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FT-900AT review by WB2WIK/6 | Radioaficion Ham Radio

FT-900AT review by WB2WIK/6

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The Yaesu FT-900AT HF Transceiver

Base station performance from a compact mobile rig!

review Yaesu FT-900AT

by Steve Katz WB2WIK/6

When given the opportunity to try out the _ new Yaesu FT-900AT for a product review, I thought. "Neat! This is a rig I thought about buying anyway—and now I can try one out before I do!N In early November 1994, FT-900AT serial number 41040690 arrived on my doorstep. By the end of that same day, I had already made 41 contacts with the little rig and had a pretty good feel for it, despite not having opened the Operating Manual at all! That's what I call "user friendly."

Overview

The FT-900AT is about as full-featured an HF rig as there can be in such a tiny box: Measuring only 238 x 93 x 253 mm (9.37 x 3.66 x 9.96*) (W x H x D) and weighing only 5.3 kg (11.66 lbs.), it packs "base-station* performance into a mobile-sized radio. The FT-900 and FT-900AT are identical, except that the "AT™ version includes a built-in automatic antenna tuning unit, me Yaesu ATU-2 (which can be added to the '900 in the field); however, the 'SOOAT, which has the tuner "factory installed," costs a bit less than buying the two units separately. All discussions herein, except those specifically pertaining to antenna tuner performance, apply to either mode!

The rig features a general coverage receiver (100 kHz through 30 MHz) and all-mode operation (CW( SSB. AM, FM, plus SSTV with outboard converter and digital modes with outboard TNC), delivering 100 watts PEP output power (within the ham bands only) from its sturdy, well-cooled transmitter. Output power is adjustable by a front-panel control down to approximately 1.5 watts for honest QRP work. Frequency tuning is accomplished by a large, easy-to-handle. rubber-coated VFO knob, or by pushing "up" or -down" buttons on the supplied push-to-talk microphone. The main display panel contains all the information needed to understand every critical control setting, with a large, easily-read LCD display of operating frequency. The features will be covered later in more detail, but the most significant feature, which differentiates the FT-900 from its predecessor FT-890. is the rig's removable front subpanel. The '900 s front subpanel. containing the most-used controls and microphone jack, disconnects from the radio's body with a push of one button ("click") and can be remotely located anywhere within about 19 feet of the radio itself, greatly simplifying mobile installation.

Opening the Carton

Impressive is the only word that describes Yaesu's excellent packaging job. Not only are all parts well-protected (the subpanel is packaged separately from the radio's body, giving the new owner an opportunity to try the panel's "mount/dismount" feature almost immediately), but Yaesu thoughtfully includes a world map showing updated amateur radio DXCC countries and prefixes, a large Yaesu decal (bumper sticker?), all the plugs required to put the radio into immediate service, spare fuses, a long DC power cable (dual-fused) and an excellent, easy-to-use, 50-page Operating Manual, complete with schematic diagrams. On the plus side for Yaesu, the manual is great. The "Operation" section contains a "Getting Started Tutorial' (2-1/2 pages) which offers sufficient informal ion to get on the air and start using the rig to its fullest, without having to read through dozens of pages of babble. On the minus side, the FT-900 manual, like most of those from the Japanese manufacturers, offers no hint of any circuit descriptions, theory of operation or a technical troubleshooting guide, Unfortunately, this is the norm for modern rigs from JA-land, so Tm not singling out Yaesu when I complain; the only manufacturer who provides essentially a complete "service manual'' right within their normally-supplied operating manual is Ten-Tec (an American company).

Controls

When I first acquire a new piece of gear, I like to see if I can make it work without opening the instruction manual. I won't even buy computer software that requires a substantial time investment in training, as I'm old-fashioned enough to consider it unreasonable for me to spend money on products that will take more time to learn than they coulo save me in the short term. The FT-900AT passed my test: 1 completed two log pages full of QSOs on both SSB and CW before I turned to page 1 of the book. Bravo! All ham equipment should be This easy to use.

