Newer TH78A modifications This contains the mod information for the NEWER Kenwood TH78A. ------------------------------------------------------------------------- From: gwalsh@kilroy.Jpl.Nasa.Gov (Gerald J. Walsh) Date: Far too long ago. >I have a friend who just purchased a TH-78A and tried the mods that, by >now, we all have a copy of. He says that his radio has two green wires >near the diodes that are, "just asking to be cut"! From the >experimenting that he has done, cutting one wire is equivalent to >removing D5 and cutting the other green wire is equivalent to cutting >D6. I followed the traces by sight and I would agree with you. >With the "CAP/Mars mod" completed (remove D6 or cut the green wire) he ^lower (W2) >does get the expanded RX range, but he gets no TX capability outside >the amateur band. > >Alternatively, > >With the "Beyond MARS mod" completed (remove D5 or cut the other green >wire) he gets the full RX capability and the extended TX capability for >the CAP/Mars mod, not the full TX capability expected!? > >BOTTOM LINE: > >Is anyone aware of a change in the mods for later versions of the >TH-78A? We are not able to fully expand the TX capability of this >TH-78A. We compared (by voice) the mods we made with another ham who >modified his. We did everything properly.... I just got the ARTSCI 5A techmod book. They replaced the page that contains the Alignment controls for the TH-78A with a mod page for 'Later Model (with green jumpers)'. I haven't done a whole lot of experimenting, but I think the list below is true. I've removed D3 D4 and D6 and have the associated capabilities. Assuming that D1-D6 are all installed: Remove D3 = Wide band xmit (maybe wide band rcv in addition) Remove D4 = Cross band repeat Remove D5 (or W1) = Mars/CAP Remove D6 (or W2) = Wide band rcv The book doesn't seem to indicate that D6 is necessary for wide band receive, so try removing only D3 (and D4 if you want) and see if you get all the capabi-lities. If not, then remove D6 too. D5 has priority over D3, so DO NOT REMOVE D5 if you want full xmit. I had already made the mods for the OLD MODEL (which included the removal of D5) and had to resolder D5. Left VFO Right VFO 50.000-85.2x (with beep) 50.000-110.xxx (with beep) 85.2x-179.995 110.xxx-179.995 300.00-399.975 400.000-511.9875 400.000-511.9875 800.00-999.9875 xxx is variable. My guess is the beep is some sort of error notation of some kind, but what? Someone, somewhere said it has something to do with the PLL... At this time, I can't do the xmit testing since I don't have a dummy load here. We had a dummy load when we were testing the mod from the 5A book and the xmit opened up to much more than the MARS/CAP mod allowed. The Complete Guide to Undocumented Features of the TH-78A The information contained in this document is derived from many sources. Unfortunately, I have not kept track of everyone who has provided input, but I would like to thank those who have helped me compile this information. This document is probably not complete: Please send any additions or corrections to aviator@athena.mit.edu (Internet) or n1jhw@ka1srd.#ema.ma.usa.na (amateur radio packet) or ma0226@ma1bbs.mawg.ner (Civil Air Patrol packet). I've had one report that the TH-78A is capable of in-band full duplex operation. I've been unable to repeat this on my unit, which only has the CAP/MARS mod perform. Confirmation of this feature would be appreciated. Please Note: I can take no responsibility for any problems which may be caused by attempting to access one of the features described here. This document may be distributed in its original form only, and not via packet radio. 1. Hardware Mods Hardware modifications for the TH-78A are performed by manipulating a series of 6 surface mounted diodes, identified as D1 through D6. The TH-78A block diagram contains a table identifying 7 configurations involving D2, D3, D5, and D6. However, none of the configurations described below are included in that table. To open the radio, follow the instructions on p. 64 of the manual. The two TX/RX busy indicators (LEDs) have rubber seals placed over them. These have a tendency to fall off when opening or closing the radio. The diodes are located on the CPU board, which is mounted inside the front panel of the radio. The CPU board is readily identified by a brass shield covering the CPU, as well as the socket for the ME-1 memory expansion chip. All position references in this document