A place to discuss internet linking of radio equipment, such as eQSO, FRN, iRLP, Echolink, and other such systems.
Posts: 72
Joined: 23 Nov 2017, 20:14
Call Sign: 26MB04
Location: Democratic Peoples Republic of Devon

Re: CB RoIP?

Post by 26mb04 » 12 Dec 2019, 21:39

By GPIO do you mean serial/PTT options? You can do that in the free Zello program, you just need to configure it. Obviously though there is no support from Zello because it's the free version... To set it up:

1: Select the channel you want to gateway into
2: Go on "create group"
3: Enter "Zello Gateway" for the name (without quotes)
4: Exit Zello
5: Find the configuration file called zello.conf
6: Open it, scroll down to the bit that says SetGatewayMode=false
7: Change it to true
8: Open Zello again and configure the new port settings, volumes etc.

If you want to change the groups, you will need to change SetGatewayMode to false again so you can sort the groups out, before changing it back.

Posts: 61
Joined: 19 Jan 2012, 14:13

Re: CB RoIP?

Post by rpcomms » 14 Dec 2019, 22:25

yes know about that,way ahead on zello configs here

GPIO control ,meaning when zello looses connection or system down
it triggers a usb to parrall I\O or a serial port say RTS activation to control channel change of radio
to switch it from ch1 "gateway mode" single CTCSS to
ch2"Parrot fallback mode" split CTCSS

GPIO can be 1 bit Hi (ch1) or Low (ch2)
Use parallel binary data 4 bit


the base (mobile unit) gateway radio will support 1 bit,some brands use 4 bit binary

Im concentrating on redundancy systems at the moment to ensure system robust,and fully automated plus adding in any addition hardware needed on the interfacing pcb from radio to pc for channel change control

A bog std Zello CB roip gateway is fine but found during tests in "meshed linking"nodes you have to improve reliability of overall system including CTCSS use esential and Parrot mode fallback,plus having the ability to change change modes could be handy if want to reconfig your Gateway to Parrot mode manually via a manual overide switch on the interface,as well as fully automated control.

Unfort Zello is a little limited in I\O alarm control,GPIO output control to an event tab.

so looking at other approaches currently

We now have a live Zello CB test gateway up running now this week and working well with iphones,tablets,laptops hooked up

Yes Zello config with
CTS=Busy COS hi=busy 5V lo=Not Busy=0V from radio

something i found when windows reboots (a we tested this on a few pc hardware and win xp/win10)
ull get 6 pulses from of tx from comm port RTS,but your hardware must have pull up resistors on a permement supply to prevent TX jam up on a PC reboot
also Transmit TOT set for about 3mins as a additional safety on base gateway jam ups.



Posts: 61
Joined: 19 Jan 2012, 14:13

Re: CB RoIP?

Post by rpcomms » 25 Dec 2019, 00:43

Demo CB ROIP now running in my local area as a tester
so far working well and positive responses from users

Biggest issue is some CB users do not understanding fm deviation on there radio kit if using export radios and ham kit really,some users running 5khz wide fm dev,not the MUlti-Norm ETSI specs 2.00khz or old UK MPT-1320 2.5Khz specs seems to be the only technical issues
Lot of old HF ham kit generally runs wider deviation\RX recovered audio(shows up as low audio when using with normal cb radios),some can switch to Narrow FM elevating over deviation issue others need readjusting tx dev to cb legal specs
and sometimes a resistor change of value in the fm discriminator audio to boost up audio recovered ,also fitting the 455HT filter in some cases.

