Simple VHF/FM receiver

[Mrnitrocker]

Sir, whts d value of the Inductor coils shown in the schematic??

[mrjimbopalmer]

@Mrnitrocker It really depends on the tuned frequency. It's just a bent piece of wire.

[nightghostyou]

thanks good stuff

[ChiIdKiIIer]

hello i'm studying electrical engineering, this was my second week and i love it, i was just wondering if i'll get to know how to do this when i graduate?

[mrjimbopalmer]

@ChiIdKiIIer Well, if you only learn from classes, you should probably at least take some electives in RF. By the time you graduate you should have learned enough principles to understand these little circuits. You shouldn't be afraid to tinker with this stuff on your own or tinker after you finish lab assignments.

[ChiIdKiIIer]

@mrjimbopalmer you mean when i graduate after 4 years? oh man, i want to study tellecommunications ( sorry for grammar) so i don't know if that includes radios, receptors and all that stuff? or as an engineer i just design plans?

[mrjimbopalmer]

@ChiIdKiIIer You don't need to take university courses if you really want to make little radio circuits like this. If you have any spare time you can just start reading.

[ChiIdKiIIer]

@mrjimbopalmer i know but i just wanted to know if i was able to do this after i'm done with college.

[velhart0000]

Sir, I build the schematic that you shared on a breadboard... but unfortunately there was a problem on the sound, only a straight sound wave coming out on a speaker, even a noise have nothing. i'll used 2n3904 transistor, and a 4 turn coil. Help plz..

[mrjimbopalmer]

@velhart0000 It's hard for me to say what the problem could be. Perhaps you may try the circuit with different 2N3904 transistors. I did not have success with every transistor. Patience is key with this receiver.

[Robert100971]

Does it work with a 5A power supplie...

[cwbh10]

Anyone have one that can go to ~30Mhz? I need one to interface with an old RC controller and an Arduino :/

[aseglkj]

Is this Ned from Bubba The Love Sponge?

[sunres7]

Do you have the circuit? and the parts lists?

[sunres7]

do you have the circuit

[AyashiFX55]

im pretty sure your output will be much more clear if you did this on pcb or soldered it. The bread board has some kind of capacitance / resistance within the board, known to increase loss.

[Neslakim]

What range of frequency does this receive?

[mrjimbopalmer]

@Neslakim It receives ~80 Mhz to ~110 Mhz. You can, of course, experiment with different coil sizes.

[Neslakim]

@mrjimbopalmer

Ok. That's a little low. I want to use 868MHz. But i found some Radio control modules on a website that sell em for 6 bucks ;)

But its more fun to make things yourself ;)

[GoGZzz1000]

dude make a tutorial i am very new to this stuff but i want to build this

[ryleyrocks222]

hell ya

[quantumbits]

How are to detecting the FM..just Slope?

[mrjimbopalmer]

@quantumbits Pretty much.

[tiputipu0052]

if i have to make transistor radio...could you just please tell me where i have to put tank coil (emitter, base or collector) and where i have to put feedback coil??? is the areal wire you have shown with 4 turns, the same called feedback coil??? what is the function of feedback coil and where it is plased in transistor please help me...dont discuss amplifier, i want to know about the first circuit,amplification comes next stage...please help.

[mrjimbopalmer]

@tiputipu0052 The tank coil will couple to the base of the transistor, via a capacitor and resistor. The feedback coil will be on the collector of the transistor. The feedback coil takes energy from the output of the detector transistor and injects it back into the input of the transistor, via mutual inductance. At VHF frequencies, lengths of the wires used and values of the components used will need to be rather precise, or the frequency will drift!

[tiputipu0052]

@mrjimbopalmer yes problem is that, im using about 10 turns 0.5 inch diameter wire with 20pf capicitor at base and about 5 turns 0.5 diameter coil at collector.....and one end of the 5 turn coil is connected to the collector and other is to my headphone speaker , and then goilng to positive to battery its like in series coil and headphone going to possitive of battery. sometimes it turns on and i can hear static voive, but sometimes its dead..

[tiputipu0052]

please tell me how many turns and diameter,should i use at base and how many at collector, to get about 100mhz fm radio frequency...also i have seen many places people use tank circuit at collector and feedback coil to base...is that wrong???please tell me thanks.

[lt322y]

in page virus !! DO NOT ENTER !!!

[callmenort]

he whistles when he talks , thats gotta be fixed !

[ttnoray]

That's being very creative,it's great ,you should have post a schematic diagram for your radio ,so other people can build it.

[mrjimbopalmer]

@ttnoray See the video description; I have already posted a link to the schematic.

[benjwgarner]

@mrjimbopalmer The link is broken.

[mrjimbopalmer]

@benjwgarner The link should be back up.

[tajiknomi]

." WHY WE USE TRANSITOR AS A SWITCH...?????? WE CAN CONSTRUCT THE SAME CIRCUIT....WITHOUT TRANSITOR..AND ALL I NEED TO OFF THE CIRCUIT ..I WILL CONNECT A KEY IN CIRCUIT....!!!