The front subpanel controls are clustered for easy use. The TUNER switch both activates the Internal ATU for use (momentary press) and operates the ATU (longer press, same button), Hooray! No reason to use two switches when one will do. The POWER switch is a "soft-starf type with electronic time delay: A quick press neither turns the rig ON nor OFF. The switch must be depressed for about a half-second to toggle the POWER function. The MAIN TUNING knob has a great feel, and adjustable "drag" using a hidden setscrew* The DISPLAY screen has a warm orange glow with dark gray alphanumeric segments, and is easy to read in almost any lighting. It displays MODE; filter selection (NAR); GENeral coverage selection (as opposed to "ham" coverage); VFO status {A, B, or SPLIT); FAST tuning mode; dial LOCK; TUNER status (WAIT appears while tuner is searching); HI SWR indicator (if mismatch is too severe for the ATU to find a match point); operating frequency displayed to 10 Hz resolution with separate decimal point indicators; +/- offsets for RPT (repeater) mode; memory SCAN and CHECK status; CHannei number (01-99); MEMory status (V/M, V>M, M>V, and M TUNE); a CAT (computer aided transceiving) indicator; as well as a multrsegmented bar graph S-meter and ALC/SWR (switchable) meter (The S-meter always operates, displaying received signal strength or transmitter power output power; the other bar-graph display switches between ALC, SWR and "off," using the METER switch.) Whewl You think that's a lot? Just wait.

The removable subpanel also contains volume (AF) and squelch (SQL) concentric controls; IF NOTCH and SHIFT concentric controls, with a center-detent on the SHIFT control and a separate switch for the NOTCH function; DOWN and UP push-buttons for stepped frequency tuning; VFO and memory function push-button keys (as described above under ' memory status*); a FAST tuning push-button (a multipurpose key for fast frequency changes using the dial or the UP/DOWN keys—^nd also serves for making 11 different "FAST" set-up adjustments); mode keys (SSB, CW, AM, FM); and four LED-lighted keys for the speech PROCessor; receiver ATTenuator; receiver preamp bypassing (IPO); and noise blanker (NB). The CLARifier control, with its separate on/off switch and indicator, serves the same purpose as an RIT An LED lighted indicator also serves as a "TRANSMIT-BUSY" light (green when BUSY, red when TRANSMITting). Now you can say, "Whew!"

Despite the quantity of controls on the sub-panel (28), the FT-900 is not a confusing rig to operate, especially if you're familiar with other modem HF gear. A proponent of "simple" rigs, I don't like a lot of unnecessary knobs and switches, and I tend to really dislike "function" keys. The FT-900's panel is not cluttered, and there are no function keys. I found it surprisingly simple to use, and the controls are intelligently labeled for intuitive use right out of the box.

Besides the subpanel controls, there are these additional "main unit" front-panel controls, which cannot be adjusted by the subpanel (and thus are lost" to the user when remoting the rig): PHONES jack; MOX, VOX and AGC-Fast switches; MIC GAIN; RF PWR (xmtr output); KEYER switch and SPEED control; BK-IN (QSK) on/off; and the 12-button keypad used for either direct frequency entry (very handy—just like a "big" rig!) or rapid band changes. I love the direct-entry keypad. My "big" Kenwood TS-850S/AT has it, as have some of my other radios, but this is something not previously found on a smaller, mobile-type transceiver This is a major product improvement over the otherwise similar FT-890: Once you use direct-entry QSY, you'll find it hard to live without.

If, say, you are on 7238 kHz and want to instantly QSY to 28335 kHz and the latter frequency is not in a previously-stored memory, all you need to do is press ENTer, followed by 2-8-3-3-5, and then ENTer again, and—bingot— you're there. Much faster than changing bands and dialing around with the VFO. I once paid hundreds of dollars to get this feature as an option for a Collins KWM-380.(a $4,000 rig). Now, it's 'free," included in every FT-900.

