Alinco_DR-735T_review_QST_2016.pdf

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1、QST Devoted entirely to Amateur Radio www.arrl.org Reprinted with permission from October 2016 QST With the DR-735T on the bench, I con- nected it to my dual-band ground plane antenna. Fortunately, the transceiver has a built-in diplexer feeding a single antenna jack. All I had to do was attach my f

2、eed line to the radio and I was ready to go. Some rigs sport separate 2 meter and 70 centime- ter antenna jacks, which is fine if you have separate antennas, but for those of us with dual-band antennas (which includes the major- ity of mobile antennas these days) it is a blessing not to have to inve

3、st in an external diplexer. While exploring the DR- 735T, I noted that it had two external speaker jacks. This is a very useful feature for base or mobile operating, al- lowing you to send the audio from, say, the 2 meter band to the left speaker and the 70 centimeter band to the right speaker. On t

4、he rear panel I also spotted a small DIN jack for connecting an external packet radio terminal node controller (TNC) for APRS and other activities. However, after consulting the manual, I discovered that the DR-735T is only designed for packet operation up to 4800 baud; you cant use the DR-735T for

5、9600 baud packet. On the Road The Alinco DR-735T is a fine indoor trans- ceiver, but it really shows its talents on the road. Since I lacked the separation kit, I mounted the radio vertically on the console between the driver and passenger seats of my automobile. It was far from an ideal installatio

6、n, but it was also just temporary. Thanks to the strong audio output, I had no difficulty hearing the DR-735Ts internal speaker. Considering the fact that I had the heatsink wedged up against the side of a leather seat, I was grateful for the potent cooling fan. One feature I appreciated instantly w

7、as the fact that Alinco designed the DR-735T with independent sets of volume, squelch, and VFO controls for each band. This is a godsend when youre driving and you dont want to take your eyes off the road to make an adjustment. I could find and grasp Reviewed by Steve Ford, WB8IMY QST Editor wb8imya

8、rrl.org If youre in need of a dual-band FM mobile transceiver with a big display and hefty RF output specs to match, the Alinco DR-735T may be worth considering. The DR-735T has one of the largest and brightest displays that Ive ever seen in an FM mobile trans- ceiver. As anyone who has operated on

9、the road will tell you, an easy-to-read display is a key feature. Distracted driving can be even more distracting when your eyes cant find the display, much less focus on it. You wont have that problem with the Alinco DR-735T. When it comes to RF power, Im accus- tomed to dual-band radios that tend

10、to offer reduced output on UHF compared to VHF. Not so with the DR-735T; it offers 50, 20, or 5 W output on both bands. The trans- ceiver case is compact, which means that space for a heatsink is limited. To solve that issue, Alinco added a powerful cool- ing fan to the DR-735T. The fan is a bit noi

11、sy, but not objectionably so. Still, you can change the way it functions when it operates and when it doesnt in the menu system. For example, you can set the fan to activate whenever you transmit and remain active for 2 minutes afterward. At the opposite extreme, you can set the fan to activate only

12、 when the internal temperature exceeds 158 degrees, although the manual seems to discourage this (for good reason). The DR-735Ts control head detaches quickly from the main body of the trans- ceiver, allowing you to place the head under your dashboard while the rest of the unit hides beneath a seat

13、or in your trunk. To separate the radio in this fashion, how- ever, youll need to purchase the EDS-30 separation kit that includes a 16-foot cable. You can plug the microphone into the con- trol head when it is separated, but the head lacks a jack for speaker. This means you may need to mount an ext

14、ernal speaker in proximity to your operating position if the radio isnt close enough for you to hear its Alinco DR-735T VHF/UHF FM Transceiver Bottom Line The Alinco DR-735T is a rugged dual-band FM transceiver with plenty of RF output power, a full feature set, and a bright, easy-to-read display. i

15、nternal speaker. The radio has plenty of audio power, though, so I suspect the inter- nal speaker may suffice for a nearby under- seat installation. Other features of note include the DR- 735Ts full crossband repeater operation, expanded 2 meter receive range to include the AM aviation band, and 100

