TS-870S_review_QST_1996.pdf

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1、Product Review Edited by Rick Lindquist, KX4V Assistant Technical Editor February 199671 Reviewed by Larry Wolfgang, WR1B Senior Assistant Technical Editor With the introduction of the TS-870S, Kenwood helps usher in a new era in Ama- teur Radio equipment design. As do the lat- est offerings from IC

2、OM and Yaesu, Kenwoods newest MF/HF transceiver in- cludes digital signal processing (DSP) at IF, but with a difference. Kenwoods competi- tors take the belt-and-suspenders approach and couple crystal filters (both standard and optional) with DSP on their latest radios, but the TS-870S requires no a

3、dditional crys- tal filters to supplement its DSP. Its the first radio in its class to make that claim. To better understand how the TS-870S implements DSP at HF, see the sidebar “DSP in the Kenwood TS-870S.” Features The TS-870Ss attractive but no-non- sense front panel has the complement of contro

4、ls you would expect on any full-fea- tured HF rig. But, not all of this radios goodies are obvious at first glance. The prominent main tuning knob has a soft- rubber grip that provides a comfortable feel and a handy finger depression to spin up or down the band. You can set the tuning steps to 5 or

5、10 kHz per revolution. The FINE tun- ing button divides this value by 10 when it is turned on, but you cannot display the 1 Hz units to go along with the fine tuning steps. With the small tuning steps, the radio sounds almost “analog” as you tune. None of that digital warbling as the VFO changes fre

6、quency! Two groups of four controls apiece (some of them concentric) flank the tuning knob and give ready access to the most-used functions. Better yet, the knobs and associ- ated pushbuttons are substantial enough for even the most fumble-fingered ops to get a grip on them. To the left of the main

7、tuning knob, one set of concentric controls adjusts the built- in electronic keyer speed and AGC attack speed. Turning the AGC knob fully counter- clockwise turns off the AGC; there is no detent or other tactile response to let you know when the AGC is off, so youll have to look on the display for t

8、he red AGC legend above the main frequency readout. Other concentric controls in this group set the speech processor and monitor volume lev- els, adjust CW, AM or FSK carrier level (or SSB output with the speech processor on), set VOX delay, and adjust microphone gain Bottom Line The first DSP trans

9、ceiver without standard or optional narrow crystal IF filters, the TS-870S offers fine receive and transmit audio, noteworthy selectivity and comfortable controls. A snazzy computer-control program and interface are standard. Kenwood TS-870S MF/HF Transceiver and power output level. Convenient pushb

10、uttons just above these knobs select the transmit metering function (options are ALC, SWR, compres- sion level and output power) and activate the speech processor and monitor function. The right-hand group of controls in- cludes single-knob controls for RIT/XIT and M.CH/VFO.CH (to change the memory

11、chan- nel or VFO channel), plus concentric con- trols to set AF or RF level and NB (noise blanker) and SQL (squelch). A CLEAR pushbutton quickly zeros the incremental tuning. As you adjust the RIT, the main fre- quency display also changes to show the actual receive frequency. The display window con

12、veys plenty of information about the radios operating sta- tus. Is the AGC on? How about the speech processor? The automatic antenna tuner? All these questions and more are easily answered at a glance. For example, one spot in the display window shows DSP filter high or low-frequency limits for phon

13、e modes, filter bandwidth for FSK and filter center frequency or bandwidth for CW. This in- formation shares display space with RIT or XIT tuning increment data, as well as with the transmit frequency in split. The left side of the display window is a digital LCD representation of an analog metercom

14、plete with an arc. In receive, the top of the display is an S meter. In trans- mit, the same segments indicate output power. In receive, the lower portion of the display graphically indicates current filter bandwidth and relative frequency shift. This portion of the display lacks numbers, so you can

