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View Full Version : Cobra 29wxnwst I know I shouldn't



stang
03-15-2014, 10:34 PM
But I thought I might put a swing kit my my cobra. I can't resist tinkering around with things. And hey the kit was 6.50 free delivery. That's a lot less than the gas would have cost to drive to Radioshack.

To tell the truth I've never tried working on a radio before. This looks like a simple parts swapping job though. I'm probably wrong about that but I hope not.

If any of you have any pointers now would be a nice time to share them.


Stang

stang
03-15-2014, 11:02 PM
Forgot to mention the kit is actually for a 29LTD my radio is a 29wxnwst. From what I have read they are the same parts though. Anybody know if thats right or wrong?

Thanks
Stang

Tallman
03-15-2014, 11:44 PM
The best advice I can give is be gentle with the circuit boards when de-soldering the parts you take out. Pressing harder with the soldering iron will not make work any faster. Have a sponge next to the iron damp with water, drag the iron tip across the sponge lightly and rotate it a bit so it cleans all the way around. Then put a little new solder(Tinning) on the tip so you have good heat transfer to the joint you are working on. Solder suckers work okay but sometimes you still need de-soldering braid to clear the solder away. Watch some videos on Youtube and you should get a good idea. Double check your work and be careful not to leave any solder debris inside the radio.

stang
03-16-2014, 09:59 AM
Thanks Tallman

I just can't resist modifying things. Don't know why, just the way I am I guess. Of course I also like learning new things.

This 29 works pretty well for a dead stock radio. Was talking to my neighbor 2 miles away he said I was putting 7-8 on the scale. Now that's in VA timberland and the foothills. About 60 ft down the back side of the hills from him. Mobile to mobile, he has a galaxy 55. He's not a CB regular he mainly uses it during hunting season. Doesn't seem to be many people around here on the radio. So I need to get up and strong to get out and talk.

Now I need to find a good base antenna. I need a vertical since it going way up and I can't build a tower right now. Looking at one of these http://www.hyelectronics.com/new-base-antenna-by-sirio/productinfo/GAINMASTER/ Kinda pricey. It's between that and a Imax 2000 unless I find something that looks better. But as I need a minimum of 60' of guyed mast pole to get through the trees. I've got a 11'x14'TV and cell ant. both on guyed masts both over 40 ft up. The tv is 20 ft over my roof though the cell is a true 40' pole.

Thanks
Stang

stang
03-16-2014, 08:31 PM
Since I made up my mind to play with this cobra 29 while I get my money together to setup a base station. I figured why stop with just a swing kit and also ordered this http://www.ebay.com/itm/IRF-520-MOSFET-FINAL-TRANSISTOR-UPGRADE-FOR-THE-COBRA-29-LTD-CB-RADIO-/251077124385?pt=US_CB_Radios&hash=item3a755ce121

I've built everything else I own might as well try building a radio too. :) If I blow it all I'm out is 16.50 for both kits and an old radio I had forgotten I had. If it works I might just get that old cobra talking LOUD AND PROUD... lol

Stang

stang
03-17-2014, 02:14 PM
Well this little project has gotten a bit more costly! I went ahead and ordered a receive kit also. Then I got to thinking that I would need a solder sucker and a small iron since all I have is a 150w gun. Then I realized I would have to have at least a couple meters. So I can see what's changing as I go. So now all that's ordered too. I don't really mind the cost of tools I'm sure they will come in handy for years to come. The basic radio parts cost about the same as a meal at a fast food joint.

Now they need to hurry up and get here! Then maybe you guys will be able to hear me shoutin out!

Wonder what kind of power I can expect from all this?

Slowly going stir crazy sitting inside, will this miserable winter ever end? My girls now have about a month of makeup snow days. Wonder if they will have any summer break?

Stang

Gordon Gekko
03-17-2014, 06:08 PM
Wonder what kind of power I can expect from all this?


Don't get your hopes up.

stang
03-17-2014, 06:26 PM
I don't have any idea what to expect. Gut feeling is better than 15 watts. Which is about 5 times the 3+- it's doing now.

Does that seem unlikely?

Stang

Tallman
03-17-2014, 06:32 PM
Wonder what kind of power I can expect from all this?

Stang

If your radio is a fet output transistor you will see some increase. If it is a 2sc1969 Bipolar transistor output you might not see any gain.

stang
03-17-2014, 06:39 PM
If your radio is a fet output transistor you will see some increase. If it is a 2sc1969 Bipolar transistor output you might not see any gain.
Thanks Tallman
From what I read the 2sc1969 was the fist step up and the 520 mosfet was the second more powerful. But who knows, I sure don't.

