update: Testing in progress as of sept,14,2021
Regards to the rules and regulations pertaining to the use of Cross-Band Radio Repeater Systems within the Canadian Amateur Radio Service.
Cross-Band Repeater systems permit radio signals received on one frequency band to be automatically re-transmitted on another frequency band.
Cross-Band Repeaters may be established and operated by persons holding either, the Basic, Basic with Honors, or Advanced, Amateur Radio Operator's Certificate; (provided that such operation does not result in exceeding the frequency limits or the technical parameters authorized by the operator's certificate). (ref: Radiocommunication Regulations, Sec. 44)
Operators not holding the Advanced Certificate are restricted to the use of radio equipment that has been commercially designed, or manufactured for use within the Amateur Radio Service.
The remote control of fixed radio stations is restricted to holders of the Advanced Certificate; therefore a Basic Operator may not make changes to the operating parameters of the station via remote means. (Mobile stations are exempted from this restriction.)
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The “Physical” modification and the use of modified Radio Transmitter Equipment employed within the Canadian Amateur Radio Service may only be performed by operators possessing the ADVANCED Amateur Radio Operator Certificate.
Provided that the equipment has been manufactured for use within a frequency range inclusive of those frequencies assigned to the Canadian Amateur Radio Service and can be configured "Solely" by means of software programming, the programming and use of these devices by an amateur radio operator holding a Basic, or Basic with Honors, certificate is permissible.
Such equipment could be interconnected and operated by a BASIC operator, as a Cross-Band Repeater, provided that there are no internal, physical modifications to the radio equipment, in so doing.
It remains the operator's responsibility to ensure that the operation of their radio station does not exceed the authorized technical parameters or the conditions imposed by their operator certificate, nor cause harmful interference to other radio services.
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Spectrum Management Officer, Eastern and Northern Ontario District, Spectrum Management Operations Branch
Innovation, Science and Economic Development Canada / Government of Canada
The Cross Band repeater system has to comply with all the normal repeater regulations, transmitter time out, control operator must ID every 10 minutes on all frequencies being transmitted on, also require DTMF control to shut the cross band repeater off.
Use a CTCSS tone or DCS code to work the cross band repeater.
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Make sure you're using a frequency that isn't allocated to something else nearby.
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"Check with your local frequency coordinator for frequencies you may use."
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This cross-band repeater has three uses that come to mind with the most likely listed first:
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Extend handheld communications over a greater range for public service events. Activities such as Marathons can cover many miles which would often require regular hilltop repeaters. Having a CBR strategically placed will avoid this and allow you to be self contained in support of public service events.
Practicing using the CBR for these events gives proficiency in its use by all involved. Important for a more serious application at some later date.
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In times of windstorms, floods, earthquakes or other emergencies that cut out normal communications, we often rely on amateur radio repeaters to cover our hilly country side. If an emergency cuts this capability, which it often does, its nice to have a portable backup that can be setup from a vehicle at a strategic location. Even at someones house if they live at a high spot or at the repeater site in the extreme case. Being battery operated means availability of 120 VAC is not a concern. Loss of power or an antenna failure is the usual reason a permanent repeater is down.
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An emergency. realistically, this is the least likely of the three scenario's
TK-760 S.Manual
TK-760 Sales sheet
TK-760g Manual
TK-760g S.Manual
So, at this stage of the project, you may be asking yourself "What about the ID part of the equation?"
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As we ALL know by reading the information above, you MUST have a way to ID the repeater on any frequency the system transmits on.
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Will, i got that all sorted out.. I think.. hehehe Have a look at the drawing below, it shows the circuit on how to build such a device, looks simple enough doesn't it?
Lets look up the price of that ISD1740 recording chip shall we:
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$13.00 plus $5.00 shipping from China? You are kidding right?
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There has to be a cheaper alternative to that price right? Right?
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Will guess what! There is, and much much cheaper!
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My idea is to try this kit with a onboard recording module all ready setup and ready to go!
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At $2.05 and free shipping, you can't go wrong with that price!
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What i will need to build now is the timer circuit, i plan to use to use the same timing circuit as the drawing above!
Will this work? Only one way to find out. The kit has been ordered, now its a waiting game for the kit to show up.
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Until then i will continue to prep the cross band repeater radios and hopefully acquire 2 frequencies from our local frequency coordinator!
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More information regarding this recording module can be found here:
https://components101.com/modules/isd1820-record-and-playback-module
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Stay tuned for further updates!
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As of July,25th,2018, i have contacted our local frequency coordinator for 2 frequencies i may use for this project, it may also appear that there could be no restriction when it comes to asking for additional callsign's for the use of cross-band repeaters because many dual band HT's and mobile's are cross capable and do not share additional callsign requirements.
