Fox Hunting


Posted on Feb 4, 2014

This is a new gear for Radio Direction Finding (RDF) known as FOX HUNT or called Transmitter Hunting (T-Hunting) or Treassure Hunting. HAM clubs, all over the world, are conducting this SCIENTIFIC GAME occasionally, being which is the only one interesting game in HAM World. This game helps every HAMs and SWLs to get knowledge about radio direction


Fox Hunting
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finding, attenuation techniques and associated things like direct signal and reflected signal detection, orientation etc. When the hidden transmitter (FOX) is at a distance of 30 Kms, we can able to find its direction by using 2-element or 3-element beam antenna (Yagi) as a direction finder to get FOX HOWL (Transmitted Signal - Direction) and we get the exact orientation. But when we are in close to the FOX (Hidden Transmitter), the `S-Meter` reading on your hand held rig shows full scale reading even if the transmitter is running in low power. Due to this we can`t get the proper orientation of the pin-point to the fox and it is because of the poor shielding (case) of the hand held rig. Normally every hunter using resistive attenuators (passive attenuators) to reduce the signal level to the hand held. But these passive attenuators can`t work in shorter distance. In close distance the hand held rig will shows full s meter reading without any antenna ! In this clever design we are shifting the exact fox howl - receiving frequency and then controlling the signal level. So there is no direct penetration of signals into the hand held. In this circuit, there are two major sections, one is the Local Oscillator (LO) and the other is a diode mixer with a level control, if we are selecting a LO frequency of 2 MHz and the fox howl frequency of 145 MHz, then the output from the circuit can be at 147 MHz or in 143 MHz. This circuit is...




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