Product Review Column from QST Magazine
December 1996 QST Compares: Multiband FM Mobile Transceivers (Alinco DR-605T; ICOM IC-2710H; Standard C5900DA; Yaesu FT-8000R) Timewave DSP-599zx Digital Signal Processor
Copyright 1996 by the American Radio Relay League Inc. All rights reserved.

Product Review

Edited by Rick Lindquist, KX4V Senior Assistant Technical Editor
QST Compares: Multiband FM Mobile Transceivers
Reviewed by Steve Ford, WB8IMY Managing Editor Why limit yourself to only one band when you can enjoy the best of two worlds (or, in some cases, the best of three worlds)? Hams who live in areas that offer FM activity on more than just 2 meters are asking the same question. The answer is simple: Buy a dual-band or multiband FM transceiver! For less than the price of separate radios, these modern multiband rigs offer two (or three) bands, plus all the features of single-band unitsand sometimes more. Its not uncommon to find such handy items as full-duplex crossband modes that allow you to listen on one band while transmitting on another, scanning features that exploit the ability to conveniently eavesdrop on both bands, detachable front panels for easier mobile installation, and much more. (Detachable panels have become even more desirable in recent years as automakers have made the drivers seat more like a cockpit, surrounded by console-mounted instruments and controls, with little room for ham radios.) Some of this current crop of units provide AM aeronautical reception, while others include extended receive and/or transmit coverage below 440 MHz (critical for working the Russian Mir space station repeater and the OSCAR 27 satellite). Others go the extra mile to offer packet operation at 9600 baud with dedicated data jacks. (See our Features table for a side-by-side comparison.) By the way, all of the units in this review have single antenna connectors and built-in diplexers. Since most hams are using dual-band antennas these days, this approach is becoming the norm. Youll need an external diplexer if you want to run separate antennas for each band. Our last comparative review of dualband and multiband radios was in our November 1995 issue, when we looked at eight transceivers. This time around, QST puts the Alinco DR-605T, the ICOM IC-2710H, the Standard C5900DA (the only triplebander) and the Yaesu FT-8000R side-byside. Kenwood continues to offer the two radios we included in our last dualband reviewthe TM-742A (which provides 2 meters and 70 cm, plus a choice of 10 meters, 6 meters, /4 meters and 23 cm) and the TM-733A. After the ARRL Lab completed its testing, four ARRL Headquarters staffers took the radios and put them through their paces. Our evaluation team consisted of Paul Danzer, N1II; Peter Budnik, KB1HY; Rich Roznoy, KA1OF; and Rick Lindquist, KX4V.

Alinco DR-605T

Multiband FM Mobile Transceiver Features
Alinco DR-605T 144/430 S S X
n/a 50 / / 5 50+CALL S X O X X S S S S X X $512 $453
Bands (MHz) Extended VHF reception (FM) Extended UHF reception (FM) Aviation band reception (AM) Specified output-power levels (W) 50 MHz 144 MHz 440 MHz Memory channels per band Band, memory and programmed scan Alphanumeric memory naming CTCSS decoder DTMF decoder DTMF autodialer 9600-bit/s packetready Dedicated TNC jack Crossband repeat Mir /OSCAR 27ready Detachable front panel Dual speaker jacks Manufacturers suggested retail price Typical selling price as of 10/96 Key S = Standard O = Optional X = Not available
ICOM IC-2710H 144/440 S X S
n/a 50 / 10 / / 10 / 5 99+CALL S X O O S X X S X S S $857 $700
Standard C5900DA 50/144/420 S S S
45 / 10 / / 10 / / 10 / S X S S S S S S S S S $1050 $ 880
Yaesu FT-8000R 144/430 S S S
n/a 50 / 10 / / 10 / 3 54+CALL S X O X S S S S S X S $700 $542
Typical selling prices represent an average of street prices obtained from three equipment retailers, exclusive of any sales, coupons or rebates.
The Alinco DR-605T offers two bands in an economy package. Although it lacks the luxuries of other radios in the group, you get the essentials at a price that wont strain your budget. Its no slacker in the performance department either (see the table). Alinco has been marketing this radio as very affordable, and its street price was the lowest of the lot. The front-panel layout is straightforward and easy to understand, and it has just 10 controls. The main and sub bands have separate VOL ume controls. You switch bands by simply pressing the VOL knobs. A large VFO knob facilitates quick tuning while the large FUNCtion buttonoff by itself on the extreme left-hand side of the front panelis hard to miss. Big buttons and knobs are appreciated most when youre trying to adjust the radio without taking your eyes off the road. The single VFO knob, means you have to select the main band before tuning. Button placement on the microphone could be a problemdepending on how you hold the mike. If youre right-handed, you might inadvertently press the UP button by mistake while pushing the PTT button, especially if you normally put the gorilla grip on the mike. Setting the LOCK switch on will cure this.

