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Setting/calibrating signal and noise levels for signal/noise level monitoring...
The WSPRDaemon script, a work largely of Rob, AI6VN, is designed to automate WSPRNet reporting of signals transmitted using the WSPR protocol. While the WSJT-X program, itself, can report the signals...
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About the WSPRDaemon noise graphs - and repurposing for use in monitoring...
What is WSPRDaemon?The WSPRDaemon program is largely a work of Rob, AI6VN and it exists for the purpose of facilitation the reception of WSPR signal off air, processing the data, and making that data...
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Pine needle what? (Keeping your coniferous antenna supports alive!)
The afflicted tree: The needles are more normal atthe top, but looking rather "thin" farther down.Because of the number of pine cones, the treelooks "browner" in this picture than it reallyis - but it...
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A "curiously sharp" 40 meter band-pass filter
At the Northern Utah WebSDR (sdrutah.org) we recently added another server (WebSDR #4) that is connected to an existing east-pointing beam antenna on site. This antenna, it is hoped, will better-allow...
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A quick look at the QB-300 amplifier
Available from many surplus sellers (e.g. EvilBay) - and (usually) for a reasonable price - is the QB-300 RF amplifier. Originally made by Q-Bit corporation, this same device has borne several...
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An ESP8266-based Temperature, Humidity and Line Voltage monitor
Figure 1:The completed Temperature/Humidity/Line Voltage webserver/telemetering device. The remote temperature/humiditysensor is the unit to the left. The AC-DC wall adapters are not visible.Click on...
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What the heck happened to this Sense power monitoring module?
Figure 1:The exterior of this Sense SM3 power sensing module.The connections are made via barely-visible holes on the left side while aWiFi antenna permits connectivity onto the user's wireless...
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An automatic transfer relay for UPS/Critical loads for the ham shack,...
It is quite common to use a UPS (Uninterruptible Power Supply) to keep critical loads - typically computers or NAS (Network Attached Storage) devices - online when there is a power failure as even a...
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Revisiting the limited attenuation high-pass filter for the KiwiSDR (or...
In the June 18, 2018 entry of this blog (see that page here) I described a device that reduced the lower-frequency (below approximately 10 MHz) by approximately 12dB while leaving higher-frequency...
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Comparing the "KiwiSDR" and the "RaspberrySDR" software-defined radios
Any reader who has perused these blog pages will be aware that I have been using the KiwiSDR for some time now, having been happy with their performance and finding various ways to maximize usefulness....
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Revisiting the "Limited Attenuation High Pass" filter - again.
In several previous posts (See: "A Limited Attenuation High Pass Filter" and "Revisiting the Limited Attenuation High Pass Filter" I described a "high pass" filter that offered low attenuation at high...
View ArticleUsing the jt9 executable to receive FST4W signals
Note: The following post is specific to WSJT-X v2.3.0-rc1. It may not apply to subsequent versions.* * *As a heavy user of K1JT's WSPR and operating on the 2200 and 630 meter bands, I have noted with...
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A high-current DC noise filter for UPS or RV use
A friend of mine (WA7X) acquired a 16 kVA UPS (for free!) a year or so ago - a commercial system consisting of four hot-swappable 4 kVA modules: With his current load, he only uses one of the four...
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Interesting signals on the 20 meter band (Probable transmitter malfunction -...
I happened to be looking at the various receivers at the Northern Utah WebSDR - as I'm wont to do (since I maintain them!) and noticed a few strange-looking signals that hadn't been there...
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Intruder at the top of the 20 meter amateur band?
It wasn't my intent to have this next post be about locating a source of a transmitter - but the temptation proved irresistible.Over the past several days I'd been working on an addition to the...
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Locking the Icom IC-910H to an external 10 MHz (GPS) reference
In late 2009 my friend Bryan, W7CBM, came to me with a project that he had in mind: "Can we lock my Icom IC-910H to my 'Z-box'?" - in other words, could the 10 MHz output from his Z-3801 GPS...
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Using surplus GE Mastr II and Exec II transmitters as amateur radio beacon...
Back in 2000, a friend of mine (Glen, WA7X) wanted to place VHF and UHF propagation beacons at his cabin located in remote central Utah. On-hand were used GE MASTR II Exec FM transceivers: These...
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RFI (Radio Frequency Interference) sleuthing with the TinySA - Part 1: The gear
Although focused on the use of the TinySA, the techniques and equipment described in this article may be applied to using any other type of Spectrum analyzer - or even a simple receiver - for the...
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The appearance of the "Chinese Woodpecker" on the HF bands
Listening about on 40 meters this morning, I heard a familiar sound - the "putt-putt-putt" of what sounded very much like the infamous "Russian Woodpecker" Over The Horizon Radar (OTHR) of the 1970s...
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Using the QRP Labs "SoftRock" as a possible crystal replacement in "rock...
As technology moves on, it is getting more difficult to find custom-made quartz crystals.Why would one need a quartz crystal in these days of frequency synthesizers? The can't really be beat for...
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