My D104 started acting up today. I got 3 months out of it. Had to plug in my old Radio shack power mic 21-1177. The guys I was talking to say the old radio shack was louder and clearer sounding than the d104. That old mic had been sitting in a box since 1999. Popped batteries in it and it kicked butt. I am a little disappointed in the astatic. I will say that the three months it was ok I did get good reviews on my audio.
The fix is simple: Solder a wire between two switch contacts. The contacts are the lead coming from the audio output (3300 uH choke) and the white audio lead. Referring to the schematic diagram, here's what's happening: as the push-to-talk switch is engaged, a metal wiper is sliding between two of three contacts. The switch has four poles, one of them being used to switch audio output. There's absolutely no reason to switch the audio output lead. Just leave it connected and active all the time. In doing so, the audio cannot become "scratchy" since there's no break in the switch path anymore. Making this mod does NOT affect the normal PTT or battery operation. In fact, it makes it better because now you can use VOX on transceivers that are VOX enabled. Another mod is to remove the 270K ceramic cartridge loading resistor and replace it with a value between 2.2 megohm and 4,7 megohm. The exact value will determine the bass response. A high value will add more bass; a lower value subtracts bass. One could actually go as high as 10 megohm and I do this with base mics. For mobile mics, that's likely a waste of bass response since the mic can become too sensitive to small hand movements. So, limit it to about 4.7 megohm maximum. In no event should someone just cut out the loading resistor. It's needed to protect the transistor gate from static electricity failure. Final mod:: add a 100-ohm resistor in series with the +9V lead. On the side opposite the battery (toward the transistor), add a 22 uF@10V electrolytic cap to ground as a bypass cap. (negative side of cap to ground). Why? For the same reason we had scratchy audio with a sliding push-to-talk switch. We want the +9V source to be stable on the transistor amplifier, Small hand movements on the push-to-talk switch can destabilize the +9V the transistor. The 100 ohm resistor decouples the supply, making the 22uF electrolytic cap more effective as a voltage stabilizer. For anyone who can read a schematic, the first fix for scratchy audio is obvious -- and easy to make. The D104-M6B is not the piece of junk it's claimed to be. Adios.
+Paul Christensen Would you be willing to tell me where to jump the wire to? Got the white wire, just not sure where to jump it to? I have this mic and it's scratchy sound is horrible. I would greatly appreciate it.
I use an Astatic Road Devil with my President Lincoln 2+ in my Subaru Forester. I get nothing but good reports and after 2 years 😂😂it's still going strong. I must just be lucky.
Yes! having the same problems. Tried running contact cleaner through the switch. I remember my first d104m6b just like the good one you have it was like 65.00 bucks new, these new ones are half the price and suck ass,even when you unkey the mike you have to tap it so you can hear your receive at volume. SUCK! Thankyou for this post, its not just me!
wish astatic would read this. i have 2 m6b mics and both cables have rotted and peeled bad really bad. you can see the wires inside easily. I called astatic and they said they dont sell the cable to the public you have top be a "cb" shop! really?! Ive been in CB for 53+ years and for sure will be the last time i ever use a astatic product of any kind. selling or trading all my astatic stuff for Turner or shure mics.
Dude, you are dead on right about the those new ones. They're shit. Period. I picked up one of the good ones brand new in the box at the shop I work at for $20!! Jumped on that in a hurry!! Always look for the D104 M6B or C with the flat sticker. Not the cheap shit with that rubber sticker.
Yes, I did this "fix" on my D104 M6B microphones and in my RD104E Road Devil microphones. I just located the points inside the microphones indicated by the schematic and the post below. The "fix" works very well. No more scratchy mic output audio.
Well , mine does have the scratch when keying up, but I have 3 different RF limited mics and on ssb the the d104m6b still wins hands down. That's what the DX'rs tell me when I swap around the mics. I do however agree, the old D104M6B is still a much better mic. I to am very dissapointed with Astattic. They could should and can do better. RCI 2970n2 RCI 2950 HR 2510
You are right on. I have an old one and it still works great. I bought the newer model and its a piece of shit. The mic cable split in many places and tried to key up and the button broke. Cheap china shit.
I'm having all the same issues as others (scratchy audio, audio cutting out,) and my PTT switch has the stopper on it. Gonna try one of the mods to see what it does.
i just scored a box of mics for $40 and an original m6b is in there. score, i hope it works. also i have a rf limited xtreme 2018 and hate it. i dont know about the audio quality as i haven't heard it from the receiving end but the mic itself is soo thick its like holding a square brick in your hand. the sucker is like 2 1/2 inches thick, no shit. plus the echo stuff, meh.
Who the fuck are putting these mics together, I recently got something similar, even the solder joints appeared to be done by a blind person, copper strands shorting galore. rubbish.
