
Forum: CB Radio Modifications
Topic: Cobra 148 GTL: Unlocking the Clarifier
Replies: 16
Views: 11725

Cobra 148 GTL: Unlocking the Clarifier

Dogem250, did you have too much coffee?!?!!? Heh Heh.... Your adding posts to just about every topic in here..... and to be honest, (well, in my opinion) many of them are very strange or incorrect answers. Many of them go against what most techs and long time users say or recommend.... No disrespect...
by RedEye
Monday 23rd Jun 2008, 2:43
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL - F No TX audio - PA is just static noise
Replies: 13
Views: 8627

Thanks for the choke value, I replaced the choke, buttoned it all back up works great again! It's great to have the help you give, even when it turns out to be a simple fix after looking everywhere, I wouldn't have found for a long time without your direction. Now I owe you another pint...... LOL!
by RedEye
Monday 23rd Jun 2008, 1:58
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL - F No TX audio - PA is just static noise
Replies: 13
Views: 8627

I believe it is a choke, The board is marked L404
by RedEye
Monday 23rd Jun 2008, 1:18
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL - F No TX audio - PA is just static noise
Replies: 13
Views: 8627

Thanks for all the help Rick, I found the needle.... (in the haystack) R 113 open, replaced and static was gone, but still just a deak key, no audio... I did a headphone for audio on pin 6 like you said, no audio... followed it all the way back to the 5 pin mic board... The small black diode or chok...
by RedEye
Sunday 22nd Jun 2008, 12:30
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL - F No TX audio - PA is just static noise
Replies: 13
Views: 8627

OK correctly lifted legs and cap as suggested, no difference. Reinstalled parts: TR27 E 2.92/2.92 C 0.0/0.0 B 2.92/2.92 ( all are the same RX/TX) TR24 E- 0.0/0.0 rx/tx C- 0.0/0.0 rx/tx B- .70/0.4 rx/tx TR22 E- 0.5/.5 C-3.0/3.0 (when E lifted it is 7.0 RX/TX) B-1.10/1.09 emits a hum when tested in TX...
by RedEye
Sunday 22nd Jun 2008, 12:08
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL - F No TX audio - PA is just static noise
Replies: 13
Views: 8627

Damn just noticed I listed TR22 as TR27

I'll go back and lift leg of TR27 and give you the results. The voltages above that say TR27 are actually TR22....
My Bad eyesight, heh heh
by RedEye
Sunday 22nd Jun 2008, 12:05
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL - F No TX audio - PA is just static noise
Replies: 13
Views: 8627

IC4 starting at the back of the radio:

1 - 8.2
2 - 13.8
3 - 8.2
4 - 0.0
5 - 13.8 - on tx goes to 0.**
6 - 8.2 - on tx drops to 0.17
7 - 0.03
8 - 0.11 - on tx goes to 8.2

Checking other voltages now...
by RedEye
Sunday 22nd Jun 2008, 10:58
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL - F No TX audio - PA is just static noise
Replies: 13
Views: 8627

Lifted points as you asked, and pulled cap 232 leg, No change... When connected: TR24 E- 0.0/0.0 rx/tx C- 0.0/0.0 B- .70/0.4 TR27 E- 0.5/.5 C-3.0/3.0 (when E lifted it is 7.0 RX/TX) B-1.10/1.09 emits a hum when tested in TX with DVOM I'll try the other caps now, and get back, Thanks for the directio...
by RedEye
Saturday 21st Jun 2008, 14:15
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 - IC4 has 13.8 volts at Pin 1
Replies: 4
Views: 3688

Thanks again Scott, I pulled a good one out of the other 148 and put it in. All problems went away. In fact to get it on freq before, I had to bottom out L23 to get AM right. Now I had to realign it and the L23 slug is back to around center. Audio is great on AM and SSB again. Freq also climbed abou...
by RedEye
Saturday 21st Jun 2008, 11:32
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 - IC4 has 13.8 volts at Pin 1
Replies: 4
Views: 3688

Thaks Scott, I did look for a thread, must of missed it. I did lift pin 1 to see if there was voltage on the board, there wasn't . 13.8 coming from the chip. I don't have a spare, but I'll pull one from a working radio to test. Only problem noticed so far, audio real distorted, and on SSB there is a...
by RedEye
Saturday 21st Jun 2008, 5:44
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 - IC4 has 13.8 volts at Pin 1
Replies: 4
Views: 3688

Cobra 148 - IC4 has 13.8 volts at Pin 1

I have another Cobra 148, Had a terrible clarifier unlock job done to it: PC-412 Board PLL 8719 MB3756 pin 1 should have 8 volts, just as pin 3, but this radio is a 13.8 on pin 1. Is the chip bad? It had a very weird clarifier mod, I am putting it back to stock , and noticed pin 1 was high. ( The mo...
by RedEye
Saturday 21st Jun 2008, 2:23
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL - F No TX audio - PA is just static noise
Replies: 13
Views: 8627

Just noticed I can get a swing above dead key by creating a squeal by touching the foil side of the board by the audio chip during key up, but no audio from the mic. Checked the mic gain switch, it's ok...
by RedEye
Friday 20th Jun 2008, 16:48
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL - F No TX audio - PA is just static noise
Replies: 13
Views: 8627

Cobra 148 GTL - F No TX audio - PA is just static noise

Board # EPT01481 3 Z PLL 8719 Cobra 148 GTL-F Problem No audio on TX, Good Dead Key no swing PA is just static Replaced Audio Chip - No change Picked up a 148 GTL-F, bought a new bezel and faceplate, worked great so only did the channel mod and talkback. About two weeks went by with no problems, the...

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