ICOM IC-2710H

Reviewers judged the readability of the display as adequate. Its visible in most conditions and at all angles except from below, but you cant change the displays brightness. The only display-related flaw involves the upside-down mirror images of button legends that appear to be reflections from the bottom edge of the plastic bezel. Theyre very visible when viewing the radio from above. You wont be able to listen to AM aircraft transmissions with the DR-605T, but it does offer extended 70-cm coverage, which places the OSCAR 27 and Mir repeaters at your disposal. Using the transceivers mainband transmit/subband receive function we made several contacts through OS-
CAR 27 while mobile and portable. Speaking of listening, the DR-605T uses a programmed squelch that you can access only by pressing the FUNCtion button, then using the left and right VOL buttons to raise or lower the squelch setting for the main and subbands. This was not a hit with users. Unless you set the squelch somewhat high to begin with and are content to leave it that way, this feature can be quite annoying. The DR-605T also does not have automatic repeater offset, a common feature these days; you have to set it manually. Packet operation at both 1200 and 9600 baud is possible with the DR-605T, but during ARRL Lab testing, we found we could not achieve more than 1.8 kHz devia-
The IC-2710H is a sleek 2-meter/70-cm radio that you can install in any automobile. Its also a rugged radio. The entire top and back of the rig are dominated by a hefty heat sink, which is bolstered by a small

December 1996 61

ICOM IC-2710H, serial no. 01117
Manufacturers Specifications Frequency coverage: Receive, 118-174, 440-450 MHz; transmit, 144-148, 440-450 MHz. Power requirements: At 13.8 V dc: Receive, 1.8 A (max); transmit, 12 A (max). Size (height, width, depth): 1.65.58.5 inches; Receiver Sensitivity: For 12-dB SINAD, less than 0.16 V.
Measured in ARRL Lab Receive, as specified; transmit, 140-150, 440-450 MHz.
At 13.8 V dc: Receive, 1.1 A (max volume,) no signal); transmit, 10.3 A (max). weight, 3.1 lb.
Adjacent-channel rejection: Not specified. Spurious response: 60 dB or greater.
Squelch sensitivity: less than 0.13 V at threshold. Audio output: More than 2.4 W at 10% THD into 8.
Receiver Dynamic Testing For 12-dB SINAD: 146 MHz, 0.12 V; 440 MHz, 0.14 V. AM (120 MHz): 0.35 V for 10-dB (S+N)/N. 20-kHz offset from 146 MHz, 59 dB; 20-kHz offset from 440 MHz, 62 dB;* 10-MHz offset from 146 MHz, 74 dB; 10-MHz offset from 440 MHz, 76 dB. 20-kHz offset from 146 MHz, 64 dB; 20-kHz offset from 440 MHz, 62 dB. IF rejection: 146 MHz, 107 dB; 440 MHz, 136 dB. Image rejection: 146 MHz, 90 dB; 440 MHz, 89 dB. 146 MHz: 0.05 V at threshold. 440 MHz: 0.08 V at threshold. 2.8 W at 10% THD into 8.
Transmitter Transmitter Dynamic Testing Power output: 146 MHz: 50 / 10 / 5 W; 146 MHz: 53 / 11 / 5 W; 440 MHz: 35 / 10 / 5 W. 440 MHz: 33 / 9 / 5 W. Spurious signal and harmonic suppression: As specified. Meets FCC requirements for 60 dBc or greater. spectral purity. Transmit-receive turnaround time (PTT 146 MHz: Squelch on, 118 ms. release to 50% of full audio output): 440 MHz: Squelch on, 118 ms. Not specified. Receive-transmit turnaround time (Tx delay): 146 MHz: 150 ms; 440 MHz: 145 ms. Not specified. Default main receiver performance. Subband receiver performance was comparable. *Measurement was noise-limited at the value indicated.

cooling fan on the back panel. The fan ran with the radio cool; the radio did not get hot even with long transmissions. The rather stylish front panel is also detachable (youll need an optional separation cable). In fact, you must detach it to connect the microphone. The HM-98 microphone supplied with the radio offers tremendous flexibility. Once you remove the cover to expose the DTMF keypad, you can control most of the radios important functions from the microphone, including direct frequency entry (not something you should try while under way, however). For example, changing bands from the mike is as easy as thumbing the BAND button. Function buttons F1 and F2 can be programmed to duplicate any front-panel buttons. The DTMF buttons automatically put the active band into transmit and provide audible feedback of the tone. The microphone buttons are backlighted for nighttime operation. An optional infrared wireless microphone system (HM-90 transmitter and EX-1759 receiver) is available for the IC-2710H, but it wasnt tested for this review. The wired HM-98 microphone uses the increasingly popular RJ11-style jack, or

