This is a first draft. Critique, corrections, and suggestions for
improvement and inadvertently omitted information welcome.





AM Synchronous Detector Review: Sony ICF-2010 vs RL Drake R8B

Two terrific SWL receivers with comparable performance up to a point.

Operating technique differs between these two synchronous detectors.
Because a synchronous detector is phase-locked on the station's
carrier frequency, it is able to overcome phase distortion introduced
in the incoming signal by dynamics and irregularities in the Earth's
ionosphere and magnetosphere. The restoration of the signal's phase
relationship results in a significant increase in readability. Both
receivers' synchronous detectors are enabled by pressing the
respective 'Sync' button. The difference in their operation occurs
when adjusting the other signal enhancing function of this remarkable
AM detector.

One of the primary tools employed by the radio operator is the
selection of bandwidth appropriate to the current reception
conditions. Narrowing the bandwidth is effective in removing two
additional types of signal degrading effects: atmospheric noise, and
adjacent channel splatter and heterodyne. T?he AM synchronous
detector provides the means to continue the exploit of this bandwidth
narrowing philosophy significantly by providing the means to further
restrict the detection envelope to only a single sideband of the
inherently double-sideband AM signal

This 50% reduction in the significant portion of the incoming signal
permits the bandwidth to be further narrowed to reduce the amount of
noise being demodulated, thus improving the signal to noise ratio. It
also permits the operator to choose the sideband experiencing the
lessor adjacent frequency interference, further increasing the signal
to noise ration.

With the Sony ICF-2010, the selection of which sideband on which the
detector will lock is achieved by changing the main tuning setting.
The RL Drake R8B receiver provides for selecting the sideband without
changing the position of the receiver's main tuning by pressing the
'LSB' or 'USB' buttons. To this point the effects of adjusting the
receivers results in similar enhancement of levels of signal
intelligibility. However the RL Drake R8B provides two additional
signal to noise enhancing functions: 'Passband Offset' and 'Notch.'

Drake's 'Passband Offset' control "alters the position of the
receiver's intermediate frequency (IF) passband without disturbing the
main tuning." Changing the setting of this control permits the
operator to emphasize a portion of the audio spectrum contained within
the sideband being detected. This function can further enhance the
readability significantly, and places the capability of the Drake
receiver above the Sony. But the Drake has another effective function
to even further improve the final quality of the radio signal for
listening.

Drake's 'Notch' filter provides the radio operator the ability to
remove narrow band of the audio spectrum (500-5kHz) contained in the
final signal output. It is useful to remove any steady tone that
remains such as an interfering heterodyne. Drake also provides a
multi-position Noise Blanker notably absent on the Sony.

While the Sony ICF-2010's synchronous detector provides superlative
signal clarification and intelligibility, the RL Drake R8B's ability
to enhance the most marginal of radio signals to pleasant readability,
well beyond that of the Sony, is nearly magical.