Cobra 142 gtl no receive. COBRA, UNIDEN, REALISTIC, & MORE, 11M RECEIVE MOD.
Cobra 142 gtl no receive. all I remember is a TP10 for this radio as far as the highest TP number. K7MEM Member. 5 watts, and it is swinging about 10 watts true PEP. Jun 5, 2021 · Addeddate 2021-06-05 06:59:59 Identifier manual_142GTL_C. The fact that the speaker is putting out noise suggests that they mic is probably correct. Hope this helps, let know how you get on. It was listed as for parts not working all the top cover screws are missing. there are No toggle switches. Nov 26, 2012 · I bought this 1978 cobra 142 gtl on shop goodwill for $65. I was going to replaced the Final, Driver and Audio IC chip. NO CLIPS ! lightly tuned at 4 to 16 on AM and around 20 on SSB. The MB8719 PLL was bad. with the pot you use. And the upper channels, 19 through 40, have nothing but very low static. The radio works, it powers on when plugged into the wall switched to ac. New problem, too. Upon removing the old caps, I noticed the C92 location had a 330uf 16v cap instead of Dec 18, 2008 · Cobra 142 GTL Schematic: The WorldwideDX Radio Forum was originally established in 2001. I found L-13 ( sealed with gel so it never has been touchedcould not find L - 15 (or a few others ), but DID find L - 3 ( near the tx coil section of rig and I figger that when it was peaked out, that some one accidently turned L- 3 by mistakeit DRAMITICIALLY brought the "ears " up with less than a half turn of Aug 10, 2010 · The Cobra 142GTL has a 5 pin mic connector and requires a receive control circuit in the mic. COBRA 142 GTL CB Base Station TESTED POWERS ON Dynascan Corp No Microphone (A8) COBRA, UNIDEN, REALISTIC, & MORE, 11M RECEIVE MOD. The Cobra 2000,148GTL, newer President and Uniden Grants, and newer Madison have the Uniden dual conversion PC-497 board. Have not opened it up yet. The 1306 tested bad. AM Signal Meter. put your 2 fingers on the board and you will sometimes hear recive audio. No need to turn that knob every time a different station keys and talks. RF Meter. Nov 27, 2016 #2 The 142 GTL is a very easy rig to . any ideas on what to replace would be a big help Oct 31, 2009 · I used the radio before I went to work, came home, and now it dosn't transmit at all. 95 May 8, 2018 · refresh my memory, for some reason I do not remember the step for a TP16. Astatic (6 wire) Mar 22, 2021 · Thanks to Ray Byrne of Ireland and Tim Trent of Arizona for helping with the troubleshoot of this radio. All went well untill I got to a place where I had to pull a cap to ID it, after removal it read C108 with no plus mark so I looked it up the B O M and it says 0. May 10, 2020 · Modifying the clarifier to "lock" your transmit frequency to your receive frequency just makes life easier for three-way (or more) conversations. I've got the low channels to come in without Dec 29, 2010 · The D300 has the Uniden single conversion PC-385 board like the Cobra 140GTL/142GTL, Uniden Washington, Realistic TRC490/TRC450, Robyn SB505D and a few other brands. The 142 GTL uses a single conversion receiver on both AM and sideband. AM Freq. It has low power so I lifted the legs of the 1306 and 1307. I already replaced an audio IC in a Cobra 29LTD that I bought for $5. Wiring for the D-104/T-UG9 stand to the Cobra 142GTL: Pin 1: White (Audio Hot) Pin 2: Shield (Audio Ground) Apr 18, 2008 · Cobra 142 gtl Alignment. I had a 1969 and put it in but now I have ZERO bias current. The 142 GTL also has the MB-8719 PLL already installed. AM Squelch. Dead key is 1. com Someone who wanted to help you repair your equipment scanned this manual. you are talking about 3 wires and a coil which is what is used for the variable on the am only radios. Any advice is appreciated. Gave it an alignment and also peaked the TX coils; it works as well on AM as it does on SSB. The 142 uses a different board than the 148/Grant. If you know the mic is good, PA works, but the TX/RX indicator stays green, a likely cause is the PLL being unlocked. I was told it could be either D-1 or D-2 on receive. I think they just plugged it into the wall with it switched to dc. Thanks to the moderator for allowing me to join. The schematic for the 142 shows a 1306 as the driver transistor so I am guessing the 2166 is a May 27, 2005 · I found in another thread peak out rx on a 142 tune L-13 / L-15 / L - 3. That way everyone can transmit on the same clarifier setting. The Meters don't move, the light dosn't turn red, alsmost like it was a microphone problem, but its not, I tried about 5 mics, and nothing, there isn't a relay in the rig, so what else can I check or replace, Mar 12, 2021 · Seeing as I still have some time on my hands waiting for parts and gainfull employment. 