Search found 258 matches

by timrim
Friday 29th Jan 2021, 14:59
Forum: CB Radio Repair and Troubleshooting
Topic: 45mhz out of TX mixer IC on general lee
Replies: 0
Views: 7676

45mhz out of TX mixer IC on general lee

The radio has no transmit. I suspect a mixing issue. There is a good strong 45 mhz signal on the output of the TX mixer IC.
I have a 10.695 signal on the TX mixer. The mixer has been swapped out.

Any ideas?

EDIT: I found bad TR8 receive mixer, the receive is now working
by timrim
Thursday 20th Sep 2018, 10:13
Forum: CB Radio Repair and Troubleshooting
Topic: RCI-2990 problems with balanced modulator/10.695 circuit?
Replies: 0
Views: 11725

RCI-2990 problems with balanced modulator/10.695 circuit?

I have an RCI-2990 that I am trying to repair. I have a complete test bench with everything. The radio has a very high dead key on USB and LSB. The AM works, except the frequency is unstable, like it it out of lock. Also, when I vary the power on AM, the transmit frequency changes. If I remove D-45,...
by timrim
Tuesday 19th Mar 2013, 9:29
Forum: CB Radio Repair and Troubleshooting
Topic: galaxy 959 coil chain problem in receive
Replies: 2
Views: 6758

Re: galaxy 959 coil chain problem in receive

Was the original FET a SK45?
by timrim
Saturday 8th Oct 2011, 9:26
Forum: CB Radio Modifications
Topic: stryker sr447hp conversion
Replies: 0
Views: 6319

stryker sr447hp conversion

what is the conversion for the new version Stryker sr447hp's?

thank you
by timrim
Wednesday 20th Apr 2011, 20:10
Forum: CB Radio General
Topic: Part needed for a Uniden Pro Trucker PTC-104
Replies: 0
Views: 6687

Part needed for a Uniden Pro Trucker PTC-104

I am looking for a suitable substitution for the following part (channel display): Part number on board: D551 Manufacturer part number: LL-2255SL Uniden part code: BDAY0530001 If no one knows of a suitable substitution, does anyone know the specs on this? Voltage, Current, Dimensions etc? If I had s...
by timrim
Sunday 15th Nov 2009, 10:41
Forum: CB Radio Repair and Troubleshooting
Topic: Wanted: Truth code(s) for Galaxy DX 88
Replies: 3
Views: 6603

Re: Wanted: Truth code(s) for Galaxy DX 88

Hi Zodiac,

Thank you for the reply, do you also have the binary data for the PLL's pins #9 - 17 on CB channel 1?

Thanks
Tim
by timrim
Friday 13th Nov 2009, 9:15
Forum: CB Radio Repair and Troubleshooting
Topic: Wanted: Truth code(s) for Galaxy DX 88
Replies: 3
Views: 6603

Wanted: Truth code(s) for Galaxy DX 88

I need the truth codes for the galaxy DX 88, if the complete chart is unavailable, please provide the binary truth data for CB channel 1.

Thanks,
Tim
by timrim
Tuesday 7th Jul 2009, 10:24
Forum: CB Radio Repair and Troubleshooting
Topic: Golden Eagle MK-IV PLL unlocking
Replies: 2
Views: 6651

Re: Golden Eagle MK-IV PLL unlocking

I found the service manual on cb tricks, so if someone is familiar with the PLL in these, please give me a place to start.
by timrim
Friday 3rd Jul 2009, 7:52
Forum: CB Radio Repair and Troubleshooting
Topic: Golden Eagle MK-IV PLL unlocking
Replies: 2
Views: 6651

Golden Eagle MK-IV PLL unlocking

Radio Make and Model: Browning Golden Eagle Mk-IV PCB Number: N/A PLL Number: MC4044 Phase Detector (IC-109) Test gear available: Complete bench Symptoms: PLL Unlock causing channel display to go blank Intermittent problem What is working: Receiver all the time and transmitter when PLL is locked Wha...
by timrim
Tuesday 30th Jun 2009, 19:20
Forum: CB Radio Repair and Troubleshooting
Topic: SS158 EDX Talkback wont shut off
Replies: 0
Views: 4780

SS158 EDX Talkback wont shut off

Radio Make and Model: SS158EDX PCB Number: EPT690010D PLL Number: MC145106P Test gear available: Complete bench Symptoms: Talkback won't turn off even with echo off What is working: everything What has been tried: checked for cold soldering Did it suddenly happen ?: that way when new Anything else t...
by timrim
Saturday 17th Jan 2009, 6:30
Forum: CB Radio Modifications
Topic: Cobra 134 / 138 channel expansion
Replies: 2
Views: 6337