Stang

Tallman
03-17-2014, 06:44 PM
Thanks Tallman


Now I need to find a good base antenna. I need a vertical since it going way up and I can't build a tower right now. Looking at one of these http://www.hyelectronics.com/new-base-antenna-by-sirio/productinfo/GAINMASTER/ Kinda pricey. It's between that and a Imax 2000 unless I find something that looks better. But as I need a minimum of 60' of guyed mast pole to get through the trees. I've got a 11'x14'TV and cell ant. both on guyed masts both over 40 ft up. The tv is 20 ft over my roof though the cell is a true 40' pole.

Thanks
Stang

This is the one I use. It does pretty good.
http://www.hyelectronics.com/BASE-ANTENNA/productinfo/M400/

stang
03-17-2014, 07:24 PM
That looks like a real good antenna for low $$. Just my kind of deal.

THANKS
Stang

the caveman
03-18-2014, 08:37 AM
That looks like a real good antenna for low $$. Just my kind of deal.

THANKS
Stang
hey stang my old 29 Wx St had just a little peak and tune done. i know i will probably catch hell but set Vr4 at about 85% or 90% and gentle space the coils with a flat plastic tool (i forgot which coils exactly) and it will do wonders. i talked plenty of skip with mine like that on a Roadpro 4ft fiberglass antenna and stock microphone off the old cobra radios.

Tallman
03-18-2014, 08:44 AM
The nice thing about that antenna is study the length adjustment chart pick out your center frequency and set the length with a tape measure. I studied mine and set it for my ten meter radios and the swr on the antenna is low. It does have good broad band capability. Although the receive is a little light because it is a 1/4 wave length.

stang
03-18-2014, 11:20 AM
Caveman, I think I have the notes on that mod here somewhere, now finding it might be a trick. lol

Tallman, Do you know if H&Y's gives any kind of price break if you order multiple items? IE antenna, coax, radio, rfx units & parts.

I think I'm going to bite the bullet and order an antenna Monday or Tuesday. H&Y's lists that M-400 as 7 db gain . Does anyone know of anything higher while staying to a straight antenna? What ever I get is going way up a guyed mast. So beams are out.

Thanks
Stang

stang
03-18-2014, 11:50 AM
One thing worries me about that M-400 versus a Imax 2000 or A99 or Gainmaster. That's the high wind gusts we get here. It's not just blowing from one direction at one speed. Here it seems to flip around and gust 30-50 in many directions at once. I think its the way the hills channel the winds. I have some experience with big antennas up in the air but not as high as this is going to go. My 11 x 14 foot tv antenna is 41-42 feet off the ground but on a tripod mount with 4 guy wires and 20 ft of mast on the roof.

Thanks
Stang

Gordon Gekko
03-18-2014, 02:21 PM
I don't have any idea what to expect. Gut feeling is better than 15 watts. Which is about 5 times the 3+- it's doing now.

Does that seem unlikely?

Stang

Cobra 29's never came with a 1969 from the factory. They come with a 2078. If you throw a 520 in there you might see 15w out of it, provided you do the installation correctly and you also do a host of other things to it. However going from 5w to 15w isnt going to change things on the receiving end. If you're so concerned about getting out the first thing you need is a proper base antenna, installed & grounded properly. Consider looking into the Penetrator, Maco v58, or Sirio GainMaster. The higher up the antenna is...the better it will TX & RX.

After the antenna situation is rectified, if you're still not getting out like you'd want to, look into an amp. We'll discuss that issue when the time comes. Meanwhile, quit screwing around with dumb shit like the MOSFET and focus on whats really important--the antenna.

stang
03-18-2014, 04:57 PM
Right now the 29 is in my jeep getting some limited use. I like modding things. Bad and costly habit but I enjoy it, always have and always will. ;) I am working on making my mind up which antenna by Monday Tuesday at the latest. The gainmaster is on the short list if I decide to go that route it'll be another week before I can order it. $$$ talk bs walks. I can only do so much at a time. For the receiving end I ordered that upgrade also. Weather I'll have a box of junk or a radio when I get done only time will tell. Reminds me of when I built a 79 camaro into a 10 second ride mom came by and asked if it would ever be a car again.? I had the subframe and all out. Yes it ran many times after best time ever was 8.73 @177 MPH on a 180 NOS shot and 10.20 ANYTIME on motor. Building it was a lot of fun and driving it was even more.
http://i129.photobucket.com/albums/p213/biggkidds/mycar001_zps6fd79eb8.jpg (http://s129.photobucket.com/user/biggkidds/media/mycar001_zps6fd79eb8.jpg.html)

Have a nice night

Stang

Gordon Gekko
03-18-2014, 05:18 PM
If you enjoy fiddling with radios, see if you can find some at the flea market. I always had decent luck at the flea market and hamfests. So if you blow up a radio you won't be out much money. Good way to cut your teeth without trashing a good working rig.

stang
03-18-2014, 06:23 PM
I don't know yet weather or not I'll enjoy foolin with radios but I'll soon find out. I just like to tinker with things in general. If you know what I mean. I live so far out in the sticks it's probably 50 miles to a flea market. But thanks for the tip. We have radio trading posts here I've been listening out for any CB's but haven't heard any for sale yet. The radio I am going to try and mod I thought was a lost cause after it being missing for six or so years. I am amazed it works at all.

