From parnass
Newsgroups: rec.radio.amateur.equipment
From: parnass
Subject: Yaesu FT-23R 2m walkie talkie anthology
Organization: AT&T Bell Laboratories, Naperville, IL
Date: Mon, 20 Sep 1993 13:55:17 GMT
Message-ID: . 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.
Scanning: The FT-23R has CHANNEL-SCAN (all 10, with
lockout), PRIORITY SCAN (checks ch. 1 every 4 seconds) and
__________
2. DTMF - dual tone multi frequency
3. CTCSS - continuous tone coded squelch system
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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
kHz/step, 18 sec
(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 oscil-
lator 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
Icom IC-02AT.
Power:Receiver drain is 19 mA in power save mode. The FT-
23R operates at any voltage from 6 to 15v. Three recharge-
able 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 invalu-
able for emergency service; AA cells are more cost-effective
than AAA's. The three NiCd battery packs require three dif-
ferent wall-charger types (15-hour charge time). The
optional automatic fast charger charges any NiCd pack in 5
- 4 -
hours.
Speaker Microphone:One is available from Yaesu. The Icom
speaker-microphone works with Yaesu transceivers if a resis-
tor 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.
MORE ON THE YAESU FT-23R
by Bob Parnass, AJ9S
Frank's comments on the FT23R walkie-talkie were persuasive.
I bought an FT23R, an extra 7.2 V 600 mAH battery, mobile DC
adaptor, PL encode/decode deck, and the AA dry cell case.
I filled the $12 AA dry cell case with six 550 mAH Sanyo
NiCd batteries, purchased for an additional $12 at a ham-
fest.
The Yaesu belt clip looks flimsy, so I bought an ICOM belt
clip (for the ICOM mini-talkie) and reamed the holes to fit
the FT23R. The spring steel ICOM clip is $2 cheaper and
fits my belt better.
If I had bought the Touch ToneTM pad with the radio, it
would have cost and additional $30. If pad is $50 if pur-
chased separately.
Since the same radio case is used in the FT23R and its
industrial cousin, the FT23R is built rugged, much more so
than its Kenwood and Icom competitors. Reminds me of how my
Motorola HT220, or a GE Pocket-Mate feels. The rubber
gasketing on the case top and side is impressive. In con-
trast, the case bottom, near the battery plate, is open,
although dust should be prevented from entering as long as
the battery is in place.
My fingers aren't big, but seem huge when trying to push the
closely spaced rubber buttons or twist the knobs on the
Yaesu.
After verifying that the stock radio worked, I carefully
opened the case, then made the modification for full 140-164
MHz coverage. There appears to be no modification to enable
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out of band receive without transmit. This made my dealer
nervous, and fearing FCC action, he posted a sign warning
that no out of band receive modification was available. The
tiny surface mount components on the circuit boards mark a
turning point in amateur radio construction, when owners may
no longer be able to service their walkie-talkies.
I connected the FT23R to a variable voltage, current limit-
ing bench power supply. The receiver section must have vol-
tage regulation, as increasing the voltage input from 7.2 to
13.6 VDC caused no difference in receiver current consump-
tion.
The fastest charger available for the FT23R is a 5 hour
unit. It contains a timer, rather than the more sophisti-
cated thermistor and temperature-0 sensing arrangement of the
Kenwood and Motorola rapid chargers. Rather than buy the
fast charger, I use a bench power supply connected though a
power resistor, and adjust the current for 180 mA, the
appropriate 5 hour charge rate.4
When in battery save mode, the current consumption alter-
nates between 5 mA and 50 mA.
Based on comparative S-meter readings, the 4.5 inch flexible
antenna supplied with the FT23R doesn't hear quite as well
as its longer counterpart.
The method of locking out channels is cumbersome, and it's
too bad that channel 0 cannot be locked out of the scan.
There must have been an early batch of 23R's with a firmware
bug, as my unit was packed with an errata sheet, which said
early units behaved differently when using the priority mode
on certain channels.
__________
4. I calculate the charge current, in milliamperes, as 1.5
* C/H, where C is the battery capacity (600 mAH for my
battery), and H is the desired charge duration in hours.
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ANOTHER YAESU FT-23R
OWNER COMMENTS
by Bob Moore WA2JFM5
I just purchased an FT23R, and like it very much. It was
chosen as the least expensive 2 M walkie talkie with over 3
memories available at the Rochester (NY) Hamfest. I con-
sidered the DTMF pad as part of the unit and price. The
unit turns out to also be rugged and well built; audio is
excellent, and size is handy. The PL does need to be pur-
chased as a single (very simple) unit. Installation of the
PL is shown in the manual, and is simple. The microproces-
sor does all the programming and remembering of PL frequen-
cies along with the transmit and receiver frequencies.
My only reservation is the relative complexity of the con-
trols -- that seems to be common in modern ham gear -- and
the size of the knobs and buttons. There is a lot more
functionality than you would ever expect in an walkie
talkie. I would also recommend purchasing the quick charger
and the large battery pack.
I hope you enjoy the unit as much as I have.
FT-23R MODIFICATIONS
copied from packet:
Msg# TSF Size #Rd Date Time From MsgID To
33018 BF 5506 0 13-Jan 1158 F1LOU 30537_ON7RC YAESU
Sb:FT23/73/211 mods
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
__________
5. Bob Moore WA2JFM, GCA/Tropel Div. Rochester, NY 14450,
ihnp4!tropix!rcm
- 7 -
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 con-
tains.
YAESU FT211/23/73 Band Mods
The uP's in the FT-23/73 and the FT-211 can be set for many
frequency and memory mode combinations. These modes are con-
troled by the jumpers (solder pads) marked 7,8 and 9 on the
"CONTROL UNIT" board of either radio. Here is a list of what
is possible:
JUMPER FREQUENCIES
7 8 9 COVERED
open open in 140 to 164 MHZ
open in in 140 to 160 MHZ
in open in 144 to 148 MHZ
in in in 144 to 146 MHZ
open open open 220 to 550 MHZ
open in open 440 to 450 MHZ
in open in 50 to 300 MHZ
in in open 430 to 440 MHZ
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 realign every elec-
tronically 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 non-amateur (commercial) memory mode will cause these
functions changes:
1. When in the MR mode, the channel number will be
displayed instead of frequency. You can toggle back to
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the original "amateur" mode display by pressing F. Pressing F bring you back to com-
mercial 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.
FT23/73 in packet-radio:
If you want to work in packet-radio, open jumper 10 to
dissable the battery save.
73's de Phil, F1LOU
--
==============================================================================
Copyright 1993, Bob Parnass, AJ9S
AT&T Bell Laboratories - parnass
