>From the Bench of: KB2Jpd ====================================================================== Extended Frequency Enhancements for the Yaesu FT-23R(2M), FT-33R(220), and FT-73R(70cm). (Revised) ====================================================================== Greetings and hello radio amateur operators. The topic is increasing the functional frequency coverage of what has been probably Yaesu's most popular handheld tranceivers. To save manufacturing costs, Yaesu engineers designed multiple personalities in the same CPU module found in the FT-23R, FT-33R,UHF FT-73R and the FT-2008/7008 tranceiver. The FT-2008/7008 tranceiver is the commercial version of the Ft-x3R series. Unique features of this mod include -the just say Mao feature (**) (NO FREQUENCY READOUT: Ch 1 thru Ch 9 appear on your display. Great when you aren't looking and some fellow ham tries to rip off your simplex frequency) -the GREAT WHOPPER (opens the CPU to 50-300 Mhz or 220-550 Mhz coverage. Full (.100 Mhz to 999.9995 Mhz) adjustable freq coverage available so far only on the FT-33R;this doesn't mean you can actually transmit but the Activity light goes in TX and you get a good fake RF bargraph that indicates that you can transmit on 750 MHz. HOW TO DO IT: 0. Contemplate invalidating your warranty. No beginners beyond this point. If you don't know how to solder, don't learn here. Ask an elmer to assist. 1. If you treasure your memories, write out your contents of your radio on a piece of paper. When you make the changes, the CPU runs a small diagnostic and see that the jumpers have been changed. It will ERASE ALL PRIOR SETTINGS. 2. Dissassemble your tranceiver. 3. Find the line of solder connections running down the CPU board. GENTLY move all wires aside so you won't melt them. 4. Using solder wick and a Good low-power soldering Iron, see chart. Read special notes for the FT-33R. 5. Rebuild radio and count your blessings. (**)NO FREQUENCY READOUT ------------------------ Removal of the solder bridge labeled number nine will activate the commercial side of the CPU module. To flip to the amateur mode, you would press F UP Arrow. To flip to the commercial mode, you would press F Down Arrow. +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+= +=+=+=+=+=+=+=+=+=+=+= FT-23, FT-73R Chart =+=+=+=+=+=+=+=+=+=+=+=+= 50 to 300 Mhz spread 220 to 550 Mhz spread -------------------- --------------------- Open bridges 8,9 Open bridges 7,8,9 +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+= +=+=+=+=+=+=+=+=+=+=+=FT-33R Chart =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+= Same chart as above, but I wanted to add my experience of the Yaesu FT-33R 220 Mhz radio. When I removed number 7 and then did a cold reset , the CPU cleared and showed me a L and a freq. I put .100 in. Press D/MR. Then a U appeared. I turned the VFo knob until 999.999 appeared. Press D/MR. I also had to reenter the Repeater Split to the proper value. On the VFO, I could QSY down to those limits (using F UP/DN) and listen to my local Channel 13 on 215.720/.660. Yes, 216-220 Mhz is available with this mod. Great if 216-220 is the next 220 subband. +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+= -NOTES-NOTES-NOTES-NOTES-NOTES-NOTES-NOTES-NOTES-NOTES-NOTES-NOTES- +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+= <1> Cold Reset of the CPU Board. With the radio upright and your nose pointing at the CPU board, look at the Lower Right Corner of the CPU chip. You will see two parallel SMT resistors. Below them is a screw with possibly a paper washer. To the right is a SMT device (it's a cap) with a pointed end facing Left. Ground that point to the screw or to the case with a flat screwdriver. Awhile doing that, cycle on/off the radio to ensure a good reset. Remove screwdriver and then reassemble radio. Dedicated to: ----- the knuckleheads in Barry Electronics who said it was impossible. ----- Yaesu Tech Support who claimed that there are no RESET circuits in their radios, when their schematic diagrams say otherwise. Special Thanks to: Ken, N2MUK, for playing the guinea pig. Bobbie, KB2IFJ, for playing surgeon when I told him not to. Please don't play with matches. W2Fwd.NY.USA.NA ---------------------- YAESU FT-23R case disassembly: ------------------------------ 1) Remove the black screws from the top panel of the radio. 2) Remove the knobs. 3) Remove the black screws from the rear panel of the radio. 4) Remove the battery. 5) Remove the 6 screws on the bottom of the radio, where the battery attaches. 6) CAREFULLY remove the front panel of the radio. 7) In the left of the microprocessor and battery are several printed circuit jumpers. The jumpers labeled 7, 8 and 9 are for the frequencie mods, like explained in the following. 8) Re-assemble the radio in the reverse order of these steps. 