Cobra 134 / 138 channel expansion

Yes, you can swap crystals. If memory serves me, you can change a mixer crystal in that radio, that will give you a whole new 23 channel group. 23 channel radios are not very wide banded however, so I would not try to go too far.
by timrim
Saturday 10th Jan 2009, 6:26
Forum: CB Radio General
Topic: Superstar 3900el & 2sc1969 question
Replies: 2
Views: 6246

Superstar 3900el & 2sc1969 question

The superstar is a nice radio, you wont fry the 2sc1969.
by timrim
Friday 9th Jan 2009, 19:27
Forum: CB Radio Modifications
Topic: more helpful info?
Replies: 7
Views: 10001

more helpful info?

Never ever jumper the diode connected to the transformer! Butcher shops do that! The diode is there to protect the modulation transformer.
by timrim
Friday 9th Jan 2009, 19:19
Forum: CB Radio Modifications
Topic: Help!!! Cobra 148gtl(uniden) mod
Replies: 1
Views: 4580

Help!!! Cobra 148gtl(uniden) mod

I am not familiar with RMC, but without a frequency counter or another radio with channels, making a roadmap won't be easy. There are just too many different ways to wire the switch for channels. This of course assumes that the switch mods the PLL. If the switch is actually part of a channel kit wit...
by timrim
Friday 9th Jan 2009, 19:14
Forum: CB Radio Repair and Troubleshooting
Topic: President Jackson No TX No RX switching
Replies: 13
Views: 25287

President Jackson No TX No RX switching

Well if your radio only keys on the a band, or if you start going up in frequency and the transmit drops out, it could be the VCO. Does the radio receive ok on all bands and channels? If so, than the VCO should be ok, then I would suspect an alignment issue between the TX mixer and output stages.
by timrim
Thursday 8th Jan 2009, 17:11
Forum: CB Radio Repair and Troubleshooting
Topic: President Jackson No TX No RX switching
Replies: 13
Views: 25287

President Jackson No TX No RX switching

Yes, it was fixed. I replaced TR-33 and C-97.

In your case, it sounds like the VCO may need adjustment.
by timrim
Sunday 4th Jan 2009, 7:16
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 53947

148gtl (4pin)

First check all voltage regulators, if they all are good, then I would take a close look at the mixers or possibly first rf amp and/or protection diodes.
CBTricks has the service manual.
by timrim
Sunday 4th Jan 2009, 7:13
Forum: CB Radio Repair and Troubleshooting
Topic: Cobra 148 GTL-DX Frequency Problem
Replies: 24
Views: 31727

Cobra 148 GTL-DX Frequency Problem

What are the VCO voltages on channel 1 and 40?

Usually the first thing I do when I suspect a PLL/VCO problem is go through the complete
alignment procedure, making notes of any incorrect readings. CB tricks will have all the info you need for that radio. That will point you in the right direction.
by timrim
Wednesday 31st Dec 2008, 8:54
Forum: CB Radio Repair and Troubleshooting
Topic: cobra 18 no tx & rx
Replies: 6
Views: 9223

cobra 18 no tx & rx

I am glad you fixed it. I have had so many of those radios come in and they all have the same problems.
Happy new year!
by timrim
Friday 26th Dec 2008, 21:30
Forum: CB Radio Modifications
Topic: Ranger 2950DX Key
Replies: 1
Views: 4332

Ranger 2950DX Key

How about a bit of info on how they work?
by timrim
Thursday 25th Dec 2008, 10:15
Forum: CB Radio Modifications
Topic: m58473p PLL channel mods
Replies: 2
Views: 6204

m58473p PLL channel mods

You can mod it, but, if I remember correctly, the PLL board will only give you up to 27.575 or 27.595, not very many.
by timrim
Tuesday 23rd Dec 2008, 11:13
Forum: CB Radio Repair and Troubleshooting
Topic: cobra 18 no tx & rx
Replies: 6
Views: 9223

cobra 18 no tx & rx

check the areas near the PLL/VCO, also pay close attention to any small circuit boards that are mounted perpendicular to the main board, those solder connections always develop problems.
by timrim
Monday 22nd Dec 2008, 17:26
Forum: CB Radio Repair and Troubleshooting
Topic: cobra 18 no tx & rx
Replies: 6
Views: 9223

cobra 18 no tx & rx

I have repaired a lot of the 18's, almost all of them have had poor solder connections, I would check that before anything else on that radio.
by timrim
Thursday 18th Dec 2008, 23:03
Forum: CB Radio Repair and Troubleshooting
Topic: 148 final gets hot?
Replies: 2
Views: 5307

148 final gets hot?

