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Sanyo RP-8880

Manufactured by Sanyo Electric Co. Ltd, Moriguchi (Osaka).

Sanyo released the large and impressive RP-8880 in about 1978; a similar tuning technique like the Sony ICF-5900W with crystal calibrator and a calibrated fine tuning scale is used.

Sanyo RP-8880

Technical data

Power supply

Dimensions

  • 480 x 240 x 150 mm, weight 4.5 kg

Accessories

Sanyo RP-8880

Operation

When Rainer Lichte wrote in his test report in the nineties: „The test unit delivered to us was in a poor condition….“ - I experienced exactly the same: All three sets I could lay my hands on did not work as it probably had been the idea of the manufacturer. In all these sets, I could with some effort bring the long and mediumwave ranges to life, but I failed to realize useful shortwave reception with any of the three sets.

Most of the switches did crackle and could be fixed with tuner spray to some extent; the whole chassis does not seem to be mechanically very stable, so that manipulations at a switch due to contact problems lead to strong signal fluctuations. In the shortwave ranges, only with great difficulty - if at all - it was possible to receive a signal, but at least the signal of the crystal calibrator was usually present. If anyone in my vicinity would like to take up the challenge of calibrating an RP-8880 and bringing it up to the original specifications, please contact me, as a non-technician I don't really dare to do it…

The plastic cabinet of the optically very impressive receiver comes with metal protection brackets on both sides and a carrying handle as well as a rotatable ferrite antenna for LW and MW (that cannot be switched off), next to it there are two telescopic antennas. The set measures 48 x 24 x 15 cm and has a weight of 4.5 kg.

On the left side of the front panel, above the loudspeaker, are the dial illumination switch and the main switch; in a vertical row of controls right next to it, the switches for AFC and the signal strength meter, the volume control (which is designed as a rotary knob that is less susceptible to contect problems), and the slider controls for bass and treble, which are in contrast are very susceptible…

On the right-hand side of the signal strength meter and the large main tuning knob are the frequency dials for the five shortwave ranges; the longwave, mediumwave, maritime communications band and FM are located to the left, a small dot-shaped LED indicates the active frequency range in each case.

The tuning knobs are located below each of the dials, the large tuning knob in the middle, marked from - 30 kHz to + 130 kHz, operates the fine tuning. Similar to the Panasonic RF-2200 or Sony's ICF-5900W, theoretically, a frequency can be tuned with good accuracy (if the set decides to work…). The BAND SELECTOR in the middle selects the frequency ranges on the two dials, the division is clearly structured and user-friendly.

A second vertical row of controls on the right side contains the switch for the crystal calibrator, the antenna trimmer and the RF gain control, which should usually be set to maximum at the right stop. The BFO switch activates the BFO for CW and single sideband reception, the pitch can be adjusted with the PTICH CONTROL knob just below it. A technically very delicate switch is the bandwidth switch WIDE/NARROW, in case of bad contact the signal level drops so much that nothing is heard, a touch to this switch can lead to loud cracks and pops in case of contact corrosion.

On the left side of the receiver is the mains socket and a 12 volt input, the receiver can also be operated from 8 UM-1 batteries, on the back you find a DIN tape jack and the external antenna connectors.

In the shortwave ranges, the receiver works as a double conversion superhet, with the intermediate frequencies of 10.7 and 455 kHz used, cheap standard components could be used and the VHF intermediate frequency could be shared in the double conversion design. Between the shortwave ranges 2300 - 5950 / 5950 - 6200 / 6200 - 10000 kHz and 11700 - 20000 / 20000 - 30000 kHz there are reception gaps due to the intermediate frequency of 10.7 MHz. In the LW / MW / maritime comms ranges, the RP-8880 operates as a single conversion set. A 4 MHz oscillator with a corresponding frequency divider for 1 MHz, 0.1 MHz and 10 kHz operates in the crystal calibrator.

Sanyo RP-8880 Operation in the LW/MW/MB ranges is straightforward, but fine tuning on shortwave is a awkward - the RP-8880 uses a nowadays exotic tuning concept with a combination of a calibrated VFO / fine tuning and crystal calibrator:
Pull out the telescopic antennas, connect the mains, set the main switch to ON, set the volume to about 4 until a hiss is audible. For AM reception, the RF gain should be set to maximum, bandwidth to WIDE and the BFO switched off. For reception in the 49 m band, the right frequency range group is selected and SW2 is used to select the 49 m band, in which tuning is quite easy thanks to the bandspread. To tune to a known frequency, the fine tuning knob is set to 0, the calibrator is activated at 100 kHz and you search for marker signal at the next lower frequency which is a multiple of 100 kHz, for 6155 kHz this would be 6.1 MHz. The BAND SPREAD DIAL knob is then set to 55 (kHz), the signal from Vienna should be audible. The 10 kHz position of the calibration marker can be used to fine-tune between two 10 kHz points, but this position is usually quite impractical. In the higher frequency ranges, the faint signals of the calibrator can hardly be perceived any more; in addition, the assignment to the correct 100 kHz mark becomes impossible when approaching 30 MHz.

Just to tune in to a station on a known frequency, this arrangement may be sufficient after you get used to is, but it nearly impossible to determine the frequency of an unknown station. You have to make your way from a station on a known frequency and interpolate… Obviously, the original user manual, translated into bad German, made it difficult for the experienced listener to understand the tuning process correctly - in the log lists of that time, the RP-8880 hardly ever appeared.

In summary, the Sanyo RP-8880 with its combination of a crystal calibrator and VFO follows an idiosyncratic and, from today's point of view, completely outdated operating concept. The set lacks satisfactory tuning accuracy especially in the higher frequency ranges (perhaps with the exception of the spread 49 m band), the frequency stability is poor and the ceramic IF filters separate just as badly. Together with the obviously questionable manufacturing quality and the receiver concept and component selection aimed at a cheap price, I cannot get excited about the RP-8880 despite its appealing appearance. As a result, Sanyo was never able to enter the business of high-quality world band receivers, and much better receivers came onto the market at the same price - so the Sanyo RP-8880 remains a technical challenge for me today, and the money for the set is only well invested in the case of an absolute flea market bargain price. But maybe you also want to document the development flops in your receiver collection…

Technical principle

Double conversion; calibration marker with interpolation scale

Components

The set is equipped with semiconductors.

Technical documentation

Development

Further information

en/rp_8880.txt · Zuletzt geändert: 2021/05/07 22:32 von mb