Cobra 25 LTD 40-Channels Base CB Radio - Answered Questions & Fixed issues

Questions? Support Cobra Electronics Corporation

you must have great knowledge of CB'S to tackle this problem.

first,a realistic plug is a 5 pin D.I.N. type and a cobra 25 is a 4 pin screw on . If you are trying to save $$ by using an old mic then let me say that you can get them prewired real cheap.

buy a different cobra 25 4 pin mic and try that . If that doesn't work than you inherited a piece of junk .

no need for wiring diagram just replace the reverse polarity diode. Look at where the power wires come into the radio and you will see a diode. that's the one to change.it should be a 1n4001

1,if your antenna is not properly tuned you may be loosing receive as well as power 2,how your swr? 3 you may want to purchase a little driver with a built in receive amp.

L 19 is the adjustment can for the N/B . If you choose to adjust it then turn it a little at a time. If it still doesn't work right then let a tech take care of it.

sounds like a voltage problem that you are incapable of handling. Take it to a tech.

did you play around on the inside of the radio???

there is the problem. a $150 repair bill for a $ 25.00 problem. After you put in this new IC did you put it on a scope to check it out.How about a frequency counter to make sure you were on the right frequency? take it to a tech and let him fix it .

turn it on

The only "adjustment" is the AM POWER trimmer. Lowering this will lower your dead key but will also lower your "swing" power. the TX circuit must be modified to lower the dead key and maintain full output. there are many articles on the web for such modification.

VR5

http://www.cbtricks.com/radios/cobra/25ltd/index.htm

not on frequency, take it to a tech.

check VR4 to make sure it isn't closed . Check D 11 to make sure it isn't clipped . Turn VR 4 clockwise till it stops then back it off a little .If D 11 is clipped replace it with another diode then try it again. If it doesn't work it could be your final or your driver so replace both..

what is your dk. just remember 4.5 watts is the limit

pin 1 audio shield pin 2 audio lead pin 3 tx control pin 4 rx control

plug it into the radio and see if it works,if it does leave it alone.

http://www.cbtricks.com/radios/general/lee/index.htm Hope that helps .