assume that you are looking at the CPU board with the rotary encoders and TX/RX busy indicators at the top. If you have installed the ME-1 EEPROM, I recommend that you temporarily remove it to facilitate access to the diodes. The diodes are located in a vertical row just below the lower right corner of the brass shield. The diodes are numbered sequentially, starting with D1 at the top. The U.S. stock configuration has all diodes in place. The function of D1 is not known at this time. D2, D3, D5, and D6 are thought to control TX and RX ranges. D4 controls cross-band repeat. Before removing a diode, Kenwood recommends unsoldering the brass shield. There are four solder points, one at each corner. The brass shield is attached to the CPU with a small piece of double-sided adhesive tape. An alternate method consists of unsoldering the right side of the appropriate diodes, which are visible underneath the shield, and bending them to approximately a 45 degree angle, forming an open circuit. Early Model Radios Only ======================= CAP/MARS mod: Remove D6 only. Yields RX 118-174 TX 142-152 RX 400-512 TX 425-455 Beyond MARS mod: Remove D5 only. Yields RX 50-180 TX 136-180 RX 300-400 [VHF side only] RX 400-512 TX 400-512 RX 800-950 [UHF side only] Late Model Radios Only ====================== Beyond MARS mod: Remove D3. Also remove jumper W1. Yields RX 50-180 TX 136-180 RX 300-400 [VHF side only] RX 400-512 TX 400-512 RX 800-950 [UHF side only] Note: The frequency ranges include the lower limit, but exclude the upper limit (i.e. 118-174 really means 118.000-173.995). Crossband repeat mod: Remove D4. Apparently, this mod is independent of the D5/D6 mods. 2. Undocumented Features Crossband Repeat: Press F for 1 second, then 0 [requires D4 mod] Repeat the same sequence to disable. Wideband RX: Press F for 1 second, then BAND [requires D5 mod] On the VHF side this yields 300-400 RX, on UHF 800-950 RX. Sample Channels: Press DUAL during power-up Programs some sample frequencies in VHF and UHF memory channels (it's a pain to undo the sample programming). Cloning: Press 0 during power-up [requires D5 or D6 mod] Allows cloning over the air. All keys except PTT and POWER are disabled. Press PTT to send DTMF cloning sequence. Presumably, receiving TH-78A must be in same mode. Toggle SHIFT/SPLIT Mode: Press SHIFT during power-up This is described in the manual, but the documentation is not complete. The TH-78A can operate in two modes: In SPLIT mode, non-standard offsets (i.e. split frequencies) are supported, but the default offset is not programmable. In SHIFT mode, non-standard offsets are not allowed, but the default offset is programmable. To select the default offset, press F for 1 second, then SHIFT. See p. 30 of the manual for details on changing the default offset. Toggle CALL Button Function: Press CALL during power-up. The CALL button can operate in one of two modes. In th default mode (CALLSW), it switches between the call channel and the last memory channel (if in memory recall mode) or last frequency (if in VFO mode). After toggling the CALL button functionality (VMC), it will switch from the VFO to the last memory channel and then back to the CALL channel. Game Mode: Press M and PTT during power-up [be careful not to accidentally reset the memory (M+POWER)] [Much of this was provided by james@brokaw.lcs.mit.edu] To exit the game mode at any time, press the LAMP key. It is not possible to change the volume, lamp, or frequency settings while in game mode. The top part of the display will show H.00, which represents the high score. The lower part shows a scrolling message, "PRESS ANY KEY". Pushing any key starts a "Follow Simon" type game. The display will briefly show one of the characters "1", "2", "3", or "F". Press the corresponding key. The game consists of repeating the displayed character sequence, which increases by one character each round. After you "win" the Simon memory game by getting correctly entering a sequence of twenty characters, the next game is a draw poker game. The way it works is that you choose your bet (from 1 to 10) by pressing 2 to increment the bet and 5 to decrement the bet. Then, press F to deal the five cards. The face value of the cards is displayed, and the suits can be seen at any time by holding down the PTT key. Any number of cards may be discarded, and to select (or deselect) a card for discarding, press the keys 1, 2, 3, 4, or 5. If a card is selected for