iiinova — where your digital self keeps evolving

Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 23/01/2026

Cold WX stay-home activity: Successfully repaired my Chameleon F-Loop3 tuning capacitor (to remove intermittent shorts) and restoring TX operation on 40 meters. More evening CW fun ahead! Details and more photos at the QSL.net blog. #HamRadio #AntennaRepair […] [Original post on mastodon.radio]

Photo of a CHA F-Loop3 magnetic antenna on a tripod inside a home office.

Photo of the inside of the tuning loop, showing variable tuning capacitor with inserted paper insulating strips, placed there to assist in troubleshooting just which of these very-many metal plates was shorting to its neighbor when turning (or pressing sideways on) the knob.

Photo of the tweaked tuning capacitor that no longer exhibits rotor-stator shorts when turning or pressing on the knob. The plastic wonder tool to the left of the box allowed precise adjustments of the plates! Success!!

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 07/01/2026

Review of the Fluke 1953A counter/timer shows it is fully working as hoped (operating under local and remote control.) Verified all inputs and operations via GPIB remote control with a simple LabVIEW program. Have a few more esoteric tests to run in near […] [Original post on mastodon.radio]

Photo of a Fluke 1953A multi-function counter on a very busy table top. Counter is under remote control and measuring a frequency of 20.123457 MHz from the TinyGTC source.

Desktop photo from above showing a NI GPIB-USB-HS module connected to the rear of the Fluke 1985A counter. Coaxial cable from the TinyGTC clock output is routed to the counter's A input jack.

Poor photo of the laptop screen showing the LabVIEW virtual instrument control panel controlling the Fluke counter via GPIB. The display shows mode control, time base, cycle LED, and output measurement of 20.123460 MHz. It works!

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 07/01/2026

What to do with an old Ubiquiti AirView2 USB spectrum analyzer when the software won’t run on Win10 or later PC? Answer: Write a LabVIEW program to read/display the raw serial data to keep using it for 2.4 GHz spectral occupancy and channel power info. Plan to […] [Original post on mastodon.radio]

Photo of a long 2.4 GHz antenna, thin coax, and a USB spectrum analyzer module (Ubiquiti AirVIEW2-EXT) with a wooden clamp mount.

Screen capture of the LabVIEW program user interface panel showing the various settings and example captured spectrum data chart and a running channel power chart to the lower right.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 06/01/2026

Slow work day = A few moments to work on 2026 goal to make the lab a little better everyday. Today’s task is to add crimped connector shrink sleeving and a length marker to this Pasternack RG-58 C/U cable. Luckily it has a SMA on one end to slip the shrink […] [Original post on mastodon.radio]

Photo of an unknown length of RG-58C/U cable terminated with BNC-Male and SMA-Male connectors. Two short lengths of shrink tubing are ready to be installed at the connector ends. This provides additional protection to the crimped shield connections.

After photo of the measured/labeled RF cable with shrink sleeving installed at the connector ends. This 15' cable is regularly used in the home lab to connect gizmo1 to gizmo2.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 05/01/2026

Was able to measure the output 1 dB compression point for the QB-150 RF amplifier (with 12V supply). Kept it simple and just measured at 100 MHz as approximation for full frequency range from HF up to VHF band. Have been looking into how to measure across […] [Original post on mastodon.radio]

Plotted data for the QB150 powered with +12V at 100 MHz. Data shows ~ 1 dB gain compression at +22 dBm output level.

Photo of test setup to measure the 1 dB compression point of the QB-150 RF amp at 100 MHz. Test oscillator output into a variable attenuator to the amp input. Amp output to 30 dB pad then into DIY RF Power Meter.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 29/12/2025

Have you noticed that some types of test equipment have gotten much smaller than the rack or half rack width instruments of the past? I am transitioning towards tiny-instruments and downsizing my home lab (having moved multiple times recently). Latest acquisition is a TinyGTC GPSDO timer counter […]

