MR8100 – UNIDEN Scanning Mobile Receiver 8100

Technical Observations:

  • Only 16 characters of the 20 character display can be programmed. The first 4 characters are reserved as follows:
  • character 1 – shows ‘P’ for priority channel, otherwise a blank
  • character 2,3 – shows channel number “ 1” to “10
  • character 4 – always blank
  • The text shown when enabling a bank for scanning such as “     BANK 1     ” is programmable via computer. Something more descriptive might be: “2m HAM    BANK 1

  • It is not known at this point whether the text “      SCAN      ” or “   TURBO SCAN   ” can be changed.

  • There is a 16 character text message (not visible) programmed via computer during the assignment of the priority channel. Uniden’s software uses “UNIDEN CORP 1989”. Other text may be substituted by custom software for identification purposes, such as date of last download, etc.

  • Cellular phone frequencies in the range 824 to 849 MHz and 869 to 894 MHz can only be programmed by software (not front panel). There may be a hardware or software solution to enable this range via front panel. Clue: a flyer states “Control of field programming options”… “field accessibility to cellular phone band”. This has not been confirmed. Uniden’s software protects this range via password, requiring the signing of a non-disclosure agreement.

  • The hardware does not restrict frequency range. The scanner can be programmed for TV audio, FM broadcasts, aviation bands, etc. via custom software. Unfortunately the scanner only receives in FM-narrow mode. FM-wide signals such as broadcast, or AM signals such as aviation thus can not be clearly discernable. The only practical benefit of this “unlimited” range may be the reception of the 222 – 225 MHz HAM band.

  • The manual claims a scanning rate up to 100 channels per second. A flyer claims a top speed of 93 channels per second “depends on how channels are programmed”. There is no clue offered by Uniden as to how to optimize scanning speed. This has to be investigated.

  • According to the data format, the scanner can in theory be programmed for frequencies up to 1.6 GHz. This has not been confirmed.

  • The 2 second scan delay (resume scanning) might be programmable to other delay times. This has not been confirmed.

  • Specifications in the manual list 5 kHz and 12.5 kHz channel spacing. This spacing was thought to be irrelevant since the scanner can be programmed for any frequency to a 1 kHz resolution from the front panel. At least the text display shows that. In reality, the frequencies entered are rounded to the nearest channel spacing. The display is misleading.

  • There is no way to determine the frequency of programmed channels unless the 16 character text message shows it. This is not a problem for frequencies entered from the front panel as the text is automatically set to contain “nnn.nnnn MHZ    ”. However, for frequencies programmed via computer where the text message could contain other information such as station call sign or city of origin, the user can not extract the actual frequency using the front panel of the scanner. This is perhaps a security feature which prevents unauthorized identification of pre-programmed frequencies.

  • The manual warns of birdies. No list of known birdies is supplied by the manufacturer. However, through exhaustive testing one was obtained. See Birdie List.

  • Confirmed available and theoretically available frequencies:

    Range Front
    0.0000 28.9950   Y   
    29.0000 54.0000 Y Y Y 0 0
    54.0050 117.9950   Y 0 ?
    118.0000 135.9950 Y Y Y 0 1
    136.0000 174.0000 Y Y Y 1 0
    174.0050 405.9950   Y ? ?
    406.0000 512.0000 Y Y Y 2 0
    512.0050 805.9950   Y ? ?
    806.0000 823.9875 Y Y Y 3 0
    824.0000 848.9875  password Y 3 0
    849.0000 868.9875 Y Y Y 3 0
    869.0000 893.9875  password Y 3 0
    984.0000 956.0000 Y Y Y 3 0
    956.01251649.2250   Y ? ?

  • Sending entire file should take 39 seconds minimum. In practise, it takes 63 seconds. (UNIDEN software takes 87)

    (111 × 21 × 2) ÷ 120 = 39 seconds

  • Receiving entire file should take 22 seconds minimum. (UNIDEN software takes 24)

    (111 × 24) ÷ 120 = 22 seconds

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