I received an Icom 7300 in March 2016. Already the owner of an Elecraft K3, I thought it interesting to do an on-air comparison between the two radios. I’m particularly interested in CW contesting and DXpeditioning, hence the aim of the test was see how the 7300 would stand up in those types of conditions.

K3 and 7300 on the bench

To do the comparison, I found a pile-up of European stations on 40m and used an antenna splitter to  split the antenna between the K3 and the 7300 and made a recording, using the following parameters:

  • Filters set to 400Hz (K3 has 400Hz crystal filter).
  • AGC = Fast on both radios.
  • NB and NR = Off on both radios.
  • Pre-Amp = Off on both radios.
  • The audio channels were fed through an SO2R box to recording software (RecAllPro); K3 in left channel, 7300 in right.
  • I then used Audacity to separate each stereo track into separate mono MP3 files.

Hence, three MP3 files are available from the following three links:

1. The stereo file with K3 and 7300
2. K3 only
3. 7300 only

There are a few glitches at the start of the files, but that sorts itself out if you bear with it. And please note – none of this is scientific!

Listening at the time (placing my headphones on one ear then the other), I had the feeling that call-signs were easier to pull out on the K3 i.e. slightly off frequency, weaker signals were more discernible on the K3. Afterwards, listening to the recordings I’m not so sure.

Viewing the MP3 wave-forms in Audacity, it can be noted that the two radios’ AGCs act differently – the K3’s audio seems much more dynamic, whilst the 7300 is fairly level all the way through.

Feedback from anyone who has the time to analyse these files is welcomed.

John Warburton G4IRN

April 2016