discard, it is displayed "face-down". Press F again to draw new cards. Your new cards will be displayed, and then if your hand is 2-pair or better, the screen will show the rank of your hand on the left (2P for 2-pair, 4K for four-of-a-kind, etc.). On the right the pay- off for that hand will be displayed. Your bet is multiplied by the pay-off factor,and the resulting pile of cash is displayed in the right hand side of the upper screen. (The left hand side of the upper screen contains your table stakes, which are initially 100 coins from winning the Simon game.) If you win the poker hand, pressing any key steps into the next stage. If you lose the poker hand, your bet is deducted from your stakes and you are asked to start another poker hand. In the next stage, you are asked "TRYB/S" which means, "Do you want to try double-or-nothing in a guessing game for Big or Small cards?" Press F for yes, press TONE for no. If you say no, your winnings are credited into your stakes and you are asked to start another poker hand. If you say yes, then a single shuffling/incrementing card is displayed on the left, and three stars are displayed on the right. You have to choose to go for either BIG or SMALL, by pressing 2 or 5. You can keep pressing 2 and 5 to change your mind. When you are ready, you must try to hit the F key to stop the rotating card display, and the card will show, and you will either win, lose, or draw. If you draw,you have to play big/small again, I think. If you lose, your winnings are gone and you can play poker again. If you win, your winnings doub le and you are asked whether you want to play big/small again. The payoffs on the poker are set against you, odds-wise; the double-or-nothing game includes a draw, so the odds are against the player there unless you can time hitting the F key to win more than half the rounds. I haven't managed to do this, so I don't know if there is anything beyond this, all I know is that when the table stakes are exhausted, you go back to playing Simon again. To "open up" as many feature as possible on the TH78A, remove diodes D4 & D5 (located under the copper shield). This allows the following transmit and receive frequencies RECEIVE TRANSMIT --------------- --------------- VHF BAND -------- 50-135.995 (AM) (NA) 136-179.995 136-179.995 300-399 (AM & FM) (NA) SUB-UHF 400-511.99 400-511.99 UHF BAND -------- 400-511.99 400-511.99 900-949.9875 (NA) SUB-VHF 50-179.995 (FM) 136-179.995 PERSONAL NOTES: I found that marine weather reports at 162.40MHz in my area were received much better on the VHF-SUB band, than on the VHF band. Possible hole? If you are having problems with intermod, try switching BANDS (ie. USING the SUB-VHF rather than the VHF etc.) Cellular Phones are in the 870-890 range, but the frequency increments are every 30kHz. The TH78A will only increment in 25kHz steps at this frequency range, so the exact Cellular channel frequency cannot be tuned in (most of the time). Removing D4 enables the CROSS-BAND REPEATER function. CROSS-BAND REPEATER ------------------- Press [F] key for 1 second, then the [0] (zero) key to turn this function on and off (MHz dot will flash when in repeater mode). ANSWERBACK FUNCTION (during paging reception) --------------------------------------------- Hold down [MHz] key and switch power ON to turn this function ON or OFF. 300 MHz AM/FM SWITCHING ----------------------- Hold down [VFO] key and switch the power ON to switch between AM and FM reception. VHF & UHF EXPANSION ------------------- Press and hold the [F] key for 1 second, then press the [BAND] key in the respective bands. CHANNEL DISPLAY MODE -------------------- Hold down [3] key and switch the power ON. Channels are displayed by number instead of frequency. (NOTE: this function only works when Alpha-Numeric memory is enabled) CLONE FUNCTION -------------- Hold down the [0] and switch the power ON. *** GAME *** (Available without any modifications) -------------------------------------------------- Hold down the [M] and [PTT] keys and switch the power ON. (Be very careful the PTT is depressed or else a memory reset will occur.) 1) Play the memory game. The radio will beep and display one of the following characters: "1, 2, 3, F" (top row of buttons). Radio starts with one character and adds a new one on after every round until 20 characters are reached. You must press the keys in the same sequence they are displayed. When you can follow the radio for 20 characters, then you will win 100 coins and enter the poker game. (Note: I am terrible at this game, so I cheated by writing down the character sequence on paper.) 