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" cross band repeaters were exempt from additional license"
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ANYWAYS, i will still continue with the ID and DTMF controller for the cross-band repeater system. At this time i have decided to try a DTMF controller that will trigger a relay which will then disconnect the PTT lines of both radios.
Below is the circuit i am thinking about trying for this part of the DTMF control project:
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While waiting on information regarding Cross-Band repeater operation, i have decided to continue on with the project with regards to the external PTT and AUDIO controller, below is the built circuit in it's unmodified form showing the PTT and AUDIO paths to each radio and the color code used for this section of the project.
With this new project board completed and ready for installation, i decided to install two LED's, one RED the other GREEN, this will show which band is currently transmitting, the voltage to power the LED's will be the 5vdc UM Line voltage from each radio depending which one is transmitting. I figured the 5vdc should be plenty enough to power the LED with a 220ohm resistor is series with each.
Current config - To change later
Setup as it is today, more to build!
So yesterday the new recording device finally arrived in the mail after a 2 month excursion around the world, time to get right back at the Cross band repeater, still got the PTT and DTMF circuits to build and incorporate into the the whole unit, hopefully this contraption will work the way i want it too. Only one way to find out.
Does this voice recorder work?
User Manual:
Time to start building the timing circuit that hopefully control the voice recorder to send it's audio to the mic jack of each radio.
No idea if anyone has EVER attempted what i am doing here with this repeater setup, but what do we have to loose? Not a thing, only gain valuable experience from the adventure. Now isn't that what amateur radio is all about?
Now where is that 6.8maga ohm resistor? LOL
SO! Here we are, finally starting to build the timing circuit using a NE555 timer chip, everything is built and connected correctly.
Of note, and first for me: I used a SMT voltage regular in this circuit! MCC 7805
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Only one thing left to do, connect the battery and see if it works!
After building, testing and powering the unit above, it never worked correctly, really tho, it never worked at all. oh well, nothing ventured nothing gained right? SO, Last evening i tried yet another circuit, this time using a couple of 2n3904's and a 12vdc relay, diagram below. The circuit would in fact turn ON the relay, but the circuit would not turn OFF or reset as it were.
Back to the drawing board YET AGAIN!
Anyways... Let's try yet another timer circuit.. Surely there must be SOMETHING out there that will work the way i want it too.. Geez
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Will this FLIP-FLOP save the day?
You guessed it! It was a FLOP. LOL
Although this FLIP-FLOP was at least trying to work, the timing was much MUCH to fast when it did work, for this circuit to operate every 30 minutes would take a very large capacity electrolytic capacitor. How large? Too large for anything i have right now!
So where do we go from here?
EBAY, Here we come!
Time to give up on building the circuits, enough transistors have been killed. LOL
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I would like to introduce you to our NEW timer controller:
Timing Delay Relay Module DC 12V 20A Cycle Timer LED Digital Dual Display 0-999H
The timer has arrived!
Even with the Canada Post strikes, took little over 1 month to get here!
Introducing the repeater interface controller!
Above "On the right" is a photo of my to-be repeater interface controller, contained inside this box will be the ID and DTMF controller module. The timer will control the PTT of both radios and trigger the Voice ID module. The timer will be set for every 10 minutes "500 seconds" to comply with the regulations, and this will trigger the PTT of both radio's and the voice module by controlling 3 external relays. The trigger time will be set to about 5 seconds, enough time for the voice module to send it's message.
So after removing the device from it's packaging i just have to apply 12vdc to the unit and try it out. I gotta say this is a very nice addition to the shack for various projects. The possibilities are endless!
In the video below i try out the timer device with a few relays, just to see how well it would work. It worked flawless!
After spending a short amount of time messing around, it was time to start building the controller. First thing that had to be built was the relay control board, this board would control the PTT action for the Crossband repeater and also switch in the audio from the Record/playback controller. Of course i also wanted a way to keep an eye on each relay in the circuit, an indicator that would tell me if the relay was working properly. RED LED's fit that need perfectly, these would turn on with the relay. Then i installed YELLOW LED's, these tell me that each relay has power to the circuit. Trouble shooting test points i guess you could call it.
In the video below i try out the timer device wired to the relay control board, also while testing the LED's i have installed to make sure they switch on and off as intended.
Now that i know the relay control board is working the way as intended, now was the time to start mounting the modules, that was easy enough, running the wire harness to the correct points was interesting. No trouble to get lost with wiring if you do not use wire management thru-out. I used wire on the relays of three different colors, i kept the 3 same colored wire on all three relays, i really only need 2 wires to switch PTT, the third wire is left in place for future expansion.
