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dgrayone

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Posts posted by dgrayone

  1. I think I cooked my A/V Transmitter

    in Service Manuals

    Posted

    Unfortunately I dont have a schematic as these where purchased RETAIL fully constructed.

    They are BADA 1W 2.4GHz A\V Transmitter receiver.

    I have searched everywhere for even a vague reference to them on the internet but alass I couldn't find them.

    I purchased them off EBAY.

    The only markings on them are 223, BAHH (five pin thin in the middle) then 473. next along is the B1206 which heats up significantly.

    223 measures 8 - 9v
    473 measures 0.1 - 0.2v

    Not sure if this helps.

    I'm throwing a bit more wood on the fire to keep the flames high!  ;D

  2. I think I cooked my A/V Transmitter

    in Service Manuals

    Posted

    Well I broke something!

    A 2.4 GHz A\V Transmitter (underside photo attached)

    I inadvertently plugged a power supply that had its polarity reversed compared to what this device was expecting.

    POOOOF, small stream of smoke and then nothing.

    I think I cooked a circuit.  I have labelled as best I can the picture with the items that go to an extreme temperature when the power is applied. (9V DC 300ma)

    Is anyone able to assist me in diagnosing what I have cooked? How to repair?

    All flaming that I am an idiot for doing this is also expected, but this is how you learn not to do these things.

    Thanks for anything constructive.

    David

    post-23807-14279143129303_thumb.jpg

  5. FM Micromitter only transmitting 8M

    in Electronic Projects Design/Ideas

    Posted

    Audioguru,

    Thanks for the INFO,

    I am using a 9v DC Power Supply that actually measures 13.3v.  I don't want to use a battery as I need this to be broadcasting for 9 days.

    I will take some further Measurements to try to determine why my voltage loss is occuring.

    As far as the attenuator is concerned, if I remove the resistors one at a time will this gradually increase my broadcast range? eg remove resistor, gain 10M transmission distance.

    I also found that by feeding my input through my mixer/amp I was able to increase my transmission distance out to about 12M.

    As far as my antenna is concerned should I just use a single strand of wire approx 84.5cm long (I beleive this is the right length for 88.7Mhz) or should I use a different type of antenna? eg dipole

    If I should use a dipole how should I attach it to the board? (which connection points should I use?)

    Thanks for your help thus far.

    David

  7. FM Micromitter only transmitting 8M

    in Electronic Projects Design/Ideas

    Posted

    Hi all,

    I'm new here.
    I have just assembled a FM Micromitter (Miniature FM transmitter).

    http://www.siliconchip.com.au/cms/A_102010/article.html

    Construction went well with very few re soldered points (put a couple of things in the wrong way round, but hey I'm learning).

    When I went to do the testing and adjustment it says that I should be reading 5v between TP GND and pin 8 of IC1 but I only get a reading of 2.5v.

    Can anyone tell me why this might be and what the consequences of this might be.

    It DOES transmitt (I am currently transmitting on 88.9) but I loose the signal after approx 8M from the antenna.  Is this related to my drop it voltage measured against what it should be?

    Should I trim my antenna to a specific length?

    Any comments or suggestions would be much appreciated.

    Regards

    David ???

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