2) Poker game. (Much more interesting than the first game, IMHO) Place the bet (1 to 10). Increase the bet with the up key [2], decrease the bet with the down key [5]. Press [F] to deal the cards. Cards are (2,3,4,5,6,7,8,9,+,J,K,Q,A NOTE: 10 = "+") Press [PTT] to see the suits. Press numbers 1 through 5 to change the respective cards. Press [F] to deal the new cards. If you win any amount, you can bet for double or nothing. Press [F] to play "BIG or SMALL". Press [LOW] to keep your winnings. BIG or SMALL ------------ A random card will be chosen. Push [2] (big) if you think this card is going to be larger than 8. Push [5] (small) if you think this card is going to be less and 8. (if an 8 is drawn, then a tie occurs, and you neither win nor lose) Press [F] to draw the random card. You either double your winnings or lost it all. Press [F] to continue playing Big or Small. Press [LOW] to keep winnings and continue playing poker. Push the [LAMP] key to exit the game mode. Note: While in game mode, receive functions still operate! Modifications for the Kenwood TH-78A Dual Band Micro-HT. By Rich Garcia N2CZF. Packet Via N2CZF@WT3V.NJ.USA Owner assumes all responsibility for modifying or using these modifications!. The following mods will provide for Crossband Repeat and extended receive and transmit on the Kenwood TH-78A HT. I believe other functions are also enabled by these mods. which I have not found yet but I will update the file as news progresses. Diode #4- Crossband Repeat Diode #5- Extended Receive and out of band Transmit. Remove all screws and open radio as explained in the Kenwood manual for installing the memory expansion module. On the back cover you will find the memory expansion module socket and a copper shield to the upper left corner of it.Under this shield their will be a row of SMC diodes which are unmarked in a vertical configuration to the lower right portion covered by the shield. #1 Remove the shield at its four corners with a solder sucker and SMALL! iron. #2 Carefully count down from the 1st diode in the row to the fourth one and remove for crossband repeat. HINT: I found if you BRIEFLY touch the iron to the right side lead while gently pulling up on the SMC diode it should completely come off without needing to apply heat to the other side and further risk board damage. I used a pair of right angle surgical tweezers for this. #3 Just as above you may remove the fifth diode to preform the extended receive and transmit modification. #4 Reset the CPU (yes you will loose all of your programed memories! argh!) by pressing Function for more than one second and then "0". YOU HAVE NOW COMPLETED THE MODIFICATIONS! #5 For 800Mhz go to the UHF band with the band switch and press Function for more than one second quickly following with a press of the Band switch again. 8---.-- will appear. #6 For 300MHz go to the VHF band and repeat as above. Original bands are restored by repeating the "F Band" sequence. MY observations... All original functions have maintained the same which is great. Aircraft band which was accessible before the mod remains with the same characteristics. It seems that VHF-High band has improved a bit on sensivity where it was dead as a dog before the mod (above 155.000MHz) but the 162.000 MHz band where weather radio is is still a bit deaf for reception at any distance but about 20 Miles. This depends on your (or my) terrain and transmitter output power. On UHF all public safety frequencies up to about 500 MHz seem to come in well but sensivity greatly drops from there (we really can't ask for more). Frequencies can be programed in up to the 920MHz ham band but I have no way of measuring sensivity. 