| The
HCD Range of Off-Air Receivers provide a frequency reference with high
long term accuracy based either on 60kHz transmissions from MSF Rugby or
on 198kHz from BBC Droitwich. An internal 10MHz crystal
oscillator is phase locked to the incoming signal and is used to provide
outputs at 10MHz, 1MHz and 100kHZ. Particular attention has been
paid to maintaining phase stability with temperature. In addition to
providing an external reference for frequency counters, a typical
application is to use the Off-Air Receiver in combination with the HCD
Phase Comparator to provide traceability for in-house frequency
standards. |
| Signal Sensitivity |
0.5 microvolt rms
60MHz |
|
2.0 microvolt rms
198kHz |
| Aerial |
Matching passive
ferrite rod aerial provided with weather proof enclosure, mounting bracket
and 20m of cable |
| RF Output |
10MHz, 1MHz and
100kHz at 2V p-p square wave into 50ohms |
| Frequency Stability |
Better than 1 x 10-8
over 1 second |
|
Better than 4 x 10-9
over 10 seconds (typically 1 x 10-9) |
|
Better than 1 x 10-9
over 100 seconds |
|
Long term: |
60kHz tends to < 1 x 10-11 |
|
|
198kHz tends to < 5 x 10-11 |
| Dimensions |
Rack Mounted Euronorm
module 21HP wide |
|
128.5mm high |
|
106.3mm wide |
|
254.0mm deep |
| Power Supply |
230V AC, 50Hz |
|
24V DC Option |
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