TH45AT.1 On the TH-25AT: (All frequencies given in MHz.) R22 in R28 out This is how the radio is delivered in the USA. TX 144-1, 141-163 (I think). R22 out R28 in The radio tunes from 142-151. This may be the modification given to US MARS members. I don't remember where the unit will transmit. It may or may not transmit outside the range from 144-148. R22 in R28 in The radio tunes only from 144-148. R22 out R28 out Frequencies may be selected from 100-200 MHz (on the display only - your PLL will not lock up in this entire range). In addition, TX is possible where your PLL locks up. R25 out Removing R25 disables automatic offset selection. R23 and R24 are used for selecting the step size for tuning. I can't remember which positions are for which step sizes, and alas I didn't write down what I found. If you want to play with this, go ahead. On the TH-45AT: (All frequencies are given in MHz.) R18 in R28 in This is how the radio is delivered in the USA. The radio covers 438-450 MHz. R18 in R20 out The radio is prohibited from tuning outside 440-450 MHz. R18 out R28 in The radio will only tune from 215-230 MHz. Note that the PLL would not lock up! (What did you expect?) Could it be possible that Kenwood originally planned a 220 version of this radio, but then scrapped their plans? R18 out R28 out The radio will tune from 200-500 MHz (on the display only - your PLL will not lock up over this entire range). Transmitting is possible anywhere your PLL will lock up. CONTINUED IN FILE TH45AT.2