800MHz works but the signals are very weak, you must be near the transmitter for reception. Assuming you are in the town or city where the transmissions originate it should work. Transmit is enabled up to and incl. 500MHz but after testing this on a frequency counter I find that a signal is only generated to about 490 MHz, even though the trans. LED shows output in the higher frequencies. Crossband repeat seems to work fine but the audio is unacceptable for use, BE AWARE the radio gets HOT! Prolonged use or use on a busy frequency would not be recommended. Also remember this is a dual band HT please use a proper antenna while in this mode to avoid a high SWR, we should all know better... Right? After first booting up the CPU in the mod I found that the message screen showed "Cloning" so it seems that this radio now has cloning capabilities. After searching I have found that holding the "0" key and powering up the radio will display the clone feature, see below for further explination.This leads me to believe that this HT may have some more "Hidden" features that I am trying to find, some may be useful. Thanks to Gary KC8UD who sent me the following via packet ..... CLONING: The TH-78 can be cloned without cloning cables or special equipment. It is done entirely with RF, and, in fact, can be transmitted over the air, and even via repeaters. This may be extremely useful for those users who do not have the patience to program their own radios themselves. This application would also be useful for clubs and user groups. (However, this can take as long as 50 minutes with the ME-1 expansion module. It is recommended that a dummy load be used to prevent unwanted QRM.) (1) Both radios must be on the same frequency. (2) Activate both radios by pressing the "0" key while turning the power on. The radios will display CLONE. (3) Now, click the PTT of the "master" radio. The radio will transmit in the conomy low power mode. This may take about 4 minutes for fifty channels. hen the data has been transferred, both radios will revert back to the original frequency. (4) Turn both radios off and then on again. They will now operate normaly while the slave radio has the same memory contents as the master radio. ** I have not tried the following modification myself, try at your own risk ** *** Rich N2CZF *** FREQUENCY EXPANSION (1) You can receive from 340 - 399.987 Mhz FM by removing chip diode D8 on the ontrol unit. To access this function, press the [F] key for one second, and then the [LOW] key. This toggles between AMATEUR, AIR band (AM) and 360 Mhz. AM and FM modes are selected automatically, depending on frequency. ** Since "F" for a second and "Low" toggles the power output, I wonder ** *** Rich N2CZF *** There is also a couple of arcade type games on the TH-78A. To start the game you pres and hold [PTT] and [M] keys while turning the unit on. The first game is a follow me type game. The radio beeps and shows a sequence of numbers flashing on the screen. You have to match the same sequence on the tone pad. Each time the sequence gets longer by one number. You have to keep remembering the sequence as one gets added each time. Once you get to a certain high score on that game, it breaks into a poker type game. To exit the game mode press the LAMP key at any time. The receiver still works in the game mode and you can adjust volume but no other features. RG> The games seem to work fine and it is interesting that they have inserted that into the programing of the chips. Does anyone know of any further features in the radio be it games or radio functions. SECRET FUNCTION MANUAL OF THE KENWOOD TH-78x PORTO TH-78E RX EXPANSION (ON) Press PTT + VFO, then POWER ON. New RX ranges after this modification: VHF Band 50 - 136 Mhz only AM) 136 - 174 Mhz (only FM) 320 - 390 Mhz (AM + FM) see note below. UHF Band 405 - 510 Mhz (only FM) 800 - 950 Mhz (only FM) VHF Band: _________ _____ _________ ---->I AMATEUR I====I AIR I--->I 320 Mhz I_____ I I_________I I_____I I_________I I I______________________________________________I UHF Band: _________ _________ --->I AMATEUR I--->I 900 Mhz I_____ I I_________I I_________I I I___________________________________I Note: Receiving mode of the 340 Mhz Band can be switched fr{m FM to AM by press and hold VFO key then POWER ON. TH-78E RX EXPANSION (OFF) _____ Reset your TH-78E by pressing the I M I key, when powering ON I_____I TH-78E TX EXPANSION Remove the diode D6 from the control unit. New TX ranges after this modification: VHF Band 136.000 - 174.250 Mhz (FM) UHF Band 400.000 - 493.000 Mhz (FM) TH-78E UHF BAND 432-438 Mhz LIMITED RANGE Remove the diode D3 from the control unit. TH-78A/E EXTENDED FUNCTION You can change the frequency range and use various secret function of the TH-78A/E by changing his destination. A secret funcion is available without modification. Destination modification The destination is determined by diodes D2,D3,D5, and D6. Change the destination with reference to table 2. For information about setting the destination by diode, see the destination column of