16、0 memories that can be scanned. The DR-735T can also function as a digital voice transceiver if you install the optional EJ-47U GMSK board. However, youll only be able to communi- cate with other similarly equipped Alinco users. We did not install the board for this review. Indoor Exploration I bega

17、n by trying the DR-735T indoors, running it from my 13.8 V dc station power supply. When running at full throttle (50 W output), the transceiver draws about 10 A of current when transmitting. Reprinted with permission from October 2016 QST ARRL, the national association for Amateur Radio www.arrl.or

18、g Table 3 Alinco DR-735T, serial number M00580 Manufacturers Specifications Measured in ARRL Lab Frequency coverage: Receive, 108 135.995 Receive and transmit, as specified. MHz (AM), 136 173.995 MHz (FM), 400 479.995 MHz. Transmit, 144 147.995 MHz, 430 449.995 MHz (FM). Modes: FM. As specified. Pow

19、er requirements: Receive: 600 mA At 13.8 V dc: Receive, 840 mA (max maximum, 400 mA standby. Transmit, 12 A, volume, max lights, no signal, one at 13.8 V dc 15%. receiver); 900 mA (max volume, max lights, both receivers); 553 mA (standby, max lights); 323 mA (standby, no lights). Transmit (hi/med/lo

20、w): 146 MHz, 8.5/5.7/3.2 A, 440 MHz, 10.4/6.3/3.3 A. Receiver Receiver Dynamic Testing* Sensitivity: FM (12 dB SINAD), 0.16 V FM (12 dB SINAD): 0.16 V (144 MHz), 0.17 V (440 MHz), 0.14 V (WX). AM (10 dB S+N/N): 0.63 V. FM two-tone, third-order IMD dynamic range: 20 kHz offset: 146 MHz, 53 dB; 440 MH

21、z, Not specified. 58 dB. 10 MHz offset: 146 MHz, 69 dB; 440 MHz, 60 dB. FM two-tone, second-order IMD dynamic range: 146 MHz, 80 dB; 440 MHz, 102 dB. Not specified. Adjacent-channel rejection: Not specified. 20 kHz offset: 146 MHz, 66 dB; 440 MHz, 65 dB. Spurious response: Not specified. IF rejectio

22、n: 146 MHz, 132 dB (main RX), 129 dB (sub RX); 440 MHz, 132 dB (main 440 MHz, 132 dB (main 440 MHz, 0.09 V (0.48 V max). S-meter sensitivity: Not specified. S-9, signal: 144 MHz, 1.27 V; 440 MHz, 1.70 V. Audio output: 2 W at 10% THD into 8 . 2.8 W at 10% THD into 8 . THD at 1 VRMS, 1.85%. Transmitte

23、r Transmitter Dynamic Testing Power output: 50, 20, 5 W (hi, med, low) At 13.8 V dc (hi/med/low): at 13.8 V dc 15%. 146 MHz, 53/22/2 W, 440 MHz, 47/19/4 W. High power output at minimum specified voltage: 144 MHz, 49 W; 440 MHz, 44 W. Spurious signal and harmonic suppression: 70 dB. Meets FCC require

24、ments. 60 dB. Transmit-receive turnaround time (PTT release Squelch on, S9 signal, 146 MHz, 166 ms; to 50% of full audio output): Not specified. 440 MHz, 167 ms. Receive-transmit turnaround time (“tx delay”): 146 MHz, 67 ms; 440 MHz, 65 ms. Not specified. Size (height, width, depth): control panel,

25、2.3 5.5 2 inches (including protrusions). rear Chassis, 1.5 5.5 7.3 inches. Weight, 2.9 lbs (panel, rear chassis, and cable). Price: $340. EDS-30 head separation cable (16 ft), $55; ERW-7 USB cable, $50; EJ-47U digital voice adapter, $200. *Main and sub receivers measured identically, unless noted.

