ไม่สามารถเล่นวิดีโอนี้
ขออภัยในความไม่สะดวก
Michigan Mighty Mite AM Voice Transmitter - Simple AM Transmitter
ฝัง
- เผยแพร่เมื่อ 12 ส.ค. 2024
- Michigan Mighty Mite with a rated power around 700mW and some simple modifications it can also transmit AM voice. You won't reach too far, but is fun to experiment.
Please note that this transmitter was built for experimenting purposes. In order to be used ON AIR, you will need a low pass filter and proper DC filtering when powering the transmitter.
73, YO6DXE
*** BLOG POST:
dxexplorer.com/michigan-might...
*** PCB BOARDS:
( coming soon )
*** SUPPORT DX EXPLORER:
www.paypal.com/donate/?hosted...
*** Check the DISCOUNTS page on the blog:
Discount codes for various products and services offered by partners and collaborators.
dxexplorer.com/discount-codes
You need to modulate the emmiter with a BIG amplifier. Can be done directly or with a transformer but you need a big voltage swing. Almost rail to rail. LM386 will not cut it for 100% modulation because it wont do that due to internal biasing. However a couple of chunky transistors will. Plus you have the advantage of biasing it yourself to get the swing.
Thanks Nigel. I was just thinking now that maybe the LM386 is not the best choice for a final version. Is nice for tests... and for fun... but clearly not enough. I will play some more and do it as you told me. I think I have an idea 😁. 73, YO6DXE.
Nice project Ciprian. I'll be watching for developments!
This coming week is dedicated to this project as I want to finish it 😁. Thank you and 73, YO6DXE.
Really cool! Thanks for sharing and 73.
It was so much fun to play with this. The LM386 amp is clearly not enough to properly modulate the signal... but I think with a better amp it could become somehow useful. I really like it. I will play some more with this and see where I can get it to 😅😅. 73, YO6DXE.
Ma bucur sa vad ca experimentezi cu AM, eu am un mic transmitter dedicat de AM si m-am jucat mult cu el. Mi-am facut casti wireless marca Sputnik, am conectat transmitter-ul la televizor cu sonorul dat la maxim si m-am asezat in pat cu castile in urechi si Sputnik in brate :)))) functiona atat timp cat nu devia frecventa la Sputnik si incepeam sa aud carrier wave-ul haha
Hahahaha. Ce comic esti. Daaaaa Doamne ce m-am mai jucat si eu ... dupa filmare. Parca eram copil mic, tot vorbeam de zor in microfon din hol sa ma aud pe receptor in camera hahaha. Experimentele astea imi aduc aminte de copilarie si ma fac sa ma bucur de hobby asa de mult. Ma bucur ca tehonologia Sputnik merge si la tine 😅😅😅.
Thanks!
Again ))) Thanks so much my friend. Sent you a voicemail. Results to the tests coming soon.
Thanks very much for the video and for trying it out. :) 73s
Thank YOU )) I would not think of trying if you didn't asked. Now it will only get better 😁. 73 my friend, YO6DXE.
I don't think this is too complicated to get it on the air. I think you said it operates on 7.2MHz. For receiver you can use the sputnik or the usdx and to switch between transmitter and receiver you can use a relay and utilize the ptt from the mic or just a regular switch. Maybe you can experiment with a local radio amateur. It would be fun trying.73 great video
I just need to build a better audio amplifier I guess... transistors only. And the rest is easy ))). It should be fun to have a CW / AM transmitter... even if on AM I won't get that far, is still fun to have it ))). 73 Nikos, YO6DXE.
@@dxexplorer You can make a BD139 modulator with a 2n2222 pre amp. To boost the power you can make a small linear amp with a irf510 and you have 6W PEP output power. Just some ideas. 73
@sv2tcb Thanks Nikos. Ohhh making a PA will change the project from simple to not so simple anymore ))). Little power is more fun fighting to make a contact hahaha. I will work on building a PA later on... from 160m to 10m... but one I can use with most of the stuff I am building. The audio amp idea is not bad though. I will search for a schematic tonight if I don't fall asleep 😅😅. 73
@@dxexploreri have a pcb and circuit for a 160m transmitter with 5W PEP i am going to build it sometime when i finish the design. Many 73
@@sv2tcb For 160m nice... let me know how it works. And the band as well... I don't hear much most of the time. 73 buddy.
That will be a fun project to try with my MMM. Yeah, using the LM386 works as a test and sounds good but a modulation transformer and a transistor amp with a wee bit more power would make for a great package 😀 73, de WA4JAT
Indeed was fun hahaha. I was like a little kid talking into the dummy load way more than what I recorded 😅😅. I agree... I will play with a proper "modulator" and see how the results will improve. I have a feeling I will make one more video on this later in the future 😁. 73, YO6DXE.
👍
🙏🙏🙏
Sorry? what is he saying now?
That you can't get far with 500mW?
As long as the antenna is good you can go quite a distance!
( from the Netherlands to Germany AND understandable! )
regards
No no no... on CW yes you can get pretty far with 500mW. I was referring strictly as AM voice transmitter on 500mW. With that power on AM voice you can only cover a short distance. 73, YO6DXE.
You can use a audio amplier as a AM modulator ,if you measure the ic audio output pin it sits at 1/2 VCC with modulated audio on it! just dont fit the coupling capacitor feed direct to tx vcc line of tx,its series modulated Am.So carrier is 4 timesxmodulation 90%,exapmle 700mW max CW@12V,Now set needs to run withaudio chip modulator at 175mW CW,no modulation.Once add test tone 1khz you shold see 90-100% @700mW PEP
here a good link to look at
th-cam.com/video/Q8foHD-RMNc/w-d-xo.html&ab_channel=JohnAudioTech
Great video
Rob P
Ohhh thanks so much Rob. Clearly I need to try. I was thinking to build a transistors based audio amp as a modulator... just for the fun of having a transistors based circuit only )). But I clearly need to try the IC version as well and see the best I can het out of it. Thanks one more time. 73, YO6DXE.
Can you.tell me.more about the circuit and the lm386 circuits you use as microphone amp
This was just a test. I want to re-design the PCB board for me so I can use it both for CW or AM Voice... the AM voice more for fun as for sure I won't get too far with such little power. But I must use a different amp for better results. I used the LM386 just because it was already made and I had no time to make anything else. I don't know when I will have the time to work on this one... but hopefully soon as I also want to update the blog article. Maybe I make two versions instead... one just CW and the other one CW and AM voice. 73, YO6DXE.
Do you think its possible to use the mighty as a driver then connect it to a 1000 watt rf amplifier or something other maybe 500 watt
I need a nice transmitter for my sputnik receiver did you remedier me
I have a nice working receiver very loud signal and low noise
@oliverfranklypartolesen9882 I guess it depends on the amplifier... some work with little power on the input... some need a little more ... something around 1 to 5 W at least in order to deliver the full power. But for CW you only need little power to talk around the world. The AM output I think is minimal unfortunately so I don't think it would be able to run an amp. But there are circuits way better out there if you want to build a proper AM voice transmitter that you can plug into the amp.