62 December 1996

what some refer to as a telephone jack, and it plugs into the body of the transceiver, behind the front panel. In labeling the pin connections, the manual labels one conductor as DATA IN. This is obviously for packet operation (no doubt the transmit audio input), but the book doesnt provide further clues. Because there isnt a DATA OUT jack on the rig, were left to assume that youd have to pick up your packet receive audio from one of the speaker jacks. That implies that the IC-2710H is suitable for 1200-baud packet only. There are two separate tuning knobs, always a welcome sight on a multiband transceiver. You can designate one to control the main-band frequency and the other to control the subband. (You can transmit only from the main band.) When the transceiver is in the memory mode, twisting the tuning knobs steps you through the memory channels. The tuning knobs also control scan direction. ICOM uses separate VHF and UHF RF receive circuits for both sides of the display, so you can dial up two VHF or two UHF frequencies at the same time and expect comparable receiver performance of either side. The IC-2710H also features separate SQUELCH and VOLUME

controlsone set for each bandadjacent to the tuning knobs. Other front-panel push buttons control DTMF encoding (on/off), CTCSS encoder (on/off), memory, scanning, VFO step size and so on. Our reviewers praised the fact that these switcheslike the tuning knobsare arranged in duplicate banks on the right- and left-hand sides of the panel. In other words, each band has its own bank of switches; and each side of the display is essentially a mirror image of the other, with the power switch right smack in the middle. This goes a long way toward reducing operator confusion! Display visibility is good, except it fades somewhat when viewed from above, and considerably from below. The IC-2710H is packed to the brim with features, but there are several that our reviewers found particularly useful. The ability to receive AM signals in the aeronautical band can provide some entertaining listening, although you must select the AM detector manually. Sub-band muting kills the sub-band audio if the main band is active at the same time. The priority watch function does more than just monitor a single memory channel for activity. You can set the watch to scan all memory channels while you monitor other activity with the VFO. The IC-2710H offers separate jacks for dual speakers. Thats a nice arrangement if you need to listen to 2 meters in one speaker and 70 cm in another. Otherwise, you can simply use the radios single downwardfiring speaker. Among the only negative comments about the IC-2710H concerned the fact that it cannot operate below 440 MHz. Many hams are discovering the powerful 70-cm FM repeater aboard the Russian Mir space station as well as the FM repeater on the OSCAR 27 satellite, but both systems operate well below 440 MHzand beyond the range of the IC-2710H. There are two optional modules for the IC-2710H that are worth considering. The UT-49 is a DTMF decoder that provides pager and code-squelch functions. It also allows you to use DTMF tones to control an IC-2710H remotely. The UT-104 is a CTCSS decoder that also offers tone squelch functions, pocket beep (to find out if someone paged you while you were away) and the ability to decode and display the frequencies of CTCSS tones. The latter feature is quite useful when youre trying to determine which CTCSS tone a repeater system is using to control access, provided the repeater retransmits the CTCSS tone, or you can hear a ham on the input frequency. Manufacturer: ICOM America Inc, 2380 116th Ave NE, Bellevue, WA 98004; tel 206-454-7619. Manufacturers suggested retail price: $857; EX-1759 wireless mike receiver, $88; HM-90 wireless mike, $167; OPC-600 separation kit, $36.

