Receiver Review: ICOM IC-R72E

IC-R72E

Year Introduced/discontinued: 1990/1998
Power: Mains, 12 V DC supply optional
Size: 241 x 94 x 230 mm
Weight: 7500g
Price: CAN$1500, £830, A$1850
Coverage: LW, MW, SW (0.1- 30.0 MHz continuous)

Value Rating: starstarstar


This review was compiled independently. The Medium Wave Circle and Radio Netherlands has no financial connection with Icom, the manufacturer of this receiver.


On the right of the front panel is the familar key pad for direct frequency access, manual tuning knob, whilst less used controls appear as a row of tiny pushbuttons along the bottom of the front panel. The tuning software appears to be similiar to other ICOM receivers, which isn't all that intelligent. Whereas you can punch in 198 kHz on many portable radios and the radio will move to longwave, followed by 25790 and the radio knows you mean a frequency in the 11 metre band, the R-72E demands you either enter a decimal point to indicate MHz, or you are forced to enter a lot of trailing zeros. ICOM have improved the manual tuning by adding two buttons marked MHz and kHz. Normally the set tunes up and down the dial in 10 Hz steps, the clear back-lit liquid crystal display also has a 10 Hz resolution (this an improvement over the old R-71A). If you then press the kHz button you start tuning in 1 kHz steps until you press the button again. If you choose MHz then turning the manual tuning knob changes the received frequency in 1 MHz steps. This is simple, and much better than so-called up and down buttons found on competing receivers.

The radio's sensitivity has been carefully chosen... not too sensitive on medium-wave to prevent overload by local stations. Then from 1.7 - 30 MHz the sensitivity is quite constant at around 1.2 µ volts, with the preamplifier switched off. The Automatic Gain Control characteristics are also carefully selected. The R-72E receiver is different from the 71A model in that the voice bandwidth filters are no longer separate from the mode switch. So when you select upper or lower sideband, you have one bandwidth option. On the AM there are two, in the wide position the bandwidth is around 7 kHz at - 6dB, 2.3 kHz in the narrow mode and on SSB. The AM wide filter is slightly too wide, but both filters have very sharp cut off slopes.

The set has a reasonable dynamic range for its price, better than the obsolete Yaesu FRG-8800 and the Kenwood R-2000, although below the AOR 7030 or Lowe HF-250E. There are 99 memories, and it is easy to swap between a memory channel and the normal tuning mode. The R-71A continued the tradition of the notch filter, although it didn't work well in the AM mode. The R-72E's notch filter doesn't work at all because ICOM have decided not to include one! A tone control on the R-72E would have been useful too.

In short, the ICOM R-72E is neat compact communications receiver. It doesn't have a notch filter or a pass-band tuning control it is less of a serious DXer's receiver than the R-71A. But as an entry level receiver for the serious shortwave listener, this radio scores well.
Radio Netherlands Receiver Test Laboratory: Full Review

 

Introduction

Communication receivers seem to have a sales lifetime of around 4 to 7 years, so just on cue ICOM in Japan launched the R-72E to replace the existing ICR-71A. Infact when the 71A appeared it was an upgrade to the revolutionary ICR-70 which was launched in 1982. The original R-70 was a breakthrough in performance, but it was extremely difficult to operate, and there were problems with quality control.

The R-71A has been a useful reference to measure other semi-professional communications receivers. It has excellent quality filters, and a very good dynamic range. Apart from some later examples, the R-71A boasted a variable bandwidth control. This allowed the user to reduce the outer limit of the bandwidth, eliminating just enough unwanted interference without degrading the audio quality too much. However,on the subject of audio quality, the R-71A has been infamous for its substandard audio quality, with distortion levels reaching 20% when used in the AM mode. Whilst this may be acceptable for ham radio use, it can be annoying for programme listening.

The new IC-R72E replaced the R-71A, but don't let the type number mislead. The new receiver has less features than the R-71A... but then it is also cheaper too! We tested an off-the-shelf model purchased in Europe during November 1990 and retested a model in November 1996. Performance wise we found this new R-72E has a lot going for it, although recent competition from Lowe and AOR in the UK is putting the value under pressure. The front panel measures 24 cm by 9 cm, whilst the unit itself is 23 cms deep. On the right of the front panel is the familar key pad for direct frequency access, manual tuning knob, whilst less used controls appear as a row of tiny pushbuttons along the bottom of the front panel.

 

Tuning

The buttons of the keypad have a cushioned feel to them, the radio beeping at you to confirm that you've pushed that key. The tuning software appears to be similiar to other Icom receivers, which isn't all that intelligent. Whereas you can punch in 198 kHz on many portable radios and the radio will move to longwave, followed by 25790 and the radio knows you mean a frequency in the 11 metre band, the R-72E demands you either enter a decimal point to indicate MHz, or you are forced to enter a lot of trailing zeros. This takes some getting use to.