The front-panel headPHONES jack accepts either stereo or monaural phones, and provides audio to both sides either way. The FT-QOO's rear-panel contains the DC power connector, ANTenna connector, and four less-frequently used controls: VOX GAIN, ANTI-TRIP, DELAY and speech COMPression level adjustments. I don't mind "losing" these controls in a remote/mobile setup, but would prefer to have at least the DELAY control right in front of me when using the rig at home, since this control adjusts not only the VOX drop-out timing for SSB, but also the drop-out delay for non-QSK {semi break-in) CW work, and might require frequent adjustment as one changes his CW sending speed One more point: The MIC GAIN control is lost when remoting the rig, and I think this is unfortunate, When operating mobile, the MIC GAIN is one control 1 find myself adjusting quite a lot, depending on background noise (low with windows closed, high with windows open) and operator's voice characteristics. (I "close talk" the mike and speak loudly, so I require a very low gain setting; others like to hold the mike back a few inches— not a good idea when operating mobilel—or speak softly and will require a much higher gain setting.)

The FT-900 does not have a receiver RF GAIN control! I didn't even notice this until Yaesu Service Manager Chip Margelli K7JA pointed it out. I didn't miss it, either: If a receiver has sufficient dynamic range and good AGC, one would very rarely have any reason to turn its RF GAIN down from "maximum." I can't remember the last time I purposely turned down the RF GAIN control on any of my rigs. Good riddance to this control. (Actually, there is just one example of when this control would be useful: When using highspeed CW on full QSK, it is nice to turn the receivers AGC "or altogether, turn the VOLUME way up, and use the RF GAIN like a "volume" control. Maybe one in a hundred operators would actually do this. I operate CW 95% of the time, and I haven't done it in years,)

Input/Output Ports

For a small rig, this one sure has a lot of I/O options! I applaud Yaesu's use of standard "RCA phono" receptacles for the following: +13.5 VDC (to power small accessories); PTT (for a footswitch or other remote PTT accessory); TX GND (circuit closes to ground on xrnit, to key a linear amplifier); PATCH IN (phone line input for patching); and EXT ALC (ALC connection to a linear amplifier). So many modem rigs place these functions on the pins of weird connectors we won't have handy. "Phono" jacks are easy to use, easy to find, and allow easy use of shielded cables to prevent RF! problems.

Besides those jacks listed above, the FT-900 also contains the following I/O ports: EXT SPKR {"mini" phone jack); DATA IN/OUT (three-contact "mini" phone jack, for TNC connection); TUNER (5-pin mini-DIN jack for the FC-800 external antenna tuner option); CAT (6-pin mini-DIN jack for external computer control of the FT-900); BAND DATA {8-pin mini-DIN jack providing control signals for the FL-7000 linear amplifier; could be used to provide BAND data for other amplifiers as well); KEY (3-contact "mini" phone jack, used for paddle connection when using the internal electronic keyert or straight key/outboard electronic keyer connection); and DVS-2 (7-pin mini-DIN jack for connection of the optional DVS-2 digital voice recorder). Also on the rear of the radio is the air inlet grill for the automatic forced-air cooling system, and a healthy GND (ground) terminal for attachment to earth ground. Sound like enough for a "mobile" rig? If you're getting the impression the FT-900 is nearly a base station radio, you're catching on. I applaud Yaesu's use of different types of connectors for the various options; there is no way one could inadvertently connect an accessory to the wrong jack—it won't fit Also, Yaesu provides detailed wiring pinouts for all the connectors, in pictorials large enough to read without a magnifying glass, on page 11 of the standard Operating Manual. And they supply every single connector you might need with the radio. (The only connectors not supplied are those which are prewired onto their unique accessories. If you don't buy the Yaesu accessories, you'll have no need for these plugs.)

The Receiver

There's a lot more to brag about with the FT-900. The rig's receiver employs "up conversion" (the 1st IF at 70.455 MHz is above the tuning range of the radio), like most modern rigs, to allow wide frequency coverage and reduce undesirable images. The 70 MHz 1st IF is shaped by two crystal filters (XF2001, XF2002) before amplification and conversion to the 8.125 MH2 "notch" IF or the 455 kHz final IE The second and third mixers are 3SK131 dual-gate MOSFETs and all injection frequencies are controlled by the rig s "LOCAL UNIT," a DDS system containing four separate VCOs (low-noise 2SK210 JFETs) to tune from 100 kHz through 30 MHz. The narrowest filtering occurs in the 455 kHz IF stage, where two field-reptaceable (solder-in type) SSB/CW filters, as well as the 6 kHz AM and 8 kHz FM filters are located. The "standard" 455 kHz IF filters are ceramic, while the narrower-bandwidth optional filters are crystal types.