26、the knob I wanted by “feel” alone. With a dual-band mag-mount antenna, I received excellent reports from local and distant repeaters. Operating at the 50 W level, I found myself enjoying simplex chats on both 2 meters and 70 centimeters. In one instance, I made a simplex contact on 2 meters with a f

27、ellow in New Jersey while cruising around central Connecticut. Granted, he was using a Yagi antenna on a hilltop station at his end, but he reported that my signal was quite strong, with out- standing audio. The DR-735T seemed to have a reason- ably sensitive receiver, although I did no- tice occasi

28、onal “intermod” reception when driving through areas where commercial two-way transmissions were particularly strong. This was an issue that some ama- teurs reported in the DR-735Ts predeces- sor, the DR-635T. To help mitigate this problem, Alinco has added a function in the DR-735T menu system that

29、 allows you to activate what the manual calls “Image Signal Rejection.” Unfortunately, ARRL Lab testing revealed no difference in the adjacent channel rejection, IMD dynamic range, or image with this feature on or off. You can toggle on an attenuator if local interference is severe. Lab testing indi

30、cated that turning on the attenuator improves adjacent channel selectivity by about 5 dB and IMD dynamic range by about 8 dB. The tradeoff is a 10 dB loss of sensitivity. An attenuator is a good function to have on an FM mobile transceiver. This transceiver distinguishes itself by of- fering full du

31、plex operation, which in this instance means that you can transmit on one band (the “main” band) while listening to the other (“sub”) band. I would imagine this would be highly useful during public service operations where it may be impor- tant to monitor activity on one band while transmitting on a

32、nother. On the other hand, should you find this feature annoying, there is a menu function that will allow you to automatically disable subband reception whenever you transmit. And Theres More The DR-735T offers more features that are sure to appeal to FM enthusiasts, especially mobile operators. Th

33、e scanning function QST Devoted entirely to Amateur Radio www.arrl.org Reprinted with permission from October 2016 QST Key Measurements Summary Alinco DR-735T VHF/UHF FM Transceiver 2 M70 cm Key: * Values shown are best case. There are some differences between receivers. See Table 3. PR109 14 Snd 2.

34、8 Audio Output (W) 60 120Img 132 133* Image Rejection (dB) 60 135 IF 132 132* IF Rejection (dB) ChRej 5090 65 66 Adjacent Channel Rejection (dB) 4070 I3 Rx 5820 kHz 5320 kHz Receiver 3rd-Order Dynamic Range (dB) I3 Rx 90606010 MHz 6910 MHz Receiver 3rd-Order Dynamic Range (dB) SINAD0.25 0.1 0.17 0.1

35、6 Receiver Sensitivity (12dB SINAD, V) is very flexible and easy to use. Best of all, you can configure the display so that it boosts to full brightness whenever the scan stops on a signal, giving you a visual indi- cation of activity in addition to the audible one. I found this to be extremely hand

36、y when I had to temporarily turn down the audio while scanning, such as when listen- ing to a news story on the broadcast radio. Another item worth mentioning is the shortcut key. This is a pushbutton that is positioned dead center along the bottom row of the front panel and labeled with a star. You

37、 can program this key to instantly toggle any “set mode” setting. For exam- ple, you can program the key to activate the DR-735Ts receive attenuator with a single press of a button, which is much easier than jumping through a set of menus. Conclusion The Alinco DR-735T is a rugged FM trans- ceiver w

38、ith all the RF output power anyone would normally need. In my tests I rarely needed to increase the output power beyond 20 W, but it was nice to know that I could call upon the full 50 W output on either band if the need arose. For mobile operation, the large, bright display is a winner. Perhaps it

39、is my 61-year-old vision, but I was grate- ful for the attention the Alinco engineers have given to creating a display that I can see from almost any reasonable distance. In addition to making it big and bright, Alinco included the ability to tailor the display pa- rameters in ways I dont usually se

40、e in other rigs (brightness, color, and contrast). With a full complement of features, includ- ing alphanumeric labeling for all those 1000 memories, the DR-735T is a worthy transceiver for the serious FM operator. Manufacturer: Alinco, Yodoyabashi Dai- Bldg 13F, 4-4-9 Koraibashi, Chuo-ku, Osaka 541-0043, Japan; . Distributed in the US by REMTronix, 1750 Murphy Pkwy, Lathrop, CA 95330; tel 209-900-1296; .