I love this. Bare wires means real hobbyist electronics. This is exactly the sort of exploration that makes the hobby my favorite. Break it, fix it, make it do something new and cool. This is truly the spirit of ham radio.
This is absolutely amazing. As someone who's tinkering with battery setup on an RT95 (messing with 12V via USB-C and a PD board), this radio is incredible. Would love to see an APRS setup going from the sound card A2C into an Android phone for use in a car/mobile setup.
TAPRN decades ago started using this approach for the Kenwood TK-705i to do APRS, I was able to buy a cable for mine already wired. Brave cable making skills required, but it is a proven way to get APRS into and out of computers. The way you sent that file is new me, and awesome!
Yes, I see a lot of potential in being able to send myself a message based off of some other computer signal - like a weather alert triggers an aprs message saying seek shelter now! For example.
The reason for.the separate grounds - balanced vs. unbalanced audio. Unbalanced, the ground just goes to the chassis. Balanced audio is actually the return signal of the audio. You need separate grounds to eliminate cross talk between mic and speaker. Impedance are different between balanced and unbalanced.
Not all grounds are created equally. When you design an rf circuit or a highspeed signal circuit you need to carefully design the return path as to not cause interference. Also GND could mean not ground depending on the type of amp driving the speaker.
Only for reception it is not necessary to create a new cable, it is sufficient to connect the audio output from the back of the radio to the sound card. Anyway thanks for the suggestion. 73 from Florence, Italy
That TRRS breakout cable is _exactly_ what I need for messing around with APRS on my FT-70! I hope that was an affiliate link, you deserve every penny.
@@temporarilyoffline I found a decent alternative previously, but it was literally just a trrs _jack_ with a breakout board to use on a breadboard. Not ideal for quick-and-dirty tests like what you did, more suited to long-term projects, you know, on a breadboard. Always a pleasure when I see a video notification from you, keep up the awesome work.
Steve, I am thinking CAT control. You could program some small signal relays to transition the audio over to some dio pins on a microcontroller and completely control the radio from USB commands. APRS radio that can QSY programmatically.
I experimented with running an APRS digipeater/iGate with my ID-5100. I used a couple of patch cables and a Signalink to do it with a mechanical A/B switch in line so I could switch between the Signalink and the hand mic as needed. Worked like a charm. I plan on replicating that setup at the new QTH with an inexpensive dedicated 2M radio so that it stays up all the time, not just when I'm not using phone.
Excellent! This thing will have a more simple interface when I'm done, but gotta make it first. Stay tuned. Looking forward to your videos on your setup.
Thanks for posting this. I'm looking at getting my Commodore 64 set up to do packet radio. Do you thing that this radio would do a good job receiving and sending?
If you're using it with a signalink you wont be able to hook the wire directly or it will trigger channel up. The solution is to have it go through a 0.1uF to 1.5uF capacitor!
@@christophermcclellan8730 The signalink does not put voltage on that line, the 778UV itself does as part of the data communication with the mic (when connected). Thats how the buttons all work.
@@lucase6407that doesn’t quite make sense. The radio will put voltage on that line when it’s sending audio, but the mic is what would be putting voltage on the line when the up button is pressed. No mic, no up button… how is voltage being put on it?
very nice work here. but a pin out starts on the other end. regardless you did the mapping correct on your needs. pin 1 is white orange / orange. pin 8 is brown. just fyi... been in networking for some years. cheers brother.
Hi, I was looking for this info. Great! How do you make the radio go into TX since you not wired the PTT line in the RJ-45? Please help, thanks. 73 Phil ON4VP
@@temporarilyoffline I saw that to. I just ordered one. I have a TNC-X from Coastal Chipworks and I will make myself a cable using the audio in/out, ground, and the PTT since the TNC has a PTT line out. So I hope to use a single cable to work APRS and packet or Winlink. 73 Phil 0N4VP
@@temporarilyoffline Another small question, the audio that comes out the RT95, is this a feix level or dependent on the volume you set on the radio? I guess volume related?