Receiver Sensitivity: 50 MHz, less than 0.25 V; 144 MHz, less than 0.22 V; 440 MHz, less than 0.25 V. Two-tone, third-order IMD dynamic range: Not specified.
Adjacent-channel rejection: Not specified.
IF rejection: Not specified. Image rejection: Not specified. Squelch sensitivity: 0.16 V. Audio output: 3 W at 10% THD (no load specified).
Receiver Dynamic Testing For 12-dB SINAD: 50 MHz, 0.15 V; 146 MHz, 0.15 V; 440 MHz, 0.18 V ; AM (120 MHz): 1.4 V for 10-dB (S+N)/N. 20-kHz offset from 50 MHz, 64 dB;* 20-kHz offset from 146 MHz, 68 dB;* 20-kHz offset from 440 MHz, 64 dB;* 10-MHz offset from 50 MHz, 97 dB. 10-MHz offset from 146 MHz, 89 dB. 10-MHz offset from 440 MHz, 87 dB. 20-kHz offset from 50 MHz, 64 dB; 20-kHz offset from 146 MHz, 68 dB; 20-kHz offset from 440 MHz, 64 dB. 50 MHz: 64 dB; 146 MHz: 94 dB; 440 MHz: 125 dB. 50 MHz: 79 dB; 146 MHz; 89 dB; 440 MHz, 54 dB. 50 MHz: 0.09 V at threshold. 146 MHz: 0.08 V at threshold. 440 MHz: 0.12 V at threshold. 4.4 W at 10% THD into 4. Transmitter Dynamic Testing 50 MHz, 42 / 10 / 3; 146 MHz, 49 / 10 / 3 W; 440 MHz, 32 / 9.5 / 3 W.
As specified. Meets FCC requirements for spectral purity. 50 MHz: squelch on, 118 ms; 146 MHz: Squelch on, 105 ms; 440 MHz: Squelch on, 105 ms. 50 MHz: 78 ms; 146 MHz: 60 ms; 440 MHz: 60 ms; 50 MHz: Receiver: BER @ 12-dB SINAD, 1.010 3; BER @16-dB SINAD, 3.310 5; BER @ 50 dBm, <1.0105. Transmitter: BER @ 12-dB SINAD, 7.1104; BER @ 12-dB SINAD + 30 dB, <1.010 5. 146 MHz: Receiver: BER @ 12-dB SINAD, 5.710 4; BER @ 16-dB SINAD, 1.510 5; BER @ 50 dBm, <1.0105. Transmitter: BER @ 12-dB SINAD, 1.310 3; BER @ 12-dB SINAD + 30 dB, 2.2105. 440 MHz: Receiver: BER @ 12-dB SINAD, 3.510 4; BER @ 16-dB SINAD, 2.710 5; BER @ 50 dBm, <1.0105. Transmitter: BER @ 12-dB SINAD, 3.910 4; BER @ 12-dB SINAD + 30 dB, <1.010 5. NOTE: For optimal receive performance: BER @ 50 dBm, 1.or less; for optimal transmit performance: BER @ 12-dB SINAD + 30 dB, 1.0105 or less. Default main receiver performance. Subband receiver performance was comparable. *Measurement was noise-limited at the value indicated.
Transmitter Power output: 50 MHz: 45 / 10 / 3 W; 146 MHz, 50 / 10 / 3 W; 440 MHz, 35 / 10 / 3 W. Spurious signal and harmonic suppression: 60 dBc or greater. Transmit-receive turnaround time (PTT release to 50% of full audio output): Not specified. Receive-transmit turnaround time (Tx delay): Not specified. Bit-error rate (BER), 9600 baud: Not specified.
in each memory. If you become a C5900DA owner, we predict youll use these a lot! Storing data in the conventional memories was less convenient, but you can copy from one memory to another and protect memories from overwriting. Another handy feature is the one-touch SCN button. The radio offers two scanning speeds, something you
dont see much. The RF squelch, which lets you set the squelch according to received signal strength, is a nice touch, and its neatly implemented. Like many radios with lots of frontpanel control and buttons, the C5900DA could offer a challenge to those with big hands. The front panel is very handsome, December 1996 63

and the radio offers separate tuning controls and concentric SQL (squelch) and VOLume controls. The SQL control serves a dual function: You press each SQL button to make that side of the radio the MAIN band. The radio can receive two VHF or two UHF signals at the same time. The PWR buttonon its own protuberance on the far leftcould have been more conveniently positioned. Some ops complained that it was too easy to hit more than one button at the same time on the busy front panel. Others would have liked it better if Standard had swapped the SQL and VOL controls, making the VOL control the inner control (and making it longer) and the SQL control the outer ring. As it is, the SQL controls arent much more than little bumps, which one op called impossible. This panel is better suited to dainty fingers. Our reviewers liked the implementation of the SQL OFF button on the mike. Its like a monitor button, but, in the C5900DA, you can set the menu to make it double as a reverse button for repeater work (this is the factory default). Its also a toggle, instead of a press-and-hold button. This handy switch eliminates the need to fumble for a reverse button if you want to see if a station youre talking to on the repeater is within simplex range, but you might find its easy to hit this button inadvertently while holding the mike in your right hand. The F unction key is well-implemented. When you press F, the subfunction legends pop up on the display behind each button (there is a row below the display), and theyre in reverse video (ie, light characters on a dark background). This way, you always know exactly what youre about to do! The C5900DA rounds out its plethora of features with a dedicated packet data jack (using a 6-pin mini-DIN connector) with operation at 1200 or 9600 baud. The manual devotes several pages to a description of TNC interconnections for the C5900DA. The rig offers CTCSS and DTMF encoding and decoding, as well as AM reception when you tune through the aeronautical band (the AM detector is selected automatically). If the C5900DAs 80 memories on each band are not enough, you can buy the optional CMU161 200-channel memory chip. Audio reports on transmit were good, but we got a few reports that the audio was a bit on the hot side, though not distorted. Backing away from the mike seemed to help. One station described it as really bright and really loud. Receive audio was fine and natural-sounding on the internal speaker. This is a fairly complex rig (what tribander wouldnt be?), but the manual helps you navigate the features with ease. It could use a quick start section, however. Manufacturer: Standard Amateur Radio Products Inc, Box 48480, Niles, IL 60714; tel 773-763-0081; fax 773-7633377. Manufacturers suggested retail price, $1049. CAW591 LCD display extension, $40; CMU161 200-channel memory chip, $48; CMB5900 display mounting bracket, $27.

