QRZ! Ham Radio 16/QRZ_16.iso/modfiles/f723txt.txt

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From [e-mail] Thu Sep 23 10:58:58 1993
Newsgroups: rec.radio.amateur.equipment
Path: news.cs.tut.fi!news.funet.fi!sunic!uunet!elroy.jpl.nasa.gov!usc!howland.reston.ans.net!vixen.cso.uiuc.edu!uwm.edu!linac!att!cbnewse!parnass
From: [e-mail] (Bob Parnass, AJ9S)
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: <[e-mail]>
Keywords: three reviews, modifications
Lines: 503






                           - 1 -



                   YAESU FT-23R ANTHOLOGY

               compiled by Bob Parnass, AJ9S




                    YAESU FT-23R 2-METER
                    HANDHELD TRANSCEIVER

                   by Frank Reid, W9MKV1

As the happy owner of several Icom radios, I went to a  ham-
fest 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.



__________

 1. Frank Reid, W9MKV, Indiana University Academic Computing
    Services, Bloomington, IN 47405 tel. [phone] (w),
    [phone] (h).  [e-mail],












                           - 2 -



Audio: 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 lan-
yard attached to epaulet of military style shirt, or  longer
string  with  sliding cord lock, over the shoulder with loop
around opposite armpit.

Antenna: Standard BNC connector.  The "short rubber  duckie"
supplied  with  the radio is more flexible than most similar
antennas, and appears very durable.

DTMF: 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
long!

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 success-
fully pressed.

CTCSS:3 The optional subaudible tone squelch module provides
"PL"  encode <AND DECODE>.  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












                           - 3 -



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  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











                           - 5 -



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 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.












                           - 6 -



                    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@WW ()
 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











                           - 8 -



      the original "amateur" mode display by pressing  F<up-
      arrow>.  Pressing F<down arrow> 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<Pri> 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 @ ON7RC.BT.BEL.EU

--
==============================================================================
                       Copyright 1993,  Bob Parnass, AJ9S
         AT&T Bell Laboratories  -  [e-mail] - [phone]