2 ms·
> But certainly HF stuff, especially below 30MHz, is like any old wire will do I've got a couple mostly horizontal wires running along the length of my living
by tzs 3y ago
> But certainly HF stuff, especially below 30MHz, is like any old wire will do
I've got a couple mostly horizontal wires running along the length of my living room--the speaker wires from my A/V receiver to my rear surround speakers.
I've wondered if that could be used as an HF antenna while simultaneously still being used for the speakers?
The audio signals for the speakers are all below 20 kHz. The radio signals I'd want to receive (and maybe transmit) are all about 1 MHz.
The idea then would be to put low pass filters on the audio connections and high pass filters on the radio connections. The cut off for the filters could be somewhere in the middle between 20 kHz and 1 MHz, so that both the audio signals and radio signals are far enough way from the cut off that the filter is flat.
Could that actually work or is it likely to fry the A/V receiver and/or the speakers and/or the radio?
- ChuckMcM 3y agoHeh, the answer is sort of. Your receiver likely already has a filter network to "ground out" any coupled electro magnetic interference (EMI) coming from those wires. All conductors "receive" to a greater or lesser degree and so people building things that connect to wires have to account for that and plan for it. So using your speaker wires directly would probably not work very well because of filter networks in the receiver. For folks just playing around receiving HF I find the YouLoop[1] is a low cost and very effective magnetic loop antenna that you can set up on a wall in a dorm room (or living room :-) or pretty much anywhere. The Airspy HF+ discovery[2] is probably the best valued HF SDR you could use with that, but it works well with RTL-SDR V4 dongles[3] as well and the RT832 ones from NoElec[4] although NoElec and the V3 or earlier dongles don't go below about 55 MHz and need an upconverter like the HamItUp! [5] to move the bottom part of the HF spectrum up into a region the RTL832T receiver can tune them. (the V4 RTL-SDR dongle has an internal up converter for this purpose). [1] Youloop magnetic loop antenna -- https://airspy.com/youloop/ https://airspy.com/youloop/ [2] AirSpy HF Discovery + -- https://airspy.com/airspy-hf-discovery/ https://airspy.com/airspy-hf-discovery/ [3] RTL-SDR "dongle" V4 (low end ~1 Mhz) -- https://www.rtl-sdr.com/rtl-sdr-blog-v4-dongle-initial-release/ https://www.rtl-sdr.com/rtl-sdr-blog-v4-dongle-initial-relea... [4] NoElec NESDR SMArT (low end 55 MHz) -- https://www.nooelec.com/store/sdr/sdr-receivers/nesdr-smart-xtr-sdr.html https://www.nooelec.com/store/sdr/sdr-receivers/nesdr-smart-... [5] HamItUp! -- https://www.nooelec.com/store/sdr/sdr-addons/upconverters-downconverters/ham-it-up-plus.html https://www.nooelec.com/store/sdr/sdr-addons/upconverters-do...