On the other hand Icom have improved the manual tuning by adding two buttons marked MHz and kHz. Normally the set tunes up and down the dial in 10 Hz steps, the clear back-lit liquid crystal display also has a 10 Hz resolution (this an improvement over the R-71A). If you then press the kHz button you start tuning in 1 kHz steps until you press the button again. If you choose MHz then turning the manual tuning knob changes the received frequency in 1 MHz steps. This is simple, and much better than so-called up and down buttons found on competing receivers. The receiver's tuning indicator shows when a station is accurately tuned in...based on the frequency readout not the RF signal strength.

 

Sensitivity

The radio's sensitivity has been carefully chosen...not too sensitive on medium- wave to prevent overload by local stations. Then from 1.7 - 30 MHz the sensitivity is quite constant at around 1.2 µ volts, with the preamplifier switched off. The Automatic Gain Control characteristics are also carefully selected.

The LCD display shows the carrier frequency in AM, USB and LSB to within an accuracy of 70 Hz. In CW mode, however, the sample tested displayed the frequencies 140 Hz too high.

The R-72E receiver is different from the 71A model in that the voice bandwidth filters are no longer separate from the mode switch. So when you select upper or lower sideband, you have one bandwidth option. On the AM there are two, in the wide position the bandwidth is around 7 kHz at - 6dB, 2.3 kHz in the narrow mode and on SSB. The AM wide filter is slightly too wide, but as the graph shows, both filters have very sharp cut off slopes.

The radio has a CW mode for the reception of morse code using the 2.3 kHz filter. But for serious work it would be a good idea to install the optional 500 Hz filter.

 

Good Dynamic Range

The receiver has a reasonable dynamic range for its price. Using the AM wide bandwidth filter, and measurements at 9.1 MHz, the dynamic range free from intermodulation produced was measured at 83 dB. This is better than the Yaesu FRG-8800 and the Kenwood R-2000, although below the (more expensive) Kenwood R-5000. On the back of the receiver are switches connected with the scanning functions (not so handy to put them there) as well as a high and low impedance antenna input. However, there is no switch between the two inputs. The manual warns you, correctly, not to try and connect two antennas or the overall performance will be severely degraded.

The radio has 99 memories, and it is easy to swap between a memory channel and the normal tuning mode. All this adds versatility. There is an optional interface which allows several functions to be remotely controlled by a home computer. The radio has a built-in timer than can be set to control a tape- recorder, although the internal relay will only switch a low voltage, not the mains current.

Back in 1982, the R-70 was hailed by many reviewers for re-introducing the notch filter. In a perfect world, radio stations would all be exactly 5 kHz apart, but in practice some international broadcasters operate slightly off channel. This can lead to an annoying continuous tone. A notch filter allows you to remove that whistle, whilst letting the remainder of the audio frequencies through unscathed. The R-71A continued the tradition of the notch filter, although it didn't work well in the AM mode. The R-72E's notch filter doesn't work at all because Icom have decided not to include one! A tone control on the R- 72E would have been useful too.

The radio does have a squelch control which can be set to silence the radio if a signal falls below a certain signal strength. The R-72E has a scanning mode which allows you to automatically search a chosen portion of the dial. The radio stops scanning when it hits a signal that's above the level set on the squelch control. This feature is not new to communication receivers, although its usually of more use on higher frequencies when the gaps between listenable signals is much higher, and the FM mode is in use.

Whilst there is considerably less distortion on the R-72E than the 71A (typically 1.1% in AM at normal listening levels), the audio is only communications quality from the small built-in speaker on top of the radio's cabinet. If you plan to listen to radio stations for their content then you will get better enjoyment by connecting a pair of headphones or an external speaker.

This is no problem because the amplifer can deliver up to Icom offers this as an optional extra, together with a circuit board to allow the radio to operate in the narrow band FM mode, a voice synthesizer unit which announces the received frequency in either Japanese or English. If you live in an area where thunder storms are frequent, then there is an option to protect the delicate front end circuitry from damage by nearby lightening strikes. There is not much you can do against a direct hit, so always disconnect the antenna during thunder.

The receiver's "S" meter on the sample we tested was accurately calibrated above S9, and below that value the meter gave readings that were slightly too low. But the scale was perfectly logarithmic up to S9 + 30 dB.

The R-72E offers a two position noise blanker which we found to be occasionally effective on the ham bands but not much use for general broadcast listening. It marginally reduces the effects of ignition pulse noises, but at the same time it compromises the receiver's dynamic range. We found that by switching it on it the high position and tuning to the 41 metre band here in Europe after the hours of darkness, all sorts of strange mixing products were noted...but these vanished when the blanker was switched off.

 

Conclusions

In short, the Icom R-72E is a neat compact communications receiver. It doesn't have a notch filter or a pass-band tuning control, so it is less of a serious DXer's receiver than the R-71A. But as an entry level receiver for the serious shortwave listener, this radio scores fairly well. The radio seems to be available worldwide, with the exception of North America. The price for the IC-R72E in the UK is £830, so it is more expensive than the AOR-7030 (a really good "DX" machine). In other parts of the world, the price difference is in favour of the Icom. So bear this in mind when making a decision.

This review first appeared on the Radio Netherlands website.