SR10 - Information on how to make your own cable.

Please refer to SR10 cable specifications with all pins/contacts labeled as described below. However, please keep in mind that whenever customer customize anything on their own especially electrical connection, we are not liable for any damage due to it nor will we guarantee normal operation. With that said, it seems like we might offer DIY kit for custom wiring for SR10’s two-way radio connection. (Pin map table is being modified.)

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20 Comments

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    Oztourer

    I downloaded your pinout diagram. Can you tell what 'NC' means? I woiuld wire NC to NC, but I am concerned that it could mean 'Not Connected'.

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    Oztourer

    Another question on making my own cable: your documentation on the SR10 states that is has a mini-DIN connector but the pin arrangement does not correspond to anything known as mini-DIN on Wikipedia - http://en.wikipedia.org/wiki/Mini-DIN_connector. Can you be more specific on the type of connector required?

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    Dan Kim

    @Oztourer

    NC refers  to "Not Connected" which means it is not used.

    We recommend you to use our provided DIN cable connector. DIN connector on our default cable has unique outer grooves for proper connection to SR10. Additionally, default cable connector is equipped with outer cover to provide protection from the environment.

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    Oztourer

    I checked your products page and you do not list the connector as an accessory, only complete leads. No connector is included with the SR10. As none of your leads fit my radio (Uniden UH073SX), where/how can I purchase a connector?

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    Dan Kim

    I was recommending any of SR10's default cables and splitting the wires within it to use default SR10 din connector.

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    Donald Moe

    Today (4/14/12) I noticed that your product section finally lists the SC-A0116 cable as an accessory for the SR-10. However, it is not yet available for purchase on your store website. How soon can I order one?  

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    Dan Kim

    @Donald

    We do not have firm date when SC-A0116 will be available for purchase. But, listing of product on our website means it will be soon. Once the item is ready for sales, we will list the item within our online store.

     

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    Kd8fqm

    The cable (SC-A0116) apparently is now available (Dec 2013) as I just ordered and received one. However, there is no included documentation showing the pin-out. I have the chart showing pin connections of all the pre-wired connectors, but nothing showing the connections for the bare wire cable.

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    Sena - D

    Kd8fqm

    Please see attached pin out diagram.

    Dean




    SC-A0116_pins.jpg
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    Herman W. van Beek

    Dean,

    Am using the SC-A0116 cable to build a ground loop isolated (GLI) connection between a bike-powered SR10 and a bike-powered Kenwood TK3101 radio.  Please confirm and/or supply additional electrical information about the PTT (pin 4) connection looking into the SR10.

    1. What is the nominal resistance we should expect between Pin 4 and Pin 6 when PTT button is pressed?  I measured about 7 MegOhms when open and 450 Ohms when PTT is pressed.

    2. What is maximum current that can be sunk through that connection?  Can it handle 14 volts/450 ohms ~ 31 ma?

    3. Has anyone already created such a GLI connection and is willing to share their implementation? If not, I'll be happy to share mine once it is working.

    Thanks,
    Herman

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    Herman W. van Beek

    Well, cobbled together a simple circuit that provides ground loop isolation between the Sena SR10 and the Kenwood TK3101 FRS/GMRS radio.  Both units are bike-powered.

    Parts came from Radio Shack, Mouser and Fry's.  The schematic and pictures of the finished product are attached.

    Note: you can use an optical isolator, e.g., NTE3042, instead of the reed relay shown in the schematic.

    Herman




    Sena_SR10_GLI_Kenwood_TK3101_03.pdf
    IMG_1473.JPG
    IMG_1476.JPG
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    Lars Janssen

    Hi Herman,

    your circuit looks great. Do you know, what happens with all the connected PINs in the following:

    PTT on SR10 pressed

    PTT on SR10 released

    I wonder, wether the MIC pin and GND are treated the same way as the PTT at a normal radio? Else, do you know whether there is already a built-in resistor for the PTT function? 

    I managed to get one of the suitable HIROSE plugs and will build my own adaptor cable... saying that, I would like to use the VCC as well.. any idea whether it is +5V or +12V?

     

    Many thanks,

    Lars

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    Lars Janssen

    Hi Herman,

    your circuit looks great. Do you know, what happens with all the connected PINs in the following:

    PTT on SR10 pressed

    PTT on SR10 released

    I wonder, wether the MIC pin and GND are treated the same way as the PTT at a normal radio? Else, do you know whether there is already a built-in resistor for the PTT function? 