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 28/12/2025

Get going with FreeDV on HF, without fears or tears - The time has come for digital voice on the HF bands by Peter Marks VK3TP. (Found this linked from Peter’s blog on blogs.radio.) #HamRadio www.wia.org.au/members/armag/2025/n…

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 21/12/2025

First (easy) test of the QB-150 Amps: Does the one with the top installed work? Answer: Yes! Measured 12.6 K Ohm on the power pin to GND. Applied 12.2VDC, measured ~120 mA current draw. Tested with NanoVNA-H4 with 40 dB pad on input side and found it has ~ +24 […] [Original post on mastodon.radio]

Desktop photo showing NanoVNA-H4 connected to QB-150 RF amplifier through a 40 dB pad on the input side, measuring S21 gain of +24.5 dBm through HF up to 100 MHz. Amp has +12.2 VDC applied. It works!

Photo showing the stop frequency extended so as to measure the 3 dB gain point for the amp (~446 MHz). Amp was originally used as a HF antenna pre-amp up to about 30 MHz. Plenty of gain (and very flat) up to that point.

Photo of the working amp and summary of test notes. DC resistance on power pin to and was 12.6 K Ohm. Measured with a 40 dB pad. Indicated gain of -15.47 dB gain at ~ 30 MHz. Approx 120 mA at 12.2 DC test voltage. Overall amp has ~ 24.5 dB gain down in HF bands. 3 dB point is ~ 446 MHz.

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Reposted by Gary @N8DMT

🇺🇦 haxadecimal 🚫👑 @brouhaha.mastodon.social.ap.brid.gy · 21/12/2025

I'm reading a 1974 issue of _Electronics Design_, and I'm amazed by all the cool new stuff. There are a bunch of things I want to order, but unfortunately they don't give any URLs.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 20/12/2025

Repair RF Amplifier Project: With some time off ahead, dug out the box of Q-Bit QB-150 RF amplifiers. Likely these are all toast, but will test and troubleshoot to confirm. (These were pulls from a field HF antenna system that occasionally had lightning […] [Original post on mastodon.radio]

Photo of a hand drawn schematic, four modular RF amplifiers, and miscellaneous parts ready to replace failed parts on the boards. May be nonrecoverable, but will test and debug to evaluate before scrapping the boards (keeping the nice cases).

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 19/12/2025

Slow work day = time for RF fun! Remeasured the Copper Mountain Technologies R54 vector impedance probe output signal characteristics to understand if it always used a fundamental output (or if it relies on harmonics like the NanoVNA-H4). TLDR: the much more […] [Original post on mastodon.radio]

Photo showing test signal at 3 GHz with no other signals present in the observed 1 to 6 GHz range on the TinySA-Ultra. Clean!!

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 13/12/2025

Home Handyperson: Had a complaint from a family member that they were not feeling well when the dryer was running. Found multiple issues with the vent: 1) clamp was loose, vent pipe had two large slits cut into it that were leaking. Cut off the hack-job, fixed […] [Original post on mastodon.radio]

Before photo showing one of the two slits cut into the vent (apparently to make it easier to install). Hose clamp was loose as well. Could feel leaking air on the bottom side as well.

After photo with a leak-free repair. Hose cut back, properly slid over the pipe and fastened a-bit back from the edge as it should be. Could not feel any leaking air with the dryer running afterwards. Repair complete!

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 12/12/2025

Ten Meters is just opening up here in EN52 Chicagoland, and seeing some single and double hop skip to the southeast. Going to be an interesting day! #HamRadio #10Meters #MagneticLoop

Screen photo of iPad running SDR-Control to an IC-705 connected to an indoor magnetic loop antenna. Photo shows example of both single and double hop skip received via FT8.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 11/12/2025

Made some progress on the low-cost noise figure & gain measurement setup, and have it running pretty well at 440 MHz. Have pages of notes and pictures to put together a how-to post or web page. Still need to check calibration at other frequencies, but […] [Original post on mastodon.radio]

Desktop photo of the low-cost DIY noise figure measurement system, with RTL-SDR, RF-Amp noise source, Arduino relay controller, and a few RF cables.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 10/12/2025

#PatchTuesday yields #WaitWedneday: Started a “how long will it run” test with the BougeRV cooler powered by a new Anker Solix C300X DC power pack. With 12V @ 50W consumed during cool down, the run time estimate is almost 6 hours. With cool down completed, the […] [Original post on mastodon.radio]

Photo of the C300X DC power pack on top of a car refrigerator, all wired up and ready to start the run-time test.

