Alinco_DX-77T_review_1998.pdf

《Alinco_DX-77T_review_1998.pdf》由会员分享，可在线阅读，更多相关《Alinco_DX-77T_review_1998.pdf（4页珍藏版）》请在收音机爱好者资料库上搜索。

1、52June 1998 Product Review Edited by Rick Lindquist, N1RL Senior Assistant Technical Editor Reviewed by Joe Bottiglieri, AA1GW ARRL Technical Information Service Coordinator With improvements in propagation on the HF bands over the last few months, sto- ries of wide-open bands and easy DX are rapidl

2、y spreading. If youre a newcomer looking to join the fun without cleaning out the bank account, upgrading from “hollow state,” or are just considering a new or sec- ond HF radio for your shack (or at that sec- ond QTH in the woods), the Alinco DX-77T may be just the ticket. Heres an economical HF bo

3、x in the $1000 price category that wont take up a lot of space on the operating desk but still has plenty to offer. Already known for its VHF and UHF products, Alinco entered the HF market in 1995 with the release of the DX-70T. This compact HF-plus-6 meters transceiver proved to be a popular choice

4、 for mobile, home station, and portable operation. A sub- sequent model, the DX-70TH, offered 100 W on 6 meters. With the introduction of the DX-77T, Alinco now adds a somewhat larger HF-only transceiver to their lineup. Whats it Got? The DX-77T is a 100 W output SSB, CW, FM and 40 W AM transceiver

5、that covers 160 through 10 meters and includes 0.5 to 30 MHz general-coverage receiving capability. It features dual VFOs, split op- eration, 100 memory channels, band stack- ing registers, a speech processor, IF shift, multiple scan options, computer controlla- bility, and a front-facing speaker. B

6、ut wait! A built-in CW keyer, 500Hz CW filter, and menu selectable CTCSS encode for 10- meter FM repeater operation also are all standard features (in the US version). In comparison, setting CTCSS tones in the DX-70T required setting DIP switches, and the earlier radio had no CW keyer. While Alinco

7、has managed to pack in some very nice capabilities, theyve also kept the front panel surprisingly simple and functional, with just a few large buttons and knobs and bold, bright labels. Physically larger than the current crop of subcompact base/mobile type HF transceivers on the market the DX-77T is

8、 a more convenient size for desktop or portable operation. Many users will welcome the generous di- mensions. You could almost operate this radio with oven mitts on! Although its on the small side, the busy LCD display offers good contrast and easy readability. Backlighting is adjustable to Alinco D

9、X-77T MF/HF Transceiver BOTTOM LINE A $1000-class desktop radio, the DX-77T is easy to use and a moder- ately good performer with some nice features you wouldnt typically expect at this price. five brightness levels (or off altogether). In addition to the operating frequency, the win- dow displays i

10、cons for mode, noise blanker, AGC slow or fast (AGC cannot be disabled), memory number, VFO A and B, split, nar- row CW filter, CTCSS tone state, RIT offset and low power. A four-section readout indi- cates the state of the two-stage attenuator/ normal/or 10-dB preamplifier RF gain level. An LCD bar

11、graph-type S meter indicates relative power output on transmit. Up Front The front panel sports 14 buttons and four knobs, with one concentric control. The all-mode SQUELCH and AF GAIN con- trols are huge by todays standards, almost 5/8 inch in diameter! The RIT and IF shift knobs are a concentric p

12、air, mounted in the upper right corner. Center detents in their travel indicate zero settings, with RIT adjustable to approximately 1.0 kHz. The RIT function is always availabletheres no way to clear it or turn it off. Some users might find this a disadvantage. The large main tuning knob spins smoot

13、hly (some users thought a little too easily, however), is lightly weighted, and includes a finger dimple. The tuning rate is fixed at 2 kHz per knob revolution for SSB/CW and 10 kHz per revolution for FM/ AM. A DIAL LOCK button is located to the lower right of the main knob. For large changes in fre

14、quency, the SELECT button used in conjunction with the front panel UP and DOWN buttons allows stepping through the band registers and memory channels, or frequency changes in 1 MHz or 100 kHz steps. Smaller mode-related step sizes are selectable in the set mode. A small front- facing speaker sends t

15、he audio in the right direction, a very nice arrangement. A jack for an 8-pin microphone connection and 3.5-mm jacks for an external key or paddles, an external speaker, and head- phones are mounted along the bottom of the speaker grille. The POWER ON/OFF switch is a large yellow push button located

16、 in the top left corner. Side-by-side green and red LEDs just to the left of the display window indi- cate transmit or receive, with the green LED showing received signal, and the red showing transmit, with increasing bright- ness on ALC peaks. Four large, black, rectangular buttons form a vertical

17、row to the left of the main tuning knob. Side-by- side white and light green legends above each button indicate their primary and sec- ondary functions. The top button in this row serves as a function button, allowing ac- cess to the secondary functions and the set mode. The lower three buttons cont

