p110 modulation
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p110 modulation
hi i have a vhf p110 that the modulation sudenly just dropped to almost nuthing.i can tap the case and barely can hear it on my other radio. its there but very very low . i checked alinement and every thing is where it shoul be.i read on bat website about a small (smc) what is this smc and what dose it look like.thanks
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Tom in D.C.
- Posts: 3859
- Joined: Tue Sep 04, 2001 4:00 pm
- What radios do you own?: Progreso soup can with CRT
Re: p110 modulation
I don't understand what you mean by "smc" but with the problem
you're having I'd start with the microphone element inside the front
of the case. The mic is attached to the chassis by a ribbon cable.
It sounds as if the microphone element itself might have gone bad.
Fastest and easiest way to check is to put a speaker/microphone on
the radio and see if the transmit audio goes back to normal.
you're having I'd start with the microphone element inside the front
of the case. The mic is attached to the chassis by a ribbon cable.
It sounds as if the microphone element itself might have gone bad.
Fastest and easiest way to check is to put a speaker/microphone on
the radio and see if the transmit audio goes back to normal.
Tom in D.C.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
Re: p110 modulation
Hello :
SMC = Surface Mount Component.
Sorry im not familar with which component this might be but i do remember in the past it being mentioned somewhere.
But a large percentage of the time this actualy happens due to the speaker/mike jack getting dirty.
I spray electrical contact cleaner into the jack openings and use low air pressure ( I DID SAY LOW AIR PRESSURE = Dont blow the jack apart due to high air pressure ) to remove the spray cleaner solvent after inserting a speaker mike conector into the jack several times to clean the audio contacts within the jack.
This many times cures the problem assuming as mentioned above the mike element is not at fault.
The P110/GP300 series also had a known neg ground contact problem which over a period of time would do the symptoms you described.
Disassemble the radio and clean all of the worn into the chassis housing spots that look like they have metal worn to grayish dirty look = Shine them all up and reassemble and test.
When you get the radio apart pay close attention to the leaf spring two legged contacts as they seem to be the culprit many times.
Clean the oposite cotact side on the metal chassis and gently raise the leaf spring contact points to produce better pressure contact for the neg grounding points.
I actualy have started removing the leaf neg contacts and puddled solder up in there place to make the bds contact pressure harder and believe it actualy eliminates the neg grounding contact points problem as after several years of doing this i dont recall one coming back with the problem as seen every three years or so.
Not saying your troubles are one of these but you might want to check into it first before doing anything else.
Also the flex strip with the four wires going to the mike and speaker have been known to wear through and ground out one or both circuits so look at them carefully to make sure they are insulated well by the paper at the point where they plug into the radios plug.
Also ohm out the wires in the flex to make sure one is not actualy almost if not open.
Satelite
SMC = Surface Mount Component.
Sorry im not familar with which component this might be but i do remember in the past it being mentioned somewhere.
But a large percentage of the time this actualy happens due to the speaker/mike jack getting dirty.
I spray electrical contact cleaner into the jack openings and use low air pressure ( I DID SAY LOW AIR PRESSURE = Dont blow the jack apart due to high air pressure ) to remove the spray cleaner solvent after inserting a speaker mike conector into the jack several times to clean the audio contacts within the jack.
This many times cures the problem assuming as mentioned above the mike element is not at fault.
The P110/GP300 series also had a known neg ground contact problem which over a period of time would do the symptoms you described.
Disassemble the radio and clean all of the worn into the chassis housing spots that look like they have metal worn to grayish dirty look = Shine them all up and reassemble and test.
When you get the radio apart pay close attention to the leaf spring two legged contacts as they seem to be the culprit many times.
Clean the oposite cotact side on the metal chassis and gently raise the leaf spring contact points to produce better pressure contact for the neg grounding points.
I actualy have started removing the leaf neg contacts and puddled solder up in there place to make the bds contact pressure harder and believe it actualy eliminates the neg grounding contact points problem as after several years of doing this i dont recall one coming back with the problem as seen every three years or so.
Not saying your troubles are one of these but you might want to check into it first before doing anything else.
Also the flex strip with the four wires going to the mike and speaker have been known to wear through and ground out one or both circuits so look at them carefully to make sure they are insulated well by the paper at the point where they plug into the radios plug.
Also ohm out the wires in the flex to make sure one is not actualy almost if not open.
Satelite
Re: p110 modulation
thanks for the info guys ill give it a try .