Screen shot from the Anker app showing ~50W power draw and an estimated run time of over 5 hours...

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 08/12/2025

Finished a first draft for my qsl.net web page documenting a low-cost DIY RF Noise Source suitable for making noise figure measurements under automatic program control (with SATSAGEN software). Still have a few more updates to the web page, but completed […] [Original post on mastodon.radio]

Photo showing DIY RF Noise Source consisting of a Mini-Circuits ZFL-500 RF amplifier and three 5 dB pads (one on input and two on output) connected via a SMA adapter to the input of a TinySA-Ultra RF Spectrum Analyzer. This setup measures excess noise ratio (ENR) needed to use the source as part of a noise figure measurement system.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 06/12/2025

US Coast Guard aircraft executing a search just south of Key West Florida. Additional assets joining in now.

Screen capture from adsbexchange showing a grid search pattern.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 05/12/2025

What is inside a Mini-Circuits ZFL-2000 RF Amplifier? Had a few minutes to take a quick look inside one of these RF Amps. Didn’t learn much, and was surprised to see a fully-cased (pins) amplifier module inside. Would take a lot more effort to disassemble […] [Original post on mastodon.radio]

Photo of a Mini-Circuits ZFL-2000 RF amplifier module with SMA female connectors on each side. Power and GND pins are on the side adjacent to the RF connectors.

Photo inside of the RF Amp, showing a small printed wiring board connecting the SMA jacks and power/GND pins to the module within. Disassembly would require removing the SMA jacks, unsoldering the center pins, removing the four screws and extracting the module/PWB from the case. Too much work just to see what module is used...

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Tom - KB9ENS @kb9ens.mastodon.radio.ap.brid.gy · 29/11/2025

4 General upgrades and 3 new Technicians. Not bad for an after Thanksgiving session. #HamRadio.

A plastic sign that says amateur radio test last Saturday of month from 10:00 through 12:00

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 28/11/2025

Looking over Black Friday announcements from HRO and DX Engineering yields an interesting takeaway: today’s “super-specials” look a lot like last year’s everyday prices for many items. Anyone else seeing this too? #HamRadio #BlackFriday

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 23/11/2025

POTA Questions: If 2 hams activate the same POTA park with each having a 10 band radio station and only contact each other, does this count as a valid activation? (…with logs submitted, etc.) Does a contact on another mode, but same band count as a separate contact? I.e., 10 bands, 2 modes each […]

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 23/11/2025

RF equipment setup complete for first low-power 2.4 GHz test using Remote SDR and Pluto SDR. Waiting for the afternoon to find/retrieve the second RaspberryPi-5 computer needed for the second transceiver controller. (Have moved multiple times with re-boxing […] [Original post on mastodon.radio]

Photo showing two Pluto SDR connected to UTC Microwave circulators and Tacoma 2.4 GHz collinear antennas. This supports simple half-duplex low-power tests of the RemoteSDR controller software.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 21/11/2025

Lower cost & performance, but more bands than the ICOM IC-905? Have been exploring how to inexpensively get on VHF/UHF/SHF bands (2m and up) and believe the ADALM Pluto and RaspberryPi5 with Remote SDR SW will support that. Many challenges to achieve all 8 RF bands to 5.9 GHz, but with […]

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 18/11/2025

Gentle Reminder: Looking for a break from the challenges of life in 2025? Check out Blogs.Radio for great reminders that adding a little radio and electronics to your topics list can positively influence your mood. Or at least distract you for a-bit… Hope you enjoy this site as much as I do […]

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 17/11/2025

Slow Work Day: Let’s sort ferrite! Made a quick ferrite material sorter using NanoVNA-H4 and a two-turn test loop. Ended up finding at least four material types. Now labeled in separate bags and ready for (easier) future use! #HamRadio #EMIEMC #SortAllTheParts

Close up of the two-turn test loop attached to the NanoVNA-H4 analyzer measuring S21. Normalized this as my calibration reference.