FM-Wide being 60% dev=3.00khz RX audio-TX dev max 5.00khz (25khz spacing system)Ham Mainly USA ONLY now
FM-Narrow MPT-1320 specs 60% dev RX audio=-TX dev max 2.50khz (11.25/12.5khz spacing system)EU\UK and other parts of world Ham & CB UK
FM-Super Narrow ETSI specs 60% dev=1.20khz audio RX-TX dev max 2.00khz (10khz spacing system)EU\UK current system Ham & CB HF

General filters used
455E-25khz spacing system
455D-11.25/12.5 spacing system
455HT-10khz spacing system CURRENT Multi-Norm ETSI CB system,while UK band is in there,the fm specs remain same as EU,this why new radio may sound a little low on tx levels to older cb kit or ham HF kit sometimes,
Mulit-Norm cb to cb should be no noticeable differences at all.only when you start intermixing old,new and outta spec kit together it becomes a bit of a battle and complaints happen.

WE tried to balance the audio feeds from the base gateway as best we can to cope with this "User Kit problem",but really its down to users to ensure TX deviation does not exceed the max 2.5khz on cb bands.
This will becomes more critical when CTCSS type ROIP gateway come into play,as its CTCSS dev+Maax audio dev=Total max deviation for bandwidth system.
example 350Hz max dev CTCSS+2.100khz audio=2.45khz max close enough to CB bandwidth limits.

Id thought id share this information for others planning CB ROIP gateways,as it is something you may come across,so also use known correct radio sources when setting up audio levels,if its new Multi-Norm CB radio radios ,well you should be bang on the money as most are set up right from factory (assuming your using a Modern legal multi-norm cb base as a gateway)
Other kit like ham HF,or USA export radios could present "issues"in some case or require switching to NFM mode.
A radio test-set or fm deviation monitor can help in most cases to check any suspect equipment.

Not a lot of technical info on this subject so posted here,hope that helps,as we experienced these "Issues"on tests.

Currently the test gateway is running via Zello and so far all's looking well but further system improvements in redundancy systems will be add\improved as time goes by to further improve reliability.
And until we happy to make it fully\semi open system.
CTCSS will probable be one of the upgrades at some point ,including "meshed linked CB gateways "to extend ranges.
Keep you posted.

Merry Christmas All

Rob 73's

Posts: 61
Joined: 19 Jan 2012, 14:13

Re: CB RoIP?

Post by rpcomms » 08 Mar 2020, 03:04

Little update on ROIP

work progression on new Radio Interface Card coming on well as we update improved features to schematics.
tests done on CB work,but showed up vunarbilities or roip in demo testing system
one being loss on internet connection-abackup extra router maybe required to improved realiability
and brown out or loss of Ac power onsite-EXtra backup AC\DC sources need to added into gateway system
Use of CTCSS is vital when "meshworklinking" base gateways on a cb or pmr UHF system
Abackup system should ALL fail to connect,this has been addressed and being worked on toensure,the gateway part still can function on a local traffic basis(non roip mode)
Voice encryption is another feature for "secure private systems"ie paying groups to sub costs of system or for some users requiring a little privacy than open system network

these are being addressed one by one

biggest crux is lack of support from CB manufacteurs to push ROIP projects-like a dedicated base CB base module unit built specifc with hardware interfacing in mind,higher duty cycles,CTCSS etc
Getting a suiatable robust CB mobile unit that meets my specifications in roipgateway use and interfacing

Yes I could hack old cb to do the job,but i require new uptodate cb radios with interfacing,CTCSS simplex and CTCSS semi duplex operation (most cb will one dosingle TX\RX tone not split tones)
and yes type approved with having to hack them isthe real problem herefor 27mhz,im currentlylooking at possible solutions.

Meshed base gateway testing proved it can work very well both 27mhz for long range Line of sight and UHF usedfor short local comms

Cost is also another issue
running it and system redundancy and reliability are key to getting 100% rugged realibability 24/7 yearly usage ,anyone can build a roip gateway,BUT get realiability and robustness is another thing and that can cost is something we found on demo tests.

Each base gateway must have a certain level of redundancy built into unit,NOT just he radio,ariel systems,power systems,routers inc back up routers,low cosumption PC ,sim cards,etc etc, thats all got to be paid for by some one to get a good success rate.

