Racal RA17 Specification & Performance

When it was launched the Racal RA17 offered a level of drift & frequency stability unparalleled by any other radio - other performance specifications were also impressive.

Racal RA17 Includes:
Racal RA17     How the RA17 was developed     RA17 technical description     RA17 specification    

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The performance specification of the Racal RA17 was very impressive for its time. The low level of drift was paricularly impressive, but so too were the other RA17 specification parameters.

Racal RA17 radio receiver
Racal RA17 radio receiver
Courtesy RSGB
Brief Racal RA17 Specification
Parameter RA17 Specification Details
Frequency range 980kc/s - - 30 Mc/s (down to 500kc/s with degraded performance).
Frequency stability Typically within 50 c/s after 1 hour warm up
Input impedance 75Ω unbalanced
Tuning Effective scale length 145 feet (44.2m), 1.5 cm = 10 kc/s
Calibration Crystal controlled in 100kc/s increments. Stability 5 parts in 106.
Sensitivity and S/N ratio 1µV for 18dB S/N (AM)
3µV for 18dB S/N (MCW)
Intermodulation >100dB down for interfering signal >10kc/s off tune.
Cross modulation For a wanted signal between 3µV and 1mV, an interfering signal 10kc/s off tune and modulated at 30% must have a level >50dB (>30dB) above the wanted signal to produce cross modulation of 3% (1%). The ratio of wanted to unwanted signal is improved up to 10% off tune by 3%.
Blocking With similar conditions to those for cross modulation, an unwanted signal must be 60dB greater before the audio output of the wanted signal is reduced by 3dB from blocking.
Local oscillator technology Wadley Loop
Conversions Triple conversion superhet
Reception modes AM & CW - SSB adaptor became available
Antenna input impedance 75Ω
Output impedance 3Ω and 600Ω
Gain controls RF & AF
AGC Long and short
Dimensions Width: 19 in (48.3 cm)
Height: 10 ½ in (26.7 cm)
Overall depth: 20 ⅛ in (51 cm)
Depth behind panel: 18 ¾ in (47.6 cm)
Weight 67lb (30.5kg)

Ian Poole   Written by Ian Poole .
  Experienced electronics engineer and author.



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