Simple HF Radio Beacon - One Transistor RF Pulsing Oscillator
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- เผยแพร่เมื่อ 7 ก.ย. 2024
- Simple HF radio beacon with only one transistor. RF pulsing oscillator. Great to be used as a test beacon or ARDF ( fox hunting ) training sessions.
73, YO6DXE
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Thank you alot, ciprian, for this nice project. This was my very first time ever trying to build simple transmitter circuit and i got very surpised when i found out that circuit had actually started working! even from the first try :D. I built the circuit with 7 MHz quartz but after small adjustment of the capacitance, i was able to make the circuit work with 4 MHz quartz. I've been watching your videos for more than a year and it always makes me happy to see your new upload. Thanks again for your work and wish you success! 73.
Thank you so much. Glad it works and happy you like the videos. Ohhh I must make you laugh. I have mine hanging here in the window and I think about a month ago I was wondering if it still works. I turned it on and voila... still worked. The fun part is that a few days ago I was on the 80m band and I was wondering where is the beep coming from. I realized the little bugger was still working nearly a month later from the same battery 😅😅😅. So it turns out it doesn't eat batteries either 😅😅. I also made some tests from the 80m band up to the 2m band. Works like a charm. O love it. 73, YO6DXE.
@@dxexplorer thats amazing 😁. Im still sitting and tinkering around the circuit. I'm planning to build the transistor amplifier circuit for it and make it a little bit more powerful. I have hooked up the transmitter to the powersupply with voltage of 6v and the current consumption is only 50mA, as the multimeter says, so i think i can try rising the power 😅
@RandomlySelectedUserName Hmmm I never tried powering it with more than 1.5v. Good thinking ))) I will play a little more then )))
@@dxexplorer haha, good luck with it then! :))
@@RandomlySelectedUserName 😅😅 thank you so much. I will play safe and start with 3V 😅
Thanks for another amazing project Ciprian. Im going to have to give this a try. Nice work!
Is a lot of fun with this one )). I am keeping it in my room and listen to it so I don't get bored when there is no propagation hahaha.
Cute little design. Very similar to the MW versions we built as kids using CK722 PNP transistors back six & a half decades ago. 73 de W8IJN
I remember a schematic I've seen in my childhood for MW that I always wanted to build back then. Still not so long ago ))). I like that this little circuit seems to bring back good memories to many people... including myself )). 73 DE YO6DXE.
Apa nama komponen dekat pemangkas variabel dan berapa ukurannya
this is how I tracked my stolen jewelry because the police wouldn’t help me! The neighbor called the police on himself. to bad The police are corrupt Chino Valley, Arizona. Now they know that I know who they are, and they know that I know who they are all hell is about to break loose I can’t wait!!!!!!
Ooooh, I like this, I may make a really small surface mount one , to fit in our cats collar, she's always getting lost in the forest behind us. fun project, make a nice change from fixing TV's 73 M0BSW
Not a bad idea at all Paul. I will try to make an SMD version as well... if I can recover the components I need from some old board and they have the good values ))). But that will be for a 2m version if I can find a crystal. 73 and good luck with yours. I just love the sound of it... cand get enough ))).
Nice little project, well made btw. 👌🏻
Thank you. It was fun and I wanted to make it for a long time. I love the sound of it. Reminds me of Sputnik... the satelitte not the receiver I made ))). 73 my friend.
Fun! It sounds like the recordings of SPUTNIK and the chirp adds further character. If you could get it going on 144MHz you could easily Direction Find it.
Thank you Paul. I had the schematic for years and wanted to build it. I love it exactly for the fact that is resembeling Sputnik. I was always fascinated about that satellite hehe. I wanted to make it for 144MHz but I had no crystals available. So I guess I will play on the 80m band for now. I will try to find a 2m band crystal and build an even smaller version )) 73 and thank you for watching.
Usually resonant filters and multiplication is used for that.
@@antennafarmer7380 I would love to know how to do that. I must search about it as I don't know how is done. Thank you. 73
@@antennafarmer7380 A 2m version might be tricky, you'd have to multiply an overtone crystal, say a 3rd overtone 48MHz crystal followed by a tripler stage. The chirp would be tripled as well. Might work. An interesting experiment!
A 16MHz cheap crystal running just 500Hz high would end up on 144.005. The inevitable chirp and drift would just add to your toy Sputniks charm. 🤓
@@dxexplorer I recommend these two channels about RF. Yes of course, those frequencies are to much for us, hobbyist. But same goes for us. th-cam.com/video/j6XAlDb0c8Y/w-d-xo.html
th-cam.com/video/XPMRzLGf4SI/w-d-xo.html
th-cam.com/video/H64A0vEBRXI/w-d-xo.html
SPUTNIK !
Yes hahaha. This time not the receiver... for a change 😅😅😅. 73 Nigel.
P.S. I got to listen to your "radio show" )). Today we finish with the bunnies and I will get back to you.
That Is totally cool! What a great school project.
It is indeed. I love it as well... even if I'm not in school anymore 😅😅.
So it's the R/C combination R2/C2 that determines the pulse frequency? Brilliantly simple!
Yes. Basically you use L1 and C3 to get the frequency just bellow the crystal's frequency... then with R2 and C2 you get the pulse as you wish to be. But the pulse is also adjusted a little through C3 as well. Is a really simple but nice circuit, love it. 73, YO6DXE
👍Nice one. 🙏
Thank you. Now I just wait for my nephew and his Easter vacation so we can have some fun ))) 73
Nice RF pulsing oscillator! 73 DK8HM
Thank you Hendrik. It was so fun to build it and even more fun listening to it. I'm still testing the battery life so far. 24 hours and still running. Is in a plastic bottle in my backyard and last night it was bellow zero.... but it still works like a charm ))). Now I just wait for Easter so I can have some fun with my nephew haha. 73 DE YO6DXE.