Technically there is NO real issue of getting ROIP that cannot be fixed and it works,my concern is for CBbeing a open system
abuse of the system (from test demo conducted)were a problem sometimes,most CB users respected the gateway roip demo,but as usual some wanted to abuse it,why i feel amore locked down system maybe better approach with a paying group to help towards maitaining the system and gateways to ensure a good standard of site installations and equipment installed meets good engineering practise levels,instead of lashed up roip systems of varing standards levels.
Then only keen users who really want roip with maintain better radio prodcedure and not abuse it,compare if its free for all roip system
we have found other methods of controlling abuser on ROIP system

lack of CTCSS control access was another issue on 27mhz which can be addressed for gateway mode,but some radios do not support split CTCSS tones for the Gateway "Fallback Mode" unfortually which from testing I feel vital to have .
neor two cb mfrs I have approached (NOT Giving names outs)have got it and understand it and will hopefully suport it in next gen CB radios 2020+

WE looked at dtmf ID accessing ,1750hztone burst etc etc but after trail testing ,CTCSS made best sense on FM and hands down best method.

Optimised ariel installations are also key in tests conducted on 27mhz for "Line of sight" gateway testing.
Being that most sights for base roip gateways will be in most cases not ideal places like Urban,Low sea level,surrounded by hills and most gateway roip users could not affored a hilltop site location fees,ariel type,height and feeder quality systems become more relevent,as ROIP gateways are specifically NOT designed for DXing!
DX ARIELS and low level mounted ariels are NOT the way to get best results,as this really is line of sight

So you must design your roip system based on optimising LOS working and terrain surroundings we have that data now
to get best performance ( in tests a 1/4GP and 1/2 GPwave peformed best when mounted 50ft asl from ground in enclosed urban\hills (use high angle radiation pattern)surrounding and a 5/8 GP when located at very high ASL having a lower angle radiation pattern),this is also where mesh linking the base gateways come together as each site will generally not be in ideal conditions.
And as stated a hilltop site logistics\cost very high on a private site,I think this is one of the main issues logistics
most wont or could not afford the high fees of maitaining this type of system in most cases.
Unless deep pockets or leave on a large hill!
most dont,so tookthe view worst case locations and get around it be linking bases together to get a meshed system to get te coverage area needed.

typical foot print of around 20-30+ miles on average depending on surroundings or more was the average based on min usable signal strengths of S4,pointless just staic background noise coming through on FM transmissions.
Some sites in tests provided much longer ranges 50miles+
this why "mesh linking" the base roip gateways proved a better way to fill the empty gaps your local gateway cannot cover
Tests have been conducted and it works very well and not to hard to do once you know the basics.

Like most of the projects takes time and money to do them right
If I can get more funding options I can speedup the process quicker,we only a little R&D team at the moment but are making progression and ironing out a lot of system bugs\hardware issues

A univeral radio interface card I am also working one to help ease connection of radios for base gateway uses.
Im unsure at this point if this willbe released or part of a package setup as a whole yet,too early to say and also depends on responses from cb radio mfrs too in support CTCSS and CTCSS semi duplex and addingthe additional function pins to access radios busy and fixed Audio levels and GPIO TTL channel change control of memory channels (with alpha text)stored in radio for Fallback mode option
I have retro fitted UK cb radios as a test units to see if can be done and yes it can as a very basic roip gateway,BUT its not for non electronic people to attempt or just a plug and play thing,its pretty specifc,plus test gear required and right tools.
The current hobby gateways Ive seen so far I feel are not upto good standards for robustness,realiability,system redundancy for a 24/7 service as a whole ,not all but most are best lash ups or homebrew,Not knocking it but commercially we need to step up the standard levels to make the service reliable and practical.

The other issue of CB ROIP meshed gateways systems is demand by CB\PMR users?
the demo tests over christmas did show a promising demands\responses ,but how much would you pay or donate to a CB roip system to keep it running 24/7 yearly ?

OR would CB users prefer to buy a complete roip base system and installation done?

oH we also tests phones,ipads and kindle fire tablets linked into the roip system and they worked a treat with radios!
That i thought was partly the missing link (very cool),including the base linking from city to city area.

