IC-7400_review_PW_2002.pdf

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1、4untimmitim.111 OA AN ENJOYABLE ENCOUNTER IC-7400 TUNER NR-9-NOTCH 3.5 2 7 3 10 4 14 5 14 6 21 7 2t 03 2! 9 OBE ?0 144 woo AX LOCK 0 / NOTCH AF -9- R F/ SOL * 444 44 FILTER a SCP t:. ? STEF MENU SSB ? CW/RTTY ? AM/FM ? FILTER The Icom 1C-7400 HF Et VHF Transceiver Even though hes on a trailing cours

2、e, Richard Newton GORSN couldnt miss out on the chance of trying the latest offering from Icom. And despite antenna limitations. Richard thoroughly enjoyed himself! ve not been so active since I moved house at the end of last summer and have not yet managed to set up a new shack! So, I was delighted

3、 to be asked by PW to take a look at the IC- 7400, a new multi-mode transceiver offering general coverage receive and c.w., a.m. s.s.b., RTTY, and narrow band f.m. (n.b.f.m.) on h.f. and also the 50 and 144MHz bands. The IC-7400 is the successor to the established Icom IC-746 transceiver (which I re

4、viewed for PW back in November 1998). I remember being very impressed indeed by the 746 and so was keen to try the new rig. Very Similar Looks Opening the box I saw that the Icom IC-7400 was very similar to its predecessor in looks. The distinctive large screen and wonderful display were there and t

5、he controls were laid out in an easy-to-follow and well designed way. There are two 50Q 50239 coaxial sockets for h.f./50MHz antenna systems and one 50Q S0239 socket for connecting the 144MHz antenna together with a grounding connection and 13.8V d.c. power socket. There are two accessory connection

6、s and a mini DIN for a dedicated data connection, and a dedicated connector for the optional external antenna tuner, and straight or bug type (c.w) key and the external speaker jack plug sockets. Phono type coaxial connectors are provided for a linear amplifier to be connected. The front of the Icom

7、 IC- 7400 carries the controls for the radio along with sockets for external headphones and an external paddle key to operate the built-in electronic keyer. All the controls for the main functions are large and well labelled. Its smart and professionally finished and definitely looks the part. In op

8、eration the controls are positive and the tuning dial spins and turns with a reassuringly well-balanced feeling of weight. Included in the smaller and less accessible controls are 24 ? Practical Wireless, June 2002 Rear panel view of the transceiver things such as output power and other adjustments

9、that you might set and then leave. These include functions such as key speed, c.w. pitch and microphone gain which you would want hidden away slightly to reduce the chance of accidental operation. Those familiar with the Icom IC-706 or IC-746 - will definitely see some similarities here. At this poi

10、nt I have to say that the radio is very user friendly.even for those who are new to the multi-layered menu system. Its so difficult to decide where to start with radios like the IC-7400. The operator is offered so much! Whats On Offer? So, lets have a good look at what the Icom IC-7400 has to offer.

11、 Features include an internal c.w. electronic keyer with memory capability, an internal automatic antenna tuner (a.a.t.u.), a 32-bit floating DSP noise reducer which is extended to a DSP intermediate frequency (i.f.) filter and an auto notch filter. The transmitter is capable of 100W output power on

12、 all bands, except when in amplitude modulation (a.m.) transmission mode where the maximum is 40W. Power is variable from just less than 5 up to the 100W maximum. Receiver and transmitter incremental tuning (RIT) is provided within a frequency range of 9.99kHz. On 50 and 144MHz CTCSS tone functions

13、are provided together with a repeater tone burst, memories and scanning options. To mention all the controls would be very near impossible in the space available here. So Ill concentrate on those of main interest. The Digital Signal Processing (DSP) is used for the received audio and on the transmit

14、 side. The transmitted audio can be changed by selectable transmit audio pass band widths, these are 2.8kHz which gives very full audio, 2.4kHz (which the manual says is useful for operators with very deep voices) and the 2.2kHz setting.good for breaking through DX pile-ups. The transmitted audio ca

15、n be further adjusted by the use of what Icom call the Microphone Equaliser. This is where the operator can adjust the bass and treble of the transmitted audio. This is all in addition to the compressor which (based on on-air tests and reports) seems to enhance the transmitted audio very effectively

16、 indeed. For my part I felt that the ability to fine-tune the all- important transmitted audio was excellent. Although I didnt take a great deal of time setting it up.l still got some great results that Ill share a little later. The Icom IC-7400 also uses the DSP technology in the Twin Pass Band Tun

17、ing (TBT) function. This electronically narrows the pass band width by shifting the i.f. to slightly outside of the i.f.s filter pass band to reject interference. Moving both the PBT controls in the same direction has the effect of shifting the U. With a little practice this is a very effective tool