18、rol vari- ous memory, VFO and scan features. Theres a second set of six buttons in two horizontal rows to the right of the main tuning knob. The top row contains single function buttons for SELECT, MODE, and TUNE (for use with an external automatic Table 1 Alinco DX-77T, serial number T000528 Manufa

19、cturers Claimed SpecificationsMeasured in the ARRL Lab Frequency coverage: Receive, 0.5 to 30 MHz;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. Size (height, width, depth): 3.99.710.5 inches; weight, 8.4 pounds. Power requiremen

20、t: Receive, 1.1 A (max); transmit, 20 A (max).Receive, 0.8 A; transmit, 16 A. Tested at 13.8 V. Modes of operation: SSB, CW, AM, FM, WBFM.As specified. ReceiverReceiver Dynamic Testing SSB/CW sensitivity, bandwidth not specified: 0.5-1.8 MHz, 107 dBm;Minimum discernible signal (noise floor), 500 Hz

21、filter: 1.8-30 MHz, 119 dBm. Preamp off Preamp on 1.0 MHz127 dBm129 dBm 3.5 MHz132 dBm140 dBm 14 MHz130 dBm136 dBm AM sensitivity, 10 dB S/N: 0.5-1.8 MHz, 10 V; 1.8-30 MHz, 2 V. 10 dB (S+N)/N, 1-kHz tone, 30fi modulation: Preamp offPreamp on 1.0 MHz3.2 V1.9 V 3.8 MHz1.4 V0.6 V FM sensitivity, 12 dB

22、SINAD: 0.5 V.For 12 dB SINAD: Preamp offPreamp on 29 MHz0.7 V0.2 V Blocking dynamic range: Not specified.Blocking dynamic range, 500 Hz filter: Preamp offPreamp on 3.5 MHz109 dB*110 dB* 14 MHz111 dB*112 dB* Two-tone, third-order IMD dynamic range: Not specified.Two-tone, third-order IMD dynamic rang

23、e, 500 Hz filter: Preamp offPreamp on 3.5 MHz92 dB*93 dB* 14 MHz94 dB*95 dB* Third-order intercept: Not specified.Preamp offPreamp on 3.5 MHz+12.6 dBm+4.5 dBm 14 MHz+17.3 dBm+9.5 dBm Second-order intercept: Not specified.Preamp off, +53 dBm; preamp on, +51.5 dBm. FM adjacent channel rejection: Not s

24、pecified.29 MHz: 60 dB, at 20 kHz channel spacing, preamp on. FM two-tone, third-order IMD dynamic range: Not specified.29 MHz: 63 dB* at 20 kHz channel spacing, preamp on. S-meter sensitivity: Not specified.S9 signal at 14.2 MHz: preamp off, 36 V; preamp on, 16 V. Squelch sensitivity: Not specified

25、.At threshold, preamp on: SSB, 14 MHz, 1.0 V; FM, 29 MHz, 0.1 V. Receiver audio output: 2 W at 10% THD into 8 .2.1 W at 10% THD into 8 . IF/audio response: Not specified.Range at 6dB points, (bandwidth): CW-N (500 Hz filter): 525-1027 Hz (500 Hz); CW-W: 150- 2288 Hz (2138 Hz); USB-W: 216-2977 Hz (27

26、61 Hz); LSB-W: 186-2834 Hz (2648 Hz); AM: 146-2894 Hz (2748 Hz). Spurious and image rejection: 70 dB.First IF rejection, 114 dB; image rejection, 104 dB. TransmitterTransmitter Dynamic Testing Power output: SSB, CW, FM: 100 W high, 10 W low;CW, SSB, FM, typically 106 W high, AM, 40 W high, 4 W low.1

27、1 W low; AM, typically 42 W high, 6 W low. Spurious-signal and harmonic suppression: 50 dB (45 dB on 30 M).52 dB. Meets FCC requirements for spectral purity for equipment in its power output class and frequency range. SSB carrier suppression: 40 dB.As specified. Undesired sideband suppression: 50 dB

28、.As specified. 60 dB. Third-order intermodulation distortion (IMD) products: Not specified.See Figure 1. CW keyer speed range: Not specified.6 to 49 WPM. CW keying characteristics: Not specified.See Figure 2. Transmit-receive turn-around time (PTT releaseS9 signal, 19 ms. to 50 % audio output): Not

29、specified. Receive-transmit turn-around time (tx delay): Not specified.SSB, 20 ms; FM, 8 ms. Unit is suitable for use on AMTOR. Composite transmitted noise: Not specified.See Figure 3. Note: Unless otherwise noted, all dynamic range measurements are taken at the ARRL Lab standard spacing of 20 kHz M

30、easurement was noise-limited at the value indicated. Third-order intercept was determined using S5 reference. tuner). The second row are dual function buttons: RF/FILTER for RF gain level and CW filter, NB/AGC for noise blanker and automatic gain control fast or slow and H/L/TONE for power output le

31、vel and CTCSS tone. All ten buttons also provide access to set mode controls, including the speech processor, display brightness, auto- matic LSB/USB selection, transmit inhibit, the step size of the UP/DOWN buttons, and several additional settings related to CW keyer and scan operations. A one page

