Baofeng LiIon charger modification

My idea was to be able to use this to charge Baofeng radio in various power conditions including in my car and this voltage was a problem. I noticed comments that charger should not be connected to higher voltage than 10 Volts. So I modded charger to fit higher voltage. baofeng-charger-mod

Iron Powder Toroid Cores Color Codes

Skraćena veza: http://pedja.supurovic.net/veza/8352

Iron Powder Toroid Cores part numbers are presented using format Tddd-m where dd is core diameter in tenths of inch and m is material grade. Also, cores are color coded to represent material grade.

Material grade defines frequency range core may be used for. There is no strict standard for coding but for informal purpose this table can be used.

Material
code
Color Frequency
range
0 Tan/Tan 50 MHz – 350 MHz
1 Blue/Clear 150 kHz – 3 MHz
2 Red/Clear 250 kHz – 10 Mhz
3 Gray/Clear 20 kHz – 1 MHz
4 Blue/White 3 MHz – 40 MHz
6 Yellow /Clear 3 MHz – 40 MHz
7 White/Clear 1 MHz – 25 MHz
8 Orange/Clear 20 kHz – 1 MHz
10 Black/Clear 15 MHz – 100 MHz
12 Green/White 30 MHz – 250 MHz
15 Red/White 150 kHz – 3 MHz
17 Blue/Yellow 20 MHz – 200 MHz
42 Blue/Red 30 kHz – 80 kHz

 


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LCD ESR tester – multimetar

Skraćena veza: http://pedja.supurovic.net/veza/8105

lcd-esr-tester-meter

Zamislite da možete da imate univerzalnim merni instrument koji meri sve: otpornost, kapacitet, induktivtet, diode (obične i zener), tranzistore (bipolarne, FET, MOSFET, JFET), tiristore…

Otiđite u maštariji još dalje: zar ne bi bilo sjajno da ne morate uopšte da se cimate nego prosto ubodete komponentu u instrument a on sam prepozna šta ste uboli i izmeri karakteristike?

I povrh svega, da to lepo pregledno prikaže na ekranu?

Luda ideja, ali još je luđe da to u stvari postoji i to čak radi i više nego što ste izmaštali. A najluđe je što je vrlo jeftino. Ovakav tester košta oko 15 do 20 dolara, a meri maltene sve što ubodete u njega. […]
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APRS/Packet Radio audio cable for connecting Kenwood/Baofeng/Wouxun to Samsung SIII

Skraćena veza: http://pedja.supurovic.net/veza/7662

Here is a schematics of audio cable connecting Samsung SIII to Kenwood/Baofeng/Wouxun or other compatible radio.

audio-kenwood-baofeng-samsung-s3-trrx

Samsung SIII uses four pin 3.5 mm TRRX connector that differs than standard TRRX.

This cable can be used for APRS/Packet Radio. Most popular program for this purpose is APRSDroid. ALso can be used for Echolink, audio recordings, or similar usage.

You have to adjust volume output on both Samsung phone and radio to avoid distortions. Cell phone cannot control PTT of radio so you have to turn on VOX on radio to enable triggering TX when signal should be transmitted.


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Remote Controlled Antenna Switch

Skraćena veza: http://pedja.supurovic.net/veza/7497
Antenna switch in a stack

Remote controller for antenna switch in a stack

As I live in apartment building I have apparent problem with setting up ham radio antenna. The obvious place to set up antenna was the roof as it  is easily accessible. Due to small space and me not wanting to make mess of a wires, I decided to use compromise vertical multiband. A friend had spare DunaX-GPN4B (40, 20, 15 and 10m) so it was obvious choice. I had to put down about 30m of coax cable to my apartment, and soon I was in the air.

Not for long I found out that I do miss 80 meter band a lot. […]
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Universal CAT and programming USB to RS232 TTL interface for ham radio

Skraćena veza: http://pedja.supurovic.net/veza/7437

As soon as I got first two ham radio rigs, I needed to connect them both to PC, to program memories or use CAT control from logging software. I realized that it is impractical to have as many USB to RS323 adapters as rigs.

As serial connection for radio requires just RX, TX and GND lines, and it is the same for most of modern radio stations. It is actually only radio connector that is different – signaling is the same.

It showed up quite easy to build simple multirig adapter. All you need to do is to use existing USB to serial interface adapter, cut it’s cable in two and insert male and female three pin 3.5 mm jack (commonly used as stereo audio connectors). […]
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Genijalno svetlo bez struje

Skraćena veza: http://pedja.supurovic.net/veza/5904

Za vreme nestašice električne energije u Brazilu 2002. godine, mehaničar Alfredo Moser smislio je način kako da osvetli svoju radionicu bez električne energije.

Izum je veoma jednostavan: izbušio je krov radionice i proturio kroz otvor providnu plastičnu flašu napunjenu čistom vodom. U vodu je dodao malo izbeljivača kako bi sprečio da se u njoj razviju alge. Tako je dobio izvor svetla koje odgovara električnoj sijalici snage oko 50 vati.

Ovaj izum je mnogima promenio život. Na primer u siromašnim naseljima na Filipinima gde ljudi žive u barakama koje nemaju prozore pa su u stalnom mraku, ovakvo osvetljenje je bukvalno preokrenulo način života tih ljudi. […]
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Spiralna vodena pumpa radi na besplatnu energiju

Skraćena veza: http://pedja.supurovic.net/veza/4385

Ideja da je energija svugde oko nas a da mi samo treba da nađemo način kako da je ekonomično iskoristimo je verovatno okosnica razvoja naše civilizacije u budućnosti. No, budućnost ne moramo da čekamo, jer priroda nas i u svom sirovom obliku itekako može snabdeti korisnom energijom.

Jedna od mašina koja je odavno privukla moju pažnju je spiralna vodena pumpa. Toliko je jednostavne konstrukcije da bukvalno svako može da je napravi, pa i tehnički neuki.

Konstrukcija ovakve pumpe je jednostavna: potreban je jedan točak, namešten tako da se slobodno može okretati. Na točak se, počev od oboda pa prema centru, namota crevo u obliku spirale. […]
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