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Message |
    
Mersberj
New member
Username: Mersberj
Post Number: 5
Registered: 8-2005
| | Posted on Saturday, September 17, 2005 - 8:21 am: | 
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Supertune: Replace the stock final with a 2SC1969 unit. Solder a jumper across R123. Solder a 68pf cap across C62. Solder a 120pf cap across C59 if there is already a 33pf across it. If there isn't, use 150pf instead. Replace R 55 with a 47-68k resistor, and solder a 33-55 pf cap across that resistor. Replace R58 with a 4.7 ohm resistor. Set VR4 just a bit to the right of half-way open. If D11 or C3 have been removed, replace them. If TR18 has been removed or cut, install a 2SA733. Spread Open L12 a bit, and adjust L16 for best swing, using a loud, steady "aaaaaaah" sound into the mic. MAKE SURE to use heat-sink compound (a light coating is sufficient) when mounting the new final, and MAKE SURE the final mount screw is tight!
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1489
Registered: 7-2004
| | Posted on Saturday, September 17, 2005 - 10:03 am: |
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check your swing output before you- 'Spread Open L12 a bit, and adjust L16 for best swing', then check it again-yes should should see some more swing. place a low-pass (tvi) filter between radio & antenna & you'll probably see a decrease of much of the increased swing. HARMONICS.
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Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 640
Registered: 9-2004
| | Posted on Saturday, September 17, 2005 - 11:54 pm: |
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since the title of the thread is "what do you think"
i'll tell you.
i believe this mod to be a waste of time and effort.
for all the work you get about 15 watts?
barely noticable on the RX end.
find the plans online for a 50 watt amp you can put inside a radio. for the same ammount of work you get much more power.
that is just what i think.
matt |
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 193
Registered: 3-2004
| | Posted on Sunday, September 18, 2005 - 11:17 pm: |
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HINT HINT.......KL40 for 29.99 can be put in a 29 fairly easy but whats the point when the amp is no bigger than a pack of Camel 100`s cigarettes. |
Tech808
Moderator
Username: Tech808
Post Number: 7234
Registered: 8-2002
| | Posted on Monday, September 19, 2005 - 6:09 am: |
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KL-40 Mobile *
$ 29.99
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Input power: 1-4 Watts
Input power SSB: 2-8 Watts
Output power: 25-30 Watts
Output power SSB: 50-70 Watts
On/Off Push Button
Fuse 5A
CLICK on the Link Below.
KL40
The EASY WAY TO MOD A RADIO. 
Lon
Tech808
CEF808
N9OSN
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Duck246
Member
Username: Duck246
Post Number: 75
Registered: 8-2004
| | Posted on Friday, September 30, 2005 - 4:38 pm: |
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A well tuned cobra/uniden puts a KL-40 to shame..
The real point of getting another 15w peak is to drive an amp.. A much bigger amp than a KL-40 |
Outkast
Junior Member
Username: Outkast
Post Number: 10
Registered: 9-2005
| | Posted on Saturday, October 01, 2005 - 12:12 am: |
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I want to see the tuned uniden/cobra that puts a kl-40 to shame. Theres a guy around here supposedly a "tech" that tells everyone that there radio is doing 50 swinging 75 when its tuned, yup bring them on over and lets see what it does on a meter that the needles havent been messed with. Most of the radios me and my buddy have tested have only really been about 10 watts so far. I have even figured out how he does this, all he did was make it so when his meter is on 100w setting its really on 10 and wallah 5=50 7.5=75 lol. Wouldnt take a broken mic to a guy like that. |
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 219
Registered: 3-2004
| | Posted on Saturday, October 01, 2005 - 3:35 am: |
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outkast LOL yea i never seen a cobra 29 outperform a kl-40 but my dog is bigger than your dog mentality is what seems to get non educated operators its comon sence realy.sure you can get 10 watts out of a cobra 29 no problem but it dont make a real big diference non anyone will notice on the s-meter.and 50 watts peak on a cobra 29 i just dont think is possible if it is then there radio sounds like
$%&@ and i personaly wont talk to someone with a radio that is so distorted i have to struggle to hear them and even with a swing kit you dont get any more peak you just drop the carrier and increase the distortion of the modulation i learned that swing stuff the hard way. a radio at a 4 watt carrier set to 100% modulation will swing to 8 watts and so on.when you start going from a 1 watt carrier to 12 watts just imagine the modulation % sounds like poop and cant be understood.I never go above 80% modulation as this i found is about the best audio u can get before distortin occurs in the amc circut. |
Hatchet
Junior Member
Username: Hatchet
Post Number: 21
Registered: 7-2004
| | Posted on Saturday, October 01, 2005 - 9:34 am: |
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The Cobra 29 swinging 50 watts is the real deal. Ive seen them and they even look respectable on a scope |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1568
Registered: 7-2004
| | Posted on Saturday, October 01, 2005 - 4:50 pm: |
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adding a 2sc2290 or sd1446 to the insides of a 29, or any radio for that matter-not just 'changing' the finals, should get you into the 50+ watt range. a bit time consuming & tweaking is usually needed. putting an amp such as the kl40 inline is nothing more then giving you a really effective power mic, actually a pretty good alternative & truly cost effective. not a bad deal if you just wanna be heard on ch 19 or just around town.
