AmateurRadio.com

I just finished a contact with a very loud Austrian station, OE3DIA on 10 metres, who took time out while working a string of stations to give me a complimentary audio report, quite unsolicited. It’s good when that happens! The comment was “Very nice audio cutting through the QRM” I was using the K3 at 80 watts and the mike was one of those Heil mikes with the dual insert, set to “narrow”. The K3 transmit audio equalisation is factory standard, in other words flat.

As it happens I had just been doing some audio comparisons between the KX3 and the FT-817. There has been a thread going on the KX3 Yahoo group started by a disenchanted American ham who claims that the FT-817 has punchier audio than the KX3. It’s rubbish, to put it politely. The KX3 has a built-in speech compressor, while my 817 has an RF processor made by Joachim, DF4ZS (more details on my FT-817 page) built into the microphone. Without it there is just no comparison.

I recorded some audio clips so you can hear for yourself:

• FT-817 with standard microphone, no compression
• FT-817 with standard microphone and DF4ZS compressor
• KX3 with MH3 microphone, mic gain and compression both set to 30

There is a bit of distortion on those clips which was not noticeable when listening on the radio. I think I might have a problem with my sound card.

I’m not sure if the difference are that noticeable in those clips, but when you look at the needle of the power meter the KX3 certainly has the more punchy signal.

Both the FT-817 and the KX3 were running off 13.8V and set to 5 watts output. I couldn’t compare them on battery power as I don’t have the charger board for the KX3 and the external battery pack (10xAA NiMH cells) I intended to use appears to be past it and the KX3 kept cutting out on voice peaks.