15、t tell the exact filter settings. For that information, youll have to look at the right side of the display window (and you may have to first turn the appropriate filter- select knob to activate the readout). In trans- mit, this same meter section displays SWR, ALC or speech compression level. Turni

16、ng on the P HOLD menu selection holds peak readings on both bar graphs for about 2.5 seconds. Most users liked the display window and its colorful legends. The bright, white main display numerals are about a half-inch high and easy to read. Red labels above the frequency display indicate active func

17、- tions, such as AGC, MONItor and speech PROCessor. Yellow labels below the fre- quency display indicate the active mode. One reviewer commented that the unlighted LED segments remain distractingly visible behind the display window lens. A darker display-window lens could lesser the effect. The ANT

18、button selects between two rear-panel antenna connectors. ATT UP and DOWN buttons select either 0, 6, 12 or 18 dB of receive attenuation. AIP (Advanced In- tercept Point)also available with the touch of a buttonhelps to reduce inter- modulation distortion by throttling back the sensitivity. On a ban

19、d crowded with strong signals, youll likely want to leave AIP on. Getting Around with the 870S The 870S has two VFOs plus 100 72February 1996 Table 1 Kenwood TS-870, serial no. 70500128 Manufacturers Claimed SpecificationsMeasured in the ARRL Lab Frequency coverage: Receive, 100 kHz-30 MHz;Receive,

20、30 kHz to 30 MHz; transmit, as specified transmit, 1.8-2; 3.5-4; 7-7.3; 10.1-10.15; 14-14.35; 18.068-18.168; 21-21.45; 24.89 -24.99; 28-29.7 MHz. Modes of operation: USB/LSB, CW, AM, FM, FSKAs specified. Power requirement: Receive, 2 A (no signal);Receive, 2 A (no signal); transmit, 16.5 A (max), te

21、sted at 13.8 V. transmit, 20.5 A (max). ReceiverReceiver Dynamic Testing SSB/CW sensitivity, bandwidth not specified,Minimum discernible signal (noise floor), 400 Hz WIDTH and 700 Hz SHIFT: 10 dB (S+N)/N: 100-500 kHz, 1 V; 500 kHz-Preamp offPreamp on 1.7 MHz, 4 V; 1.7-24.5 MHz, 0.2 V;1.0 MHz108 dBm1

22、17 dBm 24.5-30 MHz, 0.13 V.3.5 MHz131 dBm141 dBm 14 MHz129 dBm139 dBm AM sensitivity, 10 dB (S+N)/N, bandwidth not specified:10 dB (S+N)/N, 1-kHz tone, 30% modulation, 6 kHz WIDTH: 100-500 kHz, 2 V; 0.5-1.7 MHz, 32 V;Preamp offPreamp on 1.7-30 MHz, 2 V.1.0 MHz35 V (76 dBm)11 V (86 dBm) 3.8 MHz2.3 V

23、(100 dBm)0.7 V (110 dBm) FM sensitivity, 12 dB SINAD: 28-30 MHz, 0.25 V.For 12 dB SINAD, 14-kHz bandwidth: Preamp offPreamp on 29 MHz0.9 V (108 dBm)0.16 V (123 dBm) Blocking dynamic range: Not specified.Blocking dynamic range, 400 Hz WIDTH: Preamp offPreamp on 1.0 MHz128 dB*124 dB 3.5 MHz127 dB*124

24、dB 14 MHz127 dB123 dB Two-tone, third-order IMD dynamic range: Not specified.Two-tone, third-order IMD dynamic range, 400 Hz WIDTH: Preamp offPreamp on 1.0 MHz83 dB89 dB 3.5 MHz99 dB95 dB 14 MHz97 dB95 dB Third-order input intercept: Not specifiedPreamp offPreamp on 1.0 MHz+17 dBm+17 dBm 3.5 MHz+18

