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Posted: 08 Nov 2016, 23:22
by rogerbeep
Any suggestions regarding how to set up a CB remote station?
... other than buying commercial interface units and use an amateur tranceiver...

The concept of the CB radio CRT Mike could be possible to "hack" and link for two-way internet communication? Don't ask me how to do it! :(

For those who don't know this radio: CRT Mike has ALL controls and audio built into the mic unit, connected with one single plug to the RF part.
I just want to put an extension cord named "internet" between the two units :)

Re: CB RoIP?

Posted: 12 Nov 2016, 09:36
by Mad4radio
how you going to control the triggering of the PTT????? VOX???? that would work if the radio supports it if not In the ideal world you really a comport keyer as that's its job to trigger PTT once audio is detected.

Re: CB RoIP?

Posted: 19 Nov 2016, 19:49
by rogerbeep
Mad4radio wrote:how you going to control the triggering of the PTT????? VOX???? that would work if the radio supports it if not In the ideal world you really a comport keyer as that's its job to trigger PTT once audio is detected.
PTT shall be triggered with the physical button as normal, I will have the hand unit at my site and the main unit at the remote site.
Look up "CRT Mike" to see/read about the radio I consider for this project. (Mic including speaker and all controls and separate main unit.)
Obviously I need interface units at both ends. It is the construction/programming of these units which is interesting and subject in this thread.

I am not talking about COM-port connection and exchanging information between two ordinary PCs, but a more modern and independant solution like f.i. two Raspberry Pi set up in a (VPN) network.
I should have been more clear about that in the first posting.

Since the CB radio (CRT Mike) internally shares ALL in- and outgoing signals and radio functions via a single connection point, it shall be possible to convert those signals into digital values.
Sound is probably analogue and I might need to make simple AD/DA converters and an small amp for getting sufficient sound at operation side.
All values will be forwarded to the other "computer" where it is coded back to original format and fed into the remote unit. And vice versa.
On/off, PTT, TX/RX audio, channel selector and squelch control shall be connected and decoded via the Raspberry Pi's GPIO-pins ad shared between the two computers.
How to treat and forward the information from/to each GPIO between the two units is the important part in such a project.

In this way I could for instance operate my CB radio via Internet from a friends house in another part of the country - where my old CB friends are living.

I have found some info for similar setups but not with CBs, which are not standarized in the same way.
Hopefully someone at TM1 find such a CB-project interesting and can help pointing further in the right direction.

Re: CB RoIP?

Posted: 19 Nov 2016, 23:01
by Mad4radio
sounds abit confusing if I'm allowed to say & way too much work just for a CB ROIP setup, Why not just keep it simple & purchase a ready made & ready to go com-port keyer that would plug straight into the radio & pretty much ready to go once the dedicated com-port has been selected for the interface to control PTT via the software you want to run your ROIP link on??????

I have a similar sort of ROIP setup that your wanting to create with one linked radio located 90 mile away from the other & both sit side by side within a dedicated room on a private server of which can be directly accessed via an RF protocol or 3G/4G mobi phone or Ipad device etc.... should the user choose & both work extremely well & very stable, Both nodes are run on a simplex channel & both operate DMR with capabilities of been put/moved into another room on the server where both could be linked into the rest of the DMR capabilities that we carry i.e our UHF & VHF rptr systems

I think if it's a CB ROIP link your wishing to setup if i'm thinking along the same path as yourself just purchase a rig check the pins at the mic plug end & either configure or purchase a ready to go com-port keyer that will control PTT, Don't worry about the audio as the interface caters for that too as some like mine had x2 jack plugs at the other ends of which plug into your onboard soundcard or external sound card that will allow the incoming & out-going audio to be passed via the radio & of course your VPN or a private server


Re: CB RoIP?

