I just picked this mic up from a friend of mine who no longer had any use for it. Was told before it was put away the connector was changed from 4 pin Cobra to 5 pin Cobra. This thing has been sitting in a dirty attic for years. The battery connector was barely hanging on. So I threw a new battery in and it was going crazy when i keyed it and squealing. So I changed the battery connector and contact cleaned the heck outta it and put it back together. Now when I turn it up just a little bit and the screen touches or even comes near my face it squeals. You can tell its a screamer on this 29 Im using it on but would like some input before I start troubleshooting. I'm suspecting the plug because everything looked ok inside. Any ideas?
-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
Astatic 575-M6 Squeal issue
- Thread starter Frylock508
- Start date
sounds like a ground issue .sometimes they squeal when the tone is set to all bass,try running the tone wide open(all the way up).
but still sounds like a shield might be off,make sure the blue wire and shield are soldered together on pin 1
but still sounds like a shield might be off,make sure the blue wire and shield are soldered together on pin 1
Wait a second...
I thought blue was pin #4 and shield was pin #2? Am I missing something? Am I leaving pin #4 empty?
I thought blue was pin #4 and shield was pin #2? Am I missing something? Am I leaving pin #4 empty?
But its a 5 pin cobra/uniden mic plug. Am I leaving one pin empty? Whats weird is it works but at a very low volume and squeals. Does this sound typical of a incorrectly wired mic?
Yes it does, the shield everyone is referring to does just that, it shield the audio wire from stray RF and when not connected to that it becomes and antenna of sort thus allowing RF energy to act as a common mode current on the audio wire which cause many little nasty issues and that coupled with the inrush of audio there is a chain reaction that will not correct itself.
sorry i missed that it was a 5pin cobra
[SIZE=-2]1 - White[/SIZE]
[SIZE=-2]2 - Shield[/SIZE]
[SIZE=-2]3 - Black[/SIZE]
[SIZE=-2]4- Blue[/SIZE]
[SIZE=-2]5 - Red[/SIZE]
[SIZE=-2]you could try jumping the blue wire between both number 2 and number 4 and see if the squeal goes away.[/SIZE]
[SIZE=-2]sometimes its just a impedance issue and some radios just get finicky about what mic they like .[/SIZE]
[SIZE=-2]might want to try a d104m6b instead.
[/SIZE]
[SIZE=-2]1 - White[/SIZE]
[SIZE=-2]2 - Shield[/SIZE]
[SIZE=-2]3 - Black[/SIZE]
[SIZE=-2]4- Blue[/SIZE]
[SIZE=-2]5 - Red[/SIZE]
[SIZE=-2]you could try jumping the blue wire between both number 2 and number 4 and see if the squeal goes away.[/SIZE]
[SIZE=-2]sometimes its just a impedance issue and some radios just get finicky about what mic they like .[/SIZE]
[SIZE=-2]might want to try a d104m6b instead.
[/SIZE]
Ok, thanks guys. First thing tomorrow I'm switching it up. I'll post how this turns out. These mics are just too legendary to let sit in a drawer. Plus, what these things are currently selling for its almost criminal!
im a bit confused too.
you said you were using it on a cobra 29, which im assuming means a 29LTD.
those have a 4 pin mic plug on them.
you said the 575 had a 5 pin mic plug on it.
are you using a mic adapter that you forgot to mention?
the best solution is to wire a 4 pin plug to the 575 and wire it like one of the previous posts alluded to.
LC
you said you were using it on a cobra 29, which im assuming means a 29LTD.
those have a 4 pin mic plug on them.
you said the 575 had a 5 pin mic plug on it.
are you using a mic adapter that you forgot to mention?
the best solution is to wire a 4 pin plug to the 575 and wire it like one of the previous posts alluded to.
LC
Yes loosecannon you're correct. I did indeed mention my 29GTL. I originally got it for that Grant I'm rebuilding but am using it currently on my 29 and am indeed using a 5 pin to 4 pin adapter. Sorry about that guys. Now I see the confusion. Anyway, i did change the configuration and the volume is now able to go up 3/4 the way up with the dynamike maxed out on a radio thats running wide open. BUT, if I go any louder it will still squeal when it touches my face. But if I hold it away I'm able to go all the way up. So I guess thats the best its gonna get. Thanks guys!
BTW, after all that work i still think my original Dynamike Plus handheld first edition is louder than the 575. Go figure!
BTW, after all that work i still think my original Dynamike Plus handheld first edition is louder than the 575. Go figure!
you have to remember that the era of the power mic is over.
power mics were popular back in the day because they could squeeze every last bit of modulation out of a stock radio, and could bring a dud of a radio a bit of a boost.
these days, people have realized that doing mods inside the radio and using a good quality stock mic, or a good noise cancelling mic is the way to go.
if you turned up the modulation pot inside that 29GTL (same as a 29LTD), you have no need for a power mic.
if you have actually clipped the limiter diode, then a power mic is almost definitely going to squeal, and will probably distort your audio.
if you just like the idea of having a bass and treble control on your mic, regardless of what radio you are going to use it on, you are going to have to put the radio back to stock, which means re-enabling the AMC.
set the modulation pot to 100% modulation, and you will probably still end up running the mic gain at less than max.
running a modded radio and a power mic is just asking for overloaded pinchy sounding audio.
LC
power mics were popular back in the day because they could squeeze every last bit of modulation out of a stock radio, and could bring a dud of a radio a bit of a boost.
these days, people have realized that doing mods inside the radio and using a good quality stock mic, or a good noise cancelling mic is the way to go.
if you turned up the modulation pot inside that 29GTL (same as a 29LTD), you have no need for a power mic.
if you have actually clipped the limiter diode, then a power mic is almost definitely going to squeal, and will probably distort your audio.
if you just like the idea of having a bass and treble control on your mic, regardless of what radio you are going to use it on, you are going to have to put the radio back to stock, which means re-enabling the AMC.
set the modulation pot to 100% modulation, and you will probably still end up running the mic gain at less than max.
running a modded radio and a power mic is just asking for overloaded pinchy sounding audio.
LC
Yep, i totally understand. Those were great days though. Btw, i have to ask about that C95 in the Grant i replaced about a month ago. There seems to be a intermintent problem with it again. Or at least something that appears to be the same problem. Is it possible I got ahold of a bad capacitor and it only happens where there is no power every once and a while? I thought that if they went bad to the extreme where there is nothing than it was gone. I wasn't able to do a exact replacement meaning that I could only find a 35v and not a 16v or even the 10 that it came with. Think that could be the cause? Any ideas?
as long as you used a part with a greater voltage rating than the original, then its just fine.
thats not your issue.
if you bought the capacitor brand new, and didnt steal it from another old radio, then it should be fine.
try describing your intermittent problem in more detail.
LC
thats not your issue.
if you bought the capacitor brand new, and didnt steal it from another old radio, then it should be fine.
try describing your intermittent problem in more detail.
LC
The problem is this: I've been using this thing for a couple of weeks and been geting great reports. I did go out and buy a brand new capacitor as well. Here's where i hope there's not a problem. I purchased several power mics with built-in roger beeps. None of which worked. Both broken on delivery. So I purchased the beep single tone board and started installing it myself. When I realized wires were marked wrong and even got to the part where it was all done but the inline switch to switch it out I came to the conclusion that these boards are junk. So I reversed everything and took the board out. All worked fine for about an hour. Then I went to key up and no movement on the S/RF meter. After keying and unkeying several times it finally came back and started moving again. Its done this several times. I hate to think a 7 dollar roger beep had something to do with this. Any ideas?