the Process of BUILDING an Amateur Radio CAR!

Discussion in 'Ham Radio Discussions' started by WA6MHZ, Jun 18, 2016.

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  1. KI6LZ

    KI6LZ Ham Member QRZ Page

    These new car systems are too smart for us. Suggest you get code to figure out how the electrical system works.
  2. AC8UN

    AC8UN Ham Member QRZ Page

    Sir I agree completely with your viewpoint, I am just suggesting that advising Pat is a waste of keystrokes:D
    WG7X and N2EY like this.
  3. WA6MHZ

    WA6MHZ Subscriber QRZ Page

    Waiting till the local expert radio installer has time to fit me into his schedule. Till then we are running off power from the fuse box. (NO HF radio operation till then)

    Any way, I am redesigning the voltage/ current monitoring system. Now there will be a 4 1/2 digit display and a 3 digit for the current instead of the cheap Chinese dual display. That still works but needs upgrading. so now the current will be read through the PLUS leg of the supplied power with the 20A shunt.
    Here is what we got in from Ebay
    so the Voltage will be independent of the current meter. I need to determne how to use the 6 wire cable as I did before and use the same circuit I used in the ULTIMATE GO KIT for WINLINK. When the car powers up it will activate a relay which turns on the meters. Once again, I will have 8 AA batteries running the isolated power for the Ammeter. The black box will house those and the shunt. I need to go into the engine compartment and find a place to attach the ground for the radio system as I think using the negative battery terminal had something to do with the failure. Once that was torn out, the Alternator system worked fine. So there must be a sensor unit in the battery ground leg on its way to the chassis. Still need to replace the 40A resetable Circuit breaker with a 30A fuse. That should be bulletproof.
  4. WZ7U

    WZ7U Ham Member QRZ Page

    Best thing I've heard all thread.
    Had a feeling that was the problem. Never underestimate the shenanigans of an automotive electrical engineer!
    Directly to the block or even the cylinder head if necessary, away from any other electrical grounds or other sensors etc, would be my advice. Hell, ask the expert when you see him next. Exactly where that is, I don't know since I don't have a Flex to inspect for you.

    You're on the right path now Pat. Waiting for it to be right only builds anticipation, leading to higher levels of enjoyment.

    (some smart guy told me that once)
  5. AF6LJ

    AF6LJ Ham Member QRZ Page

    Snuck one in on me...
    I hadn't thought about the radio ground on the battery terminal being the problem until you brought it up.
    You may end up going to one of the body bolts or the Alternator mounting bolt.
    Just be careful how you route that lead.
  6. AA7QQ

    AA7QQ Ham Member QRZ Page

    K0BG writes a great deal about the battery monitoring systems. You may want to confer with him....

  7. WA6MHZ

    WA6MHZ Subscriber QRZ Page

    Today I got alot done.
    First was to redo the readout for the DCV/DCA. I modded the chassis from the original cheep Chinese one to
    TWO Cheep Chinese ones. The nibbler made the hole bigger, but I still had to JB WELD it into place. IMG_7062a.jpg
    They just barely fit, so no room for a CAT RANCH ELECTRONICS LABEL except on the top.
    Will hafta make another as the old label ripped removing it.
    Gotta give CAT RANCH ELECTRONICS the credit for the mod
    The big issue with the mod is the isolated battery supply.
    A relay keys when DC Power is applied connecting the 2 pairs of 4 cell AA packs inside a separate battery case.
    Once again the under dash is getting mighty crowded.
    I bought some 4 cell holders, 8 AA cells and some connectors at Frys, and installed them as soon as I got back.
    now I can see the battery voltage right to the MV and the current to .1A with 50A full scale.
    Works great except on HF where the display doesn't respond. It seems the RF still gets in, so I will hafta buy some clamp on RF Chokes.
    That operational, I went after the MAIN Battery supply again. THIS TIME I routed the negative lead to a chassis connection as the previous system bypassed the current sensor on the battery negative lead.
    now the ground is connected to the car frame.
    I installed it all again and it seems to work, SO FAR!!!!
    Crossing my fingers that there are no more alternator problems

    Attached Files:

  8. AF6LJ

    AF6LJ Ham Member QRZ Page

    Yery cool..
  9. WA6MHZ

    WA6MHZ Subscriber QRZ Page

    So I think the problems were all caused by connecting the DC power minus lead to the negative side of the battery, as it works flawlessly now. I notice the voltage is about 14.2V now except when transmitting. Thats why U see 13.9V on the display. There is some lead loss, but I can live with13.9V
    Its when it goes down to 12V that problems occur, mostly on HF.
    No need at this time for a battery booster. but should I need one, I have a MFJ ready to go.
    AF6LJ likes this.
  10. AF6LJ

    AF6LJ Ham Member QRZ Page

    Good to see all is working

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