Time too wire it up!
I spent the full day yesterday installing the wire harness, it looked.. so-so, anyways i drilled 2 holes in back of the unit and run two microphone cables thru the opening into the controller to the hookup board. After looking at this for about an hour i decided to rip out the microphone cables and install two 4-pin microphone jacks instead, looks 100% better then before. Below is a before and after photo of how it looked with the microphone cables and the other using just the two microphone 4-pin mic jacks.
Before
AFTER
The microphone connections!
The next part, hooking up the radio's to the 4-pin microphone jacks. The Kenwood TK760 only has 6 pins in which to work with, 2 pins are for PTT control while the other 2 pins are used for microphone audio. Both use ground, but they are NOT a common ground, so do not wire both grounds together.
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Having 6-pin microphone plugs is not very common to my shack, but i did have an old MAXON stock mic handy and it had the 6-pin plug on both ends! You know what happened next don't ya? Yep you guess right, i chopped the cable in half, now i have my microphone cables and plugs for both radios!
Next i had to wire the microphone cables to match the radio, for that i needed to match the 4-pin microphone jacks i now have installed on the controller! The microphone jacks are plain old CB Radio COBRA 4-pin type jacks, nothing fancy here folks!
Here is the wiring codes for the MAXON microphone cable, and the four colors that match the KENWOOD TK-760 mobile radios:
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KENWOOD TK760: MAXON color code:
Pin-1 Not used for this project
Pin-2 PTT Ground connection YELLOW
Pin-3 PTT control WHITE
Pin-4 Microphone ground connection BLACK
Pin-5 Microphone audio GREEN
Pin-6 Not used for this project
Also, i intend to draw up the block diagram of the controller with wire harness, module connections and microphone connections later on, still have a lot to do with this project before i call it completed.
The first official test of the controller
Below is the video i recorded while testing the system with the TK-760.
As with all home-brew prototype gizmos, there is bound to be bugs!
Let's just say i will have a nice little blooper reel to share later on. :-)
Houston, we have a problem!
So, with more testing performed today, i tried turning on the UHF radio while the VHF was sending it's ID, I noticed very quickly that no audio was passed to the VHF radio. So i looked into this rather interesting problem to hopefully figure out what was going on. Only to realize that by turning off the UHF radio the audio passed normally. So i tried diodes and capacitors across the microphone ports on the controller, which made no difference. So i moved onto the very first circuit that was built, and that was the PTT / Audio board that links both the VHF and UHF radio's together. The board was working perfect as it always did, but the ID audio was not passing thru to the VHF. I figured that a ground loop was caused by the controller some how when both radio's are turned on.
So with further investigation i have come to the conclusion that by disconnecting the YELLOW audio wire the VHF would now pass the ID audio to the VHF radio. I also figured since this is happening on VHF that it would also happen on UHF at the same time. So i devised a plan where by disconnecting the yellow wires with a relay while the ID was sent should fix this problem, now to put this theory into actual practice!
While this modification is being performed, just as well install a second relay for the DTMF controller so that it can turn OFF the PTT to both the VHF and UHF mobile radio's!
But that is another story!
Install the new relays
So after pondering this problem for all of 5minutes, i decided the relay has to go in to break connection of both Yellow wires, so here below is both new relays now installed.
Of note, shielded cable used here due to the presence of audio.
Also another relay was added for the DTMF circuit once it is installed.
This modification also required the installation of another 4-pin plug and 5vdc regulator to control the relay voltage and switching of both audio lines.
The photo below shows the overall design of the crossband repeater controller, i have also left enough room for the new DTMF controller once it arrives. Over all, i am pleased and rather proud with this project.
I guess what you all might be thinking now, is how well do it work? Have a look at the video below, i believe the controller is working wonderful!
Below is the sections of each part of the controllers operations, this will also help you understand what each section has been called.
So folks, a little update for you.
Finally managed to place my order for the new DTMF controller, should be here in about a month or so, the DTMF controller features 4 relays that can control 4 different functions depending on the DTMF sequence received. I have also been thinking about a control frequency to send these DTMF codes to the controller, i have decided to send the DTMF commands on a different frequency then what the cross band repeater is receiving and transmitting on. This way i send the codes without interfering with on going QSO's. I will utilize another radio for this such as a cheap scanner or another mobile VHF/UHF radio.
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Below is a photo of the new DTMF controller that i will be using with this system, it will control the repeater in 4 different ways as stated below:
(1) Convert the system to 1-way comms from VHF to UHF only.
(2) Convert the system to 1-way comms from UHF to VHF only.
