| The back panel is built up using separate modules
which slide and plug into a mother board situated within the receiver behind the
front panel. All connections are made to each module via a multiway euro type
connector. This includes RF signals which connect using co-axial connectors.
Several of the modules fitted to the E1800A are common to the
E1800/3 series
The following is a cut down description of each of the modules
fitted to this example
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HT-1710/2
This is the front end incorporating 1st and 2nd mixers. There are
two antenna N type input connectors. 0.01 to 1.6MHz and 1.6 to 30MHz. An
on board option link however can be set to connect BU1 (10K to 1.6M)Hz,
as the main input for all signals, from 0.01 to 30MHz.
1st IF is 42.2MHz. 2nd IF is 200KHz. 1st mixer post roofing filter
is 10KHz bandwidth. |
 |
AI-1800
The analogue interface accepts 200KHz IF signal from HT1710, converts
to digital and passes this data to the DP1800. After processing in the
DP1800, the AI1800 converts the digital data back to audio for distribution via the line
or speaker.
Speaker connection is via the main chassis BU602, 3 pin miniature Lemo
connector. |
 |
DP-1800
Contains 7 x NEC digital signal processors and supporting hardware,
which among other functions, calculate signal strength and provide AGC,
carry out IF filtering, passband tuning, notch filtering and
demodulation. The digital audio is returned back to AI1800 for conversion back to audio
frequency signals. |
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AO-1700/2
Synthesizer oscillator, generates all the local oscillator signals
required for the receiver's mixers. |
|
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ZF-1810
The BITE processor |
|
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NS-1820
Main power supply. An efficient switching power supply that stays
cool during use. It is very well screened and there are no fans or
exterior cooling requirements other than convection air cooling through
the main receiver chassis. |
|
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Front Panel
Showing the four front panel rack fixing holes.
The two strong handles can easily support the weight of this
receiver. |
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