20 Most Recent Magnum 257 CB Radio Questions & Answers

Hello.I have a similar situation on a Magnum 257 HP operating on SSB (AM and FM works fine). If i Transmit it works fine, but when i release the Mic button (after TX), in the bottom side were the RX level should be, it appear somth like a signal level 3 to 5 (constant and continous), but i can't get any reception at all. Only if i turn the TX power level to MAXand i transmit, then it goes back to reception, but not every time. Somtime after TX i need to push the mic button 2-3 times to make it recive somthing, but this wors only if the power level is over 60-70% an i repeat, only on SSB.Can i get some help with this issue?

you can use any amp with any radio. they must be setup to do so.

Hi,

On most mobile communications equipment, it is best that:
1. the power leads are directly wired to the battery terminals;
2. the bracket and radio body are grounded to the chassis of the vehicle;
3. a braided grounding strip be used in addition to the negative power lead; and/or
4. a gutter or trunk lip mounted antenna be used rather than magnetic. Antennas are better made of metal rod (not fiberglass) such as those made by Daiwa, Maldol, Oscar, Hokushin and others. The mount itself should use high quality RG58 coaxial cable such as those by Belden and others.

Hope that this be of some help/idea. Pls post back how things turned out or should you need additional information.

Good luck and kind regards.

Nope, your not the only one. Poor power regulation internally and maybe check your antenna swr. Higher wattage with even 1.9:1 i have seen exports have issues.. and then the magnum with there alc mod (compressor) on the op amp..

tengo un magnum 257 y necesito la COMBINACION PARA INSTALARLE UN ROAD DEVIL RD104E.

sounds like the PA has failed, I would have the radio shop serviced

I wouldn't do this...makes them splatter and sound like hell

check the reverse polarity diode and replace it if necessary.

My solution is not to use this site. It is another obvious scam to generate funds for your "experts". I had hoped to make contact with other "enthusiasts" and not be solicited for money for help. You might as well go sit at an intersection with a cardboard sign and "beg" for money. I have never seen any of these type sites provide any assistance worth mentioning, much less paying for. bOOmer

Try other mics what happen to me was the wire came lose and hit pin 6 which is power pin it may just have burnt the wire in mic plug

Ensure that the wiring is correct. Also make sure that the CB's AC is still functioning correctly. Charge your truck's batteries and test the CB on a fixed electrical output (indoor outlet). Also check to see if the power cord is the correct wattage output for the radio.

Hope this helps!
Gavin93

Hi livi, my name is John. Welcome to FixYa. If you have a MIC GAIN, turn it to MAX. If no avail, try a different mic. Are you saying you have no receive, turn the RF GAIN to MAX and the SQUELCH all the way to the left. Let me know. Thanks for choosing FixYa.....John

Notice the black mic plug has the numbers it is solder by numbers. Used rosin core silver solder radio shack sells it.Mic Wiring Stock 1-Shield (ground) 2-Yellow (audio) 3-Red (transmit) 4-White (receive) Astatic 1-Shield & Blue 2-White 3-Red 4-Black Yellow NC Turner Roadking 56 1-Shield & Red 2-White 3-Blue 4-Black Yellow NC Sadelta the is a BASE mic 1-Shield 2-White 3-Brown 4-Green

http://www.cbtricks.com/radios/rflimited/magnum_257/index.htm
Ok that above site has everything to do with your unit, there is a service and repair manual, and lots of information and links, hope they help.

This of no surprise because it is just that a display not a counter.


There must be an alignment pot for the meter display although there will be some doubt if you just align it with out using a frequency counter.

http://cbtricks.com/radios/rflimited/index.htm

you might find more alignment info under the S45 omegaforce as they have similar boards.

hope this helps...goodluck!!!!

http://www.cbtricks.com/radios/rflimited/magnum_257/graphics/magnum_257_sch.pdf
this is the one without RFX-75 on back

Have it tuned. Properly. Do not let anyone cut or clip anything inside. To makeit loud. Like others. They are using amplifiers.