64 December 1996

Yaesu FT-8000R
The FT-8000R is a surprisingly compact dual-bander, despite the fact that it offers
50 W output on 2 meters and 35 W on 70 cm. It offered the widest receive coverage of the pack, allowing you to eavesdrop from around 110 MHz all the way to 1.3 GHz (cellular telephone frequencies are blocked, of course). You can elect to receive on both bands simultaneously, or on two frequencies within the same band. The Yaesu FT-8000R is built to MIL-STD 810 standards for endurance and weatherproofing. Our review team enjoyed the large, bright Omni-Glow display, which takes up most of the front panel and is readable from any viewing angle. This is the largest display of the four transceivers we reviewed. The brightness of the display is variable.
Yaesu FT-8000R, serial no. 6G021530
Manufacturers Specifications Frequency coverage: Receive, 110-550, 750-1300 MHz (cellular freqs blocked); transmit, 144-148, 430-450 MHz. Measured in ARRL Lab Receive, Approximately 112-550, 7501300 MHz (cellular freqs blocked), with decreased sensitivity noted at some band extremes; transmit, as specified.
Power requirements: At 13.8 V dc: At 13.8 V dc: Receive, 0.8 A (max volume, Receive, <1 A (max); no signal); transmit, 8 A (max). transmit, 11.5 A (max). Size (height, width, depth): 1.65.66.1 inches; weight, 2.2 lb.
Receiver Sensitivity: For 12-dB SINAD, main receiver, <0.18 V;
Adjacent-channel rejection: Not specified. IF rejection: Not specified. Image rejection: 70 dB or greater. Squelch sensitivity: Better than 0.13 V. Audio output: 2 W at 5% THD into 8.
Receiver Dynamic Testing For 12-dB SINAD: 146 MHz, 0.19 V; 440 MHz, 0.17 V; AM (120 MHz): 0.8 V for 10-dB (S+N)/N; 20-kHz offset from 146 MHz, 67 dB; 20-kHz offset from 440 MHz, 67 dB; 10-MHz offset from 146 MHz, 84 dB. 10-MHz offset from 440 MHz, 82 dB. 20-kHz offset from 146 MHz, 67 dB; 20-kHz offset from 440 MHz, 67 dB. 146 MHz: 82 dB; 440 MHz: >135 dB. 146 MHz: 78 dB; 440 MHz: 95 dB. 146 MHz: 0.12 V at threshold; 440 MHz: 0.10 V at threshold. 2.1 W at 5% THD into 8. Transmitter Dynamic Testing 146 MHz: 52 / 9.5 / 4.7 W; 440 MHz: 34 / 13 / 4.5 W. As specified. Meets FCC requirements for spectral purity. 146 MHz: Squelch on, 85 ms. 440 MHz: Squelch on, 80 ms.
146 MHz: 50 ms; 440 MHz: 50 ms.
Transmitter Power output: 146 MHz: 50 / 10 / 3 W; 440 MHz: 35/ 10 / 3 W. Spurious signal and harmonic suppression: 60 dBc or greater. Transmit-receive turnaround time (PTT release to 50% of full audio output): Not specified. Receive-transmit turnaround time (Tx delay): Not specified. Bit-error rate (BER), 9600 baud:
146 MHz: Receiver: BER @ 12-dB SINAD, 1.3103; BER @ 16-dB SINAD, 7.1105; BER @ 50 dBm, <1.0105. Transmitter: BER @ 12-dB SINAD, 4.BER @ 12-dB SINAD + 30 dB, 7.2 105. 440 MHz: Receiver: BER @ 12-dB SINAD, 1.0103; BER @ 16-dB SINAD, 6.4105; BER @ 50 dBm, <1.010 5. Transmitter: BER @ 12-dB SINAD, 7.8103; BER @ 12-dB SINAD + 30 dB, 4.7104. NOTE: For optimal receive performance: BER @ 50 dBm, 1.or less; for optimal transmit performance: BER @ 12-dB SINAD + 30 dB, 1.0105 or less. Default main receiver performance. Subband receiver performance was comparable.

