| Author |
Message |
    
Hrdddrv
New member
Username: Hrdddrv
Post Number: 1
Registered: 3-2016
| | Posted on Monday, March 14, 2016 - 10:29 pm: | 
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First, thanks for adding me, Admin. DIY noob here, sorry for any dumb questions.
Picked up a Uniden Pro 538w that picks up S6-9 of noise all the time (hard to pin down with a 5 segment LED meter), making it almost useless except for the strongest signals. And either it doesn't have any built-in ANL or it doesn't work. Is there any way to add one or reduce receive noise? I can reduce RF gain and that even seems to sometimes slightly help separate weaker signals that weren't cut off, but it's still too noisy to really hear them. This is compared to other radios on the same antenna whose noise levels are at 3-5 and ANL and/or NB help.
Also, the mods list says adjust Q15 for modulation, but it doesn't look like anything adjustable. How do you adjust that? Noob question? |
Press_man
Advanced Member
Username: Press_man
Post Number: 914
Registered: 5-2008
| | Posted on Thursday, March 17, 2016 - 5:01 pm: |
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Sounds like it needs a good alignment and possible diode changes in the receive.
73 Pressman
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Dale
Senior Member
Username: Dale
Post Number: 2272
Registered: 12-2002
| | Posted on Thursday, March 17, 2016 - 8:11 pm: |
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i assume this is a mobile setup.with that said does it quit with engine off? if no then try this
with engine still off unscrew the antenna, you SHOULD see a drop in the s-9 reading.
now next step with antenna still disconnected restart the vehicle if ya noise comes back with NO antenna then its in your wiring.if ya only hear it with antenna installed then ya antenna is picking it up and all ya can do for that is move antenna more towards rear of vehicle .and this seldoms does much if anything. sorry 4 long post but theres alot to this. id start there befrore messing with anything inside radio.. just my 2 cents
dale/a.k.a.hotrod
cef426
cvc#64
454 [dx numbers]
38lsb
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Hrdddrv
New member
Username: Hrdddrv
Post Number: 2
Registered: 3-2016
| | Posted on Friday, March 18, 2016 - 4:40 am: |
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Thanks for the responses. Happens both in the car and the house using a mobile antenna for testing. Turning off the motor makes an insignificant difference. Removing the antenna gets rid of it, it is clearly received noise. It's the same noise my other two radios are picking up, just more of it, almost like the receive is stronger or amplified, which would be great if it had ANL/NB like the other radios.
As far as repairs, I can solder in some diodes if I'm told which ones, but i don't have the equipment or knowledge to do an alignment. I'm not sure this radio is worth spending the money to have it done.
Any info on adjusting Q15 for modulation? I found it on the board but it doesn't look adjustable. The mods list also shows cut D12 for modulation; what exactly does that do? This radio wants to be a mystery, I can't find any manual or schematic for it. |
Dale
Senior Member
Username: Dale
Post Number: 2273
Registered: 12-2002
| | Posted on Saturday, March 19, 2016 - 7:29 pm: |
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ok so its recieved noise .theres really nothing inside the radio that can change that.imo.. best advice i can say is drive away from ya house. it might be local manmade noise.
for modulation DONT i repeat DONT remove clip d12. this will cause radio to overmodulate. best advice is add a power mic coppers carry 2 i reccomend
superstar452 about 20 bucks good deal if in a budget
rflimited 2018 extreme-best sounding power mic made.. mo
dale/a.k.a.hotrod
cef426
cvc#64
454 [dx numbers]
38lsb
|
Hrdddrv
New member
Username: Hrdddrv
Post Number: 4
Registered: 3-2016
| | Posted on Sunday, March 20, 2016 - 1:10 am: |
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Ok, then how do I "adjust Q15" as the modifications list says, when there's nothing to turn? |
Dale
Senior Member
Username: Dale
Post Number: 2274
Registered: 12-2002
| | Posted on Thursday, March 24, 2016 - 8:58 pm: |
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ive never seen inside that particular radio. but most of them are on the speaker side of radio.
uually near the back of radio around the coax connector
dale/a.k.a.hotrod
cef426
cvc#64
454 [dx numbers]
38lsb
|
Hrdddrv
New member
Username: Hrdddrv
Post Number: 6
Registered: 3-2016
| | Posted on Friday, March 25, 2016 - 1:27 pm: |
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Finding it isn't the problem. Adjusting it is - I don't see a way to do that.
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Dale
Senior Member
Username: Dale
Post Number: 2276
Registered: 12-2002
| | Posted on Wednesday, March 30, 2016 - 9:46 pm: |
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i see.. from the pic it looks like Q15 is broken/or missing. sorry im not sure
dale/a.k.a.hotrod
cef426
cvc#64
454 [dx numbers]
38lsb
|
Hrdddrv
New member
Username: Hrdddrv
Post Number: 7
Registered: 3-2016
| | Posted on Thursday, March 31, 2016 - 12:08 am: |
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No, it's that black thing, lol. |
Dale
Senior Member
Username: Dale
Post Number: 2277
Registered: 12-2002
| | Posted on Saturday, April 02, 2016 - 2:14 pm: |
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i see.. i wouls just buy a super star 452 power mic . great audio and good price
dale/a.k.a.hotrod
cef426
cvc#64
454 [dx numbers]
38lsb
|
Press_man
Advanced Member
Username: Press_man
Post Number: 919
Registered: 5-2008
| | Posted on Saturday, April 02, 2016 - 4:04 pm: |
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That black thing is a transistor.
I've been all over the net looking for info and cant find any. Give a shout out to Copper member Sonoma and see if he has info. Try Coppers in house tech, he may have some paperwork on it.
73 Pressman
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