The IPO (Intercept Point Optimization) switch performs the same function as Kenwood's A IP (Advanced Intercept Point) switch: It bypasses the receiver's dual 2SK125 JFET front end (RF preamplifier stage) and routes received signals directly to the active, balanced (quad of 2SK125S) first RF mixer. This is handy on the bands below 10 MHz, where signals can be quite strong and the noise figure is unimportant. The ATT (attenuator) switch adds a 12 dB "pad" between the antenna and receiver, but leaves the preamplifier stage active. Using either or both of these controls should eliminate almost any receiver overload situation, but may reduce sensitivity to the point where weaker signals just can't be heard. Unless you live very near a powerful shortwave broadcast station or use large gain antennas on high towers from a home station, receiver overload should not be a problem. (Overload when operating mobile is almost never a problem.) I'd like to see more receiver dynamic range {extended on the high end of the scaie) and fewer Band-Aids to patch up inadequacies, but unfortunately the designs and devices required to significantly improve HF receiver dynamic range can be too costly to include in amateur-grade equipment.

The FT-900's receiver noise blanker (NB) operates in the 455 kHz IF and is activated by a single push-button on the subpanel. It does a reasonable job of reducing ignition noise pulses, but does not have any 'threshold" or "width" adjustment as some of the more sophisticated base-station rigs do. The main job of a blanker in a mobile rig is to reduce intrusion of ignition noise pulses, and this blanker is adequate. For enhanced noise reduction in base-station operation, you might consider one of the popular digitally-processed noise reduction filters on the market.

The little Yaesu contains two good QRM-fight-ing tools which work well: The IF SHIFT adjusts the IF bandpass above or below the center of the IF, thus shifting response around the desired signal. The IF NOTCH filter operates in its own 8.125 MHz IF stage and allows adjustment of a steep (30 dB) IF notch within the IF passband, tunable about 1.2 kHz above and below the IF center frequency. Both functions are similar to those found in many modern HF rigs. The standard (SSB) ceramic IF filter is perfectly adequate for most operation. Yaesu offers an optional, sharper, crystal IF filter (XF-110S, $155) with steeper "skirts" (4.4 kHz @ -85 dB or so, compared with the standard filter's response of 4.4 kHz at -70 dB) for those who may benefit from the additional strong adjacent-signal rejection. Both filters have about 2.6 kHz bandwidth at -6 dB, which leads to nice-sounding audio from both the transmitter and receiver in the SSB mode. (See the note below regarding the TS-50S comparison.) There are two optional CW filters available for the '900, the XF-110C 500 Hz and the XF-110CN 250 Hz, which sell for $149 and $155 respectively. I found in using the XF-110C that it is much sharper than the SSB filter, but not nearly as sharp as the 500 Hz crystal filter in my old (1978 vintage) Drake TR-7. (Not that this is a fair comparison: The TR-7 cost over $2,000 16 years ago. By today's standards, it would be a $4,000 rig. And it couldn't possibly fit in my car!)

A feature of the '900's that CW ops will like is the "Reverse CW Sideband" function. This feature, accessed by depressing and holding the FAST button, then depressing CW, activates a special display screen indicating the sideband carrier injection "side" (U for "upper," L for "lower"). Rotating the main tuning knob allows the operator to revise the injection frequency (tf to L, or L to U), thus altering the way stations are tuned in on CW. This can be a good QRM-fight-ing tool; tf the rig is set up for "Upside injection and you have severe QRM above the frequency of the station you're trying to receive (and within or near the IF passband), you can switch the injection to "L" and make the interference fiteraily disappear. A combination of switching sideband injection, plus using the IF SHIFT control, works well in suppressing interference that would otherwise be impossible to contend with. My four* year-old TS850S/AT has exactly this same feature, and at the time it was introduced was the only HF ham rig on the market to offer this. The FT-900 is the first mobile-type rig I've seen with reversible CW sideband injection, and I hope others will follow. It works!

