Alinco_DX-SR8_review_2010.pdf

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1、It may be budget priced but its got some real surprises for under 500! I Ive always enjoyed using Alinco equipment as its well-designed, well-made, easytouse and provides value for money. Many readers will know that I own an Alinco DX-70TH (my original DX-70 was stolen from my shack in March 2009) a

2、nd that I was one of the earliest users of the transceiver when it was first introduced in the UK around 15 years ago. However, the original tried and trusted transceiver now has a new rig on the block to contend with the DX-SR8, the first new high frequency (h.f.) model from Alinco for many years.

3、A new model such in the pricing range as the DX-SR8 around 500 should be an ideal fi rst rig for many Radio Amateurs and possibly a second transceiver for portable and mobile use for other operators. So, how did it perform? Read on to share my experience of the new rig on the block. The Overall Desi

4、gn The Alinco DX-SR8 is an h.f. only transceiver covering all bands from 1.8 to 30MHz, with the inclusion of the 5.3MHz band. Nevada will enable transmission on this band for Amateurs with the appropriate Notice of Variation (NoV). The rig provides c.w. for Morse operating, amplitude modulation (a.m

5、.), narrow band frequency modulation (n.b.f.m.) and single sideband (s.s.b.) operations. Transmission is only enabled for the Amateur Radio bands. The tuning scale employs a large easy-to-read liquid crystal display unit (much larger than the DX-70TH model), with a pale grey background and a light b

6、lack contrast alpha-numeric display. The backlight settings can be varied using the main menu control system. The transmitter section provides a radio frequency (r.f.) output of 100W when operating on the c.w., s.s.b. and n.b.f.m. modes. The power output can be varied (via Alincos new budget priced

7、rig! The DX-SR8 HF Transceiver Exclusive Review! Practical Wireless, February 2010 18 Rob Mannion G3XFD evaluates the latest h.f. rig from Alinco and discovers its a remarkable budget-priced package! Exclusive Review! the on screen menu) between 100W (High), approximately 10W (Low) and approximately

8、 1W using the menu system. Note: Its also possible to lower the r.f. output to the milliwatt range, by opening the transceiver casing and making a small adjustment. The transmitters r.f. output when its operating in the a.m. mode is a maximum of 40W (High), 4W (Low) and 0.4W (400mW) (S-Low). The mod

9、ulation systems employed are balanced for s.s.b., low-level modulation for a.m. and reactance modulation for n.b.f.m. Maximum deviation on n.b.f.m. is 2.5kHz. The Alinco DX-SR80s receiver is a double conversion superhet design with a fi rst intermediate frequency (i.f.) of 71.75MHz and a second i.f.

10、 of 455kHz. The receiver has the usual audio frequency (a.f.) front panel control, and another for varying the i.f. passband (to help overcome adjacent channel interference) and a front panel controlled radio frequency (r.f.) attenuator, which allows zero attenuation, and steps of increasing attenua

11、tion. Theres also an adjustable squelch control. Unusually, for a modern commercially produced transceiver, the DX-SR8 is fi tted with a narrow-band audio fi lter for extra selectivity, rather than by using a crystal or ceramic resonators (as used by the Alinco DX-70 series). Note: Although I havent

12、 seen a fully detailed circuit diagram, the specifi cations, as announced by Alinco and provided in the manual, are reproduced in the side panel. The transmitter is provided with a hand-held microphone (the EMS-64) and the receiver has (unlike the DX-70 series) a small loudspeaker on the detachable

13、front panel. An extension kit EDS-17 (not available for the review) is required if the panel is to be separated for remote operation perhaps for a mobile installation. Direct frequency input is possible through the control pad to the right of the main screen. The transceiver can also be controlled b

14、y a PC through the serial interface, using the optional PC interface cable. Once set up the frequency, mode, power and memory can be selected via the computer. The manual is to the usual good quality Alinco product, although there are several slightly amusing phrases due to the huge language barrier

15、 between written Japanese and English. Despite this, I feel that its generally very helpful and well up to the usual friendly Alinco standard. The design also incorporates 600 memory channels for the use of the operator. These can be registered in three banks, with 200 channels per bank. Each of the

16、 memory channels can store the operating mode fi lter setting, split frequencies, a.g.c. setting, attenuator or pre-amplifi er settings, noise blanker settings, etc. For those who enjoy chasing the DX, split frequency operation is possible and there are scanning facilities. On the whole the SR8 is c