CTCSS also help in prevent the dreaded QRM issues when driving around Noisey RFI shops,helping keeping that squelch muted!

Another advantage using a ROIP CB gateway shows modern CB handhelds became a lot more practical as well in tests conducted.
unfort at the moment CTCSS is not used until new units like the GPE Randy III become available to do further CTCSS CBHT trails.

Unsure how CB users would respond to getting CTCSS activated CB radios either ,took a while for PMR446 users to catch onto benifits of CTCSS use.
Something maybe TM1 users like to discuss a standard CTCSS CB Tone codes like PMR446
ie CB UK CH19-19 or ch9-9 tones
gateways tones
Voice security on "closed system roip cb"??
Open ROIP systems Good Idea or Bad idea (i have my own personal views on this)for CB user?
DIY or packaged ROIP systems?
Tech Support?
System costs of a base gateway system including all the trimmings and ariel systems?

I would be interested in any sensible responses from TM users interested in CB\PMR446 gateways and meshed gateway systems and User features for the mobile and handportable kit for ROIP use
to help get some feedback.

Icannot release videos or detailed techincal info on public release for certain reasons,so please dont ask,some within my contact circles have seen parts,concepts and demo vids done and are in the know,currently this is all R&D at the moment,I can answer certain generally techinical questions if CB ROIP is your thing or way see Personal radio move in this direction and adds another additional tool in the box for Users.

ROIP systems wont replace ssb,dxing,direct simplex normal cb (non ctcss),so lets not go there,the idea is to give Users additional functionality on top of what you have way already,a wayto link IT kit like phones,tablets,pc into radio adding flexability,plus a way to extend the range coverage reliable day to day communications uses by interlinking base gateways like a web radio network
is the way I see CB ROIP used for personal communications assuming there is enough demand,it may change the way cb is used as well openning up other possibilties you could not do before?

work is still ongoing but moving forward and will post from time to time progression,currently for a cb mobile ROIP unit Ive hit a issue im working on for a base unit but until it can meet my specifics delays are a problem,but other solutions to test system are being used ,modified to help keep things moving forward in testings system side of things.
keep you posted ;)

Kind regards


Posts: 72
Joined: 23 Nov 2017, 20:14
Call Sign: 26MB04
Location: Democratic Peoples Republic of Devon

Re: CB RoIP?

Post by 26mb04 » 08 Mar 2020, 22:58

I remember looking into the apt_rpt (asterisk) pre-made PCI radio interface cards a while ago but they were a bit more pricey than I would have liked, given that I know nothing about it. There's a good presentation on similar problems with an AllStar system design, it's sort-of in the same vein:

https://www.n4hsv.net/assets/asterisk_a ... tation.pdf

A proper radio interface card is definitely something I would like to get my hands on, but they are really expensive and (unless you want DTMF) they still rely on having PTT/COS lines available on the rig. Until they get cheap, self-build is still the way to go for me.

CTCSS is good because it's constant, unlike a DTMF/Selcall burst which might be missed by the gateway. In such cases the whole tx would be ignored, rather than a transient dropout with CTCSS. It's also universal, whereas DTMF/other Selcall limits you to rigs that support it.

From my end, it's basically down to price. I'm happy to build stuff myself (and learn about it!) if it keeps the cost down, but others will want a turnkey solution they can plug in. This probably adds to the cost because the components need to last, as:

a) It'll be left on forever, get buried in junk, forgotten about;
b) the user probably won't know how to replace the caps etc;
c) it needs to NOT make fire, at any point, ever.

Currently my system uses either Android handsets (Zello), or bog-standard 446 with CTCSS. I was going to use a non-standard CTCSS tone for testing purposes, but there's no point as my location ensures the total RF range is about 200m and there is NOBODY else around. The handhelds probably tx further than the base does. For a while I had a second Zello PC instance with timed announcements for ID, low battery, etc. but that got really annoying, fast.

I have yet to interface to CB, mainly because I don't have the antenna space here anymore.

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