CW BFO Offset ("Pitch") is also adjustable in the FT-900. The factory default offset is 700 Hz, but if you prefer listening to higher or lower-pitched CW signals, you can alter the offset from 400 Hz to 1,000 Hz. To remind you of the offset you've selected, the CW sidetone produced by the speaker or headphones tracks the offset. In this way, when you tune in a station so his CW *pitch" sounds the same as the sidetone frequency, you are exactly zero beat with that station. The CW BFO Offset is another function activated by a "FAST" button combination: In this case, it's FAST, plus ATT

The Transmitter

The FT-900AT's transmitter is impressive. It delivers about 100 watts output into a 50 ohm load (see the sidebar for actual test data), and then goes a bit further by delivering nearly 100 watts output into some common mismatches, even without employing the ATU. For example, while the FT-900AT tested produced 100W output into my Bird Termaline" model 8201 coaxial resistor (a perfect load up to 1 GHz) at 7 MHz, it also produced 100W output into an antenna having a 2:1 measured VSWR, and didn t begin to "drop off1 in output power until the VSWR exceeded 2.5:1 Using the internal ATU, the 2.5:1 antenna (a CW-tuned dipole operated at the high end of the 'phone band) mismatch was perfectly corrected, and the output power increased again. I found a similar situation to exist on every band—the transmitter did not fall off significantly in output power until the measured VSWR exceeded 2:1. This is better than many radios I've seen where output power begins falling off rapidly with any mismatch at all. It might allow many users to get along without the optional internal tuner (ATU-2, $239) or the more fancy optional external tuner (FC*800, $429), especially if operation only with resonant base-station antennas is intended.

Perhaps a brief circuit description of the FT-900's power amplifier stage is in order, and will help us understand how the rig seems capable of nearly constant output power over a wide range of terminating impedances. The rig's "100W PA UNIT appears to develop about 26 dB gain using three cascaded stages: The first PA driver is a 2SC2166 in common-emitter, with slight degeneration and gain peaking by a 3300 pF capacitor across its 2.7 ohm emitter resistor. The PA driver stage is a pair of push-pull 2SC3133s, with emitters grounded and base bias regulation provided by an IC 8V regulator (uPC7808H). This stage drives the final pair of push-pull 2SC2879S via a 4:1 toroid transformer. The final PA's base bias is supplied by a 2SD882 series regulator and is adjustable. The PA's output is fed to the "LPF UNIT' via a 1:16 toroid transformer which matches the 3 ohm collector impedance of the PA to the 50 ohm filter impedance. The LPF UNIT contains six relay-switched low-pass filters: one each for 160, 80 and 40 meters, plus one each for 30/20m, 17/15m, and 12/10m. Each filter is a pair of pi-sections with tuned series elements and slight imbalance to achieve broadband impedance matching. The output from the filters runs through a directional coupler sampling both for ward and reflected power. These detector outputs are fed to both the rig's bar graph display and the "TUNER-CNTL-UNIT" to provide tuning status data.

The +13.5 VDC line to the entire PA unit is relay-switched by a PTT signal, so no bias is provided to the PA stages on receive. Final PA collector current may be measured using a 1 volt full-scale meter connected between two test points (TP4001, TP4002), and 0.5V means 20A collector current. The entire design is robust, and the only changes I would make if drafting It myself would be to eliminate the switching relay (and use solid-state cutoff bias switching instead); adding another set of test points to allow monitoring the individual collector currents of the two final transistors; and making the final stage bias individually adjustable, so that matched pairs of transistors would be unnecessary.

The FT-900 uses a ducted-air cooling system and very large heat sink to keep its power amplifier transistors cool, and its internal fan is thermostatically controlled to operate when needed. I found that a few minutes of transmitting at full power, either SSB or CW, caused the fan to come on, It's quiet enough that you won't notice it when using headphones, and you'd never hear the fan in a mobile installation (especially with the rig mounted in your trunk!), but it might be slightly distracting if operating with the speaker. Yaesu recommends running at reduced power (SOW) for continuous-duty modes such as RTTY or FM, especially in hot or humid weather.

