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en:e-659 [2019/04/14 21:40] (aktuell)
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 +====== E-659: Watkins-Johnson WJ-8888 ======
 +**E-659**, **Surveillance Receiver Watkins-Johnson WJ-8888**; manufactured by [[Watkins-Johnson|Watkins-Johnson,​ Gaithersburg,​ Maryland, U.S.]].
 +
 +The surveillance receiver **Watkins - Johnson WJ-8888** had been acquired in small numbers to be used in the Swiss Army for "​special purposes"​.\\ ​
 +According to my informations,​ 23 sets WJ-8888-5 with the matching rack speaker unit S-9903E and the external tuning conrol box WJ-9588 (8 sets) as well as 7 receivers WJ-8888-7 with 16 memories and with the master - slave control unit WJ-9526 have been bought for the Swiss Army.
 +
 +Further informations about the use of these receivers are required and very welcome.
 +
 +{{:​images:​e-659-watkins-johnson-wj8888.jpg?​direct&​600|E-659 / WJ-8888}}
 +===== Technical Data =====
 +  * [[Principle]]:​ [[Double conversion|Triple conversion]],​ [[IF]] 82.805 MHz , 10.7 MHz , 455 kHz
 +  * [[Modes]]: [[A1]] with BFO, [[A3J|SSB (A3JO/U)]], [[A3|AM (A3)]], ISB, [[F3|FM (F3)]]
 +  * [[Frequency range]]: 10 kHz - 30 MHz
 +  * **Digital frequency display**, accuracy 10 Hz
 +  * [[Sensitivity]]:​ [[AM]] < 1 μV / [[Selectivity ]] (-6 dB): 0.5 / (opt 1) / 2 / 4 / 8 kHz
 +
 +==== Power Supply ====
 +  * [[Mains]]: 110 / 220 V
 +
 +==== Dimensions ====
 +  * 483 x 133 x 495 mm, 18 kg
 +
 +==== Accessories ====
 +  * optional **Rack Speaker S-9903E**
 +  * optional **Tuning Control Box WJ-9588**
 +
 +----
 +
 +{{:​images:​e-659-watkins-johnson-wj8888-front.jpg?​direct&​600|E-659 / WJ-8888}}
 +===== Operation =====
 +The professional grade communications receiver WJ-8888 is a 19" rack unit with an optional steel desktop cabinet, the receiver itself has a size of 483 x 133 x 495 mm and a weight of 18 kg, with a total weight of more then 20 kg, you will be happy to find some handles at the sides of the receiver to carry it around easier...
 +
 +Because the basic receiver provides audio only from a headphones jack and a 600 ohme line out connector, you might find an external speaker unit useful. Watkins - Johnsons recommendation is the rack mount Speaker Unit S-9903E (dimensions 483 x 92 x 160 mm), some Swiss sets were modified with an internal speaker driver amplifier. An additional very useful accessory is the Tuning Control Box WJ-9588 which acts like a wire bound tuning "​joggle"​ control, similar to the one found on video recorders. It's an external tuning control and not a second VFO as you might expect.
 +
 +The WJ-8888 tuning knob has an electronic flywheel effect to increase tuning speed, the later variant WJ-8888B comes with four pushbuttons to select the tuning speed located next to the main tuning knob.
 +
 +In the right lower corner of the front panel, you find the main power switch, the tuning knob und the big sized LED frequency display with a resolution of 10 Hz.
 +
 +Most controls consist of semi-transparent backlit pushbuttons,​ active function buttons are backlit.
 +The two pushbuttons in the left upper row set the meter to display the signal strength or the AF level. The pushbuttons at the right select the reception modes, the WJ-8888 has detectors for AM, CW with fixed or variable [[BFO]] frequency, USB, LSB and as special mode ISB - in the "​independant side band" modes, both sidebands of a signal carry two different voice channels or a voice and a radioteletype / data channel. Last but not least, the receiver can demodulate narrow band FM transmissions.
 +
 +The pushbuttons in the middle select manual or automatic RF gain control, when you depress the button "Hold AGC", the receiver keeps the RF gain in the current setting. The six pushbuttons at the right select one out of the six available IF bandwidths.
 +
 +In the bottom row, you find the headphones jack, the volume control for the line out connector which acts as volume control. A switch is used to select one of both sidebands for monitoring in ISB mode, this is very useful for ECSS reception, to select the less disturbed sideband of an AM signal under poor conditions with adjacent channel interference. Further controls are the squelch control active even in AM mode, the RF gain and the BFO control.
 +
 +The remaining controls are used to handle the memories. The standard WJ-8888 model comes with four memory channels which will store the frequency and all reception parameters as reception mode, AGC and bandwidth filter settings. While "​Receiver Control Local" is active, the set is controlled locally. When You press the ENTER button, this will start flashing. Select a memory number with the BCD switch, and press EXECUTE to store all parameters in the active memory channel. In REMOTE mode, the WJ-8888 can be fully remote controlled. This makes the restriction to four memory channels a relative one. There has been an option for sixteen memory channels, in the years when the WJ-8888 was new, memory chips were expensive and something to save money even in "​highest end" receivers.
 +
 +===== Technical Principle =====
 +
 +==== Semiconductor setup ====
 +The set is solid state.
 +
 +==== Development ====
 +[[Watkins-Johnson]] developed the WJ-8888 in around 1972.
 +
 +==== Field use ====
 +The Swiss Army used the Watkins - Johnson WJ-8888 with the Army Signals designation E-659 with the signals intelligence units.
 +
 +==== Variants ====
 +
 +{{gallery>:​images?​e-659*.jpg&​0&​80x80&​lightbox&​showtitle&​titlesort}}
 +===== Manuals =====
 +
 +==== Additional information ====
 +  * [[http://​armyradio.ch/​radio-d/​e-659.htm|E-659 / WJ-8888 auf www.armyradio.ch]]
 +  * [[https://​www.radiomuseum.org/​r/​watkins_wj_8888_wj8888.html|E-659 / WJ-8888 auf der Website von www.radiomuseum.org]]
  
en/e-659.txt · Zuletzt geändert: 2019/04/14 21:40 von mb