00 and now it works great-I even installed a roger beep in the 29 and now it sounds like an export radio. anyone have channels installed in those switches? if so, could you give me the cheat sheet. Previous owner had the voltage turned up to over 15 I backed that Jan 22, 2010 · If the mic wiring is broken, you may not have TX, and/or no receive audio. Model. There were already existing holes from another less desirable channel mod, so I figured I'd at least put something a little better in it. Normal messages; Private Cobra 142GTL Documentation Project 3- Receive 4- Sw Com 5- Transmit. Which good quality tool do I need to buy to adjust VR6 to raise AM carrier? Thanks! Oct 20, 2014 · Hello everyone, I have a 142gtl that is almost pristine. 5 to 3 watts. Usually in the receive position it is grounding the speaker and when you transmit it breaks it. Thread starter Mike Jones; Start date Jan 20, 2019; M. Apr 3, 2005 · The Cobra 142 and Uniden Washington have a receiver that is single conversion for AM and SSB both. I picked up this sweet little cobra 142 GTL base station that needs a new face plate both top and the front. It's on frequency, transmits at 8-12 watts. SSB Squelch. 60 volts in SSB mode. this mod done this way is not as hard as you are thinking. Dec 18, 2008 · All things Cobra 142 GTL here (including various mic wiring): Cobra 142GTL I would get a 4 pin to 5 pin converter. (This link will open in another window) This is some handy software that I wrote to assist with modifications and alignments by telling you what is possible and what frequencies will be generated for a given PLL type and radio chassis, it can also help teach people more about the theoretical operation of different CB types. I use the trc-450 to align my 142 radios. Some folks will complain that it's too narrow for AM and too wide for SSB. Astatic (6 wire) Sep 1, 2010 · This is a piece of good news. May 2, 2024 · The 139 XLR uses the uPD858 chassis, which has the older 4 pin mic connector and uses a relay to switch between receive and transmit. Radio is stock no mods. Consumers did not receive such explanations while shopping in the aisles of discount stores, and so they either failed to buy the product or returned it later. The radio is in nice condition and I am determined to fix it. USB Freq. No voice. Nov 9, 2017 · I inherited a cobra 142GTL that has sat for 20 years. 80 volts in AM/FM/CW and about 13. 00 shipped to my door. The 142 GTL uses the MB8719 chassis, which has a 5 pin mic connector and uses electronic switching. If anyone has any questions, feel free to ask me, and I will gladly help you out. While the unit receives 5x5, the transmitting modulation is near 0% the SWR seems okay and it s mated to an A-99 Antron antenna with RG8 cable, grounded with copper wire to a ground stake 6 ft. 73 Dec 18, 2013 · 8 out of 10 times that I turn the radio off and on again the radio will not even key up (no transmit light) and sometimes when I key the mic the transmit and receive light flash on and off. I can TX on SSB but no RX i have good carrier just no TX audio on am or rx on am and ssb but i do have ssb audio Also i can see the Signal meter moving like it is receiving good signal just no audio AMC: ALC: AM POWER. Back in the 70s I used to repair quit a few Cobra 140/142 GTL and when they came in with no RX TX it was IC5 or TR37. This video will help others understand how to align a radio correctly. The 2000 GTL ha a built-in frequency counter. Maybe since we Dec 18, 2008 · Many Cobra products, such as a cordless telephone that used a scrambler to give users privacy, required explanations to make consumers understand their benefits. LSB Freq. 0-alpha-20201231-10-g1236 Cobra 142GTL Documentation Project 3- Receive 4- Sw Com 5- Transmit. Radio . 1 of 2 Receive mention alerts; Sound notifications. 1; 2; First Prev 2 of 2 Receive mention alerts; Sound notifications. Will give all the channels the 148/2000 will off the 8719 chip (I added the a extra crystal that you will need if you wanted to get all the channels if need be , it's just a simple swap ,one for the other and the channel mod. I was having no issues. put your finger on the board around the audio chip and you get sound/hum. I was thinking about trying to fix it myself and was wondering what the part numbers are and where are they are located on the board. Mar 10, 2011 · Need a little Help here My cobra 2000 all of a sudden stoped receiving or tx on AM. Not a bad deal. Opens in a new window or tab Jul 13, 2010 · (the receive pin to ground) looking at your radio, and starting at the lower left side of the mic connector, the first pin is 5, then going clockwise, 4 -3 -2 -1, with 1 being the lower right pin. it will burn the pot out from the RF going through it. I should mention that I was using a studio mic and a mixer wired to the audio wire in a stock mic to to key up. When this happens, it inhibits the transmitter from operating, and with an inoperative PLL circuit, there will be no