CW keying envelope for W6VIO's Yaesu FT-1000 with
"stock" keying waveform.
Notice that the falling edge of the waveform is very sharp (horizontal scale is 5ms/div)
CW keying envelope for W6VIO's Yaesu FT-1000 with the
W8JI click reduction
modification installed. Notice that the falling edge of the waveform is much smoother
and slower than before (horizontal scale is 5ms/div)
"Max Hold" Spectral Display of FT-1000
Output at 1.839 MHz. The top trace is for
the unmodified FT-1000. The lower trace shows the significant reduction in peak sideband
energy that occurs after the click reduction modification is installed. The on-the-air
results are even more dramatic.
I have produced some .WAV files of the FT-1000 transmit signal characteristics which
the dramatic difference in the level of transmit signal "click" sidebands before and after the click
reduction modification is installed. The test receiver used to monitor the transmitter was a
second FT-1000. A step attenuator was used to adjust the received signal level to S9+20dB
on the test receiver (e.g. approximately -50dBm). In the all the recordings, the transmitter
under test is set to 1839.0 KHz and the receiver is adjusted to 1840.0 KHz (+1KHz offset).
The bandwidth setting on the test receiver is 250 Hz, AGC is set to fast, and the FT-1000
preamp was turned on. Loud clicks can be clearly heard coming from the stock FT-1000.
Compare this with a stock Kenwood TS-850S. While there is small bit of broadband noise
that is audible in the TS-850's transmit spectrum (about the same as the FT-1000), there are
no clicks. Similarly the modified modified FT-1000 is click free.
The following shows a picture of the FT-1000 AF-board with the W8JI modification
Even at Radio Shack prices, the cost of the modification is just a few bucks!