@@temporarilyoffline I was wondering that when you were exoerimenting with PTT I see in the manual that the microphone only supports 5 VDC to use the buttons ans leds. I you switch this port wit a low/high signal form a serial port the changes are you put 12 VDC on this port. Perhaps this is to high fot this port. It keeps me from using the radio this way ... 73 Phil ON4VP
This is awesome. But wonder if this would work on baofeng and if so if the y cable that comes with the 50x2 gen 2 would work and if btech will sale them separately
@@temporarilyoffline oh no. i am wondering if the splitter cable that comes with the 50x2 second gen would work with this. they have a splitter that splits the rj45 to a k1 and rj45
I have a whole playlist for this radio... There are some new videos since this one, but I ain't done yet!! ua-cam.com/play/PL01YuCls6edYz5xDwVqPxfc7m15PVnuBm.html
That happens every so often with mine as well. I don't have a solution yet other than to set the channel again. It survives a power cycle about 97% of the time so far and I'm working on a solution for that. Stay tuned!
Great set of videos. I came across this while searching for reviews of the Retevis RT95 as I was considering getting into LX operation beyond a simple BF. I made the purchase (a whopping $125 for radio, mobile antenna, data cable) after watching this video. As a long time build-a-pi user for HF digital use, playing around with APRS on the RT95 sounds fun. I have some experience making RJ-45 interface cables for my FT891 & FTdx10, so why not one for the RT95. Thanks for the audio out pin out location.
Steve, you need to get one of those RJ45 socket breakout boards with screw terminals or some such. Really helps to cut down on magic smoke releases when that one wire touches something it shouldn't (don't ask how I know). But using tape is a time-honored tradition and it is good that you are venerating the old ways. :) As usual, a wonderful video!
In the Direwolf documentation they mentioned some USB sound cards that have hidden gpio pins to trigger ptt. Personally, I would like to somehow use the right audio channel to trigger ptt.
@@temporarilyoffline I wish APRSDroid would allow a ptt solution, as that has been my go-to portable kit and I'm disappointed in how much dead air I must use to get a burst.
@@anduril328 I took a look now that I'm on my computer and I think I have a clone of this radio. I believe it does NOT have a speaker in the hand-mic, so you'll have to do some extra magic to make it all work - wire speaker to the rear speaker port, wire mic and PTT to the front mic port - it won't be as "elegant", but it will be certainly do-able! Keep following along for more updates as I'm working on a way to make this whole process even more easy.
Oh, Steve, you excite me! (in a manly, hamly way.) This means the RT95 can send data through its mic jack, which means I can probably use my RT95 as a POCSAG transmitter along with a Pi 3B+ with an MMDVM repeater HAT with a DB9 connector and a homebrew cable to the radio. Groovy! Like your APRS setup this would be proof of concept for now. 73 de DW7GDL.
It would be very possible to do that! I don't have a schematic yet - I have to learn that skill first. When I do, it's part of the video series plans for this radio.
I have another cheap mobile radio, a BTech UV-2501+220 (a variant of QYT KT-8900R). The pinout is different but there are AF in and out pins, per google. So this concept probably would work with that radio also.
The algorithm and yt search are awful. Ive googled the 778 for most of a year and wondered how to do just this, and I'm only seeing this now that I'm curious about the SR-94
@@temporarilyoffline we would jump station to station until we found one hooked to dial tone then hook to colleges and research stations. Read all day, lol.
Great video.Im receiving with a pi and sdr at the moment and am looking for dual band home rig. This radio is one ive been pondering on and this is helping me make my decision :)
@@temporarilyoffline it definitely seems the part and for a $hundy$. Worth maybe popping the magic smoke now and again since the radio ham hobby is all about experimentation. Its why i do it!
I did smoke this one in a later installment, waiting to get it back from China, they think its a software glitch that I caused by fake-button-mashing. ua-cam.com/video/xqZAGreTQpo/v-deo.html @@letmelooktv
I was looking for a video like this one, thank you toshare what you have learned to help others, I just order the equipment to use my radio and install a digipeater on my area! 73s! TI2GBB-Greg
@@palehorse7377 That was the smiley at the end. I was carrying the joke forward too. We're good! (you know we are going to be those guys in 20 years, right?)
I love this. Bare wires means real hobbyist electronics. This is exactly the sort of exploration that makes the hobby my favorite. Break it, fix it, make it do something new and cool. This is truly the spirit of ham radio.
Couldn't agree more!
Make cool stuff, put it on the internet. - AvE
This is absolutely amazing. As someone who's tinkering with battery setup on an RT95 (messing with 12V via USB-C and a PD board), this radio is incredible. Would love to see an APRS setup going from the sound card A2C into an Android phone for use in a car/mobile setup.
I've got this coming soon. Too many projects at the moment. Stay tuned.