Desktop photo showing many ferrite clamp-on parts ready for test. Some are labeled with part numbers (and material types), others are not marked in any way...

Example for testing a type 31 core. Blue curve is the DUT trace. Red is a previously stored trace using a type 43 core.

Phot showing ferrite sorted into three major piles. Not precise, but better than I had before. The rectangular clamp on in the upper left (from Radio Shack long ago) was the worst of those tested today. Would need many turns through it to attenuate common mode signals. Ugh!

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 14/11/2025

Have you seen video on the DIY capacity hat for a vertical antenna whip? Link below for one ham’s approach. Have purchased some 24” zip ties and found the lab stock of copper tape. Interested to see how this works on my 17’ SS-17 whip antenna! With the cooler […] [Original post on mastodon.radio]

Photo of some 24" zip ties and multiple rolls of adhesive-backed copper tape. Planning to build a DIY capacity hat for a 17' telescoping whip antenna system.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 12/11/2025

I’m sure there is a project in here somewhere: Parts for an experimental ground isolator for a 3/8-24” vertical antenna mounting system. The box goes in between the ground spike and radials/coax-feed/vertical-whip. The switch will open or close the ground […] [Original post on mastodon.radio]

Photo of a 1 gang 18" Nail on PVC box, two 3/8-24 nut, two 3/8-24 bolt, a SPDT switch, a hunk of yellow wire, a lock washer and an elongated nut fitting 3/8-24 hardware. Not shown are two 3/8" wire terminals to connect the antenna mounts to the switch. Will it make any difference?

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Reposted by Gary @N8DMT

Michael K Johnson @mcdanlj.social.makerforums.info.ap.brid.gy · 11/11/2025

I love that Elecraft let me do my own warranty repair on my PX3 panadapter. They agreed that a part was broken and offered me an RMA. I asked if I could replace it myself, and they just sent me the part. This is so refreshing a change from our disposable, no user-serviceable parts inside general […]

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 10/11/2025

DIY RF Comb Generator for less than $1.00? After evaluating the mil-spec Herotek comb generator module and Pluto SDR clock source combination, decided to try out a low cost alternative for generating combs. With an on-hand SI5351A clock source, added two […] [Original post on mastodon.radio]

Desktop photo of the comb generator setup. SATSAGEN controlled Arduino UNO controlling EtherKit SI5351A clock source, with CLK0 feeding series capacitor on proto board to shunt signal diode with clip leads attached leading to TinySA-Ultra spectrum analyzer. A large number of comb signals are displayed on the TinySA.

Close up photo of the protoboard showing a single blue capacitor in series from the CLK0 output (right) to shunt signal diode and output to spectrum monitor at left side of the blue capacitor. (Not worried about parasitics for this test.)

Close up photo of the TinySA-Ultra display showing comb pickets extending up to 500 MHz.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 08/11/2025

Finished up testing of what looked like an RF amplifier module but was really a comb generator. TLDR: It works! Now have picket-fence RF signals! Details in two posts over at the qsl.net blog site. #HamRadio #TestEquipment […] [Original post on mastodon.radio]

Photo showing Pluto SDR with HP and LP filters around 640 MHz, HP8447 RF amplifier, Herotek GCA640 comb generator with heatsink, and a TinySA-Ultra spectrum analyzer displaying a series of RF combs (pickets). A well-used HP transistorized power supply is feeding 5 VDC to the comb module. It works!