Transmitted audio reports were very good, as were reports on keying when using CW. As usual, J got mixed reviews regarding the speech processor (which operates in the transmitter's IF stage): Some stations contacted said the rig sounded better with the processor on, while others said it sounded better with the processor off* This is pretty typical. The rear-panel COMPression level adjustment and front-panel MIC GAIN control do interact a bit, and both are probably best adjusted by listening with headphones on a separate receiver. The ALC level bar graph display is also a handy tool for making these adjustments. The FT-900 does not contain a "monitor" function which allows listening to one's transmitted audio. I'll admit I miss that feature, as I find it handy on my TS-850S/AT and other "base station" radios l1ve used. With the FT-900 and most other ham rigst it never pays to adjust the mike gain or compression level so high that the ALC meter runs above its "normal" range. Too much mike gain makes anyone sound bad and increases background noise. Excellent examples of "too much mike gain" can be found on the bands daily, unfortunately.

The FT-900's speech processor has a frequency-shift feature, which allows shifting the IF passband of the transmitted signal in the SSB mode 4Jto customize your signal for your own voice characteristics" (to quote the manual). The processor offset is adjustable from -300 to +500 Hz; a minus sign (negative shift) emphasizes lower-frequency speech audio, while a plus sign (positive shift) emphasizes higher-frequency modulation. Yaesu recommends starting out with a +100 shift, to add "crispness" to your processed speech. This seemed to work fine for me. The adjustment is performed by pressing and holding the FAST button, and then the PROC button. The display then indicates the precise processor frequency shift, which can be adjusted by turning the main tuning knob. To return to normal operation, you just press the PROC button once more. Easy!

Operating

As with most modern digital radios, the FT-900 has a variety of menu functions. I've already discussed a few of the "FAST setup functions (used by depressing the FAST key plus one other key, white the radio is already powered up). There are 11 FAST button combinations, plus another 11 power-up functions. These are functions activated or toggled in status by depressing one front-panel key or another while turning on the radio. For example, to disable the beeper confirmation tone generator (which beeps every time you depress a front-panel key), just hold down the NOTCH key while turning on the radio. To adjust FM repeater offset ("shift," which has a 100 kHz factory default), depress FM while turning on the radio; this brings up a "shift" display, which can be altered in 1 kHz increments, using the UP or DOWN keys. These are just two of the power up functions. The other nine are similarly useful.

Almost all QSK (electronic break-in) radios can also operate in the Wsemi-GSK" mode. This is often required when using an outboard linear amplifier, since most cannot support full break-in operation. In many rigs, you must remove a lop or bottom cover to locate a switch that activates a relay for keying an outboard amplifier, and from that point forward you've lost full-QSK capability until the switch is returned to the "off" (QSK enable) position. Not so with the FT-900. This rig has such a switch, but it s located on the bottom of the radio and can be accessed through a hole in the bottom cover. No covers nor screws need be removed to enable or disable the amplifier keying relay. You could easily flip this switch a dozen times a day. and not mind it. Another easy adjustment can be made to the sidetone and beeper volume control, which is accessible through a hole on the left side-panel of the rig. No covers need be removed to make this adjustment, either. Very thoughtful!

Another interesting feature of the FT-900 is the RIT "Clarifier" (CLAR) tuning range and operation. The CLAR tuning range is +Z-9.99 kHz (a very wide range indeed!) and its tuning steps are adjustable by 2.5, 5.0 or 10.0 Hz increments. The factory default increment is 5 Hz, which makes the CLAR tune awfully slowly, I immediately changed it to 10 Hz, which makes the control tune faster but still have enough resolution for easy use. The CLAR works independently for each VFO, each band, and each of the 100 memories. It may be turned "on* and "off by a separate push-button, but the CLAR has no center detent to remind you when you've returned to zero offset

