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VHF Repeater system

Discussion in 'General Electronics Discussion' started by LightShow, Feb 5, 2017.

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  1. LightShow

    LightShow

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    Jun 9, 2016
    Hello once again!

    Recently i got put in charge of redesigning an entire vhf repeater setup for an army cadet excercise. (i currently dont have any photos of the old setup SORRY!) the old setup was running on a 10 year old deep cycle battery which had completely lost its charge.. when the old system was first designed it was to keep the battery topped up using a charge regulator and a solar panel so that the repeater could be remotely positioned to send signal further allthough the solar panel was never used and the repeater ended up running off the battery charger!. the old system also didnt have any fuses at all

    so the new system ive designed caters for any situation that the repeater could be put in. we have ordered a new deep cycle battery and solar charge controller aswell as fuses for the charge controller and for the repeater. we would like to be able to literally flick a switch to go from using the battery to using a 12v power supply so that if the repeater does end up getting used at the base its not running off of the battery. could someone please advise the best way to connect this up / what components i need to be able to run the setup like this

    The repeater is a "kenwood tkr751 repeater"

    regards, Lightshow
     
  2. donkey

    donkey

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    Feb 26, 2011
    ok so the question is how to select from 2 power sources?
    you can use a double throw switch. on the back will be 3 terminals or a factor thereof.
    find the contact that is common plug that to your vhf receiver, then 1 to the battery and one to the power supply

    battery ------>
    \________
    power supply----->

    the symbol above shows a simple diagram for you. you can use a dpdt and put both + and _ on the switch as long as they match up

    good luck
     
    LightShow likes this.
  3. LightShow

    LightShow

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    Jun 9, 2016
    Thankyou for the response!
    yes that is basically what i was thinking i just wasnt sure...
    the wiring for the repeater is quite thick and bulky would there be a slightly more industrial version of the double throw switch??
     
  4. LightShow

    LightShow

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    Jun 9, 2016
    would there be a way to check battery voltage from a remote location? just a side thought..
     
  5. davenn

    davenn Moderator

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    Sep 5, 2009
    that's and other info can and is often sent as a burst of data out on the repeater output freq. say once an hour. The repeater admin's can receive this and decode it
     
  6. LightShow

    LightShow

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    Jun 9, 2016
    basically i admin the repeater... how would i go about getting this data?
     
  7. davenn

    davenn Moderator

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    sensors, microprocessor, interface to the repeater transmitter
     
  8. LightShow

    LightShow

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    Jun 9, 2016
    elaborate if you could??
     
  9. davenn

    davenn Moderator

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    I cant .... do some googling ;)
     
  10. LightShow

    LightShow

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    Jun 9, 2016
    will do.
     
  11. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    May 8, 2012
    You can use the ADC input of a PIC to measure the battery voltage. This data can be outputted by the PIC in Serial Packets and transmitted via FSK.

    You can even have the PIC output your battery data as Morse Code. Something like this...

    Chris
    upload_2017-2-6_20-17-38.png
     
    davenn likes this.
  12. LightShow

    LightShow

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    Jun 9, 2016
    ahhh Great!!
    thankyou..
    would there be a way to recieve the data in number form? like on a screen? incase the operator doesnt have knowledge of morse
     
  13. davenn

    davenn Moderator

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    decode the morse with a PIC and display on a one or two line LCD
     
  14. LightShow

    LightShow

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    Jun 9, 2016
    ahh gotcha okay the whole battery voltage thing will probably be implemented by sometime next year.. for now we are going for simplicity charge controller solar panel etc.

    something that i am a little curious about though is how many fuses i should implement whether having seperate ones for the power supply and the battery or just having one on the output to the repeater
     
  15. davenn

    davenn Moderator

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    if you didn't want to go the PIC decode way ... the Morse only needs to be simple

    HI = .... .. = high voltage
    OK = --- -.- = good voltage
    LO = .-.. --- = low voltage

    that wouldn't be too difficult to learn and remember ;)
    there's really no need to monitor the exact voltage

    Dave
     
  16. LightShow

    LightShow

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    Jun 9, 2016
    yeah that will probably ill look into it next year when the training starts up again :p
     
  17. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    Actually, I suggested sending Morse code because too many hams have forgotten or for that matter, never learned to copy it in the first place. I thought it would be good for them to hear it on a regular basis. :)

    On that note I'm curious. Doesn't your repeater transmit its call sign with Morse code periodically?

    Chris
     
  18. davenn

    davenn Moderator

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    if it is an amateur one ... it is supposed to, but the OP hasn't specified that .... only commented about some cadet thing ... what ever the heck that is ??
     
  19. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    Yeah, I forgot that and as you mention I think we'd all like to know "what ever the heck that is". :confused:
    LightShow hails from your neck of the woods. I sincerely doubt that Australia lets anyone who wants to put a repeater on the air do so unregulated.
    Chris
     
  20. davenn

    davenn Moderator

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    Sep 5, 2009
    very very true .... strongly regulated
     
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