A lot of us use Anderson PowerPole connectors for DC power distribution. There’s a nearly universal standard to use red and black housings for 12 volt-ish (e.g., 13.8) lines, with the housings arranged per the “Orange County RACES Standard” like so:
Of course, to make
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One of my Gnuradio projects is a tool that records IQ data covering 375 kHz — which is enough to capture an entire HF ham band (except for 80/75M). A neat trick is to retransmit such a recording to allow local receivers to tune in The Signals From The Past
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I’ve noticed that my SDR setup, an Apache Labs Anan-7000DLE transceiver used with the PowerSDR software, seems to rest the S-Meter at a quite high level when there is no signal present. This is unnerving when I try to compare my local noise floor with others who claim noise levels
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Thanks to Graham Norbury, here is how to set up a Raspberry Pi OP25 scanner to stream audio to an icecast or other streaming server. I have updated my plug-and-play op25-rpi.img image at http://febo.com/os_images/ to include this capability (look for the 2018-03-18_op25_rpi.zip or later-dated file).
1. Copy the following
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As part of the HamSci Solar Eclipse experiment, I recorded wideband data from my SDRs on the theory that capturing the data for later study might be more productive (and less stressful) than trying to do measurements in real time. I think that theory played out very well.
I
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Since my updated post on building a P25 trunking scanner with a Raspberry Pi and an RTL-SDR dongle, I’ve created a copy-and-play image file that gets you up and running in minutes.
I’ve put it (along with a couple of other RPi image files) at http://febo.com/pages/os_images/. The filenames
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In Part 1 I described some background about SDR dynamic range as an introduction to the measurements I did on a RTL-SDR.com v3 USB “dongle” SDR. Now for the results.
I wrote a Gnu Radio program to help measure the dongle. It tunes the dongle, sets its front-end gain,
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I’m using several USB “dongle” SDR sticks from RTL-SDR.com. These nifty $20 devices can receive from 100 kHz to above 1700 MHz. They have a low noise amplifier in the front end that is adjustable from 0 to about 50 dB gain. I wanted to determine the impact of
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Since I posted my original articles on configuring the Gnuradio-based op25 P25 trunking scanner, there’s been a lot of progress in the code. In particular, there is a new fork that changes the program to a command-line version, which saves a lot of CPU resources and also offers added features.
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Here’s a waterfall showing the 80M CW band from a bit after 1600 UTC (noon) and 2000 UTC (4:00PM EDT) on eclipse day. There was clearly enhanced propagation for about an hour, starting ~15 minutes before the local maximum (73% obscuration) at 1819 UTC. There aren’t many signals shown at
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