you can drive ANYTHING with ANY radio, no matter what its output. a bone stock 29 out of the box keying 3 watts & swinging 5, into a 3 pill amp into an 8 pill amp into a 32 pill amp, & your keying over 2kw & swinging over 5kw. you will be talking dx all the time, & the locals will KNOW you're on the air. all with a 3 watt radio & stock mic. |
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 220
Registered: 3-2004
| | Posted on Saturday, October 01, 2005 - 7:04 pm: |
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you both are correct but these guys saying there getting 50 watts out of a 29 with 1 2sc1969 are not telling the truth....How would you put the 2290 in a 29? i am interested in that could it be done to a 148? |
Hatchet
Junior Member
Username: Hatchet
Post Number: 22
Registered: 7-2004
| | Posted on Saturday, October 01, 2005 - 8:19 pm: |
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Yea fusebreaker, it is correct. Its not your typical setup. My email is in my profile if you wish to see a video of a bird meter swinging to 50 watts and the video of the spectrum analyzer while testing these. Its alot more involved than just a final swap |
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 221
Registered: 3-2004
| | Posted on Saturday, October 01, 2005 - 11:57 pm: |
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ok i am interested ill drop you an email tommorow sometime. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1578
Registered: 7-2004
| | Posted on Sunday, October 02, 2005 - 9:30 pm: |
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basically, you are bolting a 2290 or whatever to the rear of the chassis, putting 12 volts to the collector through a hand wired coil, control bias with a little inductance from base to ground, as well as a little resistance to reduce harmonics. output tuning is controlled by modifying a coil already present on the board, by rewinding & adding a little capacitance. make sure the emitter tabs are well grounded to the chassis & you MUST ground the chassis to the radio's DC ground-from the factory the chassis is NOT grounded! the radios AM power control or external variable adjusted to 10 watts, & the modded tuning coil adjusted to max should see 50 watts swing, maybe more maybe less. that's where the tweaking comes into play. adequate or inadequate heat sinking, tweaking inductance & capacitance...there are values that 'work', you just have to deal with what you get, or, like i said, stay 'stock' & go external amplifier.
NO, they are NOT getting 50 watts out of a single 1969. nor dual 1969's, unless it was run up to 20 volts or so, requiring more mods to be done to the radio. not worth the aggravation, so the radio is modded for max & the amp is run on high volts.
5 leece nevilles & 21 pills on 24 volts, with a 29 doing about 12 watts rms swing, was keying over 3kw, not sure which was louder, the alternators at 3000rpms or the fans, but he was keying over 10 x 32 on 14 volts all afternoon. so, a relatively 'stock' 29 can be a rather formidable piece of equipment if backed up properly |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 416
Registered: 11-2002
| | Posted on Monday, October 03, 2005 - 6:00 pm: |
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This sounds like one of those, I strongly agree/I strongly disagree, columns.
My two cents is, I strongly disagree. You won't get 50 RMS watts out that mod, but you can get about 40 PEP watts doing that. You're probably be closer to seeing about 10 watts RMS.
Cheesy, don't knock me down. I have one of those 29's outside that I did that way. And I've seen that power on my Coaxial meter with a Bird element in it. Although I have to admit, not every Cobra 29 I've done this do, gave the same result, some were less.
Now do this mod, and run the radio off about 15 volts, and see you'll see that 50 watts of PEP swing from about 1 watt of dead key. And the RMS will be around 10-12 watts, maybe even show as high as 15.
I see I'm going to have to break out the camera and shoot some video... |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1599
Registered: 7-2004
| | Posted on Monday, October 03, 2005 - 7:01 pm: |
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put a tvi filter on the back of it & a wattmeter AFTER the filter & watch all your extra watts disappeari've already seen the video-actually, the real mc coy
it'll take more then 15 volts, the transistor will take it, the rest of the radio won't without some work |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 418
Registered: 11-2002
| | Posted on Tuesday, October 04, 2005 - 5:28 pm: |
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How dare you defy me like that Cheesy?!?!
I'll try it sometime and I'll tell you what I get. I think I need to call you... |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1603
Registered: 7-2004
| | Posted on Wednesday, October 05, 2005 - 8:24 pm: |
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