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madhak

Member Since: May 1, 2011

Country: Canada

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I’m a MAD scientist and EE interested in Virtuality, Robotic, Electronic, Programming, Networking and Forensic…

Please check out my project blog at madhak.com

  • Tutorial - SMA Antenna Connectors | about 2 years ago

    Most connector are impedance matched for their application, even if they are not, the effect is negligible for most amateur application unless you daisy chain a lot of them. An important factor is the RF losses which is caused by the weak electrical property of the contact itself, Gold, Silver and Browse if frequently used to improve the electrical property of the contact.

    The principal factor that will affect your transmission quality and range are;

    -Cable length to the antenna (keep it short)

    -Poor quality connector and presence of corrosion between contact

    -High amount of RF noise (Use a spectrum analyser to determine the less occupied frequency)

    -High amount of EMI noise (Make sure the current going to your radio is clean, use filters or separate power supply for motor and radio, learn how to use torroid and shield your radio equipment’s)

    -Harmonic, If your setup use more than 1 radio on different band you will need low pass filter on the lowest band radio TX to avoid harmonic saturation on the highest band radio RX

    -Polarization, both TX and RX need matched polarization (not talking about RP-SMA vs SMA, read light or wave polarization)

    -Antenna gain, center frequency, bandwidth, radiation patern…

    -Diversity radio (2 radio can complement them-self on different frequency, a simple circuit that monitor the RSSI can switch to the best feed automatically)

    With these in mind, I made a RC car with video feedback that can go several miles in a dense urban area without exceeding the FCC ERI limit on 433, 900 and 2400 ISM bands…

    Good luck

  • Product PRT-11475 | about 2 years ago

    Are they water proof or water resist? Suitable for outdoor use?

  • Product WRL-00155 | about 2 years ago

    Check Flytron product, they have 7W Amplifier for that frequency!

  • Product WRL-10573 | about 2 years ago

    Can this be used with a Uart port on Arduino or do I need a USB connection?

  • Product COM-11218 | about 2 years ago

    This doesn’t generate enough Amp to produce any significant amount of heat, use a Microwave oven transformer instead (Danger Danger Danger!)

  • Product COM-10234 | about 2 years ago

    On the side close to the metal nut (it touch the metal nut)

  • Product COM-11218 | about 2 years ago

    Yeah this is definitely too dangerous, I tried it and will never touch it again… I was somehow thinking this was similar to BBQ igniter (harmless and fun to shok people with), but this is to make tazer gun… Btw, my idea was to protect the drone while it was moving in the neighborhood and electro-shock activated remotely only if someone pick it up but i’ll find something less powerful, maybe a strident noise like they use in ship to repel pirate hehe, (product idea SF!!)

  • Product SEN-10724 | about 2 years ago

    I bought a SEN-10724 about a year ago, are the chip all the same on this one?

    thanks

  • Product SEN-10724 | about 2 years ago

    here’s my solution to multiple i2c with same address: CD74HC4067 or equivalent hi speed bi-directional mux/demux here

    You just need to MUX the SDA, SCL can be shared, pull all unused MUX selector pin LOW, you can even cascade the MUX’s and get several i2c, Serial ports and IO with this technique

  • Product SEN-10724 | about 2 years ago

    I know this an old post and you most likely found a solution but here’s my solution to multiple i2c with same address: CD74HC4067 or equivalent hi speed bi-directional mux/demux

No public wish lists :(