I think the final is in self oscillation, look at the output on a scope in receive mode.
by timrim
Tuesday 16th Dec 2008, 6:07
Forum: Tech Area
Topic: talkback rely
Replies: 2
Views: 7438

talkback rely

All you will need to do is simply remove all wires, near the external speaker jack, you will find a jumper that this relay went to, you will need to install the PCB jumper back in that spot. The relay is glued down, so gently pry up from board. As for putting it back in, I don't recommend using the ...
by timrim
Sunday 14th Dec 2008, 16:14
Forum: CB Radio Modifications
Topic: 2sc2312?
Replies: 2
Views: 5875

2sc2312?

Yes, these will work well in a 29.
by timrim
Sunday 14th Dec 2008, 10:01
Forum: CB Radio Modifications
Topic: Dumb question for cb experts.
Replies: 4
Views: 7353

Dumb question for cb experts.

Yes, its possible. You will need to mount it on a heatsink capable of dissapating the heat. It is easier buying a stinger board, that has the heatsink and circuit board included, however, I find the heatsink supplied too thin, so I always add more aluminum.
by timrim
Sunday 14th Dec 2008, 6:56
Forum: CB Radio Modifications
Topic: Magnum Alpha Force Mod needed
Replies: 4
Views: 7388

Magnum Alpha Force Mod needed

Hi Chevin, I know that the forum has a few bugs, but I think its still a great place. I will probably hang around until they take it down, and see if I can help out. I have had great help here already from Rick, Defpom and the others, so I can't just abandon them. I really enjoy it when I am able to...
by timrim
Saturday 13th Dec 2008, 9:50
Forum: CB Radio Modifications
Topic: Magnum Alpha Force Mod needed
Replies: 4
Views: 7388

Magnum Alpha Force Mod needed

I tried to do a search, but i get the following error: SQL Error : 2006 MySQL server has gone away

Does anyone know the conversion for this radio?
by timrim
Friday 12th Dec 2008, 9:34
Forum: CB Radio Modifications
Topic: Ranger 2950DX Key
Replies: 1
Views: 4332

Ranger 2950DX Key

Does anyone have the schematic of the "Key" that plugs into the processor on this radio?
I am very curious as to how they work.
by timrim
Friday 12th Dec 2008, 7:38
Forum: CB Radio Modifications
Topic: new magnum s-980 50 WATTS???
Replies: 5
Views: 8568

new magnum s-980 50 WATTS???

It should be doing more than 55 on AM, 15-20 watts more at least. Remember that a shop will tune the radio on a dummy load which represents a perfect 50 ohm load and a 1:1 swr, so there is always going to be some difference, but that does seem excessive. Are you sure that your not dropping voltage o...
by timrim
Sunday 7th Dec 2008, 8:50
Forum: CB Radio Amplifiers
Topic: Build this 1.5KW Mosfet amp
Replies: 1
Views: 6493

Build this 1.5KW Mosfet amp

I don't think this project is for anyone that does not wish to risk losing big money on the MOSFETs if something goes wrong, I have been doing some research and so far, I have been told the MOSFETs sell for about $165 each. I have a couple of exact price quotes on the way, but unless they are cheape...
by timrim
Saturday 6th Dec 2008, 15:38
Forum: CB Radio Modifications
Topic: EURO 3900 IRF520 conversion
Replies: 10
Views: 16500

EURO 3900 IRF520 conversion

CB20Ws are garbage, I would take the 2312's.
by timrim
Friday 5th Dec 2008, 11:18
Forum: CB Radio Amplifiers
Topic: Build this 1.5KW Mosfet amp
Replies: 1
Views: 6493

Build this 1.5KW Mosfet amp

I am going to research parts and prices, if economical, I will be building one, looks very easy, I am just not sure about cost of parts.
by timrim
Friday 5th Dec 2008, 5:50
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 115391

Test your knowledge Uniden (President) Grant PC-409

If c79, c80 and c81 test good, then at this time swap out IC2 and see if symptoms disappear.
by timrim
Thursday 4th Dec 2008, 21:50
Forum: CB Radio Repair and Troubleshooting
Topic: President Jackson No TX No RX switching
Replies: 13
Views: 25287

President Jackson No TX No RX switching

Thanks for the reply Rick, I have some 2SA1282's so I will swap that out to keep things safe.
by timrim
Thursday 4th Dec 2008, 17:06
Forum: CB Radio Repair and Troubleshooting
Topic: President Jackson No TX No RX switching
Replies: 13
Views: 25287

