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überarbeitet am 23.10.2010
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The Sony ICF-6800W had a special position in Sony's model hierarchy: according to
it's reception performance, it had deserved a CRF-xxx designation, from technical
design and build quality as well as price, it fit's in the list of shortwave
receivers for home use - the ICF-xxx designation indicates, Sony considered the
set of beeing a comsumer electronics and not a semiprofessional receiver.
After the first series, the ICF-6800W circuit has been improved for a better
dynamic range and equipped with slighly smaller i.f. bandwidth filters. The
high sensitivity of the primary version has been reduced slightly according to
the demands in high signal strength areas as Western Europe.
The circuitry of the ICF-6800W is highly complicated and suffers from components
slowly going out of their tolerance over the years - so very many ICF-6800W suffer
from "dead bands": usually, on one of the 10 MHz segments, the Wadley Loop oscillator
seem not to lock anymore, the receiver is silent and will display a number
of around 88000 in the frequency display. These sets are very difficult to repair,
there are only very few repair shops doing this. It's definitely not a matter
of putting a bit of contact cleaner to the waveband switches - believe me and not
what is usually written in eBay offers, where too many defective sets are sold
for a very elevated price.
| ICF - 6800 W
"white" |
White lettering at the lower front panel edge,
aktive preselector, slightly better sensitivity, poor dynamic range,
i.f. bandwidth filters from Murata CFT / CFU series. |
| ICF - 6800
WA "orange" |
Orange lettering at the lower frontpanel edge (thus the
set is often referred to as "ICF-6800W orange"), serial no. > 30 001
passive preselector, transistor Q72 has been omitted, improved dynamic range,
better i.f. filters from Murata CFU / CFW series. |
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Double conversion, 1st I.F. 19,055 MHz, 2nd I.F. 455 kHz
Digital frequency display, 1 kHz
AM, USB/LSB, CW, FM-UKW
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Selectivity -6 dB/ -46 dB
3,1/7,8 kHz, 4,8/xx kHz (WA) resp. 4,5 kHz/ 9 kHz (W)
Sensitivity AM 1,3 - 2 uV, SSB 0,3 - 0,6 uV
RF Gain, preselector
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The Sony ICF-6800 has it's strange rectangular "bread bin" shaped cabinet
in common with the ICF-6700, the first is a double conversion receiver based
on the Wadley Loop cirucuit and the latter a conventional double conversion
superhet with a frequency counter.
The receiver is 45,3 x 18,4 x 22,7 cm wide and has a wight of 6,2 kg, it has
carrying handles on both sides and You can attach a carrying strap, but in
fact it's not a portable but rather a desktop shortwave receiver.
The ICF-6800W can be powered from 110/220 V mains or from six UM-1 / mono
cell batteries, the battery compartment is located at the top of the receiver,
a world time conversion table and band allocation plan is printed in the cover.
The left third of the front panel is taken by the speaker grille, just below,
You find the headphones jack and the rotary volume, bass and treble controls.
On the front panel, You find the main power switch and the typical round signal
strength meter in the left upper corner, a tiny yellow pushbutton lets You
activate the dial illumination for a few seconds when the receiver is battery powered,
the black lets You switch off the frequency counter to save battery power.
At the right, You find the pushbutton band selectors for FM, medium and shortwaves,
next is a rotary control to select the reception mode in the shortwave bands:
AM with the wide or the narrow i.f. filter and single sideband USB and LSB.
Further right, You find the most cumbersome control: the shortwave band selector.
A small lever lets You select the 0 - 9, 10 - 19 and 20 - 29 MHz ranges and
the inner rotary control numbered 0 - 9 the MHz band. Most technical problems
are associated with this control: due to component ageing and shifting out of
tolerance, the synthesizer fails to lock in one or more of the 10 MHz ranges,
usually You see a frequency indication aorund 89000 and the receiver is silent.
In contrast to what is said most often on advertisements in online auctions,
a failing shortwave band range selector is not easy to mend, just a drop of
contact cleaner is no cure for this problem. At the right, You find the manual
R.F. gain control.
Below, You find at the left the auxiliary frequency dial for the FM broadcast
band and the AGC switch, at the right the frequency dial. The ICF-6800W offers
both technologies: You have a large rotating drum analog dial with an accuracy
of better then 5 kHz and a small dark red LED frequency counter. The big tuning
knob is rubber coated and can be operated without backlash.
The small linear dial is the preselector dial, the preselector control is located
just at the right of it and has to be carefully tuned for a maximum S meter
reading after each frequency change.
Aonther quite unique feature is the small reading light hidden behind a black
cover under the analog dial drum, You can operate the receiver in the dark
(then the LED frequency display can be read easier) and illuminate Your logbook.
The R.F. signal coming from the antenna has to pass the preselector and an
amplifier stage and is converted to the first intermediate frequency of 19,055 MHz in the
first mixer, after having been mixed to the second i.f. of 455 kHz, it has
to pass the i.f. bandwidth filters and is handed over to the AM and SSB product detector.
In the FM mode, the receiver acts as single conversion superhet with the standard
i.f. of 10,7 MHz.
In practical use, the ICF-6800 W is a very sensitive radio even when operating
on it's internal telescopic antenna. With a long wire antenna connected, You
can encounter mirros or intermodulation products from very strong shortwave signals.
The correct use of the preselector is essential: make sure, the preselector
is manually peaked to maximum reading on the signal strength meter after every frequency
change, the auxiliary preselector dial gives You support that You don't tune Your radio
to the signal maximum of a mirror signal.
The earlier "white" version of the ICF-6800W with it's additional R.F. amplifier stage
has a slightly better sensitivity but more tendance to overload;
the later "orange version" ICF-6800WA omits the r.f. ampifier stage
for better dynamic range but has even sharper i.f. filters in use, two stations
with 5 kHz channel spacing can be separated better.
The ICF-6800W is not very well suited for FM DXing as it's selectivity is
only fair, in parts of Central Europe with very many FM stations active, I would
rather look for a Grundig Satellit receiver for FM DXing.
The ICF-6800W is an excellent shortwave receiver, it lacks some features like
a quartz clock and frequency memories which are found as standard in moder PLL
synthesized receivers. Nor is the receiver equipped with a passband tuning
or a notch filter to improve reception of very disturbed signals - the ICF-6800W
is a consumer grade receiver living in a different world then the semiprofessional
amateur radio and the professional communications receivers.
That fact and the problems with the Waldey Loop synthesizer lock problems
leading to failure of a large number of ICF-6800W makes this radio rather
a collector's item then a hardcore DX machine, nowadays. Take Your time to
test Your radio extensively before buying one, You will probably find no one
in Your area to repair it, Sony has abstained from repairing ICF-6800W's for
years.
But if You have one, You will agree, it's wonderful to enjoy DXing with this quiet
and slightly oldfashionned rig.
weitere Lektüre:
d: Sony ICF 6800 W, getestet
von Peter Müller, kurier
d: Sony ICF 6800 W,
Kurzwellenempfänger, Qual der Wahl, Rainer Lichte
e: WRTH 1983, Testbericht von Larry Magne
© Martin Bösch
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