[Syndicated4u]

How are you pre-amplifying the signal using a 741if the 741 has a max bandwidth of 1.5MHz?I would love to know how that is possible cause I want to build a radio similar to this one :)

[mrjimbopalmer]

@Syndicated4u I am pre-amplifying the -audio-, not the RF. I want a radio like that, too!

[sandraparker100]

can you make pre amplifier circuit of receiver on bread board, step by step??? opamp is next stage..please just make the pre amplifier first stage...so that we can atleast hear small signals....and later add LM386 or strait in computer speakers....

like your video we can see the radio working but we want to know how to do it...

[tiputipu0052]

please see my videos and tell me where im wrong and what should i do????

[mrjimbopalmer]

@tiputipu0052 It is hard for me to say, since all I have to go by is the schematic. One thing I notice is that you couple the radio to the amplifier with only a 100nF capacitor. To pass audio frequencies a much larger capacitor is desirable. Another consideration is that I had to try many different transistors to find only a few that were particularly sensitive. (If they even worked at all!) The circuit is quite delicate, but your patience will persevere.

[tiputipu0051]

still making people fool with your 2n3904...but i know they are intelligent...

[izne]

can you have the receiving range of 108mhz to 130 mhz? yes, i would like to hear the atc conversations in the airport nearby :)

[mrjimbopalmer]

@izne You can have that receiving range. Just adjust the capacitance or inductance.

[vitorix24]

@mrjimbopalmer How you make VHF receiver?? Can you send the Electronic schema! It's very very important.

[mrjimbopalmer]

@vitorix24 See the video description; the link is there.

[vitorix24]

@mrjimbopalmer Yes i know, but says: ACESS DENIED. I resolved the problem. It was my anti virus, blocked the page....

oh, Thank you very much....

just a litlle question:

What do you mean the symbol that is below the transistor Q1 or ... are several ...

How many cops use? there is one that is the feedback coil, and the other is tank coil.

Excuse the English, but I am from Portugal.

[mrjimbopalmer]

@vitorix24 The symbol below Q1 is that for the ground, or common connection.

[vitorix24]

@mrjimbopalmer And i connect where?

You used 2 copper coils?

[mrjimbopalmer]

@vitorix24 As long as all ground connections are made together, the circuit will operate. You may find that actually connecting the ground connection to earth will improve the signal quality.

Yes, I used two copper coils. But copper wire isn't necessary; any conducting wire will do, with perhaps some difference in quality.

[vitorix24]

@mrjimbopalmer Thank you my friend... thanks for the help....

5* and i subscrived you :)

[qseru82]

where is the schem?

[mrjimbopalmer]

check the video description. I have updated it.

[Kronos914]

Yea pal! show the schematic for construct it. With out it, this video is nothing... No work...

But i can see, that receiver looks more simple and this is good.

The schematic please!!!!

[mrjimbopalmer]

check the video description. I have updated it.

[gonioelect]

i cant find schematic on schematic page!!!! plese canyou send me it

[bonecrime]

For us euros I'm sure a BC547B transistor will work just fine! :)

[jarkonkotisivu]

Your links don't wor anymore?

Circuit pic links..

[msajidfcc]

fuck your simple complicated project. i need 15min project. i cant spent whole day on your fucking fm radio.

[vinylseat]

This is a very brave project with F.M. The results may not appear to be very dramatic but believe me it is very difficult task to produce positive results with such limited circuitry. Great fun and that's what its all about. Have a go, the results will give you a lot of pleasure. J.

[leifvier]

cool!

But i cant open the page with the schematic?

:)

[inspecthergadget1]

ok rockymtradio i found the other link. thanks for your help

[rockymountainradio]

very welcome, good luck with the project.

and remember that if it doesen;t work the first time, then you may nead to reverse the connections on the reaction coil (sometimes called a tickler coil) in order to get the feed back in the correct phase for oscillation to take place. also, if it proves difficult to get it working on the breadboard, then you could just solder the components directly together as much as possible to keep the wiring shorter.

[inspecthergadget1]

someone try the link i cant get it page not found message

[inspecthergadget1]

the link dont work its broken or my computer cant find the page also is the tranasistor acting like a detector diode?

[rockymountainradio]

no not really, Nonlinearities in the oscillator cause it to multiply the incoming signal with it's own oscillations extracting the signal, IE non linearities in the transistor

[inspecthergadget1]

link to this schematic will not work where can i get it

[rockymountainradio]

I imagain it is very like the first of the 2 circuit examples given by decod31 in his video, mystery regen, and that looks like an op amp followed by one of those monolithic amp chips to drive the speaker?

[zezimashock]

can i ask something?

is it illegal to make your own receiver?

or only when your going to listen other thing's then normal citizens need to listen to?

[mrjimbopalmer]

It's quite legal to make your own receiver.

[frvfilms]

3:17 some old radios use to have this, that you can hear channel sounds, (fm)

[luig1985]

where is the Circuit Description ? please !!!!!!!!

[mrjimbopalmer]

Look up in the description of the video. There is a link to the schematic.

[frvfilms]

if only I knew how to

this can work for dtv !!

you just need the uhf

[skoushik333]

what's uhf?

[frvfilms]

ultra high frequency

to make a digital tv receiver,

vhf/uhf/fm../????

[skoushik333]

ya.. thanks..