The ATU-2 automatic antenna tuner works well and is easy to operate. However, the simple circuit (six fixed and two variable capacitors, seven inductors, 14 relays controlled by a microprocessor TUNER CNTL UNIT) can take quite a long time to "find* a suitable match under some conditions. I tried using a 190-foot long, center-fed doublet (fed with 450 ohm "ladder line" and a matching transformer coupling to a long coaxial feedline to the shack) as a test antenna, presenting varying impedances and phase angles to the FT-900ATs antenna jack. On some frequencies, the ATU-2 found a match very quickly, in a second or two. On others, it was still searching after nearly 30 seconds—although even in these cases it did not give up, and did finally find a match point. Thirty seconds is a long time to wait for an automatic tuner, but is still faster than manual tuning. I tried the same test doublet on my Kenwood TS650S/AT base station rig, and it found a match considerably faster on those frequencies that were troublesome for the ATU-2. The TS850's ATU RF circuitry is not terribly different from the Yaesu ATU-2+s, so the difference might be in the firmware, In any case, once the '900AT finds a good match, it retains that data in one of its 31 tuner memories which compare tuner settings to operating frequency. If you always use the same antenna for each band, the memories will automatically operate the tuner as you change bands and frequencies and make rapid QSY much easier. However if you change antennas on each band (say. you use two antennas for 20m. three for 40m, and so forth), the tuner memories cannot do their job. This problem is not specific to the FT900AT; all the ATUs work this way.

The FT-900 contains (standard) a full-featured internal iambic keyer for CW enthusiasts, and it works well. The keyer has dot:dash weighting control, "defaulted" at 1:3. If you wish to change this, you may do so with another FAST function (FAST + IPO brings up a '"weighting" display). I found the internal keyer delightful to use, but wish it had storage (memories). Stilt, not bad for a mobile rig!

Note: A local buddy (Gary K06GT) owns a Kenwood TS-50 HF mobile rig and we thought it would be fun to compare the FT-900 to the TS-50, considering that the little Kenwood may be the '900's only real competition for the mobileer market. The TS-50 is not available with an internal ATU, and lacks many of the sophisticated panel controls of the FT-900; however, it is a good working radio that has been well-received by mobile/portable enthusiasts, and some even use it as a base station. We set up the TS-50 and the FT-900AT side by side, with a coaxial switch to rapidly change antennas from one rig to the other. While the TS-50 is an excellent product and the envy of many mobileers, the FT-900 was found to be far more functional in a variety of ways. The FT-900*s receiver "sounded" better, to quote Gary, who owns a local recording studio and has an educated ear The '900 has a tighter standard IF filter, making for less hiss and more signal when tuning around the bands. While both radios were more than capable of digging down in the dirt for weak signals on the higher bands (21-28 MHz), signals sounded a bit more readabte on the FT-900. In my opinion, this was due to a combination of factors, including narrower IF filtering, different audio frequency response and a better internal speaker which produced louder-sounding signals. (Note that when "remoting" the FT-900. you lose its internal speaker and must use an external oneT which plugs into a recessed jack in its subpanel.) On transmit, Gary's TS-50 actually produced more output power than the FT-900, but he had "goosed' his rig up in output power by making internal adjustments, so this was not a fair test. Despite the field adjustment which produced greater transmitter power from the TS-50 into a dummy load, the FT-900AT produced more power into real antennas which were less than perfect. (None of my antennas are perfect. Just like their owner.) ft was an interesting comparison. Gary likes his TS-50 but admitted that he'd rather have the FT-900, and if they were both the same price (they're not), the '900 would "win" in his book. My suggestion, as always, is to try out everything, and make a product selection which is best for you.

