Grundig Satellit 650
Manufactured by Grundig, Fürth.
The Grundig Satellit 650 is a cosmetically revised Satellit 600, which underwent only minor technical changes, e.g. the addition of a connector for a longwave direction finding antenna, so that even this receiver got an approval for maritime communications. To conclude the series of large format shortwave receivers, Grundig released the Satellit 650 in a Final Edition limited to 1000 sets with special lettering and serial number on the front panel and special accessories.
- Principle: Double conversion superhet, IF 54.5 MHz, 460 kHz / FM 10.7 MHz
- Operation modes: A1 and SSB with BFO, AM (A3), FM (F3)
- Frequency range: FM, LW/MW/SW 520 kHz - 26.1 MHz (Satellit professional) or 30 MHz (Satellit international)
- Frequency display: Digital display, 1 kHz, analogue dial for preselector
- Frequency memory: 60 memories, 32 of them for SW
- Signal processing: automatic preselector, antenna trimmer, AGC/MGC, noise limiter
- Features: quartz clock
- Sensitivity: AM (A3) <2 μV, SSB <1 μV / Selectivity: 2.7/ 7 and 4.8/ 13.8 kHz (-6/-60 dB)
- Mains operation: 110, 220 V
- 505 x 245 x 205 mm, weight 8.5 kg
The plastic cabinet of the black coloured receiver is in landscape format, with 50.5 x 24.5 x 20.5 cm and a weight of 8.5 kg, the Satellit 650 also belongs to the voluminous sets from Grundig. The Satellit 650 was also available in a grey cabinet colour with a coloured keypad.
The speaker grill is located at the left side of the front panel, as in the earlier Grundig Satellit receivers, two loudspeakers are mounted. The dial on the top right looks like a frequency dial, but in fact it is only the dial of the motor-driven preselector with coarse frequency marks. The frequency is displayed in the large backlit LCD field below, alternatively the time of the quartz clock can be displayed. Right next to it is the large S-meter, which the typical Grundig non-standard 0 - 10 divisions, and even further to the right the large band selector buttons.
Below these is the tuning knob, which for the first time in the history of Grundig world band radios is really big. Of the two rings, the outer one is used to tune the frequency, the pulses are detected by optocouplers and digitally transmitted to the receiver's control logic. The inner ring is used for the manual adjustment of the preselector. The trick using a preselctor circuit gives the Satellit 600 a much better large-signal behaviour than its predecessor. A button in the centre of the tuning knob switches the preselector from manual to automatic mode. In automatic mode, the motor-driven preselector moves like a miracle to the correct position and the station is tuned to signal maximum. Underneath the S-meter and the frequency display, the push-buttons for direct frequency and time entry and for the memory management are arranged in groups.
At the bottom of the front panel, the remaining controls are arranged in a row, next to the power switch, the headphone jack in the common 6.3 mm jack format, the switches for the tweeter, the dial illumination and the noise limiter, next to them the volume and the two tone controls. This is followed by the bandwidth selector, the RF gain control for automatic or manual gain control and the single-sideband switch and BFO pitch control.
The PLL controlled frequency synthesizer is controlled by a microprocessor. The frequency can be entered via a numeric keypad or with the tuning knob with electronic flywheel effect and thus larger tuning steps with fast rotation of the tuning knob or the frequencies can be recalled - but only in the corresponding band range - from one of 32 shortwave memory channels.
The variometer preselector is tuned manually or automatically to the desired frequency. In automatic mode, a motor moves the preselector to the pre-programmed setting, and the pointer on the preselector dial moves to the correct position as if by magic, accompanied by a soft whirring noise. In the LW and MW ranges, the reliably of the automatic system is very good; on shortwaves, the signal can often be peaked by slightly adjusting the preselector tuning by hand.
In the first mixer, the signal is converted to the first IF of 54.5 MHz. Thanks to the high first intermediate frequency and the preselector, the satellite 650 is resistant to overloading and to intermodulation which might cause mirrors. After a two-stage crystal filter, the second intermediate frequency of 460 kHz is generated in the second mixer, then the two IF filters of different bandwidths are switched into the signal path. In the „narrow“ position, the narrow of the two IF filters is used, but the audio frequency response is additionally cut, and in the wide position, a 5 kHz AF filter eliminates the annoying whistling that occurs when two shortwave stations are active in two adjacent 5 kHz channels. In the super-wide position, the identical IF filter is used, but the AF frequency response is not cut here; this position is suitable for receiving strong shortwave transmitters and local mediumwave stations without interference. For SSB reception, a subcarrier of 459 or 461 kHz is mixed with the IF signal. After demodulation, the signal is passed to the audio stage, which in Grundig sets is traditionally generously dimensioned with 10 W sine / 15 W music power. The double speaker system contributes to the excellent audio response of the Grundig Satellit 600. The integrated quartz clock not only displays the current time and date, but also unmonitored timer-controlled tape recordings at night time with cassette recorder control is possible.
In terms of shortwave performance, the Grundig Satellit 650 can compete with tabletop receivers in the same price category, but its dimensions make it unsuitable as a travel radio. International shortwave services can be heard in good quality. For DXing, only the narrow IF filter can be used. With this and the SSB reception by use of a BFO, the Satellite 650 gets only a limited recommendation for amateur radio and radioteletype reception. For programme listeners and for beginners stepping into the challenging DX, the large Grundig radio is certainly a good option if you get one second-hand for a reasonable price. It is a merit of this receiver to demonstrate that even shortwave reception can become a (listening) pleasure if the reception situation is undisturbed.
Similar to the Satellit 3400, the 650 has is an excellent performer in the VHF range, even if the tuning steps and sensitivity cannot come up to its predecessor.
Double conversion superhet, PLL frequency synthesis, automatic preselector.
The set is equipped with semiconductors.
- Grundig Satellit 650, Service Manual