| Author |
Message |
    
Digger
| | Posted on Thursday, February 05, 2004 - 2:07 pm: | 
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I have a 148gtl that has a bad squeel on ssb receive ,works fine on am .any ideas would be helpfull.
Digger |
Rob5mike
Intermediate Member
Username: Rob5mike
Post Number: 108
Registered: 7-2002
| | Posted on Sunday, May 16, 2004 - 4:35 pm: |
|
Did you ever figure it out? I have an old Taiwan made 148 that is doing the same thing and I can't figure it out. |
Tech548
Moderator
Username: Tech548
Post Number: 55
Registered: 5-2004
| | Posted on Monday, May 17, 2004 - 3:08 pm: |
|
Does it squeel in the receive mode or on transmit.
Does it have a Echo board and talkback in it?
Are you using a power mic? Power Mics and talkback usually do not work well together.
A little background on the radios and modifications done would be more helpful.
Jeff. |
Rob5mike
Intermediate Member
Username: Rob5mike
Post Number: 109
Registered: 7-2002
| | Posted on Monday, May 17, 2004 - 5:06 pm: |
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AM works fine,SSB transmit works fine SSB recieve squeels with the mic hooked up but does'nt when unhooked(tried several mics no power mics)as far as mods go it has talkback and the clarifier will go up 10kc on recieve but does not on transmit.If you switch it to PA and hook a speaker to it and listen thru the PA speaker it won't squeel.
Hope this helps Jeff.
Mike
|
Jon666
Intermediate Member
Username: Jon666
Post Number: 191
Registered: 11-2003
| | Posted on Monday, May 17, 2004 - 5:50 pm: |
|
are you using a 5 wire mic
if your using a 4 wire mic
it will aqueen on recive |
Tech548
Moderator
Username: Tech548
Post Number: 60
Registered: 5-2004
| | Posted on Tuesday, May 18, 2004 - 1:50 am: |
|
Hi Rob
OK, I just have to ask--why would you need or have a talkback without a echo board?
Another question.
Is your talkback set up with a volume control or was it done with a resistor across the PA and external speaker jacks? If it was done with a resistor at the jacks, unsolder one end of it and then turn the radio back on and see if you still get the feedback. If the feedback does indeed go away, that tells me that you don't have enough resistance across the two jacks. If this is indeed the case, then replace the resistor with one of a higher value. Be advised though that I am only assuming this since you didn't mention what method was used to get the talkback.
The reason why you don't hear the feedback when the mic is unplugged is because the receive audio is interupted when the mic is removed from the radio. However, as Jon666 asked, if your radio was converted to a 4-pin mic plug, that's when problems begin to show up.
But in the meantime, just unsolder one end of the resistor as I explained above and lets see if the feedback disappears. Doing so will also disable the talkback of course. What we're trying to determine here first is what is causing the feedback.
Jeff. |
Jon666
Intermediate Member
Username: Jon666
Post Number: 195
Registered: 11-2003
| | Posted on Tuesday, May 18, 2004 - 7:09 pm: |
|
what i mean is you have a 5 pin connector
if you hook up a 4 wire mic it will squeel on recive.or take out the talkback |
Rob5mike
Intermediate Member
Username: Rob5mike
Post Number: 111
Registered: 7-2002
| | Posted on Wednesday, May 19, 2004 - 12:24 pm: |
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The radio was given to me because it did'nt work so I don't know why it had talkback in it.I took the talkback out.the mic socket was gone when I got it so I put a 4 pin socket in it,I guess I need to get a 5 pin and see if this solves my problem. Thanks guys I'll let you know if this works as soon as I get it done.
Mike |
Rob5mike
Intermediate Member
Username: Rob5mike
Post Number: 113
Registered: 7-2002
| | Posted on Tuesday, June 01, 2004 - 11:31 am: |
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Put the 5 pin socket in and it stopped the squeel,thanks guys.This radio was in pretty bad shape and now I am trying to get the rest of the radio in shape.
Mike |
Jon666
Intermediate Member
Username: Jon666
Post Number: 220
Registered: 11-2003
| | Posted on Tuesday, June 01, 2004 - 12:42 pm: |
|
good deal
glad your on the right track
jon |
