5ft diameter loop at Jewel Cave National Monument - Lost Subway passage- 620 feet deep
My diver tracking beacon in Schoharie Caverns, NY
These high efficiency 3496Hz Class-E radiobeacons are intended for use with the high performance DQ receiver. They all produce a strong continuous AC magnetic field for use with the DQ receiver's narrow 1Hz bandwidth. There is an unused +5VDC keying line (ground for ON) that could be used for pulsed operation or Morse Code.
I will sell beacon PC boards separately from the DQ receiver boards as many users want more than one beacon. The cost is $9.00 US plus postage, including the toroid and wire. I have a few of the special logic level drive power MOSFETs that have become hard to find for $2.00 US each. An alternative is to use the IRLZ44NPBF, which is the same transistor without the insulated tab. It will require a mica insulator and shoulder washer. See the construction article for details. Due to limited stock, I will sell one with each board ordered. PayPal is preferred, and mandatory for overseas orders. Email me for a quote and my PayPal account.
A complete article with theory, construction, and operation along with several loop antenna designs is found here as a downloadable PDF for printing or offline use.
I will sell beacon PC boards separately from the DQ receiver boards as many users want more than one beacon. The cost is $9.00 US plus postage, including the toroid and wire. I have a few of the special logic level drive power MOSFETs that have become hard to find for $2.00 US each. An alternative is to use the IRLZ44NPBF, which is the same transistor without the insulated tab. It will require a mica insulator and shoulder washer. See the construction article for details. Due to limited stock, I will sell one with each board ordered. PayPal is preferred, and mandatory for overseas orders. Email me for a quote and my PayPal account.
A complete article with theory, construction, and operation along with several loop antenna designs is found here as a downloadable PDF for printing or offline use.