President Jackson No TX No RX switching

Has anyone else discovered that the schematic calls for a 2SD355E for TR31 and a 2SB525 for TR33, but yet the radios actually come with 2SD355E installed in both locations, apparently they had TR33 in backwards with a 2SD355E, and it must have worked, but I simply replaced TR33 with a 2SA473, and it...
by timrim
Thursday 4th Dec 2008, 12:21
Forum: CB Radio Repair and Troubleshooting
Topic: President Jackson No TX No RX switching
Replies: 13
Views: 25287

President Jackson No TX No RX switching

I just found out why the PLL was unlocked, C97 was shorted (10volt cap) Radio now receives, transmit not working, transmit light not working. Voltage on pin 8 of PLL is now 8 OK now for the new voltage readings on the following: TR31 E=7.7 Rx 0volt Tx B=8.3 Rx 0 TX C=8.8 TR32 E=0 B=.8Tx 0Rx C=8.4Rx ...
by timrim
Thursday 4th Dec 2008, 12:08
Forum: CB Radio Repair and Troubleshooting
Topic: President Jackson No TX No RX switching
Replies: 13
Views: 25287

President Jackson No TX No RX switching

0 volts on pin 8, so that means the PLL is unlocked I did not suspect that, because when I got the radio TR 33 was bad and I replaced it, so I assumed the problem had to be in switching...Another lesson learned! Unhooking 1 end of R171 allows the receive light to go out when I press transmit, but no...
by timrim
Thursday 4th Dec 2008, 8:18
Forum: CB Radio Repair and Troubleshooting
Topic: President Jackson No TX No RX switching
Replies: 13
Views: 25287

President Jackson No TX No RX switching

Radio Make and Model: President Jackson PCB Number: PB042 PLL Number: MC145106P Test gear available: Full lab setup Symptoms: No TX and RX Switching What is working: It lights up What has been tried: Tested TR31, TR32, TR33, D59, D61, D66 check ok on ohm meter Pulled and tested R187,R202,R168,R203,R...
by timrim
Wednesday 3rd Dec 2008, 22:37
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 115391

Test your knowledge Uniden (President) Grant PC-409

Is the 11Mhz signal at TR-29 clean?
by timrim
Wednesday 3rd Dec 2008, 13:34
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 115391

Test your knowledge Uniden (President) Grant PC-409

Check 10.240 signal at PLL, if noise is there, replace the 10.240. If still noisy, replace the PLL chip.
by timrim
Wednesday 3rd Dec 2008, 9:17
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 115391

Test your knowledge Uniden (President) Grant PC-409

I would take out c-90 and c-92 and test them.
Is the signal on TP-10 normal?
by timrim
Wednesday 3rd Dec 2008, 8:10
Forum: CB Radio Modifications
Topic: EURO 3900 IRF520 conversion
Replies: 10
Views: 16500

EURO 3900 IRF520 conversion

They are discontinued, and, if you do find them, they are quite expensive, I would not hesitate going with a mosfet at this time, they work really well.
by timrim
Tuesday 2nd Dec 2008, 9:28
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 115391

Test your knowledge Uniden (President) Grant PC-409

Are the voltages on IC5 normal?
Is the VCO output at TP2 clean?
by timrim
Tuesday 2nd Dec 2008, 9:20
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 115391

Test your knowledge Uniden (President) Grant PC-409

Do the DC voltages on IC 4 (Voltage reg) look clean on a scope?
by timrim
Tuesday 2nd Dec 2008, 9:10
Forum: CB Radio Repair and Troubleshooting
Topic: Test your knowledge Uniden (President) Grant PC-409
Replies: 43
Views: 115391

Test your knowledge Uniden (President) Grant PC-409

If you examine the output of IC 5 (TX Mixer) on a scope, does the signal look normal or is it distorted? If you also examine the input and output of IC 6 on a scope (Audio output) does the signal look normal or is it distorted? Do the DC voltages on IC 4 (Voltage reg) look clean on a scope? Given th...
by timrim
Monday 1st Dec 2008, 10:38
Forum: CB Radio Repair and Troubleshooting
Topic: Need help figureing out resistor Value Needed
Replies: 5
Views: 7437

Need help figureing out resistor Value Needed

3 of those will work ok, they may get warm on transmit, but should not be a problem. I suggested double the max expected current just to have a hefty margin for error.

They are rated at 3 amps, so you can pull up to that through them without frying them.
by timrim
Monday 1st Dec 2008, 10:25
Forum: CB Radio Repair and Troubleshooting
Topic: Need help figureing out resistor Value Needed
Replies: 5
Views: 7437

Need help figureing out resistor Value Needed

You would need a monster resistor because the current draw of the radio on transmit may be approx 2 amps. You can run the radio off 15 volts, but if you need to get it down, a better way would be to use 3 diodes in series with the positive lead, the diodes will need a rating of at least double of yo...