Arduino Project: dds vfo install cobra 21 and Cobra 25 ltd CB Radios
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- Опубліковано 9 лип 2024
- In this video I install the Arduino DDS VFO I built in the last video.
The radio used is a Cobra 21 LTD with the same chassis as the Cobra 25 LTD Classic.
Both CB radios use the same chassis circuit board and layout.
Please
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Thank You! - Навчання та стиль
Wow! This takes me back. My dad had an identical radio in our car when I was a kid.
That is awesome!
Im glad I found your channel before it blows up. This is fantastic content. I am bringing a pair of Cam 89s back with your help.
Thank you! Those are awesome classic rigs!
Superb peace of work, and keeping the design simple is spot on, I congratulate you, great to see your interest in cb radio fantastic video too, I have been busy too, I designed a transmitter/receiver circuit on the 40meter band that plugs into the cb and it transmits on the correct frequencys, no mods to the cb.
Thank you! 40 meter that's awesome!
Just a quick question!.. the tx wire on the opto_cupla does that go to the tx on the pll, or does it connect to put switch 🤔 thank you for your help.
That goes to the tx on the mic connector that is pulled to ground on transmit.
Hi nice work, those radios using that pll couldn't be modify back in days till now you did it.
I got a cobra 148 gtl that was in bad shape pll vco and tx output was not working, I got it to receive by installing a Arduino vfo but I trying to incorporate the lsb and usb offsets in the code but still no luck ( I am new in cc++ programing about one year), that will by a nice project for you.
Right on, yeah I plan on doing a side band radio as soon as I can. The VFO designs I have done so far are AM and possibly FM/CW only. The switching for side band is a bit more involved, the clarifier is another challenge, good luck with the 148. I always wanted one of those but could never justify the expense since everyone I talk to are on AM all the time.
A friend buy an cobra 18 ltd and the pll is the same 9106 you think can i do the same process for 21 or 25 ?? The 18ltd dont have the L16 vco
If you can locate the vco and identify the output pin of its last transformer there should be no problem. Confirm that with a frequency counter with a coupling capacitor.
I have a cobra 29ltd classic I will donate for you to do a video on... 😊
Thanks for the offer!
I see you used an incremental encoder, which is good for mobile use.
Do you know of an absolute encoder that will work with the kit? Thanks:)
An absolute encoder would require a complete rewrite, and it would be extremely cost prohibitive.
@@CircuitSecrets I actually am in the process of putting an arduino together now and took the encoder apart to have a look for the detent. There is a ring inside that is close to the shaft end that has the detent built in. I took a small screwdriver and flattened it out some and re-raisd the ring back up, the put it back together. In my case, I wanted smooth tuning, and this absolutely worked without any problems, and it still functions normally.
I don't recommend anyone doing that for a mobile, tho.
@@Guns_N_Gears That is awesome! As long as it still works. The encoders I used to build the prototypes were really cheap and easily messed up so they would not read if too much side to side pressure was applied, seemed to damage contacts. Good luck!.
@@Guns_N_Gears get one from Yaesu for an HF rig.
@KarlM777 I have since found smooth mechanicals on the web @ about the same cost.
The encoders that Yaesu and the like are optical style, and would require a program change. The style used like this video are mechanical type, basically a couple of pushbutton switches ganged into 1 rotary unit.
I need help, I have try to install the kit in a cobra 25 everything works fine but the transmit does not have done everything but have no luck can someone who has done it give me a hand?
Did you bypass the transmit lock? If everything else is working, and the radio was transmitting before, that is where I would look.
