The fuse for my cobra marine vhf radio blows as soon as I turn it on? I think that I may have crossed the + and - wires before turning it on and realized it after it belew the fuse and then I swapped them back, could this of caused an internal short in the radio that can be fixed or is it trash.

SOURCE: Transmits but does not Receive

Check your microphone by swapping with another duplicate. If no differance, you will need a SWR meter (standing wave ratio) to find the culprit. It attaches in line of the coax and determinds power out and reflected power. The reading should be 25 watts foward and max of 1 reflected.

Patrick Patterson

• 109 Answers
• Posted on Dec 16, 2008

SOURCE: Need an operating manual for a Cobra MR F75 VHF Marine Radio

Howdy from South Texas and Merry christmas.

Here is your link and enjoy the Holidays.

http://cobra.com/downloads/manuals/MRF55_manual-Eng.pdf

Patrick Patterson

SOURCE: Need an operating manual for a Cobra MR F75 VHF Marine Radio

http://www.cobra.com/downloads/manuals/MRF75_manual-Eng.pdf.

SOURCE: cobra marine band radio will not transmit more

Before changing out the radio try the radio on a ANTENNA RADIO TESTER or try it on a different antenna. Good luck.

Electro Med Services

• 6694 Answers
• Posted on Sep 24, 2011

SOURCE: I have a Cobra 18

Hi,
Connection that you have made are correct. One thing you hve to check is the Black wire is properly connected to the ground or not. If you have a multimeter set the meter to Ohms then check the Ohms between the Red and black wire of the Cobra 18 WX ST II. If its bellow 100 Ohms there is some short inside the Cobra 18 WX ST II. May be the protection Zenar diode inside the system become faulty. If there is no such short then you have to change the 2A fuse to higher one Like 4A or 5A. And the connect the system.

When you connect the multimeter if there is any short its will show the reading instandly. If there is no short then the multimeter will show random values.
OK