Walkie Talkie circuit PART2 But on the frequency of 315MHz

[@BabakStars]

Please like the videos 👍🙏

[@Stefan0719]

These modules use a super regenerative receiver in the RF part. Followed by that is an IC circuit usually LM358 that is set up as "schmitt trigger". The purpose of the op-amp (358) is to convert data signals into a proper square wave signal, so the micro controler can use the data... as these modules aren´t really intended for voice transmission - instead they´re used for data transmission. You can, however modify the transmitter by "half key-ing it" to transmitt a mix of Narrowband FM and AM. On the receiver side the voice is decoded, but if you pick it up after the schmitt-trigger circuit it gets "chopped" and altough it may be understandable to some degree, it is not working to well. I also played around with similar modules years ago, and when I picked up the audio before the LM358 schmitt trigger chip the audio was more or less clear and un distorted. You might try that. The first 433MHz module sounded like the receiver´s quench frequency has been set a bit low... that is just 1 resistor on the board which needs to be changed to make it work as it´s supposed to work. The resistor can be found close to the SMD RF transistor, look for it´s base connection.

[@BabakStars]

Hello my friend, thank you for your comment. Of course, I said in the previous video that these modules are not suitable for sending sound. But with this comment, you said something that I didn't know and it was very interesting. Previous video: kzbin.info/www/bejne/l4HaZ4auatGmr9U

[@Stefan0719]

@@BabakStars I have been given a kit containting 2 or 3 "pairs" of 433MHz transmitter and receiver unit. The board features a 2 transistor receiver (RF preamp and Receiver) plus said "LM358" as schmitt trigger to convert received data signals into a proper suqare wave signal for the micro controler. I did play around with them a bit, but the receiver is faulty (that is why it was extremly cheap). It has all parts installed for the RF preamp, but the actual transistor is missing. The "spot" where it´s supposed to be installed is empty... and so the result is... the set does work, but the range is only like 30ft, whilst if I´d use it´s transmitter at maximum power, the range would be more than a mile (to a communications receiver). If you don´t pull the "data pin" to ground (or was it to B+?) fully, but instead use a transistor, potentiometer (sth like that) you can modulate the transmitter with an audio signal by "half keying" it. Depending on how high the RF level you want to get out from it is, you either get acceptable AM, or AM with parasitic narrowband FM. On a good receiver, such as a communications receiver, you will then have to either use "N-FM" for hearing the transmitter, or use am + slope detection. As a super regenerative receiver is very wide banded, the small ammount of FM won´t be noticeable if you receive the transmitter modul with the "supposed to be operated with" receiver unit. I didn´t really transmitt / use these devices (like turn it on, let it transmitt music, and see how far it goes) because they work on a fixed frequency of 433.92MHz, and that is a frequency used by a lot of devices... be it your wireless temperature sensor, or an older car-remote-key to open the car. I didn´t want to "block" that frequency, because the devices that work at it usually just send a

[@Top.Training]

داداش عالی بود دمتگرم

[@BabakStars]

❤️❤️❤️❤️❤️❤️❤️

[@ayahsadam9817]

Nice sharing

[@BabakStars]

Thanks

[@RUPJITCHOWDHURY]

Very nice , you r the best, nice implementation

[@BabakStars]

Thanks a lot🙏🙏🙏🙏🙏🙏❤️

[@UpinkProduction]

I love it good 👍

[@tusmu3rtoz669]

How do you make the interconection from 2 walkie talkies, You know, when i press "the talk buttom" in the first walkie talkie, sounds The message from The other walkie talkie

[@BabakStars]

Hello. I explained in the first part. Watch if you have any other questions. Ask me. kzbin.info/www/bejne/l4HaZ4auatGmr9U

[@tusmu3rtoz669]

​@@BabakStarsthanks, another question, do You have diagram from Baquelite walkie talkie with push buttom incluide, because You don't show the backside

[@LigiaElenaBritoperez]

Me encanta 👍👍👍 pero podrías traducir por favor 🙏🙏🙏

[@BabakStars]

You can translate it with the help of subtitle settings.

[@holizhimomi1588]

Sir give me schematic diagram plz

[@BabakStars]

GitHub link in the description

[@МихаилСеребрянский-ю4в]

видео ни о чем.для того что бы сделать рацыю не обезательно мудрить до такой степени.в интернете полно робочих схем таких раций.как на транзисторах так и на микросхемах.с дальностью роботы по прямой видимости до 1 километра.при этом схемы содержат всего 3-4 транзистора в качестве унч,и один транзистор в вч части.и все.и не надо изобретать велосипед.

[@BabakStars]

You don't need to be a genius to upload a video to KZbin. In the previous part, it was said that this video was made at the request of one of the contacts, and because my contacts are important to me, I made this project. I'm also getting more experience in rebuilding the wheel and maybe I can share more tips to avoid making wheels like Tupolev.