17、ertainly not presented as a budget receiver judging by the facilities provided. On The Air After I had familiarised myself with the rig I certainly enjoyed using it on the air and inevitably I was continually comparing the new transceiver to my Alinco DX-70TH. I listened on all bands, but kept my op

18、erations to the 3.5, 7, 10, 14 and 18MHz bands, as conditions werent that good. I operated on c.w., a.m., s.s.b. and n.b.f.m. The a.m. and n.b.f.m. transmissions took place on 70MHz (via my 28 to 70MHz transverter and the audio reports were very satisfactory). Though the display looks blue in the he

19、ading shot, this is a trick of the photography, in reality the display looks blue/black text on an almost pure white background. Practical Wireless, February 2010 19 The simple back panel has little more than sockets for the power, antenna, accessories, Morse key and external speaker along with a co

20、axial socket to add in an external ALC voltage. The whole front-panel pivots off for remote operations after releasing two screws various length leads are available as extras. Alinco DX-SR8 Most of my s.s.b. contacts were achieved around the 100W level, although I carried out one short test at 1W wi

21、th my friend and PW author Phil Ciotti G3XBZ, but even though it was on a noisy 3.5MHz band, we are very close neighbours radio-wise! Incidentally, to achieve power levels of less than 1W (milliwatts) the SR8 has to be opened up and a pot-style control adjusted (I didnt do this as the rig was on loa

22、n). As part of my tests to check the transmitted audio quality, I again had the help of Phil G3XBZ, who lives on the opposite side of Bournemouth to me. Despite being less than 8km (5 miles) apart, conditions on 3.706MHz (obviously ground wave) s.s.b. contact werent too good, although Phil commented

23、 favourably on the audio quality. Despite the favourable report, I was a little disappointed because normally I receive excellent audio reports especially when Im using my Alinco EMS-14 desk microphone. However, we had another QSO later after I had realised that the built-in speech processing was in

24、advertently switched on (not really necessary for local contacts) and the the noise (we were both affected by a persistent noise on the band, not local to us) on the fi rst QSO had abated. So, during our second test contact Phil gave me the sort of report that seems standard for Alinco h.f. transcei

25、vers. “Excellent audio Rob, very well rounded, defi nitely you and a pleasure to listen to!” The report came after I had changed microphones several times from the supplied hand-held microphone to the EMS-14, Phil said that the desk microphone sounded better than the fi rst microphone. This isnt sur

26、prising, as I tend to speak rather loudly into a hand-held microphone whereas I speaking farther away dont tend to overload the EMS-14 so much! The reports I received from QSOs on all the bands operated on were all very favourable using the hand-held microphone but after establishing contact, for my

27、 own convenience I switched over to the desk microphone. The receivers sensitivity is excellent, more than adequate for the h.f. bands and the selectivity is also adequate for todays crowded bands for s.s.b. operating outside of contest periods. During one of my QSOs with Phil G3XBZ because of adjac

28、ent channel interference I selected the audio fi lter on via the main menu and it certainly helped reduce the QRM by reducing the audio bandwidth. Unfortunately, in common with all fi xed bandwidth audio fi lters the SR8s fi lter affected the audio quality I was receiving from Phil. So, as soon as t

29、he QRM eased (as band conditions changed) I switched the fi lter out to regain the pleasing audio I had enjoyed before the adjacent interference began. Unfortunately, during the review period the 14 and 18MHz bands didnt provide much DX opportunities but I worked stations all over western Europe, ga

30、ining many more favourable comments on the transmitted audio. From my end I found the receiver delightfully easy to use and the large, display was pleasant to use and although the brightness can be varied, I preferred to leave it at the default settings. On several occasions during s.s.b. QSOs on 3.