There are separate concentric VOLume and SQL (squelch) controls for each side of the display; press the left or right VOL knob, and the radio shows you the dc supply voltage. The front panel features a single tuning knob that doubles to select memories and function settings. For big excursions, pressing the tuning knob increases the tuning ratedepending on how long you press. A row of eight multifunction buttons, each with an LED, is below the display. The correct legend for each appears on the display window above the appropriate button. The FT-8000R also won praise for its implementation of an RF squelch that uses the S-meter level to determine the squelchs break point. Yaesus Intelligent Band Display was another nice touch: A blinking green LED on each side lets you know when that particular receive channel is active (handy if the volume is turned down). This same LED turns red when you transmit, or remains steady on the main-band side when no signal is heard (you also can turn off this function if youd like). The front-panel CNTL button lets you change the sub-band display without changing the status of the main band. Alternately, you can use this button to set up VHF-VHF or UHF-UHF operation. The FT-8000R provides 55 memory channels per band (54 conventional channels plus a call or HOME channel) to store frequencies, repeater shifts (including odd offsets) and CTCSS tones. If youre traveling in strange territory, or if youre using the rig for the first time, you can press the SCH button on the front panel to use the FT-8000Rs Enhanced Smart Search feature to automatically sweep through each band and store active frequencies in 50 dedicated memories (25 above the starting
point and 25 below)! You can set it up to search all or part of a band. It lets you do multiple sweeps, too, an improvement over the Smart Search implementation in the single-band Yaesu FT-3000M (see Product Review, QST, Nov 96), which would overwrite its 20 dedicated memories on subsequent sweeps once they were filled. The FT-8000R provides separate speaker outputs for both bands, a nice touch for mobile or base installations. The upward-firing internal speaker provided adequate audio. The FT-8000R is equipped for 1200 or 9600-baud packet via a mini-DIN jack on the rear panel. There is no need to disconnect the microphone jack when youre running packet. When your TNC goes into the transmit mode, the microphone audio path is automatically interrupted. Our review team found the FT-8000R simple to program. If you have a computer running Microsoft Windows, you can purchase the optional Yaesu ADMS-2C software (includes connecting cable) and program the radio entirely from your PC keyboard. Setting up a rig doesnt get much easier than that! CTCSS and DTMF encoding is standard in the FT-8000R. If you want CTCSS decodingincluding the bell function that alerts you to incoming callsyou must buy the FTS-22 module. DTMF decoding is not offered in the FT-8000R. The MH-36B microphonesimilar to the one that came with the single-band FT-3000Mis nice and large and plugs into the front panel. It has lighted DTMF keypad buttons as well as ACC and VFO/MR buttons. You use the ACC button to change bands on the FT-8000R. The mike also sports three user-programmable buttons (P, P1 and P2), but, as the manual explains,