25、dBm+2 dBm 14 MHz+16 dBm+4 dBm Second-order intercept point: Not specifiedPreamp off, +63 dBm; preamp on, +63 dBm. FM adjacent channel rejection: Not specified88 dB at 20 kHz channel spacing (29 MHz). FM two-tone, third-order IMD dynamic range:Preamp off, 84 dB; preamp on, 79 dB at 20 kHz channel spa

26、cing (29 MHz). Not specified S-meter sensitivity: Not specifiedS9 signal at 14 MHz: preamp off, 176 V; preamp on, 50 V. Squelch sensitivity: Not specifiedAt threshold, preamp on: FM, 0.03 V; SSB, 1.3 V. Receiver audio output: 1.5 W at 10% THD into 8 .2.4 W at 10% THD into 8 . IF/audio response: Not

27、specified.Range at 6 dB points, (band width): CW-N (400 Hz WIDTH, 700Hz SHIFT): 489-906 Hz (417 Hz); CW-W (1000 Hz WIDTH, 700 Hz SHIFT): 195-1203 Hz (1008 Hz); USB-W (LO=300 Hz, HI=3000 Hz): 230-2988 Hz (2758 Hz); USB-N (LO=400 Hz, HI=1800 Hz): 391-1804 Hz (1413 Hz); LSB-W (LO=300 Hz, HI=3000 Hz): 2

28、25-2967 Hz (2742 Hz); LSB-N (LO=400 Hz, HI=1800 Hz): 386-1798 Hz (1412 Hz). Notch filter depth: 40 dB or more.As specified. Spurious and image rejection: 80 dB or better.Preamp off, 98 dB; preamp on, 114 dB. IF rejection: 80 dB or better.Preamp off, 115 dB; preamp on, 124 dB*. TransmitterTransmitter

29、 Dynamic Testing Power output: SSB, CW, FSK, FM, 100 W (max),CW, typically 113 W (max), 1 W (min); SSB, 118 W (max); 1 W (min), 20 W or less (min), continuously adjustable. AM, 25 Wvaries slightly from band to band. AM, typically 24 W (max), (max), 20 W or less (min), continuously adjustable.1 W (mi

30、n). FM, typically 109 W (max), 9 W (min). Spurious-signal and harmonic suppression: 60 dB or more.60 dBc on all amateur bands. Meets FCC requirements for spectral purity. SSB carrier suppression: 50 dB or more.As specified. Undesired sideband suppression: 50 dB or more.As specified. Third-order inte

31、rmodulation distortion (IMD)See Figure 1. products: Not specified. CW keyer speed range: 6-60 wpm.As specified. CW keying characteristics: Not specified.See Figure 2. Transmit-receive turnaround time (PTT release toS9 signal, 14 ms. 50% audio output): Not specified. Receive-transmit turnaround time

32、(“tx delay”):15 ms. Composite transmitted noise: Not specified.See Figure 3. Size (height, width, depth): 4.71313 inches; weight, 25 pounds. Note: Dynamic range measurements were made at the ARRL Lab standard signal spacing of 20 kHz. *Measurement was noise-limited at the value indicated. Expanded P

33、roduct Review Test Results Report Available The ARRL Laboratory offers a 30-page test result report on the TS-870S that gives in-depth, detailed technical data on the transceivers performance, outlines our test methods and helps you to interpret the numbers and graphs. The report also includes spect

34、ral purity charts and receiver sensitivity figures for all bands, all CW keying waveforms (not just worst-case) and other facts to help you make an informed buying decision. The report even includes a summary of how this radio stacks up with similar, previously tested units. Request the TS-870S Test

35、 Result Report from the ARRL Technical Department at $7.50 for ARRL members and $12.50 for nonmembers, postpaid. February 199673 memory channels to make bandhopping and frequency swapping a breeze. Unlike its DSP competitors, the ICOM IC-775DSP or the Yaesu FT-1000MP, the Kenwood TS-870S does not ha