31、5 and 7MHz, I found that it helped if I wore my headphones, but (again to my surprise) I found that was rarely necessary because of the extremely effi cient and cleverly designed speaker and enclosure. Indeed, I was so impressed at the performance of the small-sized front panel speaker (after some c

32、omparison tests) I preferred it to the extension speaker I use with my Alinco DX-70. The placing and the performance of the built-in loudspeaker may, at fi rst, not seem to be important. However, with careful design the built-in speaker and enclosure may save us having to take an extension speaker f

33、or portable/ mobile operations and Alincos carefully thought out design has led to one of the best quality communications speaker Ive ever come across. I found it was a great help on the noisy Amateur bands (see later section for general coverage receive comments). The front panel controls for the s

34、tepped r.f. attenuator and pre-amplifi er were very useful although, as the sensitivity on the SR8 is excellent, the extra gain from the pre-amplifi er wasnt needed. Indeed, I found the r.f. attenuation was much more in demand because of the high noise levels on the bands. The built-in noise blanker

35、 also proved useful in reducing the annoying clicks that are so prevalent at this time of year as badly designed thermostats do their job! Unusually, there wasnt a contest on during the review period. This meant I didnt get the opportunity to see how well the receiver coped during the free-for-all a

36、nd jumbled everyone-on-the-same frequency melee that weve all experienced during a contest! Time will tell but the rig seemed to perform very well on the busy h.f. bands. On The Key As a keen c.w. operator I was looking forward to operating the SR8 on c.w., even though Im not so good on the key nowa

37、days due to arthritis. Because of the arthritis Ive gradually been operating more often with a separate electronic keyer with my own Alinco DX-70TH, but thats brought its own problems because of nerve damage in my hand, effecting my sending accuracy. However, the vast majority of Amateurs I work are

38、 very forgiving of any errors I make. So my message must be even if youre not too sure of yourself on c.w., have a go, youll be made most welcome by other operators. We can also be sure to get a c.w. QSO at any time of the day on the h.f. bands! The built-in electronic keyer on the SR8 intrigued me

39、just what would the key be like on such a budget priced rig? I neednt have been worried it coped extremely well with my sometimes erratic paddling. No details of the type of keyer design is given in the manual by Alinco but I wouldnt be surprised to discover that its based on the well known Curtis k

40、eyer integrated circuit (i.c.). Im not a fan of menu operated rigs and can honestly admit that Im very old fashioned, preferring as many controls to be immediately available on the front panel. Years ago rigs had very crowded front panels! Again, despite my initial disappointment that the SR8s keyer

41、s controls particularly the speed control werent on the front panel, I immediately found that even my slow old brain became accustomed to adjusting the speed via the menu system. The supplied hand microphone attaches to the remote- mountable front panel rather than into the main unit. This means no

42、extra microphone lead is needed to use it this way. Practical Wireless, February 2010 20 It turned out to be the proverbial piece of cake and my reluctance quickly melted away. The keyer has a comprehensive range of settings, covering speed, keying dot-to-dash length ratios (we tend to refer to this

43、 as weighting as we place a slighter or heavier emphasis on the dashes (usually referred to as dits and dahs) more than enough to satisfy someone being introduced to luxury Morse as one old Telegraphist said to me when I demonstrated one of my fi rst keyers many years ago! The sidetone frequency is

44、adjustable from the main menu and is very simple to change. However, I found that the keying sidetone volume level to be far too loud for me on the default setting. Unfortunately, this feature isnt controlled via the main menu and as I didnt want to open up a brand new rig (to adjust the level), on

45、loan to me for a short period, I gently placed a small towel over the speaker grill. This reduced the sidetone volume effectively and if necessary I could then adjust the main receiver volume using the a.f. gain control. Once on the air, I found that I was most comfortable operating at around 12 to

46、14 words per minute (w.p.m.) but the keyer will work very well indeed up to around 30w.p.m. for the machine gun operators if they so wish! Incidentally, in days past I was quite comfortable operating at around 20 to 25w.p.m. but because my handwriting is so slow nowadays and I prefer to copy everyth

47、ing down in block capitals as the Royal Navy trained anyone they taught Morse I prefer to operate at a slower speed. Even then, I struggle to write everything down fast enough! Theres a choice of sending and receiving change-overs offered on the SR8, ranging from full break-in, where its possible to

48、 listen in on your transmitting frequency, to semi- automatic, with pre-set (menu controlled) delays. And this is where I cam across my fi rst real little niggle with the transceiver the clattering relays! When full break-in is selected, the SR8s internal relay system seems to be relatively noisy co

49、mpared to the Alinco DX-70TH. In fact, I found it to be quite distracting although Im sure it would eventually fade into the background as I got used to the rig. To get over the problem I used the main menu settings to introduce one of the pre-set delays, which enables the receiver to drop back into receive after a key-up delay. This turned out to be very successful and after experimenting with different delays, I settled on one that gave me about two seconds or so key up before the rig turned to rec