Modifications for the Yaesu FT-23
FT-23R power save off mods
Hi All, I would like to thank all who sent replys to my request for info
in trying to disable the power saver circuit in the 23r. I use it for
mobile and portable packet and have not had much luck in making it work
unless the freq. would stay busy.
The mod is as follows. Take apart the 23R and look at the control board.
There will be a bundle of wires tied together basically over pad #10.
It is marked, as 10. Soder a jumper across this pad or bridge with soder,
put the radio back together.
You will find that the battery life is not near as long with out the
saver circut. I would guess if you wanted to do some mode mod ification.
(Sorry Wasnt watching the line)
One could put in a very small switch and just disable it when needed.
I basically always use the battery eliminator so the battery life dosent
bother me. Thanks again to all the help.
Randy WD8EJC @ WD8EJC.NWOH.OH.USA.NA
FT-23R extended frequency range
Modifying 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.
Instructions on modifying the Yaesu FT-23R 2M handheld radio for operation in
the Civi Air Patrol service.
* * * * * * * * * * * * * * W A R N I N G * * * * * * * * * * * * * * *
This radio is NOT type accepted other to show Part 15 compliance. Operation in
any service requiring the use of type accepted equipment is in violation of FCC
************* ANOTHER MODIFICATION ************
Remove the 3 screws from the top of the radio.
Remove the dial knob
Remove the 2 screws from the back of the radio.
Remove the battery
Remove the 6 screws on the bottom of the radio, where the battery attaches.
CAREFULLY remove the front of the radio.
To the left of the microprocessor and battery are several printed
circuit pads. The pair labeled 7 will have a blob of solder across them.
Using a small soldering iron and solder wicking, remove the blob of solder.
Re-assemble the radio in the reverse order of these steps.
The Microprocessor will PROBABLY reset all the memory contents.
Operation of the radio remains the same, except that the transmit and
receive coverage will now extend from 140.000 Mhz to 164.000 MHZ.
THE YAESU FT-23R HT MAY BE MODIFIED TO RECEIVE(AND TRANSMIT) FROM
140MHz to 164MHz. TO DO SO, REMOVE THE SOLDER BRIDGE MARKED "7".
IT IS NEXT TO THE LCD DISPLAY INSIDE.
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 in 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:
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.
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.
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.
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%.
The band scan is now even more useless. The uP will painfully
count from 50 to 300 MHz.
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!
Extended frequency for FT-23,33, and 73
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
How to do it:
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.
(**)NO FREQUENCY READOUT
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.
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.
Dissassemble your tranceiver.
Find the line of solder connections running down the CPU board.
GENTLY move all wires aside so you won't melt them.
Using solder wick and a Good low-power soldering Iron,
see chart. Read special notes for the FT-33R.
Rebuild radio and count your blessings.
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.
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.
----- 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.
Yaesu FT-23R 2m walkie talkie anthology
by Frank Reid, W9MKV1
As the happy owner of several Icom radios, I went to a hamfest
intending to buy a new IC-u2AT but my friends talked me
into a Yaesu FT-23R instead. I'm glad!
Construction: The case is die cast metal (u2AT is plastic)
and is well protected against weather except as noted below
(see DTMF). The carrying case is rather unattractive, made
of odd smelling material; I don't trust its belt loop or
Velcro flap closure. I removed the belt loop and cut a slit
for the (optional) belt clip. I used a paper punch to round
the ends of the slit to prevent tearing.
Human Engineering: Yaesu did an excellent job of making a
complex radio easy to operate. I especially like the rotary
knob which selects presettable channels (10) or tunes in 5
or 10 kHz steps. Six keyboard buttons (one is an alternate
function key) control programming and scanning. UP/DOWN
keys duplicate the knob's function, and have an alternate 1
MHz "giant step" capability.
The keyboard lock function does not affect the rotary
switch. Keyboard lock (indicated by an "L" symbol on the
display) is remembered when the radio is turned off (good
idea!). The FT-23R has odd offset capability. A button
above the transmit switch unsquelches the receiver
(transmits tone burst on European model).
There is no display illuminator, which would be practical
with knob tuning; display lights in keyboard controlled rigs
are nearly useless when it's too dark to see the keyboard.