BOTTOM LINE

The DSP-599zx earns high marks for its filter characteristics, noise reduction, and ease of operation. A superb station accessory!
Table 1 Timewave DSP-599zx Audio Noise Reduction Filter, serial number 31255
Manufacturers Claimed Specifications Measured in the ARRL Lab Power requirements: 12-16 V at 1 A (max). As specified. Tested at 13.8 V. Size (HWD): 1.97.68.5 inches; weight: 2.5 lb. Frequency response: Range at 6-dB points, (bandwidth): CW, 10-600 Hz; attenuation, 55 dB at 60 Hz outside passband at 600 Hz, 384-1020 Hz (636 Hz);* at 500 Hz, 434-973 Hz (539 Hz); at 100 Hz, 634-771 Hz (137 Hz); at 10 Hz, 689-716 Hz (27 Hz). Voice: High-pass, 100-1000 Hz; low-pass, 1000-5000 Hz; 300/1800 Hz, 268-1843 Hz (1575 Hz); attenuation, 60 dB at 180 Hz outside passband. 300/2100 Hz, 267-2145 Hz (1878 Hz); 100/5000 Hz (max), 47-5050 Hz (5003 Hz). RTTY: 60-600 Hz; mark/space bandwidth, 60-100 Hz; 2210/170 Hz; center frequency, 2140 Hz: center frequency, 2210 Hz, plus option of 1300, 1360, 2080-2190 Hz (110 Hz); center frequency 1530, 1700 or 2125 Hz; attenuation, 40 dB at 60 Hz 2300 Hz: 2250-2360 (110 Hz). outside passband. AMTOR, SITOR: Same as RTTY. Center frequency, 2210 Hz; shift, 200 Hz: 2200-2040 Hz (160 Hz). PACTOR: Same as RTTY. Center frequency, 2210 Hz; shift, 200 Hz: 2000-2205 Hz (205 Hz). SSTV: 1100-1300 Hz and 1500-2300 Hz; attenuation, 1100-1300 Hz; 1500-2300 Hz: 1070-1330 Hz (260 Hz); 50 dB at 75 Hz outside passband. 1480-2340 Hz (860 Hz). Random noise reduction: Up to 20 dB; varies with noise. As specified. characteristics. Notch rejection: up to 50 dB; varies with noise characteristics. Manual notch, 50 dB; automatic notch, 45 dB. Time to notch: 5 ms. 7.5 ms to 50% points on oscilloscope. Filter shape factor: Not specified. (60 dB/6 dB): Voice (typical), 1.07:1; CW (typical) 1.1:1. Input/output delay: Voice (HP and LP), 24 ms; CW, 40 ms; voice, 24 ms; data, 37 ms. CW (BW >20Hz), 40 ms; Data (FSK), 38 ms; Data (fixed) 20 ms. Audio output power: 1 W into 8 ; 1.5 W into 4 , 1.3 W at 7.5% THD into 8 ; 2 W at 10% THD into 4. (THD not specified). Test instrument functions: Audio generator: single or two-tone, single sine wave tunable, As specified. 20 Hz to 10 kHz; two-tone, 700 Hz plus 1900 Hz: Audio millivoltmeter: true RMS from 1 mV to 2000 mV, 20 Hz to 10 kHz: As specified. CTCSS encoder-decoder: Decodes and displays CTCSS As specified. tone, 67.0 Hz to 254.1 Hz.
*All CW tests made at 700-Hz center frequency.

cially from my location 300 feet from a major parkway! During subsequent on-the-air testing, weak stations were worked that might otherwise not even have been heard because of the noisy conditions and QRM. It even yielded excellent results with the transceivers crystal filter in its widest position, relying only on the DSP-599zx. The Timewave DSP-599zx is the third DSP box I have had in my shack. The first, several years ago, came from a different manufacturer and belonged to a local ham who wanted me to verify how bad it was and it was! The filtering was pretty good and the noise reduction fair, but it had no margin on dynamic range. A very small input signal increase overloaded the filter, and the result was garble. In preparation for The ARRL Handbook (1996), I also tested the W9GR DSP. No question, the state of the art had advanced. That relatively lowpriced unit was a good addition to the shack, and I returned it with reluctance. Real hams dont read instruction books, so the first thing to do is wire it up and turn it on! The power jack was labeled, so I could not connect the 12-V supply backward.

66 December 1996

Connectors for two channels of audio A and B were on the back panel. Well, you cant go wrong by choosing channel A for both AUDIO INPUT and SPEAKER OUTPUT. So far, so good. Next, a quick look at the front panel. Theres a neat 2-line-by-16-character backlighted alphanumeric display window that shows mode and settings, so you know right away what youre doing. There is a GAIN control with an off position, so turn it on and the display reads Initializing, followed by a two-line message. The first line is VCE, which I guessed stood for voice. The second line said HP LP. The other two front panel knobs were labeled HIGH PASS/CENTER FREQ and LOW PASS/BANDWIDTH, so I think we have broken the code. Tune in a sideband station in QRM alley (here, about 14,300 kHz) and start turning knobs. The DSP-599zx passed my first test can I figure out how to turn it on? For people like meand perhaps youthe instruction manual has a one-page summary right up front. It starts by saying: Here is the absolute minimum information you need to get started, So I guess I am not alone.
DSPs, Yes or No? The primary advantage of a well-designed DSP box is a good filter. The primary disadvantage is the filters location in the transceivers audio output line where it cannot undo any mixing of signals and AGC action that occurs inside the receiver itself. The Timewave DSP-599zx is no different; if the interfering signal and the desired signal are within the dynamic range of the receiver (by whatever definition), then the signals will not mix. In this case, unwanted signals may be attenuated by as much as 60 dB with little perceptible distortion, which makes this filter seem like a dream, compared to what was available a few short years ago. Analog-to-digital (A/D) range is one of the key numbers used to compare the models of different manufacturers. Timewave uses a 16-bit A/D converter, and the performance is naturally better than earlier units with 10-bit A/Ds. The other key number is the processor speed, and Timewave claims a capacity of 36.8 million instructions per second (MIPS). As with many computer numbers, the real test is not only the processing speed, but the algorithms

