Cobra CB radio

[3.0ranger1227]

Is it possible to change the backlight color of the screen on the cobra CBs? I got one of the cheap Cobra's as a gift and have it in my truck but the orange display is wearing on me a little.

Is it just an orange LED soldered into a chip inside? could I just melt it out and then drop in a blue one to match the rest of my interior?

 

[4x4junkie]

If the radio has a backlit LCD, then chances are good you may be able to get in there and change a LED or two.

If the numbers in the display themselves are orange, then you'd have to change the LED display itself, which is more involved (not to mention finding a suitable display unit might be tough).

 

[3.0ranger1227]

The numbers are black, the background is orange. This radio was bought last christmas.

 

[4x4junkie]

Sounds like LCD then.
Just hope they didn't use microscopic surface-mount chip LEDs that are next to impossible to solder without having the thing disappear onto the tip of your iron, because if so, there's likely to be no room to put a conventional LED in there (even a small one).

 

[3.0ranger1227]

Thanks. Hopefully it will be a normal LED. Is there anywhere I can find a schematic for these radios?

EDIT: Never mind I found a schematic, can someone decode it for me? lol I've dealt with diagrams like that before but I can't make heads or tails of it anymore.

 

[feellnfroggy]

The cobra your referring too if its the small little 4 inch unit is worthless, you can change the backlight color, but I highly recommend not investing anything into it. Even being a gift I have to suggest you get online and find a used cobra classic model or uniden something alot bigger with more quality. They have kits for these radios for changing lights, alot cheaper, and also you can have them tweaked and get alot more power out of them. THe small cobra makes less than 4 watts, the bigger ones can be tuned as far as 250 watts. Also there is no gain control on the small ones which makes wheelin with clear communication almost impossible. Myself and hatman are running a pair of these because they are all we have at the moment. I have an upgraded antenna which helps, but I still cant pick him up half the time.

 

[3.0ranger1227]

I know it is not a great unit but its what I have. Unless I can find a similarly sized unit that is better I probably won't change for a while because A) It's not a major deal right now and B) I would like it to fit in the same spot without smashing into my knee. Also i'm in the middle of some serious other upgrades and this isn't a top priority

 

[feellnfroggy]

Then the best I can suggest is a power mike, and a better antenna, firestik or something comparable. Minimal slack as possible in your antenna cable, no loops in the wire or anything and an interference module in the power line to prevent background noise from the sparkplugs. As far as the background light, I dont see why you cant swap out led's.

 

[3.0ranger1227]

Amazingly there is almost no slack in my antenna cable. Where can I get an interference module?

I'll look into the mic and firestik a little later when I get some more $

 

[feellnfroggy]

I dont know if its the correct name but the interference module is one of those little black boxes that you find on CD players aftermarket. ANy audio installation shop sells them and Im sure CB shops sell them too. It just mounts inline to filter out any excess elctrical noises.

 

[4x4junkie]

THe small cobra makes less than 4 watts, the bigger ones can be tuned as far as 250 watts.

I assume this is a typo, as that's simply not possible without an external booster (which can be put on any radio).

 

[feellnfroggy]

I was sittin at Mikes CB shop at exit 417 in dandridge TN. He was testing radios. One metered in at about 199 watts the other at 250. Whether or not they had external parts I dont know, but they were light enough to still be held in one hand and had no extra bulk on the casings of the radio. Remember your pushing FM signal, not electricity through speaker wires, so watts is relative to an extent I would say. But its still 10 miles worth of signal+

 

[4x4junkie]

Sounds like he may have been feeding you a line of rubbish then lol (and had his meter set to the wrong scale or something).

No radio is even close to remotely capable of that much power even after peaking unless it's a so-called "export" radio that has a linear amp module attached to the bottom or rear of it (you'd know this by the large heat sink fins on it).

The Cobra 29LTD is the most potent US-market radio I've come across as far as output power after peaking, and it's still only 6-7 watts carrier power, with a PEP (swing) of about 25-28 watts. Most radios only come out around 5 watts carrier, swinging somewhere between 15-20 after peaking.

Standard CBs are also AM (along with a variant known as SSB on some radios), not FM. Though FM again can be found on many of those export and/or ham radios.

 

[ronclark]

THe small cobra makes less than 4 watts, the bigger ones can be tuned as far as 250 watts.

There is nothing wrong with a 4 watts, just have everything tune and have the right antenna

Not to spoil anyone fun

FCC Rules
RULE 10 - Power Output
{A} Your CB station transmitter power output must not exceed the following values under any conditions:
AM [Amplitude Modulation] - 4 watts carrier power [CP]
SSB [Single Side-Band] - 12 watts peak envelope power [PEP]
{B} If you need more information about the power rule, see Part 95/ Subpart E.
{C} Use of a transmitter which has carrier [CP] or peak envelope power [PEP]in excess of that authorized voids your authority to operate the station.

RULE 11 - Linear Amplifiers
{A} You may not attach the following items (power amplifiers) to your type-accepted CB transmitter in any way:
[1] External radio frequency [RF] power amplifiers, also called linear amplifiers, or linears;
or
[2] Any other devices which, when used with a radio transmitter as a signal source, are capable of amplifying the signal.
{B} There are no exceptions to this rule and use of a power amplifier voids your authority to operate the station.
{C} The FCC will presume you have used a linear or other external [RF] power amplifier if-
[1] It is in your possession or on your premises; and
[2] There is OTHER EVIDENCE that you have operated your CB station with more power than allowed by CB Rule 10.
{D} Paragraph C above in this section does not apply if you hold a license in another radio service (HAM, etc.) which allows you to operate an external RF power amplifier.

 

[strvger]

am: amplitude modulation

fm: frequency modulation

2 different methods of getting voice and music transmission/reception.