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Repair of a (lightning struck?) Yaesu FT-1000 MP Mark V
The background - and initial assessment:A month or so ago an acquaintance of mine in the local amateur community asked me to take a look at his radio - a Yaesu FT-1000 MP Mark V. While I don't...
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Characterizing the RTL-SDR Block (Version 3) for HF reception using the...
An inexpensive option to reception on the HF (low frequency) bands is one sold by "RTL-SDR Blog" - the current iteration being Version 3. Originally intended for digital VHF/UHF TV reception - and...
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A high power, high-sensitivity remote repeater covering deep river gorges in...
From the late 1950s until about 2021, there was a (mostly) annual event held in southeastern Utah that was unique to the topology: The Friendship Cruise.The origins are approximately thus: In the...
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Pink bits of rubber causing a blinking light...
A bit more than a week ago I volunteered for an aid station along the route of the Wasatch 100 mile endurance run - which, as the name implies, is a 100 mile race, starting and ending some distance...
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Quieting a Samlex 150 watt Sine Wave inverter
A few weeks ago I was on vacation in remote Eastern Utah - in Canyonlands National Park, to be precise. Because we had some "down time" in the evenings, after hiking, after dark, I was able to set up...
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Fixing the CAT Systems DL-1000 and AD-1000 repeater audio delay boards
Figure 1: The older DL-1000 (top) and the newer AD-1000, both after modification.Click on the image for a larger version.A few weeks ago I was helping one of the local ham clubs go through their...
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The case of the Clicky Carrier (that can sometimes clobber the upper part of...
Listening on 20 meters, as I sometimes to, I occasionally noticed a loud "click" that seemed to pervade the upper portion of the band. Initially dismissing it as static or some sort of nearby...
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Testing the FlyDog SDR (KiwiSDR "clone")
As noted in a previous entry of this blog where I discussed the "Raspberry Kiwi" SDR - another clone of the KiwiSDR - there is also the "FlyDog" receiver - yet another clone - that has made the rounds....
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High power Tayloe (a.k.a. Wheatstone) absorptive bridge for VSWR indication...
Figure 1: The completed absorptive VSWR bridge.Last year, I was "car camping" with a bunch of friends - all of which happened to be amateur radio operators. Being in the middle of nowhere where...
View ArticleImplementing the (functional equivalent of a) Hilbert Transform with minimal...
I recently had need to take existing audio and derive a quadrature pair of audio channels from this single source (e.g. the two channels being 90 degrees from each other) in order to do some in-band...
View ArticleFixing a TS-570G
A couple of months ago I happened to be at a swap meet in Northern Utah and talking to a gentlemen - with whom I had a passing acquaintance - as he was unloading his vehicles. One of the things that...
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The use case for a blinking infrared LED
Many years ago at a company where I worked, we had two sets of computer systems: The ones that we used every day for engineering purposes, and the "corporate" computers that were used for things like...
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Improving my ultrasonic sniffer for finding power line arcing - new microphone
Figure 1:The packaged MEMs microphone, along with theultrasonic receiver.Click on the image for a larger version.Years ago - probably 20+ - I constructed a superheterodyne "Bat Listener" to eavesdrop...
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Making a "Word Metronome" for pacing of speech
Figure 1:The completed "Word Metronome". There are two recessedbuttons on the front and the lights on on the left side.Click on the image for a larger version.One of the things that my younger...
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Using an ATX computer power supply to run KiwiSDRs - and as a general purpose...
At the Northern Utah WebSDR (link) we run a number of KiwiSDR receivers. These receivers, which are inherently broadband (10 kHz to 30 MHz) allow a limited number of users to tune across the bands,...
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An ultrasonic superheterodyne receive converter (e.g. "Bat Listener")
In the mid 90s I decided to throw together what I called a "Bat Listener" - a simple receiver used to convert ultrasonic sound down to the audible range.Figure 1:The exterior of the ultrasonic...
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Using an inexpensive PT2399 music reverb/effects board as an audio delay (for...
Figure 1: Inexpensive PT2399-based audio delay boardas found on the usual Internet sites.Click on the image for a larger version.In an earlier blog post (Fixing the CAT Systems DL-1000 and PT-1000...
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An LCD Retrofit and color display for the SI 4031 Communications Test Set
Figure 1: The front panel and original green monochrome screenof the 4031. A close look shows the "blistering" on thescreen protectors due to delamination, making thedisplay more difficult to...
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Exploring the NDK 9200Q7 10 MHz OCXO (Oven-controlled Crystal Oscillator)
Figure 1: The NDK 9200Q7 OCXO. This unit, pulled fromused equipment, is slightly "shop-worn" but stillserviceable. The multi-turn tuning potentiometeris accessible via the hole at the...
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A 2 meter band-pass cavity using surplus "Heliax"
The case for filteringIf you operate a repeater - or even a simplex radio such as a Packet node - that is located at a "busy" radio site, you'll no doubt be aware of the need for cavity-based...
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