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  1. rfeng1

    Hand-held logarithmic antenna needed

    Hi, I would appreciate pointing me to a company / website with hand-held logarithmic antennas, for frequency range ~800 MHz to ~3 GHz. I have seen one, on the Internet, looking like a hand-gun in a black plastic, but I can not find it anymore. Also, I need non-metal tripods. Regards, RFeng1
  2. rfeng1

    Logarithmic handheld antenna needed

    Hi, I would appreciate pointing me to a company / website with hand-held logarithmic antennas, for frequency range ~800 MHz to ~3 GHz. I have seen one, on the Internet, looking like a hand-gun in a black plastic, but I can not find it anymore. Also, I need non-metal tripods. Regards, RFeng1
  3. rfeng1

    FCC Part 15.249

    Hi Zappedagain, Operating below 50 mV/m allows fixed carrier (at a chosen frequency), with "old" FM-like modulation (FM, FSK, PSK, ..., also AM, OOK, ...). To generate 500 mV/m a spread spectrum is needed, complicating the transmit/receive circuit. The spread spectrum usually is FHSS or DSSS...
  4. rfeng1

    FCC Part 15.249

    Hi, I would appreciate helping me with interpretation of the FCC Part 15.249 regulations. Section 249 allows for low power (EM field less than 50 mV/m) devices to operate with a fixed carrier - no spread spectrum. That section points specifically to “fixed” entities. So, the question is … Is a...
  5. rfeng1

    Dipole-coaxial antenna at 915 MHz

    Hi, Thanks to all, for your feedback on my question. I think, the more complex coaxial dipole is built, instead of 1/4 wave one, to avoid large ground plane, as some RF modem enclosures are quite small, and not a plane at all. The gain at 0 dBi is surprising. I will test may antennas soon, so...
  6. rfeng1

    Dipole-coaxial antenna at 915 MHz

    Hi, I see a number of 915 MHz radiocomm systems with a dipole antenna, being fed through one arm of the dipole - coax cable run through a brass pipe, with shield solderd to the pipe (in the middle of the antenna) and the central wire extanding about 1/4 vave length. Actually, most antennas have...

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