TAPRN decades ago started using this approach for the Kenwood TK-705i to do APRS, I was able to buy a cable for mine already wired. Brave cable making skills required, but it is a proven way to get APRS into and out of computers. The way you sent that file is new me, and awesome!
Yes, I see a lot of potential in being able to send myself a message based off of some other computer signal - like a weather alert triggers an aprs message saying seek shelter now! For example.
thanks for the diagram, found this while trying to find the speaker wire in the at-778uv mic.
Excellent!
Nice Steve, your like a scientist!
I try
Thanks, so..this should be able to be used for regular packet radio I assume?
Yes, APRS is just a subset of packet radio. Should be fine.
The reason for.the separate grounds - balanced vs. unbalanced audio. Unbalanced, the ground just goes to the chassis. Balanced audio is actually the return signal of the audio. You need separate grounds to eliminate cross talk between mic and speaker. Impedance are different between balanced and unbalanced.
Thanks for the info!
Not all grounds are created equally. When you design an rf circuit or a highspeed signal circuit you need to carefully design the return path as to not cause interference. Also GND could mean not ground depending on the type of amp driving the speaker.
Thanks for the info!
Only for reception it is not necessary to create a new cable, it is sufficient to connect the audio output from the back of the radio to the sound card. Anyway thanks for the suggestion. 73 from Florence, Italy
You're welcome
That TRRS breakout cable is _exactly_ what I need for messing around with APRS on my FT-70! I hope that was an affiliate link, you deserve every penny.
Thanks! It comes in handy for prototyping a lot of projects.
@@temporarilyoffline I found a decent alternative previously, but it was literally just a trrs _jack_ with a breakout board to use on a breadboard. Not ideal for quick-and-dirty tests like what you did, more suited to long-term projects, you know, on a breadboard.
Always a pleasure when I see a video notification from you, keep up the awesome work.
@@b4ux1t3-tech Stay tuned for this one. I'm working on a no-audio-cable solution next, just waiting for parts to arrive.
Steve, I am thinking CAT control. You could program some small signal relays to transition the audio over to some dio pins on a microcontroller and completely control the radio from USB commands. APRS radio that can QSY programmatically.
That would be cool! There is no end in sight!
@@temporarilyoffline that micro could also control the PTT. There IS NO END in sight 😀
I experimented with running an APRS digipeater/iGate with my ID-5100. I used a couple of patch cables and a Signalink to do it with a mechanical A/B switch in line so I could switch between the Signalink and the hand mic as needed. Worked like a charm. I plan on replicating that setup at the new QTH with an inexpensive dedicated 2M radio so that it stays up all the time, not just when I'm not using phone.
Excellent! This thing will have a more simple interface when I'm done, but gotta make it first. Stay tuned. Looking forward to your videos on your setup.
Thanks for posting this. I'm looking at getting my Commodore 64 set up to do packet radio. Do you thing that this radio would do a good job receiving and sending?
I don't see why not. I have the gear to do it (c64+Pakratt64>, just haven't had the time. So many fun things to do in this hobby.
I’m a new Technician, learning a lot and this is pretty cool. Thanks
Awesome. I do stuff like this all the time. I'm waiting to get this radio back to continue the project.
If you're using it with a signalink you wont be able to hook the wire directly or it will trigger channel up. The solution is to have it go through a 0.1uF to 1.5uF capacitor!
Nope, not using a signalink. Although they are great devices!
@@temporarilyoffline Yeah I saw, I was just letting other viewers know :)
I’m curious why that is. How would the signalink be putting voltage onto that multiplexed line? How does the capacitor solve it?
@@christophermcclellan8730 The signalink does not put voltage on that line, the 778UV itself does as part of the data communication with the mic (when connected). Thats how the buttons all work.
@@lucase6407that doesn’t quite make sense. The radio will put voltage on that line when it’s sending audio, but the mic is what would be putting voltage on the line when the up button is pressed. No mic, no up button… how is voltage being put on it?
Cool sketch of Kirk and Spock behind you.
Thanks, my mother-in-law found that for me.
TO over here blurring the lines between science and magic. 🤣
👍
Exactly!
very nice work here. but a pin out starts on the other end. regardless you did the mapping correct on your needs. pin 1 is white orange / orange. pin 8 is brown. just fyi... been in networking for some years. cheers brother.
Thanks!
Hello. Audio from radio transfers via UP pin? And do I need to enable hand speaker in my retevis settings?
You'll need to enable speaker mic in settings. Check the diagram in the video for pinout.
