|03-07-1999||IC-T81 AM/FM/Wfm function English language|
|05-09-1999||IC-T81 Frequency Expansion English language|
|30-07-2000||ICOM IC-T81A Cellular Mod English language|
Note: from firstname.lastname@example.org - Chet
Hello....on the mod to expand the receiving capabilities, (powering up while holding the multi and squelch keys), If the xcvr was previously programmed via Icom software and cable via PC, and the mod was enabled, you cannot re-program the radio via PC. The software reports an error that the version doesn't match.....the only way to access the xcvr via PC again is to do a CPU reset (power up while holding the squelch, vfo, and, mr).....
05-09-1999 IC-T81 Frequency Expansion
Remove the Diode D53 and D61.
If you've performed the mods listed on this site to open up the receive range to 999.95MHz, cellular is no problem. All you have to do is dial in the image frequency for cellular. That is, dial in a freq that is the cellular freq minus 2 times the IF frequency for the T81A, which is 69.4 MHz.
The cellular band (for analog phones only) from handheld to cell site is 824-849 MHz. Transmit back from cell site to handheld is 869-894 MHz. (There are a few control and data channels interspersed in those ranges too.) That corresponds to 685.1 to 755.1 MHz display on the T81A.
So, for example, to receive transmissions from a cellular phone at 826 MHz, just set the T81A to 826 - 138.9 = 687.1 MHz.
Towers Output (display on T81A 730.1 to 755.1 MHz) to RX 869-894 MHz
Cellular Input (display on T81A 685.1 to 710.1 MHz)to RX 824-849 MHz
|Have you any tips, trick or modifications you can't find here, please E-mail them to me, or use the mail form.
Can't you find a mods, please don't e-mail to me. All mods i have is listed on this site. Back to start page