Radio direction finding...

Been maaany years since used one; can someone refresh the method to discern if the beacon/transmitter is in front or behind when the signal reception is at its peak ?

Will soon have to build a 100KHz beacon and a direction finder receiver. Suggestions and links are welcome.

It is possible to measure the delay (phase shift) if you use a second antenna and compare with the main one but most people still rely on triangulation.

Brian.