Thanks
Stang

stang
03-19-2014, 11:45 AM
Putting the cart before the horse again. I picked up almost 1,000 ft of guy wire for my antenna today. Now I just need to make up my mind what kind of antenna. lol

Did make a 20+ mile contact this morning mobile to mobile. It ain't skip but still not bad.

stang
03-22-2014, 09:56 PM
Still waiting on the rest of my parts and tools I ordered. Wish they would get here already. The cobra is honestly doing better trips talking local than I expected. No skip yet, guess thats to be expected with a bone stock old radio in a mobile.

My base antenna plans had to take a back seat as my jeep broke down 80 miles from home yesterday. Set me back several weeks to a month or so. :( I just love doing parking lot repairs after walking to buy parts and tools, since I wasn't prepared. The good news it's fixed now. Made for a long LONG day in the city.

You all have a good weekend.

stang
03-24-2014, 10:04 AM
Just opened up my radio thinking I would install these parts today. Mosfet supertune, swing kit, receive kit. Now I'm not so sure. Think I may have bitten off more than I can chew! LOL The kits came with instructions but most of it is greek to me. I really want to do this but when I'm not even sure which parts are which.....

Tallman do you work on cobras? If so please PM me with an estimate to install the three kits. Or better yet if you would be willing to walk me through the process I would really like to learn.

Thanks

stang
03-24-2014, 06:06 PM
Okay got most of the parts in and it still works. I am a bit disappointed the power actually dropped. I was getting 3.5 watts now less. Channel 1 close to 3.5 channel 40 just over 2 watts. Don't understand how the power can be different across the channels. But it works it's way down from channel one all the way through 40. I'm confused. Still have the receive kit to put in but both the mosfet and swing kits are in. Everyone I spoke with on it said it sounded real good though. But I need POWER! At least a little. you know 15-20 watts

Guess I could have done something wrong. IDK

Gordon Gekko
03-25-2014, 05:32 AM
Power dropped when putting in the MOSFET. Not surprised.

stang
03-25-2014, 04:57 PM
Power dropped when putting in the MOSFET. Not surprised.

Really ? Why would that happen? Is there a fix to boost this thing? If I can get 15-20 watts that would be a good start.

stang
03-26-2014, 04:05 PM
Anyone have any other ideas what might be going on with this thing. It's swinging from 1 w to 3-3.5 but that's it. Someone mentioned the mic might be weak not modulating hard enough to make it swing like it should.. Any thoughts?

Thanks

stang
04-04-2014, 07:24 PM
Well good news my new meter is junk. My mods turned out great after all I just found out. Also found out today we have a local radio guy who's been working on them 40+ years. Took my radio to him this evening told him what I had done & that I thought I had messed it up. He put it on his meter dead key 1 watt swing 18 watts. Clean & clear sounds pretty damn good. Guess now I need to go get busy doing the schottkey receive mod and it'll be done. While I was there I got a D 104 desk mike, a frequency counter and a Uniden PC-122. So now I get to see if I can do the same mods to the uniden I did to the 29. Even better I talked skip a couple times on the way home so it was a gooooooooooooooood day!

:300 (193):

halfwatt959
07-13-2014, 06:37 PM
The irf520 mosfet conversion/mod is capable of produceing 30-35w when you tune everything else. Be sure not to turn any cans and if you are or are planning to run an amp make sure the deadkey is set at no more than 3w. Also be carefull when tuneing the coils. It is real easy to mess things up. But I encourage you to learn and good luck

222DBFL
07-13-2014, 09:13 PM
Hey stang leave that PC122 alone. They pack a mean Punch stock!! Great ssb radio!! I have a pc122xl and it is one nice radio. Small package that packs a mean punch. The 1969 final in the 122 is a rugged device and is clean. I wouldn't mess with that particular radio. Buy a cobra 25 or a other 29 and play with those IMO. The pc122 is just a good radio without any mods IMO. Anyway hope all is well and that you are feeling better. God bless.