Superjank. You better trademark that immediately. Strong work Steve.
The whole gas station cable thing is mine... but I think I borrowed superjank from somebody.
I really want to get one of these to use as an iGate with a decent antenna . There is such a lack of APRS digipeaters and iGates in my area
That's where I'm headed too
An old android with phono and a k1 and baofeng with aprs droid would use very little power
@@pen25 it would, but 5w(ish)
@@pen25 I’m looking to service my entire area. 25w with a decent gain antenna will be fantastic.
Hi, I was looking for this info. Great! How do you make the radio go into TX since you not wired the PTT line in the RJ-45? Please help, thanks. 73 Phil ON4VP
In a follow-up video, I got PTT working. ua-cam.com/video/26Bsd2BWSm4/v-deo.html I still want to make it prettier!
@@temporarilyoffline I saw that to. I just ordered one. I have a TNC-X from Coastal Chipworks and I will make myself a cable using the audio in/out, ground, and the PTT since the TNC has a PTT line out. So I hope to use a single cable to work APRS and packet or Winlink. 73 Phil 0N4VP
@@temporarilyoffline Another small question, the audio that comes out the RT95, is this a feix level or dependent on the volume you set on the radio? I guess volume related?
@@pvdk it is a speaker, so radios volume knob will lower the audio
@@temporarilyoffline I was wondering that when you were exoerimenting with PTT I see in the manual that the microphone only supports 5 VDC to use the buttons ans leds. I you switch this port wit a low/high signal form a serial port the changes are you put 12 VDC on this port. Perhaps this is to high fot this port. It keeps me from using the radio this way ... 73 Phil ON4VP
This is awesome. But wonder if this would work on baofeng and if so if the y cable that comes with the 50x2 gen 2 would work and if btech will sale them separately
It would work on a baofeng if you adapted the cable and used VOX
@@temporarilyoffline oh no. i am wondering if the splitter cable that comes with the 50x2 second gen would work with this. they have a splitter that splits the rj45 to a k1 and rj45
I don't know, but if btech wants to send me the amp, I can look into it 😉
Do you have any "update" related videos?
I have a whole playlist for this radio... There are some new videos since this one, but I ain't done yet!! ua-cam.com/play/PL01YuCls6edYz5xDwVqPxfc7m15PVnuBm.html
Following along here - however when I plug into the 778uv, it starts doing channel up. Any ideas what I'm getting wrong here?
That happens every so often with mine as well. I don't have a solution yet other than to set the channel again. It survives a power cycle about 97% of the time so far and I'm working on a solution for that. Stay tuned!
Great set of videos. I came across this while searching for reviews of the Retevis RT95 as I was considering getting into LX operation beyond a simple BF. I made the purchase (a whopping $125 for radio, mobile antenna, data cable) after watching this video. As a long time build-a-pi user for HF digital use, playing around with APRS on the RT95 sounds fun. I have some experience making RJ-45 interface cables for my FT891 & FTdx10, so why not one for the RT95. Thanks for the audio out pin out location.
Glad it helped! Thanks for watching!
Steve, you need to get one of those RJ45 socket breakout boards with screw terminals or some such. Really helps to cut down on magic smoke releases when that one wire touches something it shouldn't (don't ask how I know). But using tape is a time-honored tradition and it is good that you are venerating the old ways. :)
As usual, a wonderful video!
Thanks! I've looked for those before, but it's always good to start in the junk drawer! I've let the smoke out with unprotected wires too... not fun!
@@temporarilyoffline Yes, always start with the junk drawer!
In the Direwolf documentation they mentioned some USB sound cards that have hidden gpio pins to trigger ptt. Personally, I would like to somehow use the right audio channel to trigger ptt.
The CM108 based chips have that feature built in and I've got a 2pack on order... 2 videos away in this series.
@@temporarilyoffline I wish APRSDroid would allow a ptt solution, as that has been my go-to portable kit and I'm disappointed in how much dead air I must use to get a burst.
Pi zero with an android front end? More devices though...
@@temporarilyoffline I just think use a tone on the right channel of audio to trigger PTT. I think APRSDroid is open source.
Forgot to add the radio will be connected to a Pakratt-64.
I have one of those... It's on the long term to-do list.
Think this would work on the 779uv too?
I don't have one, but check the manual for Mic pin out and test it out.