9) The Microprocessor will loose all what the memory contains. YAESU FT211/23/73 band mods: ---------------------------- The uP's in the FT-23R and the FT-211R/H can be set for several frequency and memory mode combinations. These modes are contorlled by the jumpers (solder pads) marked 7,8 and 9 on the processor board of either radio. Here's a list of what can be done: JUMPER CONFIG DISPLAY MODE 7 8 9 NUMBER open open in 1 140 to 164 MHz, amateur mode open in in 2 140 to 160 MHZ, amateur mode in open in 3 144 to 148 MHz, amateur mode in in in 4 144 to 146 MHz, amateur mode open open open 5 220 to 550 MHz, commercial mode open in open 6 440 to 450 MHz, amateur mode in open open 7 50 to 300 MHz, commercial mode in in open 8 430 to 440 MHz, amateur mode Both of my radios (USA) were shipped from the factory in config #3.. They can be converted to config #1 without re-tuning just by changing the jumpers. Tuning range can be further expanded by changing to jumper config #7. The FT-211 has separate VCO's for transmit and receive and will lock over about 38 MHz from approx. 130 to 180 MHz. The FT-23 has only one VCO and the overlapping lock range (Xmt & Rcv) is about 25 MHz from approx. 135 to 175 MHz. Don't forget, if you adjust the VCO you must re-align every electronically tuned stage in the front end of the radio. The transmitters can be tuned for somewhat higher power output above 164 MHz but at a great power loss at 2m.. The commercial memory mode will cause these functional changes: 1.When in the MR mode, the channel number will be displayed instead of frequency. You can toggle back to the original "amateur" mode display by pressing F. Pressing F takes you back to commercial mode. However, when switching from D to MR, the display will always revert to the commercial mode.. 2.The function of the Dot button will be exactly reversed. That means now you can press just one button (Dot) to get into or out of the Primary function. The Pri funtion (in memory mode) will be indicated by a large "P" on the left side of the display.. 3.The only indication of low power operation is in the memory mode.. A "C" will appear in the upper left corner of the display (where the primary "P" used to be). The bargraph will always read 100%.. 4.The band scan is now even more useless. The uP will painfully count from 50 to 300 MHz. I have been able to modify my FT-211RH to scan at about 10 chan/sec by speeding up the uP clock. This also speeds up every other uP function by x5, so you have to be fast on the "F" key. No squelch sensitivity or synthesizer lock-up problems have been encountered with this modification while scanning.. Basically, I replaced the 800 KHz ceramic resonater (pn CSB800K) with a Radio Shack 3.58 MHz color burst crystal. The resonater is located on a small (2.5 sq cm) sub-board that is stuck with double sided tape to the radio's processer board. This sub-board is actually an outboard clock for the uP. The schematic I got with the radio showed the uP's internal osc. being used - so I don't know if my version differs from newer radios. This mod works fine untill you turn the radio off and then back on again. A startup glitch then wipes out all of the memories. To delay the oscillator start up, I added a 220uF 10V electrolytic cap between the red wire on the sub-board and ground. Positive goes to the red wire. A convenient ground is the bare wire located diagonally across from the red wire (on the sub-bd).. So far I have been unsuccessful with this mod on the FT-23R H-T.. Since it uses the uP's on board osc, there seems to be no way to delay it's startup. Every time you turn on the power the uP resets.. If anyone can solve this problem I would be very interested in hearing from you! These are not intended to be step by step instructions. Also, you will want to have a service manual before you begin. If you're not familiar around surface mount components you may want to "learn" on something with cheaper consequences. Finally, don't adjust the VCO's unless you are familiar with how a synthesized radio works. Use your own judgement! The mods also worked the same way on my FT-73, therefore I can't get it to work from 430-450 MHz, unfortunately.. Hans W4/DG3SAJ @ WB4TEM.#BCRFL.FL.USA.NA ---------------------- Date: Wed, 18 May 88 10:25 EST From: To: MBRAMWEL@BUSINESS.UWO.CDN Subject: YAESU FT-23R EXTENDED FREQUENCY RANGE: "Circumcising" the FT-23R is remarkably simple. Removing one solder blob (pad #7, clearly marked, 10 o'clock position from the speaker, 9 o'clock from the microprocessor) lets the radio receive and transmit from 140.0 to 163.995 MHz. The two circuit boards with surface-mount components are uncluttered. When opening the radio, be careful not to lose the tiny coil-spring inside the battery-release button. I haven't measured receiver sensitivity, nor do I know about performance in big-city RFI; the FT-23R is considerably more sensitive at 162-MHz weather frequencies than is my modified Icom IC-02AT. [source: W9MKV] Copied from the QRZ! Windows Ham Radio CDROM