From parnass@cbnewse.cb.att.com 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: parnass@cbnewse.cb.att.com (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: 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. (812) 335-0711 (w), (812) 339-7305 (h). reid@gold.bacs.indiana.edu, - 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 . 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. 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 @ ON7RC.BT.BEL.EU -- ============================================================================== Copyright 1993, Bob Parnass, AJ9S AT&T Bell Laboratories - parnass@ih4gp.att.com - (708)979-5414