Posted: 20 Nov 2016, 01:37
by rogerbeep
Well, as I indicate in the first posting I want to avoid using my most expensive radio with the additional cost of interfaces to operate remotely.
For instance, Remoterig RRC-1258-series for my Icom 706 has a retail price of close to 500 USD plus my import fees and then 25% tax. That will give me full remote access to that radio, but via an old type of interface even if it is independent from using a computer.
Not to forget: It would be an overkill and waste of money to use such hardware combination as a remote rig at the CB band - because of the total price, and the fact that I will need yet another IC-706 for my shack. :)

I may mislead the readers when using the word RoIP. My intension is to set up a remote controlled CB radio, which only I can use via internet.
Repeater function is not planned, since another radio is needed - but this would of course increase the user value a lot, since I can operate from my car as well.

What kind of com-port keyer are you using for your setup? I am not quite sure if I understand which concept you are talking about. I would like to know more.
My impression is that this might sound like the setup needed to use FRN for typical PMR/DMR radios equipped with a two pin Kenwood-plug.
I could be wrong, but it seems that FRN is not ideal for remote controlling a CB radio actively.
Can you change channels, modulation type, rf gain and adjust the squelch? I cannot do this (yet) but would love to solve the problem! :)

I want to have full remote access to a CB radio situated somewhere else - just as if I was present at the other location.
This involves having the main radio unit at the remote location, and the microphone with all built-in controls/speaker in the palm of my hand when sitting in my own radio shack.
Ideally it shall not be any differences between operating the remote station and to the other radios in the same room.

We might have different approaches and thoughts about RoIP, the grade of networking, third party connection possibilities and types of radio equipment, but still I appreciate all types of feedback, possibilities and suggestions.

Re: CB RoIP?

Posted: 20 Nov 2016, 09:37
by mercury888
The CRT Mike is a CB in two bits with a lead. It should be possible to extend that via an Internet (or any other) link but that's 'should', not 'will' and it's potentially a heck of a lot of work!

Speaking fairly generically here, you first have to figure out how many wires (not clear from the pics I saw) are in the lead and what they do. Then you need to figure out how they do what they do. For example, let's say there are 4 wires that perform all the functions - there are so many functions that there might be some sequencing to how those wires are used, and we've not even got to what voltages or pulse durations are involved.

If - big if - you can figure that out then you can figure out an interface, probably some diode / transistor interfacing to get the voltages right, and some way to make the sequencing work. If it were me (it isn't!!) I'd be looking at a Raspberry Pi for each end of the link plus control circuitry.

If you managed the above then the rest is programming. For example, you change frequency, the Pi at your end sees the various control signals and sequence and realises what it is, sends that data to the remote Pi which activates the relevant wires in the right order and pulse lengths.

If all the above actually worked then remember you also need top are it fail safe - if your system crashes while on ptt there needs to be something to shut it down. Also consider which bit starts the process - you may need to power the remote bit first before you can even send it any signals - easy to do with a separate o/p from the Pi and a relay...

Take the Pi out of the equation and replace with hard-wired logic and the above is the beginning and end of any such control system.

This is why standards are useful - someone makes a standard interface and tells everyone how it works and what you need to interface to it. Of course for all I know this CRT Mike may even use some standard.

Hard work if you ask me - but should be possible given time, patience, and test gear. In the Old Days I even connected a Nixie readout on an analytical machine to a pre-PC computer via wires and voltage sensors to record what digit was displayed. But that's a walk in the park compared to this...

Re: CB RoIP?

Posted: 20 Nov 2016, 12:56
by Mad4radio
Nice Comment "mercury"

Another thing as well is that all this can be done via a simple program called teamveiwer.......... When I was playing on HF using an FT100 I had it cat cabled up via HRD which could control the freq i wanted to play on as well as PTT Using teamveiwer to remote into the machine the radio was connected too & using skype to relay voice on & worked very well & leaving some folk very impressed with how easy it was to setup to do.

Pretty much the moral of the story is the simple ways do sometimes always seem to work & work well

Re: CB RoIP?

Posted: 20 Nov 2016, 23:43
by rogerbeep
Mercury, RPi is described further up in the thread as prefered hardware for the intefaces.
CRT Mike has a TOT - Timeout timer.
Remote shutdown will be initialized when/if control signals are lost (i will include a check routine between the RPis).
In general signals should be easy to decode, since this is a simple an cheap Chinese radio design. I don't know the coding of controls as I need to purchase the radio and analyze, I hoped someone else already did this.