(mathematical equations) used and the resulting performance. Certainly a DSP with a higher MIPS capability will be able to implement a better filter, all other things being equal.
Its Fast, But What Can It Do? The answer in a nutshell: The DSP-599zx can make interfering signals disappear. With a moderately strong signal, but not one driving my receiver to saturation, the filter provides what DSP proponents (and filter manufacturers) like to call a brick wall. As an example, in the Data mode, the mark/space bandwidth can be set as small as 60 Hz. Tune 60 Hz up or down from the initial frequency, and the claimed 40-dB rejection makes the signal go away, in actual on-the-air tests. Although I could not find a live example on the air, two 170-Hz shift RTTY signals could be interlaced (ie, mark 1, mark 2, space 1, space 2) and this filter would probably separate them! One of the best features of this unit is that the LCD window, which displays the mode and the low-cut and high-cut frequencies (or, alternately, the notch frequency and notch width). Unlike most other units, the HIGH PASS/CENTER FREQ and LOW PASS/BANDWIDTH controls are continuously tunable optional encoders that set the desired filter frequencies in 5-Hz steps. This gives you a lot more precision than fixed-rotation pots, but some ops might find them touchy at first. They turn very easily, so you have to be careful. Some also might find the tiny front-panel labels hard to see or read. The CW filter claims to have a 10-Hz (!) minimum bandwidth (the ARRL Lab measured it at something greater than thatbut not much greater), so you have to tune very, very carefully to take advantage of it. Scrunching the bandwidth imparts a ringy quality to the signal, but you wont hear another station except the one youre tuned to. Even at the 50-Hz setting, its difficult to monitor two stations in QSO, unless theyre
on exactly the same frequency. The CW center frquency can be set between 200 Hz and 2095 Hz. As with other DSP boxes, we found the results less striking on SSB than on CW. It wont replace good crystal filters inside your receiver, but it will ease reception in the face of QRN and QRM.
More than a DSP box The Timewave DSP-599zx offers a range of modes and submodes for voice, CW and data reception, but its also an RTTY TNC and a test-bench instrument modes you wont find in run-of-the-mill DSP boxes. For voice modes, it has both high and low-pass filters; noise reduction, line-noise reduction (for AM only); and heterodyne-eliminating notch filters. For CW, it offers a band-pass filter, noise reduction and a manual notch filter as well as a CW marker tone (to make it easy to match the filters center frequency to the pitch of the received signal) and a tone pitch shift. You also can bypass the unit altogether. The unit also has specific filters for all data modes, including RTTY, the various TOR modes, HF packet and Clover, plus SSTV and WEFAX. In addition to functioning as an RTTY TNC (we did not test this mode), the DSP-599zx also can remodulate a received RTTY signal as clean AFSK that your TNC should find easier to handle (especially if you didnt spend a lot of money on your TNC). The DSP-599zx also can be used as an audio test and RTTY FSK test signal generator, as a millivoltmeter and as a CTCSStone decoder. The unit can deliver a twotone output (700 and 1900 Hz), but you cannot independently adjust the level of each tone, which limits the value of this feature for SSB transmitter alignment. The audio millivoltmeter can measure the voltage, frequency and bandwidth of a signal (up to 2000-mV RMS maximum). You wont find those modes in similar units, and they could come in handy. Each mode is selectable from the front panel, by pressing (you guessed it!) the

control. As already noted, noise reduction and tone or heterodyne reduction are available in all modes. It can really be funat least here on the East Coastto tune the 40-meter phone band at night and never hear a broadcast station carrier. The automatic notch nails each oneeven as you tuneand its 50-dB rejection really does a job. The manual notch filter is equally superb, but accessing it is not a onebutton operation. Own two receivers? No problem. Both can work through the same box. There are two set of inputs and outputs, selectable on the front panel. Have a CW sked at 0100Z and a SSB net at 0130Z, and need a different set of filters for each one? There are six memories to store a complete configuration setup. Hit a few buttons to recall your favorite setting. Like some other DSP boxes, this unit has an automatic gain control (AGC) feature. One failing of many earlier units was a high sensitivity to audio input levels. As the signal increased, so did the distortion and noise. This AGC seemed to work smoothly without marked side effects. By the way, both the line and headphone output levels are adjustable to match your needs.
In Summary The Timewave DSP-599zx is a modern DSP box, with the emphasis on the P for processor. As with any audio DSP unit, however, it can only make the most of what it hears. The unit offers a wide variety of modes, logically controlled, and provides memories to store your favorite selections. The built-in RTTY modem and test instrument capabilities are interesting and helpful additions. Manufacturer: Timewave Technology Inc, 2401 Pilot Knob Rd, St Paul, MN 55120; tel 612-452-5939; fax 612-4524571; Web, http://www.timewave.com (includes manual and technical data on the DSP599zx). Manufacturers suggested retail price: $379.