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MP3 car modulator
Posted: Sat Aug 27, 2016 2:29 pm
by radium98
hello guys
anyone could help me after building many transmitters fm and stereo encoder
i finally want to try to build this transmitter from mp3 modulator i saw many sites doing it and work but mine no all sites i could see are from india etc....
using modulator c930 double stage and c2053 anc c1970 or c1971 maybe transistors of mine are fake again as i bought 2n3866 and fake c1971 and also c1947 be aware none work even there is chinese bgy33 or bgy133 that only give 6-7 watts with silver metal pins and not gold pins
if anyone can do a layout print pcb using bfr91 bfy92 to amplify this modulator is good .
thanks.
Re: MP3 car modulator
Posted: Sat Aug 27, 2016 2:33 pm
by teckniqs
Amplifying an MP3 transmitter is never a good idea. The amount of nasty spurious harmonics it will produce means it's not recommended to be used as a transmitter.
Re: MP3 car modulator
Posted: Sat Aug 27, 2016 2:45 pm
by radium98
yes thanks tecknics i know that is not clean but thousand better than those vastelec and chinese 7w transmitter .and it is just for a hobbie to

thnaks for reply
Re: MP3 car modulator
Posted: Sat Aug 27, 2016 5:41 pm
by wolfmanjack
I also bought one of those BGY33´s..
Legs came off before we even had soldered to the board,totally waste of money and energy!
Some of the 1971´s seems to have different pinout compared to the originals.
Re: MP3 car modulator
Posted: Sat Aug 27, 2016 9:04 pm
by Albert H
The "1971s" with the "different pin out" will be AOC (Any Old Crap) transistors remarked. The stupid fakers don't even realise the importance of the order of the terminals.
I got caught once, with some "power FETs" from a Korean seller. When they arrived, they had been visibly re-marked. Luckily I was going to South Korea two weeks later. Imagine their surprise when I arrived at their big lock-up "industrial unit" and demanded my money back! I still don't know what they'd actually supplied, but I got the cash and an apology. Since I was pretty pissed off, I reported them to Ebay anyway and they were banned.
Re: MP3 car modulator
Posted: Sat Aug 27, 2016 9:06 pm
by Albert H
By the way - don't amplify those useless stereo modulator ICs. Build a proper rig. It doesn't need to cost much and it's easy to make one work properly (at low power).
Re: MP3 car modulator
Posted: Sun Aug 28, 2016 7:14 am
by radium98
totally i agree with you guys.
@albert H i already made some pll like the pira and many veronica.
this one modulator i just need for completing the hobbie and to give for a freind in his village as a gift .
Re: MP3 car modulator
Posted: Mon Sep 05, 2016 10:00 am
by wolfmanjack
About those BGY33's..
We suspect that those units that only gives a few watt isn't BGY33' and instead are BGY32,wrong labelled or by purpose to mislead the buyer! Bough the first unit wich was dead on arrival,bought a second one,this unit did actually work but drop output as soon as one gets above 88mhz. The print on the capsule seems to be sand papered and the print is at the wrong place,seems like a lottery buying those units! Complained and the seller promised to send another unit. Probably i get another BGY32, kind of useless when you are on air around 107mhz
So if you are getting only a pair of watts out of your BGY33,are you sure it really is a BGY33....
Re: MP3 car modulator
Posted: Mon Sep 05, 2016 11:25 am
by radium98
heheheh fake product chineseeeeeeeeeeeee

shits
Re: MP3 car modulator
Posted: Mon Sep 05, 2016 2:01 pm
by wolfmanjack
BGY32=68-88mhz
BGY33=88-108...
Re: MP3 car modulator
Posted: Thu Nov 24, 2016 7:01 pm
by radium98
Hello again on this topic any of you know a way to feed an mp3 modulator that have only usb port from a line in another way i dont have line in in mp3 modular so how i can active a line in ? i putted from a deck tape two lines between pin 2 and 3 but nothing happen 1-4 are gnd and +5v
2-3 data
Re: MP3 car modulator
Posted: Fri Nov 25, 2016 10:52 am
by Albert H
Why waste your time? These useless modulators will just generate interference.
Also - if you don't understand the circuit enough to modify it yourself, you shouldn't be messing about with it.