(3) Disconnect the main DC supply to both radios thus killing the link.
(4) Reserved.
A word of warning to other amateurs within range that may think about messing with the DTMF commands from a remote location:
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(1) The remote control of fixed radio stations is restricted to holders of the Advanced Certificate; therefore a Basic Operator may not make changes to the operating parameters of the station via remote means.
Now that, that is out of the way, i have also went ahead and built 2 new interface cables that connect each radio to the ID / DTMF controller system, the cables that i had first built did not look all that nice considering the amount of time and effort i have put into this project.
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Below is the new radio interface cables that i built today to replace the old original ones that i had built earlier.
Notice the use of regular 4-pin phone style jacks in place of the standard 6 pin that is normally used with the Kenwood TK-760 mobile radios.
This evening i decided to permanently mount the VHF and UHF radio's along with the controller to this piece of board i had kicking around shown below, also reworked the power and interface cables and installed two 12vdc computer fans for each radio to help keep them cool during time of high transmitting times "Not that that will ever happen..LOL". But to be safe and help save the RF power modules i think this is a very good idea.
Below shows the new wire harness that i installed tonight to keep everything nice a tidy, also to help keep any connections from getting faulty due to movement or vibration.
Here is all the hook up cables that connect to the rear of the controller. While building the new harness, i decided to add a plug in DC jack to the back of the controller for power, as it sits right now there are two power studs mounted on back, my intention to the remove both of the binding posts and install just one DC power jack. My buddy Bill has the DC jack that i need to finish this part of the project.
The new DC plug can be seen on the left in this photo.
The wait is over, my 4-channel DTMF controller finally arrived in the mail, now to get the module installed inside the cross-band repeater controller and configure the circuits i plan to control with this device.
Spent pretty much the full weekend installing and incorporating the DTMF controller in the cross-band repeater controller, all in all i think its went rather well.
Today i performed the final touches on the cross-band repeater system. The DTMF controller has been fully incorporated and tested fine. The DTMF module will except mono audio from another receiver. Just need to make sure that the audio input to the DTMF module is not set too high, just enough for the unit to hear the tones and switch the relays normally.
DTMF controlls the following 4 circuits:
(A) Turn ON/OFF TX link from the VHF radio.
(B) Turn ON/OFF TX link from the UHF radio.
(C) Turn ON/OFF FAN #1
(D) Turn ON/OFF FAN #2
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Both relays turned on disconnects both radio links, thus killing the cross-band repeater.
VHF / UHF Bi-directional cross-band repeater. Full DTMF controllable.. Will ID on both bands at the same time every 10minutes regardless if someone is talking or not and has a 3 minute transmitter timeout and CTCSS controlled access. Radios are 100% programmable and settings can be changed when required via PC.
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Took about 4 months to fully construct and finally complete. Time well spent. As a added bonus the controller can be removed and used on a in band repeater if needed.
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Can't ask for any better then that now can ya!.
All the best... and 73. Project completed.
System updates
Current configuration:
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VHF 146.900 RX/TX 233.6hz tone
VHF 443.200 RX/TX 233.6hz tone
KENWOOD TK760 for VHF
KENWOOD TK860 for UHF
Scanner for decoding DTMF commands
Full VHF/UHF ID every 10 minutes
Callsign used for the ID: VO1HMS
ID: VO1HMS Crossband repeater project - Voice
Special thank you:
Since September,11th,2021, VO1TAD and myself have been hard at work tuning up the VHF - UHF Cross band repeater that i had built in 2018.
The system has been online for 4 days between 8am-10pm.
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This system transmits and receives on VHF 146.900mhz, which then cross bands over to UHF on 443.200mhz transmit and receive and vice versa. The tone at the moment is set to 233.6hz CTCSS
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Basically, you transmit on 146.900mhz and your buddy can hear you on 443.200mhz, Your buddy would respond to you on 443.200mhz, and then you will hear them on 146.900mhz!
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This system is known as Bi-Directional, meaning it works both ways!
Testing is continuing over the next few days, while we do our best to make the system sound the best possible over both bands.
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This system has full ID capability on both bands, as well as DTMF control, as well as a 60sec timeout timer.
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This makes the system 100% legal to operate
I am currently in communication with our local frequency coordinator to help us find the best frequencies for this system to operate on, while not causing any interference to other users on either VHF or the UHF band!
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Thanks for the help Thomas, i could not have tuned this system properly without your help.
Preparing the mast and coax for the uhf antenna
tram 1486 antenna all tuned up
tram 1486 installed and ready for action
Further updates to follow as some circuit changes had to be made to the controller.
Stay tuned for more!