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 06/11/2025

Getting the lab organized a-bit more: Printed out a data sheet for a pair of Narda RF couplers. Have both couplers back in the same storage package again. What is the RF Geek equivalent of the old hammer-nail saying? When all you have are RF couplers […] [Original post on mastodon.radio]

Photo of two Narda RF couplers, one larger and one smaller, both with red plastic connector covers. The larger coupler covers 0.5 to 2 GHz and the smaller coupler covers 1 to 3.5 GHz. Both provide 20 dB loss on the coupled port. These are useful for return loss measurements in RF systems measurements.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 04/11/2025

Random RF Component Find #308: Herotek GCA640-258 RF comb generator. Was stashed in one of the garage lab boxes. Needs cleaning! This appears to be a 640 MHz input comb generator that will output multiples of that frequency up to ~ 18 GHz. Includes a […] [Original post on mastodon.radio]

Desktop photo of a small packaged RF device with SMA connectors and pins for +5V and GND connections. It is bolted onto a small gold colored metal heatsink. Per the part number, it appears to be a RF Comb Generator. Will be fun to check out and add to the lab stock.

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Reposted by Gary @N8DMT

gosha ⁂ @gosha.gosha.net.ap.brid.gy · 03/11/2025

Bring back BeOS style iconography

A screenshot of a gloriously colourful BeOS desktop, with a blue background, vibrant yellow window title bars, and colourful isometric icons

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 03/11/2025

@kr1st Looks like a lot of fun! Was part of a walkie-talkie design group in years past and have great appreciation for the effort level (and many subsystem interactions during integration and operation). This is the exciting phase - proposing features and making tradeoffs. They may hit the “too […]

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 03/11/2025

Adventures in totally indoor ham stations #307: Changed antenna for the IC-705 over to a 1/4 wave mag mount (on a poor ground) to casually monitor 50.313 FT8. Magic Band - Make it happen! If I hear anything today, I might work a-bit harder for a better 6m antenna. (Maybe a 1/2 wave dipole from […]

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 02/11/2025

2M FT8 Monitor: Setup the IC-705 with 16’ of RG400 coax feeding a DIY 2 Meter halo perched on top of the office closet door. Using SDR-Control on the iPad for FT8 decode. Will monitor 144.174 FT-8 to see if I can hear anything (only seeing always-there power […] [Original post on mastodon.radio]

Photo of a small DIY 2 meter halo antenna constructed using a SO-239 jack and number 14 solid copper wire.

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 01/11/2025

Testing the new 33 cm Pluto SDR controlling software: Have basic RX/TX working and tested on FM mode using a local (second Pluto) SDR linear translator “repeater” controlled by GRC. Notes on using F1ATB’s Remote SDR SW over on the QSL.net website (3 postings) […] [Original post on mastodon.radio]

Desktop photo of the Remote SDR Pluto SDR with its Raspberry Pi 5 controller, along with a second Pluto SDR being controlled by GNU Radio Companion running on a laptop.

Simple GRC program providing a 33 cm 5 MHz split all-mode repeater on the Pluto SDR.

Screen capture of a browser window showing Remote SDR loop back test. Boom headset plugged into laptop: Speak into microphone and hear voice in headset. It works!

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Gary @N8DMT @n8dmt.mastodon.radio.ap.brid.gy · 30/10/2025

[USPolitics #Defiance] New Group Formed: WASHINGTON, D.C. — In response to a sweeping campaign of political retaliation by the Trump administration, a coalition of national security veterans, whistleblowers, and pro-democracy leaders today announced the launch of DEFIANCE.org, the first […]

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Reposted by Gary @N8DMT

Michael K Johnson @mcdanlj.social.makerforums.info.ap.brid.gy · 26/10/2025

We had a surprise opportunity to go to the beach this weekend, near Southport NC. I have the weird preference to sling my hammock under the house, between the clotheslines, instead of sleeping indoors. Half camping? I use a big rubbermaid box as my […] [Original post on social.makerforums.info]

Map showing lines indicating 57 Morse code ham radio contacts, throughout much of the US and one in Canada. All done on 5W or less of power; some were 2–3W.

Sunrise with a ham radio wire antenna dangling from a fiberglass push-up mast at one side. The picture doesn't do the sunrise justice.

Hammock slung under an elevated beach house, tied to pilings, with a beautiful sunrise in the background. It was a great way to wake up!

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