This Separation Isn't Painful

The FT-900 front subpanel detaches in about one second and the operation involved could easily be handled by my three-year-old (no chance that I'll let hert). To remote the rig from the subpanel, you'll need to purchase Yaesu's YSK-900 Separation Kit. which retails for a mere $56 and includes a 19-toot cable to Interconnect the two, plus a mounting bracket for the subpanel and a set of mounting brackets for the rig's "body," Since the mobile PTT mike plugs right in* to the subpanel using an 8-pin telephone-type modular plug ("click"—it's in)t all you need to add for a neat mobile installation is a speaker (a mini phone jack is in a recessed socket in the rear of the subpanel), and something to mount the sub-panel on. Yaesu recommends a gooseneck-type mounting fixture (not supplied), but I think even Velcro strips would work, as the subpanel weighs almost nothing. Yaesu provides a sheet titled "Important Advice on Mobile Installation and Operation," which recommends routing the DC power cable, antenna coaxial cable and sub* panel control cable in separate paths (not bunched together in parallel). The DC power cable shouid, of course, be connected directly to the car battery and not taken from the cigarette lighter or fuse panel. Even following Yaesu's careful precautions, mobile installation should not take more than one hour. I tried it, and had the rig professionally installed in 45 minutes, including routing all the cables under the carpeting (ugh!) and hanging a mike bracket on the dashboard.

Mobiiing with the FT-900AT is a breeze. While mobile whips usually don't load up well across an entire amateur band (especially below 20 meters), the ATU helps generate a powerful signal from even modest antennas like my Hustler system. My first mobile contact with the FT-900AT was with JA1LZR in Tokyo on 17 meters. Joe gave me a u56" report. My next contact, with ZP6CW, yielded a "559" report on CW, also on 17 meters. (Yes. I'm one of those nuts who operates mobile CW.) The best part is: I was using a 20 meter whip! (My HustJer RM-20S was all tuned up on 14.150 MHz and had an SWR of greater than 3:1 at 18 MHz. I used it anyway, and the ATU-2 did its job and got me some DX!)

Options and Accessories

I've already mentioned some of the available options for the FT-900. There are others. The TCX03, a high-stability reference oscillator for the '900 frequency synthesizer, is available for $95. The DVS-2 digital voice synthesizer, capable of recording from the FTSOO's mike or from its receiver (playing back other hams so they can hear themsejves is kind of fun!) retails for $279, The SP6 base-station speaker is $149. The mobiie bracket, if you want to mount the radio as one unit without the separation kit, is $29. A sharper SSB IF filter model XF100S, retails for $155.

While I would opt for a CW filter (XF110C, $149; or XF110CN. $155) because I work a lot of CW, my feeling is that if you load up on lots of accessories to make this a base station, you might be better off with a real full-featured base station rig like an FT-1000, Jf a small, mobile-type radio could become a wonderful do*everything base-station, then not many FT-1000's would have been soid. On the contrary, lots of FT-10O0's have been sold, and this is one of the choice radios tor big-gun DXers and contesters. They know what they're doing.

On The Air!

If you've read this far. you know I like the FT-900AT It's a very worthy radio that would make a great addition to my shack or car (and probably will). But how does it work in real life, on the air? Just great!

 

The FT-900 does most things well, and some things superbly. It is not an FT-1000, but then, it doesn't claim to be. It's a well-

equipped mobile-portable-Fieid Day rig that witl serve as a good base station for many operators. Small as it is, if you're revamping your station and wish to replace an older-generation HF rig, you're in for a great surprise— the FT-900 will perform rings around many older radios, at a price not much different from the original acquisition cost of the older gear. For mobiieers, what can I say? The FT-900 is a bright star shining in the vast darkness created by too-small automobiles and too-large radios. All in all, I loved this rig.

Note regarding the FT-900 bar graph output display:

The FT-900 uses a 31-segment LCD bar graph to indicate power output (W) and S-meter readings. This allows very fine resolution for small incremental changes In output or received signal strength and is one of the best bar graph displays reviewed. Its accuracy was equivalent to many of the analog meters found on similar or higher-priced equipment, and of greatest surprise was its "S-meter" accuracy on FM. Most "S-meter" readings on FM receivers, whether the display be analog or digital, are highly inaccurate and might be used for relative indications only; not so with the FT-900, where the "S-metef readings on FM are almost as meaningful as they are on SSB/CW modes. I wish the VHF/UHF FM equipment makers would find out how to do this! (Data taken by WB2W1K/6 11-23-94)

FT-900 Measurements

review Yaesu FT-900ATreview Yaesu FT-900AT

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