Yes I did, the tx circuit works reducing the 5v to 2v going to D13 arduino right
@@GusNava I think you are confusing the tx lockout feature on the pll with the tx rx switching on the vfo.
hello, you think is possible to install it on a cobra 29 ltd with the D2816C pll ic, is the 22dip
Sorry I have not gotten the 29 virtual install video done yet, have a couple of things on the bench I have been dealing with. Yes that pll is similar to the one in the 25/21 ltd. The pin out is a bit different on the pll, the LD out (loop detect/lock detect) transmit disable is on pin 15, pin 17 is the output to the vco. I am not sure about the frequency offsets, but I would assume it runs a 10.240mhz reference and local for mixing and standard 455khz offset for receive. If this is the case installation is very similar to the 21/25 ltd and will work with the default offsets. Check the output of the vco with a frequency counter to make sure you are using the correct offsets.
@@CircuitSecrets i did the same process as the 21/25 but at the moment i delete the vco and Connect the si5351 and Connect the pin 13 of the arduino to the tx of the radio the led of tx/rx turn Orange and the arduino reset
@@messinasog did you forget the opto coupler on pin 13? The led should be on until you press to talk, then the led should go out.
@@CircuitSecrets Can u xplain me more about the opto connection arduino and the resistors
@@messinasog There is a schematic for the opto coupler in circuit in the video at the 1:25 mark. To understand more about opto couplers for background on how they work check out this video. ua-cam.com/video/OWG4863rusc/v-deo.html Let me know if you have any questions after that.
Hello again, i install it on a cobra 25, but at the moment i press the mic the cb transmit in other frequency, but i recive ok and i can listen the frequency but i cant transmit
If you are using the pro mini the built in led should go out when you transmit to indicate the ground connection to pin 13. Did you connect pin 13 to an optocoupler and resistors as shown in the schematic in the video? Or did you wire pin 13 directly to the tx pin on the mic connector?
@@CircuitSecrets IT WORKS!! Now you can do it on a cobra 29 ltd? i have one but the expanders are only for hi or low channels
@@messinasog Unfortunately I do not have a 29 on hand. If you want I can do a virtual install guide though using a schematic and diagrams. I will not be able to confirm it works though since I do not have one to test it on.
@@CircuitSecrets yes please
no compatible with cobra 29? or 148?
I have not gone through the 29 schematic or taken readings to confirm, but it should work with it, however the connections will be slightly different than the 25 and 21 ltd, I believe the tx and rx offsets will be the same. The 148 is a side band radio so the vfo will likely need modifications for lower side band offset and additional functionality for the clarifier (voice lock). I intend to add those features to future designs and a few other options and ports to other micro controllers as my series on vfos progresses.
@@CircuitSecrets I have a 25, but I have problems about the tx connection, could you explain a little more, I want to install it and try it with my cb
@@messinasog Which portion of TX? The connection for the tx/rx switching which is connected to the mic plug? All it does is sense if the ptt switch in the mic is in tx or rx. You can use standard mic wiring diagrams to find the correct pin. You can also use a continuity test, the tx pin is the one that is pulled to ground only when the mic is keyed. I think I explained the tx lock out in the video. Tx from the vco connection point is the same circuit as rx but the ptt switches the frequency offset. I hope this helps.
@@CircuitSecrets Do u have other way to talk about it? whatsapp or facebook?
@@messinasog No I am sorry I don't currently.
So I should be able to do this to a president washington base?
The Washington is a SSB radio, unfortunately the current vfo design has no offset for side band and no fine tune for clarification. I intend to add those features to a vfo design in the future. This design works great with AM, CW...
@@CircuitSecrets there is one on the market I've seen that has ssb capibility.
@@KarlM777 Yeah I saw that, my final version will be similar, but all open source. The firmware will be totally free as will the schematic design. I am not trying to sell anything, just educate as best I can. That is why the series on I2c explains all of the parts for the VFO, then I show how the vfo can be built with two different micro controllers, then a couple of installation videos.
@@CircuitSecrets I'll wait for yours. I like building things
no code no use
All of the code for the VFO is on the circuit secrets website. circuitsecrets.com
shame your website looks almost vacant!.
Yeah I only post things that I think people will find useful. I try to avoid the typical youtube trap of just posting empty repeats of others work and filling a website with things like mailing list collection and blog posts. The VFO source code is there for this project.