Receivers

Commercial

Some HF receivers and transceivers will receive LF signals, including the 73 kHz band. A number of people have commented in the Usenet newsgroup uk.radio.amateur about the capabilities of various equipment. Comments to date are summarised by manufacturer's name in alphabetical order.

Many modern HF rigs can be modified to transmit throughout the HF spectrum, often by a simple adjustment. It is doubtful whether any of them will do `general coverage transmit' to the same lower frequency limit as the general coverage reception capability.

Datong

David Corney (G4UPT) says the VLF Converter from Datong Electronics works very well at 71 to 74 kHz.

Icom

Iain Philipps (G8SJP) says that the Icom IC726 covers the new band:

   Having a few idle moments, I just made a quick check:-

	CW, 10 dB S/N      -81 dBm [400 Hz filter installed]
	FM, 12 dB SINAD    -72 dBm
        AM, 10 dB S/N      -61 dBm

   Unsurprisingly, the preamp makes ZERO difference. The test
   equipment I used is an IFR 1200S, which although calibrated,
   may or may not produce valid results at LF :-)

Simon Lewis (GM4PLM) says the IC706 covers this band too.

Kenwood

Scott Earle (G0SWG, AA2WX) says his TS-950SDX ``receives 60 kHz fine, so I imagine it'll be OK on 74 kHz".

The TS450S (and presumably the TS690S) covers down to 30 kHz on receive. Richard Lamont (G4DYA) (yup, it's me) did a quick and dirty measurement of the receiver sensitity, and got a figure of -115 dBm for a 10 dB S/N (SSB) at 73 kHz. I didn't try CW as I didn't have enough attenuators!

Lowe

Walt Davidson (G3NYY) said his Lowe HF225 receiver ``seems to work quite well at 74 kHz''.

Racal

John Morrice (G4OAJ) mentioned that the RA17L and RA137A cover down to 10 kHz.

Homebrew

If anyone is working on homebrew equipment for 73 kHz, please let me know and I will put the details here.

One person who has taken me up on this offer is John Hey (G3TDZ). He sent me some notes and drawings on an experimental transceiver.

Last updated 30th December 1996.