Not surprisingly, the tiny flat speaker isn't very
loud, and rattles terribly at full volume. Speech from a
belt mounted FT-23R is easily drowned out. It fits a shirt
pocket, somewhat inconveniently with DTMF2 and large battery
installed. It can be secured in a shirt pocket by hand lanyard
attached to epaulet of military style shirt, or longer
string with sliding cord lock, over the shoulder with loop
around opposite armpit.
Standard BNC connector. The "short rubber duckie"
supplied with the radio is more flexible than most similar
antennas, and appears very durable.
The optional Touch ToneTM generator mounts between the
radio and battery, plugs into a 4 pin internal socket, and
is attached by 4 long screws. It makes the radio about 3/4
inch taller, and 1/8" thicker. Other accessories, e.g., the
mobile power adapter, also mount between radio and battery;
one envisions a future fully equipped wlakie-talkie 3 feet
The delicate looking membrane type DTMF keyboard is not
sealed around the edges. There could be trouble if it takes
water. The DTMF keyboard has neither tactile nor audio
feedback, however, an LED lights when a button is successfully pressed.
3 The optional subaudible tone squelch module provides
"PL" encode . Actual tone squelch frequency is
displayed during programming (nice!). The tiny module ($61)
mounts above the battery attachment plate, and does not
extend the radio's length. CTCSS modes are "Encode" and
"Encode/Decode" but no decode without encode.
Memory Cloning: A cable from the earphone jack of one FT-23R
to the microphone jack of another transfers memory contents
(useful for emergencies). A switch on the bottom of the
radio (accessible by removing the battery) puts the radio
into clone mode. You cannot reach the clone switch if the
DTMF module is installed.
The FT-23R has CHANNEL-SCAN (all 10, with
lockout), PRIORITY SCAN (checks ch. 1 every 4 seconds) and
BAND SCAN (no presettable limits). There is no timeout
resume scan mode. Scan rate is 2 preset channels per
second. Band scan is much faster; 1 MHz in 9 seconds @ 10
kHz/step, 18 sec @ 5 kHz/step. I encountered NO "BIRDIES"
(spurious receiver responses) during 140-164 MHz band scan,
with a shielded 50 ohm dummy antenna.
Instructions: Well written in good English, but the book
contains NO schematic or block diagram (Boo!). The receiver
first IF is 10.7 MHz (not listed in specifications). Being
careful not to transmit, I connected the antenna jack to a
spectrum analyzer and found a -6 dBm (75 ohms) local oscillator
signal 10.7 MHz below the receiving frequency. The
spectrum analyser revealed a unique signature: the FT-23R's
battery saver feature turns the receiver off (for 600 ms)
and on (300 ms), in a cycle beginning a few seconds after
the receiver is squelched (and not scanning). I have
observed no bursts of TVI when the PLL relocks. Knowing the
IF allows using the image response trick to listen to ATC
while at airports. (Multiply first i.f. by 2, add to the
desired aircraft frequency, tune the radio to the sum; AM
comes through weak but readable.) I tried it at the local
airport; the Yaesu's FM detector does not perform nearly as
well on AM as does the Icom IC-02AT or IC-28H.
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. Too bad it won't do
National Park frequencies.
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
Receiver drain is 19 mA in power save mode. The FT-23R
operates at any voltage from 6 to 15v. Three rechargeable
battery options offer small size, long duration, or
high power. Rated output at 7.2 v is 2.5 watts; a friend's
rig and my own both produce 3.5 w with FNB-10 (7.2 v, 600
mAH) battery packs. Two replaceable cell battery packs are
available (six AAA and six AA). Alkaline cells are invaluable
for emergency service; AA cells are more cost-effective
than AAA's. The three NiCd battery packs require three different
wall-charger types (15-hour charge time). The
optional automatic fast charger charges any NiCd pack in 5 hours.
Speaker Microphone: One is available from Yaesu. The Icom
speaker-microphone works with Yaesu transceivers if a resistor
inside the spkr-mic is replaced with a lower value, and
It still works with Icom radios afterward.
My FT-23R, with DTMF and 7.2 volt 600 mAH battery, was $249
from some nice folks from Kansas City who didn't soak me for
sales tax, at least overtly.
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