Mad4radio, I am still curious about the questions I asked in my previous posting.
I have HRD but am not sure about if the software accepts transmission outside ham bands even if the radio is capable.
If I use skype or other SIP, I believe I need same setup in both ends.

I have found some descriptions for RPi used for remote operation, I will have to spend time reading that.
Thanks for your feedback so far guys!

Re: CB RoIP?

Posted: 21 Nov 2016, 12:36
by Mad4radio
rogerbeep wrote:Mad4radio, I am still curious about the questions I asked in my previous posting.
I have HRD but am not sure about if the software accepts transmission outside ham bands even if the radio is capable.
If I use skype or other SIP, I believe I need same setup in both ends.
If your radio is widebanded at both ends & will TX & RX out of band I don't see the problem, The way's of which my links/nodes work are based on commercial gear & using the rear pin-out's on the radio's to connect an accessory connector to the pin-out's that will carry both incoming & outgoing audio as well as controlling PTT using a basic interface purchased from the tinter web.


Re: CB RoIP?

Posted: 23 Mar 2019, 20:27
by rpcomms
Yes can be done,I done it
Zello via comms ports
FRN Via comms port
NO VOX avoid like plague!
Add lag to system

Use busy LED or mute pin inside CB to control COS signal from radio to RS232 comms port CTS (set activate hi or low depending on logic level of Mute\Busy voltage) ,best used with a opto isolator
Use a opto Isolator to control PTT to radio using RTS activate hi

Hint for CB tap of speaker audio,use a 8ohm resistor load and 1K resistor then to tap off audio,very important as using the external speaker socket
it needs to see a proper load,the resistor being that load ie a speaker!

Feed AF signal thru a audio transformer to isolate PC ground from Radio ground
Terminate the PC side LINE IN\OUT with a 100-150R ohm resistor,this prevent noise on leads.
Adjust CB volume using another cb for around 75% level on sound card input LINE IN

Use a 1khz Wav sample loop to set up TX side again around 60-70% from sound card
to test your interface use this simple software.
Micro ridge RS232 tester
it will feed a 1khz test tone into your cb to check deviation

I found 50-100mV (RMS) for 60% modulation was rule of thumb into the LINE IN\OUT sockets of PC sound cards for best S\Noise,needs to see from CB radio.

I would also suggest set the FM squelch to S-5 signal as anything less than that is just to noisy

it may sound complicated but its not,just do each step a bit at a time
the hardest part is probably finding the Busy signal generally 0V=Busy 5-8Volts Not Busy,but can be inverted.
best place to find it signal is Busy LED or Mute pin on audio amplifier
this signal drives the RS232 to tell system its seeing a valid signal from CB
it works 200% better than VOX

IF you have a deviation meter and a RF signal generator,it makes that task sooo much easier on first one,but even with thats,as long as have a second cb radio to act as the mobile,and set on bench as the gateway u can get levels to sound right.I found say 5555555 and adjust PC sound card slider for around 75% on bar levels was about right.
Peak fm deviation was around 2.0khz no more using ETSI spec current equipment (not MPT1320 UK)

Once you done a couple its really easy.

Zello Free\Works
F6DQM Simplex repeater

all worked fab on cb

One more note,if doing CB gateways or CB meshed networks the one thing to really consider is the use of CTCSS decode on the base gateway,i think this is really important to help protect gateway from QRM,27mhz skip and busrt noise open the squelch line up,causing havoc.
I think this is part of the reason why some go wrong .

With new cb coming out 2019 with CTCSS i can see ROIP becoming quite popular and practical
From experiments done on 3 cb gateway built so far CTCSS was vital I found to make it practical FM was best option,but did try Am mode and that did work too but lacks CTCSS.

But u can retro fit CTCSS encoders to your CB mobiles\hand-portable very easily,but new sets will make this a lot easier having CTCSS feature built in.
I know theres a new GPE Randy III handportable due,this does has CTCSS
CRT do cb cb with CTCSS and DTMF control access microphone

So if your real determined ,like I was,wanted to show the negatives out there,YES it can be done,BUT you will need certain skills to modify the radio and build the interfaces,test kit to check levels correct.

