I purchased a WR-G31DDC Excalibur from Grove Enterprises prior to a price hike. I lacked, and still lack, a proper antenna. I borrowed an AM loop antenna from an unused CD/radio set, attached the provided SMA-Male to BNC-Female adapter, and stuck one end of the antenna into the inner conductor of the BNC side.
I tried attaching the other end to the outer conductor, but all I got was a material reduction in gain with no material reduction in noise. Evening noise floors are typically about -135 dBm to -130 dBm in the 40 m, 20 m, and 17 m amateur bands, and -125 dBm to -120 dBm in the 49 m and 31 m broadcast bands. That sounds pretty good in that it's not amplifying noise, but then again there's no signal gain to speak of, and the receiver does pick up strong, -110 dBm interferers.
For what amounts to a random piece of wire, and a very short antenna in wavelength terms, it does pretty well for transmissions where I'm in the target area. Today was a particularly good day for Sackville's DRM relay of Vatican Radio, and for most of the broadcast I was getting -95 dBm across 10 kHz, although partially in the teeth of a -120 dBm interferer. Still, that's 25 dB SNR, right? Good enough for 64-QAM, and I had very few drop outs.
And of course, CRI is impossible not to hear.
What I've been dying to receive is The Disco Palace on 17875 kHz. I'm in the target area (i.e. North America), and yet I've only ever gotten sporadic audio when SNR is on the border line of 13 dB. Most times, it's below 10 dB. I figure I'm going to need another antenna to even have a shot at a listenable experience. That should be remedied soon.
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