18、 for use in reducing the interference suffered where a strong adjacent frequency signal is present. The Icom IC-7400 has three pass band width i.f. filters for each mode. According to the manual the pass band for the s.s.b. and c.w. modes can be set within a range of 50Hz to 3.6kHz. This can be done

19、 in 50 or 100Hz steps, and provides a total of 41 pass band widths. For the RTTY mode the pass band width can be set within a range of 50Hz to 2.7kHz in 50 or 100Hz steps, giving a total of 32 pass band widths. The n.b.f.m. and a.m. modes have three fixed pass band widths which are independently ava

20、ilable. Theres also a built-in 100kHz calibrator.and the default setting on the model I had was On. So, the strong 100kHz sproggie I found was soon sorted when (by selecting the appropriate menu) the calibrator was switched off. Its unusual to have it on rather than off though - but if in doubt.read

21、 the manual I say! Demodulator For PM Perhaps the most interesting function I found was the RTTY demodulator and decoder which Icom have built-in. This means that for decoding Baudot an external terminal unit is not required. The transceiver will decode and display the text on its main display scree

22、n, and it has a twin peak meter to assist tuning. This meter changes the receive frequency response by boosting the 2.125 and 2.295kHz frequencies for improving the chances of copying the desired RTTY signal. Obviously, additional equipment to transmit RTTY is needed, but I thought that it was a won

23、derful idea to include the decoder. Pre-Programmed Bands Amateur bands on the IC-7400 are all pre-programmed into a keypad on the front panel. Three memories are allocated to each band - referred to as Stacking Registers and are overwritten on a rotational basis, remembering the last three operation

24、al frequencies and modes. An example: I selected the 14MHz band by pressing the Band button, resulting in 14.325MHz USB being displayed. There was an interesting station.but I wanted to quickly tune the band. I then pressed the same button a second time and used this setting to tune around. By press

25、ing it a third time I checked around 14.150MHz in RTTY mode, for any teletype activity. Having found nothing I pressed the same button again, and this took me directly to 14.325MHz USB. You may also be wondering how easy the radio Would be to actually operate.but fear not! The IC-7400 is very user-f

26、riendly and the manual is extremely easy-to-follow and is well written. Away From Home I was keen to see what the Icom IC-7400 could do on the Practical Wireless, June 2002 ? 25 AN ENJOYABLE ENCOUNTER Icom IC-7400 100W h.f., 50 and 144MHz transceiver. Icom (UK) Ltd Tel Sales: (01277) 741741 Pros: I

27、am certain the Icom IC- 7400 will be just as popular as the IC-746. Its a relatively compact and certainly portable rig (see below). Due to its very forgiving a.a.t.u. and variable power settings it lends itself to portable working as I experienced when doing the review. Cons: The rather large curre

28、nt drain the IC-7400 has, even on receive, does not lend it to working from a battery power supply. 1568.63 inc. VAT Providing you have a good power supply I think that this radio will give you excellent service wherever it is situated. It is, in short, a lovely radio. IIIMESZE1111I11b My thanks go

29、to Icom (UK) Ltd., Sea Street, Herne Bay, Kent CT6 8LD. Tel: (01227) 741741, FAX (01227) 741742, for the loan of the review unit. Richard GORSN (In his father-in-laws shack) thoroughly enjoying himself on 144MHz using the Icom IC-7400. (Photo courtesy of Terry Wood G7VIUM3T1W) air. However, Im away

30、from home at the moment on a course in Bramshill near Hook in northern Hampshire and have a small room in an accommodation block, which is on the third floor. The IC-7400 was only available for a limited time so I had to find a suitable antenna. My first idea was to borrow a dipole from my father-in

31、-law, Terry G7VJJ/ M3TJW. The Icom IC-7400 was then set-up my rooms desk and I attempted some antenna erecting. Fortunately, there were several large trees outside the 3rd storey window.but it was not going to be easy to support the dipole centre. Eventually I erected the dipole (10 metres long on e

32、ach leg) but feel unsure about sharing the following information with you! This is because the antenna ended up with one leg draped around the room, over the wall light, through the high cupboards and ended dangling down into the sink! The other leg I threw out of the window and hoped for the best.

33、Next, falling to temptation, I put the IC-7400s auto a.t.u. (a.a.t.u.) to the test and went on.hitting the tune button and getting onto 7MHz. The IC-7400 whirred and whizzed and soon a 1:1 v.s.w.r was showing on the multi display. I wasnt sure whether to be impressed or downright scared that the a.a

34、.t.0 would tune an antenna system (I use the term in the loosest possible sense) such as my Bramshill Bodge! The problem then came when I heard Ray HB9VW from Bern in Switzerland on 7.066MHz. What a massive signal.so throwing all caution to the winds I called him, and we had a very enjoyable chat an

35、d received a 5 and 6 report. Ray was 5 and 9 + from his home 32km (20 miles or so) North West of Bern. Success! Back & Prepared The following week I went back to Bramshill prepared and took my 20 metre (66ft) long wire with magnetic balun. This was easily strung from my window to a nearby tree, alth

