Hello, I'm kinda new at this. I'm trying to see if I can buy an affordable handheld DF scanner/reader. They're the ones you see people carrying on their hands on fox-hunting events that sometimes have a tape measure yagi antenna attached. I'm not much of a builder so I'd like to see if I can buy the equipment with an antenna manufactured already. Also, I'd like the range of the receiving antenna to be HF and up at least. Thanks for reading!!
Affordable handheld DF equipment used in fox hunting?
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prcguy
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There used to be some reasonably priced DF antennas for VHF/UHF sold in the back of some ham magazines but I haven't seen them advertised lately. A beam antenna or tape measure Yagi is not a very good antenna for direction finding. At best its beamwidth is at least 60 degrees wide and you have to guess where the center of the beam is.
For direction finding you want an antenna with a steep null which can be only a few degrees wide or less and instead of looking for the peak signal you look for the null or absence of signal. For HF and even VHF/UHF a very small loop will give very sharp nulls and allow you to pinpoint a source. There are also TDOA or time difference of arrival systems that use two resonant whips and some circuitry to feed a simple receiver to get pinpoint bearings. With a null type antenna you will walk right past the person struggling with a Yagi and go right to the source.
You might find a shielded magnetic loop for the HF bands at a reasonable price on Ebay and you can make a small VHF/UHF DF loop, otherwise there is no cheap date when it comes to commercially made versions. A small portable antenna system that covers HF through UHF used for military DFing can cost more than a nice car and its usually part of an entire DF system with receivers and display unit.
For direction finding you want an antenna with a steep null which can be only a few degrees wide or less and instead of looking for the peak signal you look for the null or absence of signal. For HF and even VHF/UHF a very small loop will give very sharp nulls and allow you to pinpoint a source. There are also TDOA or time difference of arrival systems that use two resonant whips and some circuitry to feed a simple receiver to get pinpoint bearings. With a null type antenna you will walk right past the person struggling with a Yagi and go right to the source.
You might find a shielded magnetic loop for the HF bands at a reasonable price on Ebay and you can make a small VHF/UHF DF loop, otherwise there is no cheap date when it comes to commercially made versions. A small portable antenna system that covers HF through UHF used for military DFing can cost more than a nice car and its usually part of an entire DF system with receivers and display unit.
RDF Equipment Ideas for VHF Foxhunting and Radio-Orienteering
Equipment Ideas for Radio Foxhunting
Tons of information and images on Google:
fox hunting directional finding equipment - Google Search
Be careful out there!!!
Equipment Ideas for Radio Foxhunting
Tons of information and images on Google:
fox hunting directional finding equipment - Google Search
Be careful out there!!!
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