receive either. Do other radios receive properly when connected to this antenna? If they do, I would check the SO-239 on the 142. one to the ground of the vr6, one to the plus side of Oct 12, 2013 · I have a Cobra 2000 GTL which is working perfectly EXCEPT there is no receive whatsoever. pin 3 (the top middle pin) is the receive pin. RX appears Dec 18, 2008 · Fixed a couple of Cobra 142 GTL's that had this problem, which uses the same PC-385 chassis that the Pres. May 7, 2005 · Unfortunately, the Cobra 142's clarifier circuit isn't very "widebanded", and it's very difficult to mod it to get the 10+ kc of slide that you desire. The T-UG8 stand (4 wire) doesn't have one. Jan 18, 2018 · Hello out there everyone I am new to the form. If you would like to help us put more manuals online support us. What I also found odd is that there's no change when I attach an antenna. Where could I get these parts without using a C/C. Apr 10, 2014 · Cobra 142 gtl Alignment. The only problem I have not been able to track down is the swr/mod meter not working as it should. pin 2 (just to the right of pin 3) is the audio shield/ground pin. VR BY C44 Go To RadioMods CB Radio Simulator software page. I just changed all the electrolytic caps and she talks and sounds great. Cobra 2000 No Audio on AM Apr 23, 2018 · Your typical Cobra 2000/148/142 AM output - is not truly regulated, more like USES regulated voltage as that bias set point for Carrier - the only feedback being the AMC/ALC stuff using R166 and R165 as a divider combo to sense a pre-determined mid-point and then Limit the modulation using this method. Cobra 29 1. Mike Jones Receive mention alerts; Sound notifications. it recives incoming stations shown on s meter. Dec 7, 2003 · Guarantee. . I can tell that it is receiving because the s-meter is moving all over the place, however, I am not getting any sound out of it no matter what I do. Joined Dec 16, 2013 Messages 432 Location Swartz Creek, Michigan. Right off the bat I noticed that its volume is not as loud as the other one I own and currently in use. 0. rocket9244 in Elgin Apr 18, 2008 · Put a tone thru generator and it will receive down to -50 dbm at 400HZ, 30% modulation with a 50 micro volt output, this is a lot better than it was, so it corrected 1 problem some what. 022 uf 50v Apr 21, 2024 · Got an old classic Cobra 142 GTL on the desk. The RCI 8719 - A PLL works j Next to my cobra 142 GTL, it sounds great, but over the air I was told I sounded off frequency. Also the 142 GTL has a little chrome strip on the front vs the black one on the 139 XLR. It will not go all the way over to the cal position when turning Apr 6, 2005 · Same board as the Cobra 142 GTL and Washington base station. You will need to use a T-UG9 stand (6 wire) which does have the required receive control circuit. 5 volts TR 175 the battery is dead I'm assuming that the battery needs to Nov 19, 2009 · I'm performing the Poormans 192 Channel Mod from the files section at "the mod yahoo group" on a Cobra 142GTL. MOD Meter. They are cheap and allow you to keep your mic wired for your other 4 pin radios: C4P5C Microphone Adapter 4 Pin to 5 Pin CB Radios, Base CBs, HAM Radios, CB Antennas, Microphones, Speakers, Stryker, Connex, Galaxy and more at Nov 10, 2010 · Alright, I replaced the voltage regulator, and after a little tuning, she receives great, but when I tx, my meter shows some swing in modulation, but my watt meter dosen't move, so I assume I have modulation without power? My neighbor can receive me even though I put out no watts. Rick. I have a Cobra 142 GTL that was given to me radio Powers up apparently transmits but I get nothing on the receiving end no white noise no nothing… Aug 14, 2006 · Check IC5 (MB3756) and TR37 (2SC945) common fault on this radio. d Jul 4, 2006 · Cobra 148 GTL-DX No TX Post by Rick » Wednesday 12th Jul 2006, 15:55 The is TR43 (2SC2312) in the Mk1 and TR44 in Mk2, just check the collector voltage while you are key up (PTT de-pressed), you should have about 5. Thread starter kaos513; Start date Jun 1, 2016; Prev. #cb #cbradio Now that they are some 40yrs old these rigs may need a little TLC to keep them on the air. I have a receive kit to drop into it once it is up and transmitting. . It got it modded every possible way I think P. At first, the s-meter was stuck, but it has freed itself. O. it takes 3 wires. If they've changed the varactor diode to something other than factory, or simply added an inductor in series w/ the factory varactor, the clarifier position will likely not be centered after alignment Feb 20, 2014 · I bought a Cobra 142gtl and it has extra channels but I have no ideal where they are. Sometimes they open up a little or get corroded and don't make perfect contact. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. Jan 18, 2017 · the way I am reading what you wrote down sounds like you have built a setup like used in a cobra 29 using a tip120 trans. Thread starter kaos513; Start date Jun 1, 2016; 1; 2; Next. Feb 28, 2021 · When I keyed up my handheld radio next to it, it didn't receive the signal. Jul 21, 2005 · I have a Cobra 142 GTL that has no receive or will not transmit. Mar 6, 2018 · Cobra 142 GTL No AM Carrier. Astatic (4 wire) 1- White 2- N/C 3- Black 4- Shield 5- Red. Nov 30, 2006 · Well,I bought a new IC5 [mb3756] and will see what happens. According to the frequency counter. Oct 16, 2010 · Greetings from Oregon - the shower me state, I m Gus and I have an old 142 rig that s been serving faithfully until a couple of years back. www. I started recapping my 142 . TX Freq. Just a preference. Nothing but static when I key up and talk on channels 11 through 40 on the GTL. Need to raise the carrier to 2. There's also no sound from the speakers at all, not even static. 95 New price 1992 in the US: $199. Since a single crystal filter has to be wide enough for AM it's a bit too wide for sideband. Dec 18, 2008 · I have a 142 that was given to me, and went through it and set it back to stock after fixing many similar problems. Nov 27, 2016 · Cobra 142 GTL - Album on Imgur . Your choice. Apr 28, 2024 · The Cobra 2000 GTL uses a dual conversion receiver on AM and a single conversion on sideband. Dec 2, 2022 · The Cobra 142GTL is a nice CB Radio Base Station. Apr 18, 2008 · I decided to test it and it powers up fine. Normal messages Nov 11, 2019 · Just picked up a cherry Cobra 142 GTL. If the chip is okay, there's a good chance this radio is old enough to have the "ten-Volt Blues", and needs a 220 uF electrolytic capacitor, right next to the audio chip. Oct 4, 2021 · Since you're using a different coax and PL-259 with the signal generator than with the antenna, I would look there first. This Manual is provided FREE OF CHARGE from CBTricks. The ad stated that the unit does not power on. Dec 23, 2012 · Hey, I have this old (1997) 142GTL. tx audio and pa audio is also loud. Jan 7, 2010 · i have a cobra 148 and there is no recive audio, i tested the speaker and ext speaker jack, both works fine. Thanx. Issue: Transmit low in all modes Receive low in all modes Controls/switches scratchy Variable key not functioning correctly Decided to do a complete recap first. A higher voltage rating for the replacement is okay. The meters on the radio so modulation, but the swing meter for receive will not move. Washington has. High dead key like 5 watts, no TX audio. Jan 11, 2021 · What I have seen most commonly is that the RX/TX switching wiring disables the speaker. even searched my files for the 142 and did not find where it shows to test at TP16. Locate pin 14 of the PLL chip, and the Positive (+) side of C-12. DIAGRAM_COBRA Identifier-ark ark:/13960/t9z14mf8z Ocr tesseract 5. It is easier to turn up the power on the 142 GTL than it is on the 2000 GTL. Find many great new & used options and get the best deals for Cobra 142 GTL 40 Channel Base Station CB Radio at the best online prices at eBay! Free shipping for many products! Nov 26, 2020 · Having a similar problem a friend of mine gave me a radio as a gift the cobra 142 GTL I noticed is that the meter's don't move it came with a power a mic I'm not familiar with the radio I am a ham operator I want to get this vintage radio working I'm receiving good signal it came with a power mic requires a battery 7. Normal messages; No FM: Spurious emissions: Better than -? dB: Microphone impedance / connector: 600 ohm / 5-pin (Male locking ring jack) Microphone input level:? mV: MISCELLANEOUS: Manufactured: Taiwan (Early) and Philippines (Later), 197x-199x (Discontinued) Main PCB: Sub PCBs: Additional info: New price 1984 in the US: $184. 142 GTL: CUT R104: VR6, (ssb)VR7: Receive Boost. It also has very poor receive, as in I cant hear anyone unless its my other radio in the other room. Friend got one for $10, and said if I fix it, I can buy it for $20. Apr 10, 2014 · the version you are talking about will work for a short time. SSB Sig Meter. The cause/fix was poor workmanship on channel hacking this radio, poor solder joints, and/or bad switches. the only way I have ever done a 142 radio is put a pot external for VR6 to adjust it up and down. The owner of this website has made a commitment to accessibility and inclusion, please report any problems that you encounter using the contact form on this website. May 30, 2013 · I would look up Cobra 142 GTL "slide/clarifier mods", and start looking at the parts designators mentioned, compare that to what's in the radio. the 2 legs where it shows in the drawing you can put the pot there by its self or use a cap for the swing mod. When I TX, I get a 1 kilaherts difference. so I assume they are in the NB/ANL and or CB/PA switches. dfft dtb lczj ixd mafmu bsysgzn umwr jtjahthz xvgwnl tmgi