    I managed to get one of the suitable HIROSE plugs and will build my own adaptor cable... saying that, I would like to use the VCC as well.. any idea whether it is +5V or +12V?

     

    Many thanks,

    Lars

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    Herman W. van Beek

    Lars,

    Back to the drawing board!  After building the interface and testing it on the bike I was continuing to encounter noise during transmission.  Finally pulled circuitry off bike and built a test bench inside the house where I could continue debugging the system.  Let me provide a little background and then I'll try to answer your questions.

    Have been experiencing all types of reception and transmission problems with my SR10. Submitted a support request to Sena and talked with a tech support person last week who recommended that I replace my SR10 with a newer unit.  The first four numbers after the "SR10" in the serial number designate when it was built: mine was 1110 or October 2011.  My FRS/GMRS radio is a dependable Kenwood TK3101.  Built a voltage regulator for it so that it can be bike-powered.  Also built a special cable with four diodes in series to power the SR10 with bike power.  That is the circuitry inside Sena's 12 volt cigarette charger type bike-powered kit mentioned in section 4.4 of the user manual.

    The circuit, as shown in the schematic shown in my previous posting, works to the extent that I can hear transmissions from other radios and I can transmit with it via a bike-powered TK3101.  The only problem is that the transmission has a noticeable buzz on it - the very thing the groundloop isolation circuit was supposed to solve!

    Now to your questions...

    When PTT is pressed, it forward biases the transistor because the resistance between PTT and GND changes from almost an open circuit to a few K ohms.  The reed relay has a resistance of 1035 ohms so we have about 12 ma flowing through the coil and it closes the switch.  It opens back up when you release the PTT switch.  My next mod of the circuit will be to add some series resistance to see if that eliminates the buzzing sound.  Replacing the reed relay with an optical isolator may also solve the problem.

    You can check with Google that most "normal radios" short PTT to GND in order to complete the MIC circuit.  Kenwood's approach is slightly different and I guess I need to study that schematic again!

    You can charge the lithium polymer battery with a USB connection (+5 volts) or with the special +9-10 volt setup they call the bike-powered charger.  The latter will charge much quicker than the former.  

    Herman 

     

     

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    Lars Janssen

    Many thanks Herman, thats very usefull... Do you know what this Vcc-PIN is for? I would think you could power the SENA SR10 with an external source, but havent found any details on that. At least this PIN doesnt show any activity, checking with my meter...

    Dont you htink your noise is coming from using the same ground for MIC and speaker on the kenwood side? Are you sure, that this doesnt have a bridged amplifier and there for you need to seperate MIC-GND and SPK-GND?

    At least some of the PMR devices I know using a bridged amplifier for better audio results...

     

    Cheers

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    Lars Janssen

    And btw, sorry to add that, how would you integrate the optical isolator? do you have an example circuit?

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    Herman W. van Beek

    Lars,

    You may be correct.  However can not test your assumption because I just sent my SR10 back for repair/replacement.  Am not familiar with the "Vcc-PIN" you mention in previous post. 

    When my unit returns, I will certainly test this out.  Attached please find an updated schematic with the extra ground connection removed, an optical isolator replacing the reed switch, and the home-made power supply for the SR10.

    Cheers,

    Herman

     




    Sena_SR10_GLI_Kenwood_TK3101_04.pdf
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    Rbser

    Here is the CN4 Connector layout INSIDE the SR10... I found an empty land at the PTT section on the board.... can a chip resistor be added here to change the PTT resistance signal level??




    IMGP5214.JPG
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    Melissa Hussel

    Herman did you ever get this working? I too am experiencing noise when I attempt to transmit via the SR10 to my Yaesu FTM10r. Thanks!

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    Herman W. van Beek

    Melissa,

    Sorry for the delayed response. Was in New Mexico avoiding the recent heavy rains in the DFW area...  

    The short answer to your question is "I don't know."  Reason is that I received the new SR10 from Sena while working on modifying the circuit board to incorporate Lars' comment (see the _4 schematic version.) The new SR10 had a build date of 1407 (July 2014) compared to the original unit's build date of 1110 (October 2011).  Hooked the new SR10 to my system with standard Sena Kenwood cable and it worked without a noise problem! The SR10 is powered by the 4-diode supply line shown in the _4 schematic and the TK3101 Kenwood FRS radio is powered by a simple voltage regulator, both sourced by the bike's switched power supply.   

    Herman

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