@@temporarilyoffline the manual is terrible. Doesn’t have the pin out listed
@@anduril328 I took a look now that I'm on my computer and I think I have a clone of this radio. I believe it does NOT have a speaker in the hand-mic, so you'll have to do some extra magic to make it all work - wire speaker to the rear speaker port, wire mic and PTT to the front mic port - it won't be as "elegant", but it will be certainly do-able! Keep following along for more updates as I'm working on a way to make this whole process even more easy.
Wicked Awesome Video!
Thanks!
I know this is from a long time ago. Did you ever get this thing working?
It's in China getting repaired.
Last update vid: ua-cam.com/video/xqZAGreTQpo/v-deo.htmlsi=oEVSOdhP6exwCMDc
Right up my alley, love this stuff. Thanks for taking us along !
More to come
Awesome !
Oh, Steve, you excite me! (in a manly, hamly way.) This means the RT95 can send data through its mic jack, which means I can probably use my RT95 as a POCSAG transmitter along with a Pi 3B+ with an MMDVM repeater HAT with a DB9 connector and a homebrew cable to the radio. Groovy! Like your APRS setup this would be proof of concept for now. 73 de DW7GDL.
It's still proof of concept at this point. It does work, but need refining. I'm still working on it. Stay tuned.
I would like to make digital my Qyt K-8900D, any ideas?
From looking in the owners manual, it looks very possible with a custom cable. Also the QYT looks like 5w extra power too! Nice!
Looking at this video, I wondered if anyone has wired a headset to these rigs. Does anyone have suggestions?
It would be very possible to do that! I don't have a schematic yet - I have to learn that skill first. When I do, it's part of the video series plans for this radio.
I'm going to make one also!
Sweet! Good luck!
I have another cheap mobile radio, a BTech UV-2501+220 (a variant of QYT KT-8900R). The pinout is different but there are AF in and out pins, per google. So this concept probably would work with that radio also.
I bet it would.
APRS MacGyver style
That's how we do it!
The algorithm and yt search are awful. Ive googled the 778 for most of a year and wondered how to do just this, and I'm only seeing this now that I'm curious about the SR-94
Yes, I agree. It took me a long time to figure it out also.
early 90's digital right there.
I'm looking forward to being in range of a packet radio bbs one day!
@@temporarilyoffline we would jump station to station until we found one hooked to dial tone then hook to colleges and research stations. Read all day, lol.
@@jtcgunn Hams Lead The Way!
First! Engage!
Almost!
Nice hack. Now it needs a splicer so you can still run the mic and APRS at the same time.
Possibly! This might be my go-box digipeater/igate - so stow-and-go.
Great video.Im receiving with a pi and sdr at the moment and am looking for dual band home rig. This radio is one ive been pondering on and this is helping me make my decision :)
It's a great functional radio at a great price. Hard to beat.
@@temporarilyoffline it definitely seems the part and for a $hundy$. Worth maybe popping the magic smoke now and again since the radio ham hobby is all about experimentation. Its why i do it!
I did smoke this one in a later installment, waiting to get it back from China, they think its a software glitch that I caused by fake-button-mashing. ua-cam.com/video/xqZAGreTQpo/v-deo.html @@letmelooktv
Still wanting to get our "Linux" on!
Let me know what you have in mind and we'll do it.
You have too much time to tinker but we enjoy seeing your work!😊👍
I showed up for work ;-)
This is piratey work right here! You must have digital pirate DNA! A piratey cheer was had by all!!!
Arrgh!
Next video add PTT and terminate it in the KPC-3 standard DB-9 please.
Next is PTT, after that is a RJ-45 to USB cable direct - my Raspberry Pis don't have DB9
@@temporarilyoffline Kantronics KPC-3 radio port not for a Pi.
I was looking for a video like this one, thank you toshare what you have learned to help others, I just order the equipment to use my radio and install a digipeater on my area! 73s! TI2GBB-Greg
Glad I could help
Been there done that.
Awesome!
Cool!
More to come
sweet I cant wait to type to delmer about muh diabetes instead of that once a month repeater net we had! riveting.
Hey man, I'm just here to make your life easier ;-) I can even write a script out for it and we'd never have to talk about it again 😊
@@temporarilyoffline Hey Im making fun of ham radio. not my favorite hamtuber ;)
@@palehorse7377 That was the smiley at the end. I was carrying the joke forward too. We're good! (you know we are going to be those guys in 20 years, right?)
you really need to learn in post how to balance your audio some of us dont buy budget gear like you ha.
Great feedback!