Saturday, January 12, 2008

Learning to Use the FT-1000MP MkV

Click HERE to listen to a brief MP3 audio file I recorded tonight. It will give you some idea of what my radio is able to hear. I picked a weak signal on 160-M to better demonstrate the dramatic ability to improve on what might be considered a very difficult signal to copy.

I have recorded a CQ being sent by SM5EDX at about 0550 GMT. This is 1 hour and 45 minutes before his sunrise.

The first 7 seconds of the CQ are with my 400 Hz filter in line. Then, I switch in the 125 Hz filter. I think you will hear a marked decrease in the QRN and a resultant improvement in the signal-to-noise of the received signal. Then, at 12 seconds into the file I switch on the VRF (Variable RF Front-end Filter). This is a narrow band-pass "preselector" filter in the RF circuit path. As you can see, it turns the signal into nearly arm-chair copy when it would have been very difficult (if not impossible) to copy it otherwise.

Below is a graphic showing the resultant waveform of this audio file. The improvement in noise reduction added by the 125 Hz. filter is obvious. And, you can see a further noise reduction when the VRF is engaged.

I am still learning about all the controls on this radio but the more I use it, the better I like it. I expect the receiver (and the filters) are part of why I am able to hear so much on the Inverted-L, don't you think?

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