Cobra 148gtl tx/rx flashes between green/red and meter vibrates while mic is keyed, but only when you talk on sideband. Recieve is good. mic is old, but did work fine and all mic contacts are solid in plug and switch (re-soldered them to make sure)

SOURCE: cobra 148gtl

i am having this trouble as well. The ics was my thought too, but I think it is in the modulation circuit somewhere. another article i read said to check this. "Look for the collector of TR-23, you should read about 4.5 V with a dead key. If you find that this voltage is not present, check on the opposite side of R-120 for 6.5V. Most likely this voltage will not be present; if this is the case, C18 has shorted and needs to be replaced. This is a 330uf, 10V electrolytic capacitor beside L31. To prevent "future" problems, replace with a 16V unit." As of yet, i havent gotten that far. note this is from the cobra 2000, but they are very much alike. you might cross check the resistor capacitor numbers though. btw, isnt the mb3756 the pll ic?

SOURCE: cobra 148gtl

tomcat 1 back ...i have found the fault no modulation on am/usb/lsb.tr -23 a bc458 transister .replaced this transister and wow modulation on all 3 modes thanks zeppfrog for telling me where to look .

SOURCE: 29 help

hi, sounds like you have a problem with the SWR' S Probably too high. Tumbleweed01

SOURCE: Cobra 148GTL Missing TX Modulation

The problem is most likely the audio ic . open the radio and see if the diode 44 is blown or see if you see anything that looks like it got hot around the plug area. if not contact me and i will buy it. is it an old or new 148 gtl.Read more

SOURCE: 148GTL Cobra (no tx)

the dx 2527 has a fine ransmitter. it is choked out by the factory to pass FCC reg's. With about $4.00 in parts from the rat shack you can really make it talk. my personal 2527 dead keys around 3 watts with around 45 50 watts on rms with bird meter around 60 with crappy dosey.