36、ough it sloped downwards. Inside top view of the IC-7400. Next, I connected the antenna to the IC-7400 with the longer coaxial cable lead that Id remembered to bring along, and set about tuning around. The a.a.t.0 made it almost too easy.and in seconds it tuned up on 7, 14, 18, 21 and 28MHz. Tuning

37、to 21MHz and heard Vijay VU2VVP (India), unfortunately despite his being a terrific signal with me I was unable to break into the pile-up. I was however, impressed at hearing India! Next, I tuned up the band and found V01.a callsign prefix Ive never heard before. The station was Mark VO1ONE from New

38、foundland, Canada. Mark was providing a good 5 and 5 and gave me a 5 and 3 report and was running 100W from an Icom IC-706 and a mobile whip from his stationary vehicle. We had a very enjoyable chat until the QSB beat us and he faded away. Bedtime approached, so I decided to have one more try on 7MH

39、z and found James GM4MKU and Chris GM4ZJI in QSO on 7.056MHz. I called in and they were kind enough to allow me into their contact.James was a 5 and 9 signal from Lossiemouth in Morayshire and Chris was 5 and 7 from Glenrothes near Fife. I had some problems due to strong adjacent frequency signals,

40、but the pass band filter was soon put to good use. Chris and James both gave me favourable reports on the audio quality from the IC-7400. James said, The audio is excellent, clear, sharp and punchy. Chris commented, Its superb audio. The audio was so good that James even correctly identified that I

41、was trying to keep my voice down, as Id now noticed the time and expected a sharp bang on the wall from my neighbour at any moment! I thanked James and Chris for their time and went to bed. Up & Early Next morning, Spurred on by my first ever contact into Newfoundland and my splendid QSO to Scotland

42、 I decided to get up early and try out my luck on 14MHz. I had almost given up when I heard, Chuck WD9GWG, providing a large 5 and 8 signal from 26 ? Practical Wireless, June 2002 Manufacturers Specifications These are for the Europe version intended for use in Great Britain, Germany, Sweden, The Ne

43、therlands, Austria, Luxembourg, Finland and Ireland. General Frequency coverage in MHz Receive ?0.500 29.999 50.000 54.000 144.000 146.000 Transmit (All Amateur bands 1.8 to 144MHz). Mode Memories Usable temp Frequency Stability to 60 min after power on. After Frequency resolution Power supply Curre

44、nt drain Dimensions (mm) Weight Transmitter Output power (Watts) Continuously adjustable Modulation systems s.sb. a.m. n.b.f.m. Spurious emissions Carrier suppression Unwanted sideband Microphone impedance Receiver Receiver Type Intermediate frequencies Sensitivity SSB/CW/RTTY Pre-amp on (10dB S/N)

45、AM ( 10dB SIN) NBFM (12 dB SINAD) Selectivity SSB (BW 2.4kHz) CW (BW 500Hz) RTTY (BW 350Hz) AM (8W 6kHz) FM (BW 15 kHz) Spurious image rejection ratio (Except i.f. through on 50MHz) Audio output Rntenna Tuner Matching impedance Range c.w., a.m., s.s.b., n.b.f.m. and RTTY 99 regular, two scan edge an

46、d 1 call -10C to 60C Less than t 7 ppm from 1 min that less than t 1 ppm/hr at 25C 1Hz 13.8V d.c. t 15% negative ground (Transmit) max 23A (Receieve) Standby 2.2A, 3A (at max audio out) 287 x 120 x 316.5 (WHD) 9kg 2.4kHz/-6dB 500Hz/-6dB 360Hz/-6dB 6kHz/-6dB 12IcHz/-6dB 70dB 60dB (144MHz) 2W (at 13.8

47、V d.c. with 80 load) HF Bands 16.7 to 1500 unbalanced (less than v.s.w.r 3:1) 50MHz 20 to 1250 unbalanced (less than v.s.w.r 2.5:1) 27 Osceola, Polk County, Wisconsin in the USA. He was running 400W from a Yaesu FT-1000. You know the great thing about Amateur Radio is the terrific people you meet on

48、 the air. Chuck and I had a wonderful talk.so interesting I almost missed breakfast! Chuck reported that the audio from the IC-7400 was Really good and Rather mellow. He then complimented the rig for doing a really good job and sounding nice and crisp. Later that day I had a sked with my Father-in-L

49、aw Terry, G7VJJ using his new M3 call sign, M3TJW on 7.067MHz where exchanged 5 and 9 reports. I was running about 80W and Terry his maximum lOW from his Icom IC-706 Mark II into his wire dipole. The distance from Bramshill to Terrys QTH in Bournemouth is about 97km (about 60 miles). Terry complimented the IC- 7400, saying that it was A beautiful signal, baritone audio, very listenable to. He also commented that It really is lovely audio Richard.