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ICOM IC-208H Extended RX-TX mod.

AudioShockwav

Extraterrestrial
Staff member
Apr 6, 2005
8,964
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Nor Cal Sierra Nevada
  • Place the radio with the front panel toward you and bottom side / speaker side UP.
  • Remove the (4) screws located in each corner.
  • CAREFUL! Go slow, you will need to disconnect the speaker cable while removing the cover. Look at the lower right hand corner of the main printed circuit board.
  • You should see a silver crystal with the number "D196D3C" printed on it.
  • Just above the crystal, you should see an (8x8) matrix pad (see below diagram). o o o o o o o oo o o o o o o oo o o o o o o-o <-- Removeo o o o o o o-o <-- RemoveNote: there are ONLY (2) resistors in place. (Bottom right and the one directly above it).

  • REMOVE BOTH RESISTORS [Do NOT attempt this unless you know how to use a low wattage soldering iron]
    ic-208h_trx.jpg


  • RESET THE RADIO, hold the [SET LOCK] and [S.MW-MW] buttonsdown during power-up.
DONE! New RX/TX Ranges 118.0000 - 135.9875 RX-AM only136.0000 - 173.9875 RX & TX (15% RF power fall-off at lower freq, Full power at high freq)230.0000 - 399.9875 RX only400.0000 - 478.9875 RX & TX (Do NOT transmit below 410MHz on HI-PWR, VSWR fold-back)479.0000 - 549.9875 RX only810.0000 - 849.0000 RX only849.0000 - 869.0000 RX only894.0000 - 999.9875 RX only
 

I came across a modded IC-208H with the expanded frequencies. I am able to select these frequencies and can monitor them, however when attempting to transmit (462.650 for example) I receive the message "off" in the display and of course no transmission occurs. What am I missing?
 
  • Place the radio with the front panel toward you and bottom side / speaker side UP.
  • Remove the (4) screws located in each corner.
  • CAREFUL! Go slow, you will need to disconnect the speaker cable while removing the cover. Look at the lower right hand corner of the main printed circuit board.
  • You should see a silver crystal with the number "D196D3C" printed on it.
  • Just above the crystal, you should see an (8x8) matrix pad (see below diagram). o o o o o o o oo o o o o o o oo o o o o o o-o <-- Removeo o o o o o o-o <-- RemoveNote: there are ONLY (2) resistors in place. (Bottom right and the one directly above it).

  • REMOVE BOTH RESISTORS [Do NOT attempt this unless you know how to use a low wattage soldering iron]
    ic-208h_trx.jpg


  • RESET THE RADIO, hold the [SET LOCK] and [S.MW-MW] buttonsdown during power-up.
DONE! New RX/TX Ranges 118.0000 - 135.9875 RX-AM only136.0000 - 173.9875 RX & TX (15% RF power fall-off at lower freq, Full power at high freq)230.0000 - 399.9875 RX only400.0000 - 478.9875 RX & TX (Do NOT transmit below 410MHz on HI-PWR, VSWR fold-back)479.0000 - 549.9875 RX only810.0000 - 849.0000 RX only849.0000 - 869.0000 RX only894.0000 - 999.9875 RX only
Old thread I know, but I just got asked if my IC208H had the MARS. I couldn't remember as it has been sitting in the box since I bought it new in 2005. I usually do the MOD, but in this case I hadn't, so thanks for having it posted here.
It is now MARS capable. I've been using my FT-2600, but I may hook this up, I don't remember why I shelved it, maybe coz my base antenna was only 2 meter. I have a tri-band now.

Thanks again.
 

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