table 2. The diodes are protected by a shield plate. Remove the shield plate, then remove the appropriate diodes. Refere to your schematic diagram TH-78A/E 2/2 Control Unit Board X53-342X-XX A/5 __________________ Cupper shield plate : :/ Table 2 : ___________ : ____________________________ : I I : I I I I I I : I CPU I : I DestinationID2 ID3 ID5 ID6 I : I IC 7 I : I------------I---I---I---I---I : I I : I 0-00 (J) INo INo INo IYesI : I___________I : I------------I---I---I---I---I : _:_ I 0-11 (K) IYesIYesIYesIYesI : I_:_I D1 I------------I---I---I---I---I : I_:_I D2 I 0-21 (M) IYesINo IYesIYesI : I_:_I D3 I------------I---I---I---I---I : I_:_I D4 I 0-22 (M2) IYesINo IYesINo I : I_:_I D5 I------------I---I---I---I---I :________________I_:_I D6 I 0-71 (X) INo IYesINo INo I I------------I---I---I---I---I Control unit I 2-71 (E) INo IYesIYesIYesI I------------I---I---I---I---I I 2-72 (E2) INo IYesIYesINo I I____________I___I___I___I___I Secret functions after modification The following functions are added if you modify the destination. See the appropriate description for details. Frequency range change Change the diodes (D2,D3,D5, and D6) as shown in the destination column of Table 2. Cross-band repeater _____ _____ Remove D4 and press the I F I key for one second, then the I 0 I key, to turn this I_____I function ON or OFF. I_____I Answerback function (during paging reception) _____ Hold down the I Mhz I key and switch the POWER ON to turn this function I_____I ON or OFF. 300-Mhz band AM/FM switching _____ Hold down the I VFO I key and switch the POWER ON to switch between AM and FM. I_____I VHF expansion band _____ ______ Press the I F I key for one second, then the I BAND I key,to change the band. I_____I I______I UHF expansion band _____ ______ Press the I F I key for one second, then the I BAND I key,to change the band. I_____I I______I Channel display mode _____ Hold down the I 3 I key and switch the POWER ON to change te frequency I_____I display to the memory channel. # If you remove D1, only the channel is displayed. Normally, leave D1 # in. Clone function _____ Hold down the I 0 I key and switch the POWER ON to use this function. I_____I Secret function available without modification.(Game function) _____ _____ Hold down the I M I and I PTT I key and switch the POWER ON to use this function.I_____I I_____I Cross-band repeater When one band becomes busy, the cross-band repeater function retrans- mitts the received signal on the other band. As soon as the BUSY signal for the receiver band goes low, the transceiver enter receive mode on both bands. Note 1: DTTS and paging are not checked. Note Y: If TONE of the transmitter is on, a subtone is output. Note 3: If the transmitter does not output a subtone, CTCSS is checked. Cross-band repeater ON/OFF You can turn the cross-band repeater ON and OFF by pressing the _____ _____ I F I key for one second, then the I 0 I key. I_____I I_____I The dot indicating Mhz on the frequency display (both bands) flashes while the cross-band repeater function is on. Note 1: The cross-band repeater does not turn on during dual watch. Note 2: If you enable the cross-band repeater when the bell function is on, the bell function is turned off and the cross-band repeater function is turned on. You can turn the repeater on only if the bell function for the operation band is off. Note 3: A dedicated jumper is used to select whether to use the cross-band repeater. Note 4: The timeout timer is set to three minutes. Cross-band repeater operation Operation band BUSY band:change band:change _____________________:_______}______________:______ : : ______ _ :_____________ :_ Non)operation band I I I I I I I I BUSY __I I__I I______I I________I I____ ______ ___ _____________ ___ Operation band I I I I I I I I transmission __I I__I I____I I________I I__ ->I---I<- ->I---I<- 500 ms 500 ms Answerback function If the transmitter pages a receiver, it does not know whether the receiver has received the paging signal. When the answerback function is ON, the receiver returns a code automatically if the paging code matches to indicate that it has received the paging signal. The transmitter can thus confirm that the code it sent was actually received. Operation If the paging code matches and the busy signal goes low, the receiver returns a code. If the paging code does not match, the receiver does not return a code. The answerback function is related to the bell function: if you turn the