[1000mp] Front end mod

[1000mp@mailman.qth.net]

I did a comparison in 1998 was to see what receiver was best at pulling
weak CW signals out of the noise.  I had five transceivers connected to a
coax switch to allow quick switching of receivers to the antenna.  The
rigs were an FT-1000MP (without INRAD front-end mod), a Kenwood TS830S, a
Kenwood TS-870S, an Icom IC-775DSP, and an Icom IC-756.
 
Tests were made on weak but steady signals in the 160-meter and 10-meter
bands with antenna directivity on both bands adjusted so that the signal
level was at (or in) the ambient noise level.  The 160-meter carrier used
was the 3rd harmonic at 1830 kHz of a local AM BC station on 610 kHz. 
The 10-meter signal was an amateur CW beacon station in Long Beach on
about 28242 kHz.
 
Narrowest possible selectivity on every receiver was used for maximum S/N
ratio and resulted in best reception.  This meant using the 250 Hz
filters and the 60 Hz DSP filter in the MP, the 250 Hz filters in the
TS-830S along with its VBT to further narrow the passband, the 50 Hz mode
in the TS-870S, the 250 Hz filters plus the 80 Hz APF in the IC-756, and
the 250 Hz filters and the 80 Hz APF in the IC-775DSP.
 
Both Kenwoods tied for 1st place.  The MP was not quite as good, placing
2nd.  The IC-775DSP was in 3rd place, behind the MP.  The IC-756 was in
last place, below all other rigs.
 
After installing the INRAD front-end mod in the MP, the same test was
done.  The MP was now a bit better than the Kenwoods on both bands.  When
the antennas were adjusted so the the signals were just audible in the
MP, they could not be heard at all in the Kenwoods or Icoms.
 
No tests were made in the SSB mode.
 
73, de Earl, K6SE