Go Back   WorldwideDX Amateur Radio Forums > Citizens Band Related > General CB Services Discussion


Amateur Callsign Lookup
Enter Callsign:

Need some help with my Cobra 29 LX and AMP

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 03-07-2012, 11:06 AM
Junior Member
iTrader: (0)
 
Join Date: Mar 2012
Posts: 6
ztothej is on a distinguished road
Default Need some help with my Cobra 29 LX and AMP


Hey Guys,

New here and sort of new to "tweaking cb's"

I have a couple questions and hope you guys can help..

First off I just got my amp in, its the new KL 203P and plan on hooking it up to my Cobra 29 LX.

The only this is I'm not to sure how to lower the output of the Cobra so its in the range of the amp.

The Cobra has been tuned by the shop I got it from and puts out about 30-35 watts.

The other option I have is to take the bone stock one I have in my motorhome and tune down the watts in that one while running the amp on this Cobra.

I hope I gave the correct information for some help, if not let me know and ill do my best to add in what is needed.

Thanks Sean.


Reply With Quote
  #2  
Old 03-07-2012, 11:25 AM
Junior Member
iTrader: (0)
 
Join Date: Mar 2012
Posts: 6
ztothej is on a distinguished road
Default

also can I take one of the RF switches from an older 29 Classic and use it for a power adjustment? if so will it lower the dead key to run the amp on the I can turn it up and not run the amp?

Id rather add a knob the hack up the factory one.. course if thats what it will do is lower the dead key..

Reply With Quote
  #3  
Old 03-07-2012, 11:45 AM
Wire Weasel's Avatar
Senior Moment
iTrader: (17)
 
Join Date: Dec 2008
Posts: 2,679
Wire Weasel is on a distinguished road
Default

Hi guy, several things

No your Cobra LX is not swinging to 30-35 watts. They won't come anywhere close to doing that much.

Your local CB shop has a "happy" meter that has been turned up. That is the one he shows the customers to show them how he gets a single final CB to do 35 watts and how great he is. We have a guy like that over in this area by the interstate who rips off the truck drivers.

Do you own a set a decent meters? Maybe you ought to get a set and check that radio yourself.

The power adjustment is in the back of the radio right across from the final and is that big barrel with copper wire wrapped around it and a big plastic slug screw that you turn. You need to get your dead key down to no more than 4 watts for your amp. 3 or 3.5 watts might be better.

Add a fan to your amp if you're going to do a lot of taking or it will overheat.

Good luck

Reply With Quote
  #4  
Old 03-07-2012, 12:42 PM
Junior Member
iTrader: (0)
 
Join Date: Mar 2012
Posts: 6
ztothej is on a distinguished road
Default

Quote:
Originally Posted by Wire Weasel View Post
Hi guy, several things

No your Cobra LX is not swinging to 30-35 watts. They won't come anywhere close to doing that much.

Your local CB shop has a "happy" meter that has been turned up. That is the one he shows the customers to show them how he gets a single final CB to do 35 watts and how great he is. We have a guy like that over in this area by the interstate who rips off the truck drivers.

Do you own a set a decent meters? Maybe you ought to get a set and check that radio yourself.

The power adjustment is in the back of the radio right across from the final and is that big barrel with copper wire wrapped around it and a big plastic slug screw that you turn. You need to get your dead key down to no more than 4 watts for your amp. 3 or 3.5 watts might be better.

Add a fan to your amp if you're going to do a lot of taking or it will overheat.

Good luck
Thank you for your help, I figured something was up because I do have a SWR/ Power meter and Ive never seen 30-35 on it.. anyways.

I keep hearing about this "final" not to sure what or where it is on the board. I know its in the back just not sure what part is it.

So if I'm reading this correctly there s screw inside the final I turn down for the input watts that will go into the amp or is that to set the dead key??

In order to run this amp I've been told I need to have 15 watts into the amp with a 2 watt dead key.

If thats part you were talking about is the power adj. can you explain what the modulation (VR4) does??

Sorry for the questions, just want this amp to run good with the radio and be nice and clear sounding.

However I do have a meter and a left over Cobra 29 Classic that I can use for parts..

Thanks Sean

Reply With Quote
  #5  
Old 03-07-2012, 01:08 PM
Robb's Avatar
Yup
iTrader: (3)
 
Join Date: Dec 2008
Location: Silicon Valley CA, Storm Lake IA
Posts: 7,829
Robb is on a distinguished road
Default

Adjust L 10 until you get 1 watt output dead key with the mic gain turned all of the way down. DO NOT adjust L 20; that is the 54MHz trap coil!!! Your RM Italy amp likes a low dead key. They will get damaged if you input much more than that.

KL203 Amplifier

http://www.cbtricks.com/radios/cobra...a_29ltd_sm.pdf
__________________
BASE: Kenwood TS-2000, GAP Titan DX, Diamond X50A, Sirio SY27-4, and IMAX 2000.
MOBILE: Galaxy DX99V w/RF Limited CR-577 mic, Sirio Z-180. Yaesu FT-8800R & Diamond NR-770.

Reply With Quote
  #6  
Old 03-07-2012, 01:34 PM
Junior Member
iTrader: (0)
 
Join Date: Mar 2012
Posts: 6
ztothej is on a distinguished road
Default

Quote:
Originally Posted by Robb View Post
Adjust L 10 until you get 1 watt output dead key with the mic gain turned all of the way down. DO NOT adjust L 20; that is the 54MHz trap coil!!! Your RM Italy amp likes a low dead key. They will get damaged if you input much more than that.

KL203 Amplifier

http://www.cbtricks.com/radios/cobra...a_29ltd_sm.pdf
Ok cool, what about the out put? how do I tune down the watts going in to the amp to a more suitable watt?

also my Modulation is set to 100% right now.

Reply With Quote
  #7  
Old 03-07-2012, 01:40 PM
Robb's Avatar
Yup
iTrader: (3)
 
Join Date: Dec 2008
Location: Silicon Valley CA, Storm Lake IA
Posts: 7,829
Robb is on a distinguished road
Default

Quote:
Originally Posted by ztothej View Post
Ok cool, what about the out put? how do I tune down the watts going in to the amp to a more suitable watt?

also my Modulation is set to 100% right now.
The radio output is set by L 10.
Adjust L 10 for 1 watt output - or even 1/2 watt output if it will adjust that low. That amp will work at 1/2 watt; so that is where I would set the radio output for that amp. It will sound cleaner and run cooler that way.
__________________
BASE: Kenwood TS-2000, GAP Titan DX, Diamond X50A, Sirio SY27-4, and IMAX 2000.
MOBILE: Galaxy DX99V w/RF Limited CR-577 mic, Sirio Z-180. Yaesu FT-8800R & Diamond NR-770.

Reply With Quote
  #8  
Old 03-09-2012, 10:02 AM
Junior Member
iTrader: (0)
 
Join Date: Mar 2012
Posts: 6
ztothej is on a distinguished road
Default

Thanks for all the help, still working some bugs out but otherwise all good..

I've been thinking about just buying a Stryker Radio and using it on CB.

I know the newer one puts out close to 100 watts.. so that will be good and close to the amp.. ( I think)

If I do get the Stryker I won't be running the amp on it, what does everyone think of this?

Sean

Reply With Quote
Reply

Bookmarks
Worldwide Radio Forum



Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 10:02 PM.


Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0
Worldwide Radio Forum