32、 “Controls Quick Reference” table in the manual gives a description of the functions performed by each of these ten buttons in their primary, secondary and set mode ap- plications. New users will definitely want to photocopy this chart and keep it handy. The only part about using this radio that can

33、 be confusingat least at firstis that June 199853 you wont find the set mode functions all in one place. Once you enter set mode, youll have to push different buttons to access different “menu” items. Theres a certain logic to it, however, and after a while, you will remember which settings reside b

34、ehind which buttons on the front panel. To the Rear! The back panel has jacks for connection of the required external 13.8 V dc, 20A power supply, an SO-239 antenna connec- tion, and an attachment point for station ground. RCA (phono) jacks for amplifier relay and ALC controls, a five-conductor conn

35、ector for control of an external auto- matic antenna tuner, and a 3.5 mm REMOTE jack for the optional Alinco ERW-4 com- puter-control interface also are included. This REMOTE jack allows memory cloning between two DX-77Ts. Simply connect the two radios with a length of cable with stereo 3.5-mm plugs

36、 on either end and ac- tivate the clone feature. Alinco says memory programming and remote control are on the horizon for the DX-77T. The software has not yet been de- veloped, however. The control is via a serial port connection directly from the computers COM port to the stereo REMOTE jack on the

37、rear panel (Alinco supplies the ERW-4 cable as an option). With suitable software, a user will be able to set and control most of the radios features including transmit and re- ceive frequencies, output power, scanning start and stop, priority, split, mode, RF gain, AGC speed, noise blanker, CTCSS e

38、ncoder, tune mode, filter, and various menu func- tions. The transceiver can report out its S meter reading, PTT status, squelch status, RIT status, memory channel information, split mode, and VFO or memory mode. Attachment of equipment for operating the digital modes (RTTY, PACTOR, AMTOR, etc.) is

39、via the front panel micro- phone connector. Alinco thoughtfully in- cludes fixed-level audio at this connector for easy hookup. The manual includes a micro- Figure 3Worst-case tested spectral display of the Alinco DX-77T transmitter output during composite-noise testing. Power output is 100 W at 3.5

40、 MHz. The carrier, off the left edge of the plot, is not shown. This plot shows composite transmitted noise 2 to 22 kHz from the carrier. Figure 2The default CW keying waveform for the Alinco DX-77T showing the first two dits in full-break-in (QSK) mode using external keying. The equivalent keying s

41、peed is 60 wpm. The upper trace is the actual key closure; the lower trace is the RF envelope. Horizontal divisions are 10 ms. The transceiver was being operated at 100 W output at 14.2 MHz. This is excellent keying. The waveform was nearly identical using semi-break-in mode with the “auto” delay fe

42、ature. 246810121416182022 140 130 120 110 100 90 80 70 60 Frequency Sweep: 2 to 22 kHz from Carrier Reference Level: - 60 dBc/Hz Vertical Scale: dBc/Hz Figure 1Worst-case spectral display of the Alinco DX-77T transmitter during two- tone intermodulation distortion (IMD) testing. The worse-case third

43、-order product is approximately 30 dB below PEP output, and the worse-case fifth-order product is approximately 41 dB down. The transceiver was being operated at 100 W output at 21.250 MHz. 1086420246810 80 70 60 50 40 30 20 10 0 Frequency Offset (kHz) Reference Level: 0 dB PEP phone wiring diagram.

44、 Two holes for mount- ing bracket hardware are on each side of the cabinet, although no mobile mounting bracket is currently available from Alinco. On the Air! Operating the DX-77T is fairly simple. A few seconds spent looking over the front panel and a quick glance at the aforemen- tioned “Quick Re

45、ference” table should be enough to get most operators up and run- ning. Once you have a feel for the interac- tion between the SELECT and UP/DOWN buttons, moving between frequencies, bands, or memory channels is easy. Major controls on this transceiver are very conve- niently located, especially for

46、 right handers. Voice operation is a simple matter of selecting the mode with a few presses of the MODE button (the DX-77T steps through its modes), tuning to the desired frequency, setting the volume and squelch levels, and away you go! Power output level is limited to two levels: high power is 100

47、 W output; low power is 10 W output (an internal switch allows switching these to 50 W and 5 W respectively). The microphone gain level is factory set. Those needing to make adjustments for their individual voice characteristics will find the location of and adjustment pro- cedures for an internal m

48、ike gain control in the manuals maintenance chapter, but this probably will not be necessary. Our review- ers reported very good to excellent trans- mit audio reports with the included mobile microphone at the factory gain setting. While this radio has an audio-level speech processor, it does not ha

49、ve VOX. Receive audio reports were mixed. The included speaker is considerably smaller than the front-panel grille would suggest. Most reviewers felt that with the internal speaker, the audio was somewhat tinny- sounding. Predictably, using a larger exter- nal speaker helped quite a bit. Alinco located the external speaker jack on the front panel. While this may be convenient in some situations, for most station arrangements the rear panel would be a better site for this jack. Maybe an additional jack on the back would provide the ultimate solution. We had complained some