bell function on when the answerback function is on, the answerback function works; If you turn the bell function off, the answerback function does not work. If the answer- back function is off, only the bell function can be turned on or off. To turn the answerback function on and off, hold down the _____ key and switch the POWER ON. I Mhz I I_____I Note : This function is available only if reception is modified. __________ ______________________ BUSY I I I____________________________________I Receive : _ _ _ _ _ _ _ : code : I I I I I I I I I I I I I I : __________:___I I_I I_I I_I I_I I_I I_I I______:______________________ : : : : : : Paging code : : : :<----------------------->: : ->:---:<-250ms(450/750ms for shift, split channel) : : .....................................: : __________: ___________________ TX ON I I I_______________________________________I : _ _ _ _ _ _ _ : I I I I I I I I I I I I I I __________:___I I_I I_I I_I I_I I_I I_I I_____________________________ Transmit : : : code : : Paging code : : :<----------------------->: ->:---:<-250ms(450/750ms for shift, split channel) ______________ _____________________________ Microphone OFFI I I_________________________I VHF expansion band You can change the reception of AMATEUR band, AIR band, and POLICE band by pressing the _____ key for one second, then the ______ I F I I BAND I I_____I I______I key, when the VHF band is VFO. _______________________________________________ I I Police band I I===================I===========================I I Step I 10, 20, 12.5, 25 Khz I I-------------------I---------------------------I I Frequency range I 300.000 -- 399.995 Mhz I I-------------------I---------------------------I I Initial frequency I 340.000 Mhz I I___________________I___________________________I UHF expansion band You can change the reception of AMATEUR band and CAR TELEPHONE band by pressing the _____ key for one second, then the ______ key, I F I I BAND I I_____I I______I when the UHF band is VFO. _______________________________________________ I I Car telephone I I===================I===========================I I Step I 12.5, 25 Khz I I-------------------I---------------------------I I Frequency range I 800.000 - 949.987.5 Mhz I I-------------------I---------------------------I I Initial frequency I 800.000 Mhz I I___________________I___________________________I Note 1:Program scan cannot be performed over bands. It can only be performed within each band. Note 2:You cannot change the band in MR and CALL modes. Note 3:The AIR band frequency range is shown below. It is contiguous in the VHF amateur band frequency range. Note 4:The initial step is the same as the VHF amateur band step. Note 5:If the AIR band is received as the UHF subband, FM reception is performed. Note 6:The step is the same as the VHF band step. _________________________________________________ I I Air I I===================I=============================I I Step I 5, 10, 15, 20, 12.5, 25 Khz I I-------------------I-----------------------------I I Frequency range I 50.000 - 135.995 Mhz I I___________________I_____________________________I Channel display mode Select the channel mode by cutting D1 on the CONTROL UNIT. If you cut D1 on the CONTROL UNIT, you can use channel display mode only. You cannot change it to normal display mode from the panel. If you do not cut D1 on the CONTROL UNIT, you can change between channel display mode and normal display mode by holding the _____ key and switch the POWER ON. I 3 I I_____I Note :Memory channels for both bands must contain frequencies. If nothing is stored in memory, an error occurs. ------------------------------------------------------------------- Subject: KENWOOD TH-78A MOD WARNING In the course of performing mods on my Kenwood TH-78A dual band handheld, I've discovered a potential flaw in the case design. While handling my walkie one day (after the mods were done), the display went blank and I could not turn the radio back on. With the radio split in half again, I could turn the radio back on but discovered all the memories were erased. The cause turned out to be some component pins on the front face coming in contact with the square bodies of the two volume/channel/squelch switches, when the case is screwed back together snuggly. I placed small strips of electrical tape on the sides of the switches to insulate, and reassembled; problem solved. Now I have to reprogram the darn thing.... Mark WB1E @ K1RQG.ME