Молодец! 👍
Большое спасибо. Мне очень нравится, как это звучит. Напоминает мне спутник... спутник, а не приемник, который я построил ))) 73 мой друг.
👍👍
Thank you 🙏🙏 73
where are you from?
Brasov - Romania 😁 Well.. I don't like the city life so I live in Prejmer... a village about 18km away from the city ))). 73 my friend.
Nice work! How do you cut those traces in the PCB?
Thank you Eduardo. Yes I cut them with a thin file hehe. I find it really easy when I want to build a simple circuit that doesn't need some complicated PCB ))). 73 my friend.
@@dxexplorer thanks for you reply! 73!
Always a pleasure my friend. 73 DE YO6DXE.
I tried it on 27 Mhz but it's not pulsing. Because the smallest inductor I had, was 6,5uH I just used a 2-18pf trimmer for the oscillator at C3 (and left C4 out). I did try it with a 1 uF and 4,7 uF capacitor for C2 because these were the parts I have rn. But it's just sending a carrier.
Any idea how I can get it to pulse?
You can try using Coil32 app to calculate the resonant frequency of the LC tank... the inductor and the capacitor together... would be great to be able to use both a capacitor and a trimmer in parallel so you can make adjustments. Anyhow... if I remember ... ( I know I spoke about this in the video )... the frequency must be smaller than the resonant frequency of the crystal ? I can't remember... smaller or bigger one of these two. You can try to make an inductor by hand also by calculating the inductor using Coil 32. It will not be the perfect value you calculate there... but you would be close. You just need a small PVC tube or something similar ( from a pen as example ) and to know the exact diameter of the wire you are using ( i use enameled copper wire recovered from old transformers ). If that doesn't work... come back and let me know. We will figure something out.
@@dxexplorer I used the online calculator you mentioned. I should have a coil now that's around 1.5 uH and I added a 15 pf next to the trimmercapacitor. This should give me a range where I can adjust the LC frequency close to the 27 Mhz. Like before I get a signal from it but it's still just the carrier with no pulsing or no signal at all depending on how I adjust the trimmer.
We are not sure if is exactly 1.5uH... but let's guess it is. If the value turned out close to 1.5uH then maybe the capacitance is too much. Remove the fixed capacitor and play just with the trimmer instead. See how that works. Or instead of the 15pf you can try smaller values (5pf maybe ?). In theory you would need around 23pF in total (fixed+trimmer) to have about 27.096. I need to watch the video again as I can't remember if the frequency has to be smaller or bigger than the one the crystal has )).
@thesciencefurry ok I double checked... so the LC tank circuit frequency has to be just a little lower then the crystal's frequency. So let's say... 26.8-26.9 something like that.
P.S. make sure you are not listening to it into an FM CB radio as it won't sound properly since the signal is AM basically.
@@dxexplorer I tried it with a 6 pf and it didn't work at all. I'm listening and seeing the signal with a sdr stick and there is definitely just the carrier with no modulation.
What would be the required modifications to use a 7 mhz crystal?
Salut... trebuie recalculata bobina si eventual schimbata valoarea trimerului. Stiu ca am explicat in video, dar trebuie sa ma uit si eu la clip ca nu mai tin minte daca frecventa de rezonanta trebuie sa fie un pic mai mica, sau mai mare decat cea a cristalului. Da parca mai mica cu 10 - 20Hz daca imi aduc bine aminte ))). Ma uit la clip imediat si revin. Stiu ca am facut si varianta de 7MHz, dar nu mai tin minte ce valoare am pus la bobina si la condensator.
No... am revenit 😁. Am facut repede un calcul... si ar trebui sa schimbi doar cristalul pe o frecventa in 7MHz... si condensatorul ceramic ( cel in paralel cu trimmer-ul ). Valoarea ar fi undeva intre 47pF - 68pF. Dar depinde acum si de lungimea antenei etc. Dar pe acolo pe undeva ar trebui sa fie. Se mai fac ajustari si din trimmer. Valoarea inductorului ramane tot 10uH.
@@dxexplorer Multumesc mult! Cred ca m-ar ajuta la testarea si/sau reglarea receptoarelor, cred ca e mai comod un sunet intermitent decat sa folosesc un emitator de cod morse. Sa vedem numai cand mai am timp de lumea radio... :))
@bobi_lopataru Cu mare drag. Pai cam tot la asta-l folosesc si eu de obicei 😅. Imi e usor da lucrez cu el. Ma rog... cand apare nepotul in vizita... devine iar "vulpe" si scot nepotul la vanatoare 😅
De unde pot cumpăra și eu unul?
73
Yo6TT
Nu stiu daca mai este inca disponibil la RoWaves. Intra un pic pe site si vezi. Daca nu... trimite totusi un email poate mai au un kit ramas 😁. Eu vreau sa fac inca unul dar cu ceva mai multe modificari... dar sa ramana tot asa simplut ca si asta. Dar asa... sa o iau de la zero sa vedem ce iese ca sunt super faine astea asa simple. Chiar daca rezultatul nu e musai ceva WOW. Eventual poate intre timp invat si Morse ca ar cam fi timpul haha. 73 DE YO6DXE.
Apa nmaa komponen pemangkas variabel itu teman, saya inggin mencoba membuatnya sendiri
Nama komponen pemangkas variabel
Di menit 3.31
Kapasitor Pemangkas.
@@dxexplorer terimakasih temanku saya sangat ingin mencoba rangkaian ini
@@dxexploreruntuk kapasitor 3,3 mikrofarat berapa volt