We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Author Topic: 27.255 MHz - RadioShack On-Site Paging System Waveform (Waterfall) Test Video  (Read 461 times)

Offline R4002

  • Moderator
  • DXing Phenomena
  • *****
  • Posts: 2984
    • View Profile
    • R4002 - YouTube Videos
https://www.youtube.com/watch?v=VrtAHDOtVII

It seems that the data transmissions heard on 27.255 MHz (and the other RC channels) during band openings are not from these paging systems...at least not the Radio Shack PG-99 17-6020 or 17-6023 (which is a 4-watt transmitter, and may work on 26.995 MHz instead of 27.255 MHz...not 100% sure there).

Thanks to Chris S. for providing the SDR and the test transmissions from the RadioShack 7 watt paging transmitter pager system (with stock back of set CB radio antenna). 

Unlike the signals noted on 27.255 and 27.195 lately (27.195 only during band openings) - this system transmits a single FSK signal about 500 Hz from center frequency 27255.0 kHz.  Center of the FSK signal is 27.2545 or 27254.5...usually there are two FSK signals - usually about -2.5 kHz or -3 kHz from center frequency and + 2.5 kHz or +3 kHz from center frequency.

« Last Edit: October 20, 2021, 1213 UTC by R4002 »
U.S. East Coast, various HF/VHF/UHF radios/transceivers/scanners/receivers - land mobile system operator - focus on VHF/UHF and 11m