Icom IC703 QRP Transceiver

Introduction

The rig has now been in use for several years and I have never had so many filled pages in my log book! It is a SUPERB rig for the QRP enthusiast and does just about everything that one could want. The antennas used have been modest: a 50-60 ft long wire at about 15 ft average height and a V2000 vertical on 6m.

The IC703 features a built-in DSP filter and auto ATU as well as speech processing an a CW keyer with 3 message memories.  

It is an ideal "all-in-one" ham station for QRPers.

 




Likes and Dislikes

Some points of note

1. The RX is nicely quiet, but sensitive, even without the DSP switched in. It reminds me of my old FT7 in this respect: that was the best receiver I'd ever used and this one rivals it.

2. DSP filter works nicely. Not having used a heterodyne "remover" before it was unbelievable how well it worked. The progressive step DSP noise filter works well too.

3. Dial backlight was a relaxing amber colour. I had expected it to be a harsh yellow.

4. Menus are easy to follow (although I'd seen similar in an IC706).

5. The auto-ATU loaded the longwire on ALL bands except 160m! Much better than expected. I was surprised how, once stored, the ATU reset to a band change almost immediately - clatter of relays for a few milliseconds and it was there.

6. One on the air it works well with worldwide QSOs on SSB and CW achieved. Audio reports have been excellent with the ability to punch through a few pile-ups being noted.

7. It is an excellent performer on 6m (most of Europe, N.Africa including EA8 worked with just a modest vertical). 2m and 70cms would have been nice too but I expect that will be in the IC703 MkII.

8. A QRP version of the IC7000 with internal ATU like the IC703 but with all the DSP IF filters would be nice!

Specs

 GENERAL
Frequency Range      Depends on version but covers 30kHz - 60MHz RX plus ham bands TX.
Mode    USB/LSB/CW/RTTY/AM/FM
Temperature range       -10°C to +60°C; +14°F to +140°F
Antenna Impedance     50 ohms(SO-239)
Frequency stability Less than ±0.5 ppm (0 to 50°C; +32 to +122°F)
No. of Memory Ch. 105(99 split, 6 scan edges)
Frequency stability Less than ±0.5 ppm (1 min. after powered ON/0 to 50°C; +32 to +122°F)
Power supply voltage 9.0 to 15.87 V DC (negative ground)
Current Drain
Tx

Rx
  10 W
    5 W
  Standby
  Max. audio
  3.0 A
  2.0 A(9.6V)
  0.25 A (typ.)
  0.45 A (typ.)
Dimensions
(projections not included)
167(W) × 58(H) × 200(D) mm;
6 9/16(W) × 2 9/32(H) × 4 7/8(D) in
Weight (approx.) 2.0 kg; 4 13/32 lb 
   
 TRANSMITTER
Mode USB/LSB/CW/RTTY/AM/FM
Modulation system USB/LSB    Blanced Modulation
AM      Low Level Modulation
FM      Variable Reactance Frequency Modulation
Spurious emission 50 dB (HF bands)  
Carrier suppression More than 40 dB
Unwanted sideband
suppression
More than 50 dB
Spurious Emissions <30 MHz: Less than -50 dB
>50 MHz: Less than -60 dB
Microphone Connector 8-pin modular jack (600 ohms)
Output Power USB/LSB/CW/FM/RTTY  0.1 to 10 W (at 13.8V)
AM                            0.1 to 4 W (at 13.8 V)

USB/LSB/CW/FM/RTTY   0.1 to 5 W (at 9.6V)
AM                             0.1 to 2 W (at 9.6 V)

   
 RECEIVER
Receive system Double conversion Superheterodyne system
Intermediate frequencies 1st 64.455 MHz (for all modes)  2nd 455 kHz (for all modes)
Sensitivity (typical)
Frequency Range
(MHz)
SSB, CW, RTTY
(at 2.4 kHz BW)
AM
(at 6 kHz BW)
FM
(at 15 kHz BW)
0.50 - 1.799 __ 13µV*1 __
1.80 - 29.99 0.16µV *1 2µV *1 __
28.0 - 29.7 0.16µV *1 2µV *1 0.5µV *1
10 dB S/N for SSB, CW, RTTY and AM, 12 dB SINAD for FM
*1 Pre-amp is ON
Squelch sensitivity
 (Pre-amp: ON)
SSB, CW, RTTY
FM
  Less than 5.6 µV
  Less than 0.32 µV
Selectivity
 (typical)
SSB/ CW (BW: 2.4 kHz)
  
AM /FN-N (BW: 6 kHz)

FM (BW: 15 kHz)
  More than 2.4 kHz/-6dB
  Less than 4.5 kHz/-60 dB
  More than 8.0 kHz/-6dB
  Less than 30.0 kHz/-60 dB
  More than 12.0 kHz/-6 dB
  Less than 30.0 kHz/-60 dB
Spurious Response More than 70 dB
AF output power More than 1.0 W  with an 8 ohms load
RIT variable range ±9.99 kHz

Links

ICOM (Japan) IC703 page.
IC703 Yahoo Group.

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