| Author |
Message |
    
Cbblackbeard
Intermediate Member
Username: Cbblackbeard
Post Number: 150
Registered: 12-2003
| | Posted on Wednesday, January 26, 2005 - 9:38 pm: | 
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I hooked up my Astatic Mobile Max to a Cobra 29 Classic and I'm getting a wicked squeel. The dynamic on the radio can't be turned up past the first line or the squeel starts, but then there is no audio. How do I fix this? It's hooked up in a Freightliner Columbia. |
Troublemaker
Member
Username: Troublemaker
Post Number: 69
Registered: 2-2004
| | Posted on Thursday, January 27, 2005 - 10:59 pm: |
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was the limiter clipped in the radio? if so there's the reason! |
Cbblackbeard
Intermediate Member
Username: Cbblackbeard
Post Number: 153
Registered: 12-2003
| | Posted on Thursday, January 27, 2005 - 11:26 pm: |
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I don't think it was. I had it peaked and tuned. |
Racer X (Unregistered Guest)
Unregistered guest
| | Posted on Friday, January 28, 2005 - 4:03 pm: |
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It sounds like there is too much gain from the MobileMax for your radio and it's causing the audio chain in your radio to be overloaded and go into oscillation which you hear as the squeal. I looked at the information on the Astatic website and they say that if it happens to cut back the gain on the radio until it stops.
If the audio level is still low then make sure you have the gain for the microphone on the MobileMax set to the proper level. The meter should show the last red LED blinking occasionally on voice peaks.
Are you using a power mic? |
Tech808
Moderator
Username: Tech808
Post Number: 4665
Registered: 8-2002
| | Posted on Friday, January 28, 2005 - 4:55 pm: |
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Cbblackbeard,
A lot of people will clip the mod limiter when doing a Peak and Tune or do a SUPER SWING WING DING MOD to them to show GIANT swing on a meter.
If all else fails turn the mic gain down on the radio and the Mic and see if that helps.
One Important Question here, Are you drawing your Power for the Radio direct from the Batteries or thru the Factory Dash Wiring?
You can also be getting feedback from the factory wiring as they were designed to handle a Factory 4 watt radio only and then do a very poor job at that.
Lon
Tech808
CEF808
N9OSN |
Bc910
Intermediate Member
Username: Bc910
Post Number: 250
Registered: 7-2004
| | Posted on Friday, January 28, 2005 - 7:39 pm: |
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OK OK OK...
I have had three mobile maxes and have had this problem with EVERY SINGLE ONE!
First I must clarify that I LOVE this little box! It's sweet! the quality is top notch! Unfortunately Astatic forgot that most CB radios used are either dirty or have amplifiers connected (therefor, dirty... with most amps any way) The problem, from my experiance is RF feed back. RF seems to get into tho box at either the mic input or output side (I've had both) The solution for me has always been RF chokes internaly on in and output, On top of that I went to RadioShack and got some of those "clip on" chokes and clipped one on the mic cord and one on the mobile max's cord. Most of the times that all solved the problem except the one time I tryed to use a very over modified dirt, filthy Galaxy, then in order to get rid of the squeel I had to do all I said earlier and use the stock mic instead of the amplified one I normaly use. Even after all this I still had to turn the mic gain on the radio down a little bit but the mic gain on the mobile max more than made up for the loss.
Also one more thing, off the subject a little, if you havn't done so yet, try to hook up the Mobile max through the recieve audio also then the DSP will work for recieve too! Definately inprooved my 2950's audio quality.
Sorry for such a long post
BC |
Jose22
Member
Username: Jose22
Post Number: 85
Registered: 2-2002
| | Posted on Saturday, January 29, 2005 - 2:10 am: |
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BC910
Can you tell us more about hooking up the Mobile Max for receive? I have not heard of that.
Jose |
Bc910
Intermediate Member
Username: Bc910
Post Number: 251
Registered: 7-2004
| | Posted on Saturday, January 29, 2005 - 12:09 pm: |
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hmmmmm?
If I remember correctly there is a female phono plug on the back you need a patch cord and an external spk. the patch cord runs from the radios ext spk jack to the back of the mobile max then the external spk plugs into the front of th mm
BC |
Cbblackbeard
Intermediate Member
Username: Cbblackbeard
Post Number: 155
Registered: 12-2003
| | Posted on Saturday, January 29, 2005 - 3:15 pm: |
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Thanks everyone,
I'll try to pick up those chokes and see what happens.
Yes Lon I'm using the dash wiring. I have to turn down the mic gain on the radio almost all the way down for the squeel to stop. Then when I try to get a radio check I get no response, so I figured I must not be getting out.
I hooked up the mobile max to my general lee in the house and it worked like a charm, but in the big truck I have big problems. I'm going to hook it up to my girlfriend's Cobra 25 and see how that works.
BC910 where can I get that patch cord? I would like to have both an external speaker and talkback. |
Bc910
Intermediate Member
Username: Bc910
Post Number: 253
Registered: 7-2004
| | Posted on Saturday, January 29, 2005 - 10:34 pm: |
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radioshack man
duh 
also one more thing
CHEC K YOUR SWR !!!!
BC |
Cbblackbeard
Intermediate Member
Username: Cbblackbeard
Post Number: 157
Registered: 12-2003
| | Posted on Sunday, January 30, 2005 - 2:49 pm: |
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OK,
I Hooked up the Mobile Max to a Cobra 25. Dynamic on the radio all the way down. Mobile Max mic gain at 12 O'clock position... no squeel.
I asked for a radio check and got good reports.
Now I'll try it in the big truck the same way, and see what happens. |
