The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

RedEye

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...

RedEye

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!

RedEye

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!

RedEye

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

RedEye

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...

RedEye

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!

RedEye

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 so...

RedEye

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....

RedEye

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...

RedEye

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...

RedEye

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.

RedEye

Dodge, That radio dosen't use a "needle" meter. 30 years didn't help this time!!!! Heh Heh.....

RedEye

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...

RedEye

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!

RedEye

I believe it is a choke, The board is marked L404

RedEye

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...

RedEye

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...

RedEye

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

RedEye

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...

RedEye

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...

RedEye

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...

RedEye

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...

RedEye

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...

RedEye

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...

RedEye

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...

RedEye

Many times it is just the ribbon cable from the board to the channel selector, the wire has a high tinsel strength, so it breaks easily when you bend it, check both sides and I suspect you will find one or two broken. look closly, as the other wires in the ribbon will hold them close together....

RedEye

Follow the remaining foil and attach at the closest place that you can get a a good solder connection. Gently scrape off the green coating, tin the area with solder first, then tin the jumper ( or a proper sized piece of wire, indsulated would be better.), then use as little heat as possible to sold...

RedEye

It can be as simple as: 1) Replacing the final 2)Remove R55, R56 and C61. 3)Add a 68Pf cap accross C59. 4)Install a EN1230 ( for the ERF2030) or a EN369FN (for the IRF520) in the R56 spot. Correct polarity for both is with positive(+) torwards R123 (front of radio when installed on the component sid...

RedEye

What even worse, he dosen't even give the winner the proper Bias part, the en-1230....just a resistor!!!!!
He has another auction for a 2030 final and 2 resistors, (Power Kit) he calls it..... No Bias part... LOL

RedEye

I am sorry, I usually don't post stuff like this, but I have tears rolling down my face from this Ebay ad. http://cgi.ebay.com/Cobra-CB-SUPER-TUNE-UP-KIT-with-TA7222AP-AUDIO-IC-CHIP_W0QQitemZ180246592587QQihZ008QQcategoryZ40055QQssPageNameZWDVWQQrdZ1QQcmdZViewItem This is hilarious!!!! I love the JO...

RedEye

Andus91, You haven't really told what problem you have, I'm sure most don't what to say.... You had bad SWR's.... OK... does the radio still transmit? Does it receive? Have you hooked up another antenna? Have you changed your exsisting antenna? You said a friend heard clicking, did he see a carrier ...

RedEye

Check the speaker leads, or insulators around the jacks. I had one doing the same, turned out to be the speaker was grounding completing the circuit just like the resistor mod!

RedEye

X-13, You may be right, I may have jumped a little hard.... I apologise. Rick has been a very helpful tech here and I see his frustration in many of his posts when people don't take the time to say thanks. Comments like yours, even if it was meant to be non bashing, I worry, will run off many techs ...

RedEye

This mod isn't correct, or at the very least is over complicated...
Clarifier mod is the same as prev models with a change in location and one resistor number.
Thanks to Rick on this one from a previous post in the archives!

RedEye

I had a similar problem with a new model 29, Old models are great, pop it in , PROPERLY tune it. 35 watts clean. NO cheap capacitor kit. (Don't use em) I played with the 2007 model for about a week, This is what I was able to get out of it.... I replaced the driver with a 2SC1957, changed the 68pf c...

RedEye

Removing sideband won't gain any AM power. Sideband doesn't rob power. That would be like taking the turn signals off your car so you can turn faster?!?!?!?!? (heh heh)
73's

RedEye

Thanks Rick, A thousand pardons, The squelch is correct, I was looking at the wrong pot on the dual switch. The above wiring is for the volume. Squelch is properly hooked up, and both the knob and VR3 are working. voltage through R45 to TR 12/17? varies with the knob, center is .70v ground leg is go...

RedEye

Got a Cobra Soundtracker / Weather ... the weather board has been removed. The squelch does not work at all even with adjusting VR3. It seems to be muffling audio audio all the time, (slightly) , when middle tag and high tag (not ground tag) of the switch are together, audio sounds good. the high ta...

RedEye

Thanks a ton Rick, I'll check tonite, Found a local Icom dealer, I'll look into getting a new PRT.

RedEye

There are several 858 PLL mods to expand channels, but one specific shows having to add a circuit to get one band on the 29XLR... Anyone know why? Can you do the 2 switch mod on the AM version radio? What is the recomended pll mod to get the best expansion out of the 29 XLR 858 pll? Thanks in advance!

RedEye

Both the 29 and 25 (US ver.) have an am audio chip, you cant pull FM without more mods than cost making it worthwhile. It might be useful overseas, but not a ton of action here in the states....

Rick would know the way to do it though!

RedEye

Check the cb/pa switch, also check for audio when in pa mode on pa jack, check that out and let us know!

RedEye

Those RM Italy KL60 boards are crap. I have removed them from radios when they come in for repair. TERRIBLE RF around them and like you said, almost every one locks up on TX from poor rf shielding. Don't do the SSB mod in the directions, it will short and they won't replace it.... They actually only...

RedEye

Board # A2347 - 4 - 0 ? (Only number I saw) Does anyone have the clarifier mod for this as It is a different board design that side mic models. How about the receive mod diodes? Any help would be apreciated! I think these are the worst 148's cobra put out, but my freind wants the mods, so I am tryin...

RedEye

Westgate has everything you need, just google them or i believe it is westgateparts.com

RedEye

I have 2 Icom W2A dual band VHF/UHF handhelds that were given to me. Both work very well, and both will charge batteries through the Ext power plug on the top. However when the ext power is removed the radios power off, 3 different batteries (one new) all hold and maitain charge well. I found out th...

RedEye

I may have all of the stock parts if you need them to convert back, I do the dual mod (IRF520's) and have had good results. PM your address and I'll gather the parts up and mail to you.....With a copy of the erf-2030 mod reversal and IRF520 reversal too 73's 949/959 are great radios! The really good...

RedEye

"In your case, Rick, from your post, I learned nothing. zilch. . Regards, Rick (Triple 7)" I will take the advice of a WORLD CLASS and TOP TECH any day over anyone who repeats cheap internet mods to someone who is trying to find legit ways to create real RF power gains. For you to put dow...

RedEye

GRTS, Great guess!!!! The 8719 must have been the fault. I removed it and put in a socket just in case I needed to swap another one back in. Put in a spare from a 949 and the problem disapeared! Thanks for the idea, it was right on! ( It was a 2001 chassis too, your comment about older models...)

RedEye

Just ran all the channels, on RX it receives, static sounds normal, but when someone keys up in range, the RX has the same Ocilation noise as when it TX's ... I'm about to try a new 8719 to see if it resolves the problem, I'll let you know!

The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

Search found 140 matches

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