It also does not stop there..either! if you want a successful and 100% reliable system
You got to consider your site location..its no good placing it at your home QTH is operating cb as well,thats one thing I learnt!
Otherwise your gateway will be on and off due to QRM on your other cb in house,it must be place in a RF quiet noise-floor location on 27mhz,that can be difficult in itself.

You must have either a 4G router or wired internet access on your planned site,dont use wifi (another mistake commonly made) it slows and lags system
The PC machine must be 100% reliable on 24\7 and have cooling ,the operating system must be stripped to basics and dedicated just for ROIP use,dont use your home machine as its cluttered up with all sorts!
I did find mini Intel PC will work well and can run 24\7 but consider heat and internal environment of your site,does it over heat,can heat dissipate easy,does it get too cold on site!
these things are very important to consider when getting into this on a reliability scale.
Cooling fans on your CB radio if gateway very Busy have to be considered in the design, and duty cycle of the power supply system.

Mains-fail back up for PC\gateway\Router-also has to be considered and any alarms to indicated a fault-Big UPS

and lastly ensure you have a Time out timer on CB,either thru the software gateway,internally of external hardware so in an event something goes down,the the CB is not stuck permanent in Transmit mode!
Yes I had that happen and it nearly cooked my cb radio,oversight!

So there's my experience of CB ROIP,YES it can be done,Yes it does work well,Yes you can mesh up to PMR446 & Network radios too....
BUT.. To do this you going to need at least some extra pair of hands to help out initially,do it cheap and nasty it will fail or be at best okish,do it right and put time and effort in ,it work fab,reliable and very practical.
I would say this is for the beginner,but maybe best suited as a group venture as ull need help in other departments not just the electronics.
Take each step bit by bit.
Take some time to consider before building a CB gateway
have i got the resources?
a site with electrics,internet and a place to mount a mast and antenna system?
test equipment?
PC knowledge?
electronics and soldering skills?
Can read or understand CB radios schematics or where i need to tap signals off?
Who or what interface im i going to use?PCB skills can be very handy ?
Do i need to bring in more skilled people to make this succeed?
Antenna System hardware,coax,brackets,and equipment to fit the antenna mast?

Im not trying to put people off,but I think ROIP on CB is very new concept and because CB radios do not have an easy interface port purpose designed ready for this role it could present certain challenges.
And the site installation work to maintain your CB gateway can\could also present challenges if you want a reliable service from it and not having constant issues and problems with it.

But once you have done one and taken notes or Dos & Donts it will become easier as ull form your own rule book manual,like I have done.
Im personally holding off a 100% operational one,till i get hands on new CB due out mid year 2019 with CTCSS decoder built in,by then then hopefully the new President Electronics Randy III hand-portable will be out which will be ideal for CB ROIP use,plus I know new models due soon,that support CTCSS functions built in.
In mean time i continued to experiment and build up equipment needed for the site installation work,and racking up CB gateways into 19"rack enclosures,takes time and money im afraid like most thing in life!

All the best def have a go,dont be put off by the negatives!
Just need determination and a will to do it.

I will do an update once i have new CB (CTCSS model) kit in my hands,ive had software modified for me from china specially for this job.

Early days yet for CB ROIP

Rob P 73'

Re: CB RoIP?

Posted: 08 Apr 2019, 21:45
by 26mb04
How are you sensing the RX SQ logic level on the CRT2000? Be really careful, they're not as bombproof as the old style rigs when it comes to plugging things in. It's much easier with a purpose built rig like an 817 or similar, all the signalling/control ports are there on the back, you can then select whichever band you want to use. Building a serial RX/PTT/audio interface isn't too hard, try and stay away from VOX as others have said.

I can definitely recommend Zello, configured as a gateway it works well. One thing to note with an older computer, sometimes the audio lags when the PC is under load, I changed my Zello exe to run at High/realtime priority which helped a lot.

Re: CB RoIP?

Posted: 12 Apr 2019, 14:43
by UK018
This sounds like a lot of hard work to me.
Well a lot of talk.
good luck with it.
73 de Wes