HFU HF Underground
Technical Topics => Equipment => Topic started by: Robot Matrix on January 27, 2025, 0832 UTC
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This made a HUGE difference in my reception. Previously, I was using a TV balun because I didn't have anything else and it reduced noise. But, it was degrading everything the closer you got to 5 MHz. LW was worthless. Now, I can get WWVB on 60 kHz and the Navy transmitters around 20 kHz as long as it's grounded.
Made from a plastic box from Walmart, and parts from Lowe's and Amazon, including a 43 mix toroid. Very light weight. Made for just reception.
(https://i.ibb.co/8mNfVRL/20250126-170159-01.jpg) (https://ibb.co/yNdZJMc)
(https://i.ibb.co/92STpMr/20250126-170248-01.jpg) (https://ibb.co/82t5mh7)
Tomorrow, I'm making a fan dipole-ish assembly for it, as currently I'm using uneven lengths of wire on each side. I'll share pics.
EDIT: I tried the dipole and was still getting too much noise from the neighborhood. Will use later on the new property in the quiet country later. Opted for the loop (see other post)
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As you have figured out, that cable TV balun is not going to work very well below ~50 MHz.
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As you have figured out, that cable TV balun is not going to work very well below ~50 MHz.
It was OK down to around 5MHz. Most TV stuff is rated for at least that low nowadays. Even then, I could get a decent chunk of the AM broadcast band.
But now, I built a loop and abandoned the dipole idea. It was just too noisy here. Loops are nice and quiet... and easier to change direction. I have another post on this.