36、ve dual receive capa- bility. You can transmit or receive on either VFO or a memory channel, however. Press the appropriate buttons in the RX and TX columns to the right of the MODE buttons to make a selection. A small LED lights in each active button. A single memory chan- nel can store separate tr

37、ansmit and receive frequencies as well as mode information. The inability to store filter settings in any memory channel or band register was a common complaint from reviewers, how- ever. It seems odd in a radio this sophisti- cated that you cant save a particular filter setting with a certain frequ

38、ency, but the radio does remember what filter setting you used last with each mode. UP and DOWN buttons let you switch bands in sequence or (with the 1MHZ button activated) change frequency in 1-MHz steps instead. Additionally, a ten-key, multifunc- tion keypad allows direct frequency entry, as well

39、 as storing memory data, selecting scan functions and controlling the memory keyer features. In VFO mode, you use the M.CH/VFO.CH control to make large fre- quency excursions within a band in steps of 1, 5 or 10 kHz (menu settable). For split-frequency operation you sim- ply select one VFO (or memor

40、y channel) for receive and the other VFO (or memory channel) for transmit. Or you can program a memory channel with both frequencies. If you select different VFOs or memory data for transmit and receive, you press and hold the TF-SET button and use the main tuning knob to set your transmit frequency

41、. One reviewer, who was used to the typi- cal “split” button, found this a bit confus- ing. It does take getting used to. The Figure 2CW keying waveform for the TS-870S in the semi-break-in mode showing the first and second dits. The upper trace is the actual key closure; the lower trace is the RF e

42、nvelope. Horizon- tal divisions are 10 ms. The transceiver was being operated at 100 W output at 14.2 MHz. Figure 1Worst-case spectral display of the TS-870S transmit- ter during two-tone intermodulation distortion (IMD) testing. The third-order product is approximately 32 dB below PEP output, and t

43、he fifth-order product is approximately 47 dB down. The transceiver was being operated at 100 W PEP output at 14.2 MHz. Figure 3Worst-case spectral display of the TS-870S transmit- ter output during composite-noise testing. Power output is 100 W at 3.5 MHz. The carrier, off the left edge of the plot

44、, is not shown. This plot shows composite transmitted noise 2 to 22 kHz from the carrier. right side of the display shows the transmit frequency and the word SPLIT in small red letters above it. There is no other indica- tion. One contest group that used the radio liked the fact that the 870S displa

45、yed both receive and transmit frequencies but felt it was too easy to transmit on the wrong fre- quency. Would You Like a Menu? As weve suggested, all the 870Ss fea- tures are not obvious at first glance. Theyre “hidden” within a menu system that our review team found easy to use. The MENU button pr

46、ovides access to dozens of user- definable operating parameters, while the M.CH/VFO.CH button selects the appropri- ate menu item. Two identical menu banks (68 items each) let you define two com- pletely different sets of operating condi- tions! This is useful for operators who want the radio to per

47、form one way for contesting or DXing, but yet another for rag chewing or operating digital modes. Ham families using the same radio also might find the two menu banks helpful. Youll want to have the manual at hand as you make your menu selectionsat least at firstbecause the abbreviated word dis- pla

48、y can be a bit cryptic. Among many other things, the menus let you set or adjust AGC release times for various modes, CW rise and decay times, CW pitch, speech processor frequency re- sponse, panel brightness and various DSP parameters. DSP Goodies Four pushbuttons along the upper right- hand side o

49、f the front panel access the radios DSP functions: AUTO NOTCH, BEAT CANCEL, N.R. and TX EQ. The first three are adaptive filters that can identify various interfering signals or noise and modify their filtering characteristics based on the par- ticular noise or interference. (You can switch between SPAC or Line Enhance using a menu selection.) Auto notch only works in SSB mode. This DSP filter identi- fies interfering tones in the receiver pass- band and attenuates them. Beat cancel works in both SSB and AM, and is similar to the auto notch filter, but can be more effective f