Icom’s IC-R75 tabletop HF communications receiver came into the market back in 1999 and was taken out of production in late 2015. Frequency coverage is from 30 Hz right to 60 MHz. This allows one to catch the 6 Meter amateur band as well. USA versions include a “Floor Brick” AC power supply. For most samples, this will be an unregulated linear transformer, but in mid-2009 this was changed to a switching-type supply (see below for more information on this subject).
Continued ICOM’s trait of poor audio, but it’s not as bad as the old IC-R71 “Distortion Beast”. It’s a muffled sound with the IC-R75. This “cloudy audio” ill is detected more so in the AM mode “super-wide” 15 kHz bandwidth. One can improve on this with 2 separate internal audio modifications that can be done by Kiwa Electronics in MN USA. However, from my own “before and after testing” this does NOT totally cure the problem either (when compared to the AOR AR7030’s super good audio, the old Kenwood R-1000 does much better in the 12+ Khz bandwidth even after the mods). The standard R75 comes with 15k and 2.4k in 9MHz 2nd IF and 15k, 6k, and 2.4k in 455kHz 3rd IF.
Important: One should have BOTH Kiwa audio mods done to help the audio, but at LEAST the “High Fidelity Audio Filter Upgrade” one. I have tested this in 2 steps, including before and after digital recordings, so I have experience with both of the Kiwa audio mods. The Sync detector is the other real stinker but Kiwa has a mild modification for that as well that sort of helps on this too (or not). More on the “Sync” topic from others below.
But overall it’s a great tabletop set for the money even on the used market. The tuning knob even uses an optical encoder, so no cheap stuff here.
Other IC-R75 features
The set features “Twin PBT” (Pass Band Band Tuning) as used in many of Icom’s Amateur Transceivers. The optional DSP is the same board that goes in other ICOM Amateur sets, so it’s using the old AF type of DSP stuff. Rubber pushbuttons have been used, that seems to be the norm with ICOM these days. Of course, this type of button may not hold up in years to come as air reacts to the plastic/rubber, and also the printing on these types of buttons can have a tendency to wear off. But I have not seen any groans on this over the years either (at the time of writing).
The manual for the R75 is ok (but far from the excellent 7030 manuals). The Schematic is not included (not even a block diagram).
Even at this price point, Icom is using a 1 Hz synthesizer. So you can tune AND DISPLAY razor sharp. No one else has ever come close in this price range with this super fine-tuning step.
Alas, the linear “transformer” version of the AD-55 floor brick power supply (USA versions) is unregulated and provides way too much voltage even fully loaded (17.65 volts which are way over specs.). So the set runs super HOT as the internal voltage regulator has to burn this excessive voltage off.
I would rate the R75 sensitivity as good and high enough for serious DX-ing. There are two preamps, +10db and +16dB, that work more and less over the entire spectrum (+16dB is mainly used for 20+ MHz). Judging from S-meter readings and assuming that both S-meters are correctly calibrated (YES I know, this is not the right way) the R75 with preamp 1 equals 7030 w/o preamp on shortwave. With preamp 2, the R75 exceeds the 7030 with the preamp. On mediumwave, the 7030 is better overall.
At a glance review, 1-5 (bad-excellent):
- Price/performance: 5
- Design: 5
- Controls: 4
- User-friendliness: 5
- Sensitivity: 4
- Features: 4
- Specific functions/features:
- Filters: 3-4
- Sync-AM: 2
- DSP: 4
- Setup menus: 5
- Frequency range: 0.03-60.000 MHz
- Mode: AM, AM-N, FM, FM-N, USB, LSB, CW
- Number of channels: 101 (99 regular, 2 scan edges)
- Antenna impedance: 50 ohms (SO-239)
- Power supply requirement: 13.8 V DC +/-15%
- Current drain (at 13.8 V DC): RX: 1.2 A (max. audio), TX: 20 A (HF)
- Dimensions (W x H x D): 241 x 94 x 239 mm
- Weight (approx.): 4.5 kg
- AM (10 dB S/N): 0.1-1.8 MHz: 13 µV, 1.8-30 MHz: 2 µV, 30-60 MHz: 2 µV
- FM (12 dB SINAD): 28-30 MHz: 0.3 µV, 30-60 MHz: 0.3 µV
- SSB, CW (10 dB S/N): 0.1-1.8 MHz: 2.5 µV, 1.8-30 MHz: 0.5 µV, 30-60 MHz: 0.5 µV
- AM (6 dB): 2.4 kHz (-6 dB), 6 kHz (-60 dB)
- FM (12 dB): 12 kHz (-6 dB), 25 kHz (-60 dB)
- SSB, CW (6 dB): 2.4 kHz (-6 dB), 4.5 kHz (-60 dB)
- Image rejection: More than 70 dB (except for the 21 MHz band)
- Audio output power: 2.0 W (at 10% distortion with an 8-ohm load)
- Audio output impedance: 4-16 ohms
Icom R75 FAQ
What is the frequency coverage of the IC-R75 receiver?
The IC-R75 receiver has a frequency range of 0.03-60.000 MHz, which covers a wide range of frequencies including shortwave, medium wave, and long wave.
What modes does the receiver support?
The R75 receiver supports a variety of modes including AM, AM-N, FM, FM-N, USB, LSB, and CW. This allows you to listen to a wide range of signals including voice, data, and Morse code.
How many channels can be stored in the IC-R75 receiver?
The IC-R75 receiver has a total of 101 channels, which includes 99 regular channels and 2 scan edges. This allows you to quickly and easily tune into your favorite stations.
What is the sensitivity of the IC-R75 receiver?
The IC-R75 receiver has a high level of sensitivity, which allows it to pick up weak signals with ease. For example, in AM mode, the sensitivity is 13 µV at 10 dB S/N for frequencies between 0.1-1.8 MHz and 2 µV at 10 dB S/N for frequencies between 1.8-30 MHz. This makes it an ideal choice for DXing and other long-range listening applications.
In conclusion, the Icom IC-R75 is a solid option for radio enthusiasts who are looking for a versatile and reliable receiver. I enjoy mine and it still gets lots of use. With its numerous features, including DSP filtering and IF shift, the IC-R75 allows for a high level of customization and control. Additionally, its wide range of frequency coverage and compatibility with multiple antenna types make it a valuable addition to any radio operator’s collection. While it may not be the most modern or cutting-edge receiver on the market, the IC-R75’s solid performance and durability make it a worthwhile investment for those seeking a dependable radio receiver.