Introduction The addition of an artificial horizon to a Marine Sextant allows measurements to be taken when you don’t have a water horizon nearby. I purchased an Artificial Bubble Horizon and adapted it to fit on my existing Sextant. The mounting slot on the Horizon was the mirror image to the slot on my Sextant,… Continue reading Celestial Navigation – Artificial Horizon_a
HF SDR-IQ for Shortwave Radiogram
Introduction Several years ago I received a Shortwave Radiogram broadcast (Ref.1) using the RTL-SDR and 125MHz up-converter (Ref.2). It has been 4 years so I thought I would try again. As I mentioned in previous posts, I am using an HF loop antenna due to it’s ease of setup and noise rejection & directionality, since… Continue reading HF SDR-IQ for Shortwave Radiogram
AIS & GNSS on OpenCPN
Introduction In previous posts (Ref.1/3) I looked at using a new GNSS receiver with AIS on various combinations of Win10/RPi4/OpenStreetMap/OpenCPN. In this post I look at GNSS on full receive 921600bps with AIScatcher. Equipment Block Diagram Figure 1 shows the receive block diagram. To receive all 4 satellite constellations you have to have the maximum… Continue reading AIS & GNSS on OpenCPN
HF Marine Weather 8764KHz_USB
Introduction Further to my previous post (Ref.1), I was hoping to receive a DRM transmission on the 31m band at 1900DST/2300UTC. I used the same equipment: SDR-IQ with HF Loop antenna tuned for 9.5MHz. There were several very powerful signals but no DRM. I did receive a strong USB signal on 8764KHz which turned out… Continue reading HF Marine Weather 8764KHz_USB
HF SDR-IQ on 19m VOACAP Prediction
Introduction It’s been a while since I have monitored the HF bands, so I thought I would do a bit of scanning. In the last several years there has been a tremendous amount of construction near me and the HF noise level has increased quite a bit. I am right next to a power line… Continue reading HF SDR-IQ on 19m VOACAP Prediction