Manufactured by Sony Corp., Tokyo.
The Sony ICF-6700 W/L has a cuboid „breadbox“ format, similar to the better known Sony ICF-6800W. Its „sibling“ is a conventional double conversion superhet covering longwaves / mediumwaves and three shortwave ranges, each about 10 MHz wide, with a manually adjustable preselector and digital frequency counter.
- ICF-6700W: the small switch next to the band selector activates the AFC in the FM broadcast band, no longwave coverage.
- ICF-6700L: the small switch next to the band selector switches between long and mediumwaves.
- Principle: Double conversion superhet, IF AM 10.7 MHz and 455 kHz / FM 10.7 MHz
- Operation modes: A1 with BFO, SSB, AM (A3), FM (F3)
- Frequency range: FM broadcast band, LW, MW, 3 x SW (1.6 - 29.5 MHz)
- Frequency display: analogue dial, digital display, 1 kHz
- Frequency memory: none
- Sensitivity: AM (A3) 1.2-1.3 uV, SSB 0.8-0.9 uV / Selectivity: Narrow 3.2/9.1 kHz, Wide 5.2/21 (-6/-60 dB)
- Mains operation: 110, 220 V
- 453 x 184 x 227 mm, weight 5.5 kg
As the little „sibling“ of the Sony ICF-6800W, the ICF-6700 also has the breadbox shape that is characteristic of the Sony sets from this family. The anthracite coloured set measures 45.3 x 18.4 x 22.7 cm and has a weight of 5.5 kg. It can be powered from 110/220 V mains or from six UM-1 batteries, the battery compartment is located under the hinged cover on the top of the unit, on which a world time table and a radio band overview is printed.
The perforated speaker grille takes the left third of the front panel, below it are the headphone jack, the separate treble and bass controls and the volume control.
In the right part of the front panel, the power switch and the classic round S-meter, calibrated 0 - 9, are located. A small yellow push-button activates the dial illumination when the unit is running on battery power and sets the instrument to display the battery voltage, a toggle switch activates the digital frequency display.
Below this is the rotary band selctor switch, with the positions SW1 - SW3 and FM. The last switch position is marked MW/LW in the ICF-6700L, the switch to the left selects between the two ranges. On the ICF-6700W, this last position is only for mediumwaves, the toggle switch only activates the AFC function in the FM broadcast band.
On the right side of the front panel, you find the dark red LED display of the frequency counter, next to it the coarse preselector dial and the corresponding knob.
The horizontal frequency dials have only coarse frequency marks an can be used to find orientation in the shortwave spectrum; the activated band segment is indicated by an orange arrow.
Below the frequency dials you find the operation mode switch, in AM mode, two IF filter bandwidths can be selected, and in SSB mode the two sidebands. To the right is the RF gain control and the tuning knob. The latter has quite a nice flywheel effect, that helps to crank through the entire band with 39 turns. But it almost feels like tuning a nice old demostic radio from the fifties.
In practical use, the Sony ICF-6700L is uncomplicated to operate - the only pitfall is the preselector:
After the set is switched on, use the band selector to choose the corresponding frequency range: SW1 (1.6 - 10 MHz), SW2 (11.5 - 20 MHz), SW3 (20-29.5 MHz), mediumwave or FM broadcast band, and set the desired frequency with the main tuning knob. The signal from Vienna on 6 1 5 5 kHz can be found in the region of the 49 m dial mark in the band SW1. Maybe you can already hear some waltz music, in a next step it is imperative to adjust the PRESELECTOR with the top right knob, the correct setting just to the right of the 5 (MHz) mark can be found by observing the sound getting louder and the S-meter which should swing fully to the right. The preselector must be tuned to maximum signal strength, each time frequency is changed over more than 0.5 - 1 MHz.
The circuit with a manually adjusted preselector is somewhat tedious, but is rewarded with good mirror frequency rejection and immunity to overloading when operating on long-wire antennas - the preselector only allows signals from a narrow portion of the entire shortwave spectrum to pass. This is the reason, the Sony ICF-6700W handles weak signals in amateur radio bands in vicinity of the bomb signals of BBC or R.Moscow on adjacent frequencies well.
SSB reception is possible, the sidebands can be selected separately, but since tuning to a single kHz is tedious and a BFO fine control is missing, ECSS reception is challenging.
Unlike the Sony ICF-6800W, the set does not suffer from the synthesiser problems that make it a nightmare for everyone attempting a repair. The ICF-6700L seems to be a quite „rare bird“, (those who could raise enough money, usually saved for a 6800W), but the sets are reliable performers, which is not at all the case with 6800Ws often found in online auctions.
Of course, with the analogue receiver without electronic memories, the quick comparison of parallel frequencies in different bands is tedious, the filter skirts could be steeper, and you might have to pay for a separate world clock.
Nevertheless, the ICF-6700L is not only a collector's item, but also a good entry-level radio for serious shortwave reception, it allows you to listen to SSB transmissions of radio amateurs and is suitable for longwave / mediumwave DX.
The radio frequency signal from the antenna has to pass a low-pass filter to eliminate FM signals, then the preselector and is converted to the first intermediate frequency of 10.7 MHz. After conversion to the second IF of 455 kHz and having passed the IF filters, the signal is fed to the AM demodulator, where the subcarrier of the BFO is also mixed in for SSB reception. After a tone control stage, the signal is feed to the power amplifier.
The IF of 10.7 MHz commonly used in FM broadcast band radios is the reason why there is a frequency coverage gap between 10 - 11.5 MHz (between SW1 and SW2), but less costly and available standard components were used.
The set is equipped with semiconductors.