14 Apr 2017

VLF Transmitter

This image has been posted before.

The link takes you to my 5W transmitter that I used a few years ago from my old QTH to cover 6km by utilities assisted earth-mode. I tried a test using this TX over a 32km radiated path without success.  A test in 2014 from the new QTH was a total failure! The TX is based on a TDA2003 audio IC. It used a keyer to produce a preprogrammed message in either CW or QRSS3.

At some point I want to do more VLF tests but my health has been against this. I need to improve my earth-electrode "antenna" before doing more tests.

See https://sites.google.com/site/g3xbmqrp3/vlf/8-97khz-earth-mode-transmitter

1 comment:

Kenneth Watson said...

I am currious what impeadance you believe the earth to be?

Is there any reason to not use a 100+watt stereo audio amplifier as a transmitter?
Another question. There are farms with long fences, miles long in some cases, have you tried these as xmit or recieve antennas?