BA1404 FM Transmitter without using 38khz crystal

[etsusera]

Pahelp naman po mga hobbyist at mga advance hobbyist out there...

gusto ko po sana gumawa ng fm broadcast transmitter,,, like ung nasa electronics-diy.com gamit ang BA 1404 ic,, problem is ung hard to find 38 khz crystal at ung 3.5 turns variable coil.... anu pong mainam kong gawin..


meron din akong nakita sa EE issue 61 page 114,, di gumagamit ng 38khz crystal kaso medyo di ko maintindihan kulang sa instruction ... patulong naman po....

[maldihtah13]

Yung nasa magazine din ginawa ko OK naman.

[nucleus]

yung 3.5 turns na variable coil ay iyan din yung nasa AM reciever alisin lang yung capacitor

We will soon carry the following tunable RF coils that are perfect for precise frequency tuning of your transmitter. The magnet wire is halfway embedded within the plastic, providing excellent frequency stability. One of these coils have been tested in the TX200 transmitter as a substitution for an air coil and a variable capacitor. As a result the frequency stability was greatly improved. The coils are 7mm x 10mm and each comes with its own metal can, which may be removed. Tunable RF coils come in the following inductance ranges:

2.5 turns 48 - 59nH (Red)
3.5 turns 65 - 79nH (Orange)
4.5 turns 90 - 109nH (Yellow)
5.5 turns 109 - 132nH (Green)

bili ka nung may yellow na color code at alisin mo yung capacitor sa ilalim



yung crystal hindi ko parin alam nakatengga yung BA1404 ko dito dahil sa wala akong makuha nyan

[etsusera]

 


@malditah

-pwede po bang pa assist ako pag sisimulan ko na tong gantong project.. beginner lang po kc... san po kaya mabibili un whole kit??

@nuke

yellow?? 4.5 turns po un? ok lang din ba??  tapos ung ibang variable coils na nakita ko is 3,4 or 5 naman ung connector... panu un??

Salamat sa replies...po

[etsusera]

  pahabol po.... suggestion po kung panu ko maeeliminate un gamit ng 220 mains and un transpormer... para po portable sana..

anung part ba ng circuit un sinusupplayan ng 220v/transformer??? tnx

[maldihtah13]

All parts are available at alexan though I don't know if BA1404 is still available?

[nucleus]

All parts are available at alexan though I don't know if BA1404 is still available?

dito samin meron pa

[amadjo01]

bakit wala nang BA 1404 na available??
saan pa pwedeng makakuha nyan?

[rdpzycho]

RF Prototyping Tricks: kung walang variable inductor, mag-wind lang ng coil. to adjust inductance, itulak ng screwdriver 'yung coils unti-unti palayo. pwede ring mag-wind sa screw na varnish coated, then turn the screw to adjust inductance. pero mas madalas kong nakikita 'yung first method, even on some production run.