Pipe Cleaners and .22s

I wanted to swab the chambers on this High Standard and my bag of pipe cleaners was handier than my .22 cleaning rod, so I figured I'd give it a try. Doubled over the pipe cleaner is a snug fit that still pushes through easily. You could even use it to clean a rifle bore by cutting a short section, folding it in half, and then pulling it through with a thin line. You're not going to be doing any serious scrubbing but it'll work for applying solvent or oil.

You can get pipe cleaners with embedded plastic bristles which would be slightly more aggressive but they are probably not needed unless the bore or chamber are really crusty, although I do find them handy for cleaning hard to access spots in guns.

Fixing a High Standard R-108 Sentinel Snub Revolver

One of my favorite guns is a High Standard Sentinel R-101 .22 with a nickeled finish and 3" barrel, that I bought in near-new condition about 5 years ago. It's given excellent service.

A couple years ago I found a later Sentinel R-108 snub with a 2" barrel, and the original box and papers included.I jumped on that because the shorter barrel makes it a lot more pocketable, and 9 rounds of CCI Stingers or Federal Punch .22s is nothing to sneeze at.

Unfortunately, the snub gave me problems at the outset with the cylinder binding. I tried swapping cylinder assemblies with one I grabbed off eBay but that was for nought. It needed to have the cylinder disassembled to find the problem. I figured it would be a burr or some grit had managed to work its way inside.

The problem is that the Sentinels are notoriously difficult to put back together once taken apart. They are held together with pins and you need to align all the holes just right, often under spring tension. So, the gun sat until today when I finally got tired of it occupying space.

After removing the cylinder from the frame, which isn't difficult, to get the cylinder stripped I had to remove the cylinder lock plunger pin (part # 7112). This pin is about as thick as a pencil lead and 3 or 4mm long. It's under pressure from a couple springs (#7513 and #7576).

I managed to drive it out and not shoot any parts across the room. Upon pulling everything apart I found that ejector rod spring (#7576) was splayed out on both ends, causing cylinder rotation to bind. I clipped both ends which still gives plenty of spring pressure for the ejector rod to rebound.

Now came reassembly. I had to hold three parts under spring pressure in alignment and drive that tiny pin back into place. Aside from a small diameter drift punch I found a small hook from a Harbor Freight set indispensable.

You also need to stick your tongue out at the right angle, squint correctly, cross your toes, and pray. In extreme cases you may need to sacrifice a chicken.

After reassembly and a few cylinder's worth of dry firing (safe to do with the Sentinel) it seems to be working smoothly.

Part of self reliance is being able to work on your guns. To that end, you should have a gunsmith's screwdriver kit with an assortment of bits that properly fit gun screws, a set of drift punches, a non-marring mallet, and a bench block. A vise with non-marring jaws will also be very handy. Also, magnetic parts trays help keep you from losing small parts when you've got a gun apart.

I feel like I earned a bowl of Half and Half in my Falcon pipe, along with a can of Yuengling Lager.

Hopefully I'll get to do a live fire test soon.

Graphing RF Line of Sight

I have a few friends who live within a reasonable distance for 2M simplex communications, if there is line of sight. Today I found this tool that allows you to graph LOS between two points on a map:

https://www.scadacore.com/tools/rf-path/rf-line-of-sight/

Here's a plot between my house on the left and a friend's on the right, assuming an antenna height of 10M:

Back in 2015, we were able to hold a conversation on 2M simplex, with Yagi directional antennas on both ends. In that test my antenna was only about 1M above ground, while my friend went up the hill behind his house and hung his antenna from a stick, about 1M up. See my two posts on that test, here and here.

Since there is a ridge about halfway between us, it is likely that knife edge diffraction played a role in the success of our QSO.

Expedient 10M Dipole Antenna

I whipped this up in about 15 minutes this afternoon.

I used a wire stripper/cutter and the reamer on the Victorinox Pioneer Swiss Army Knife. I could have used just the SAK.

Bill of materials:

• BNC-to-Binding post adapter
• No.36 bank line for a center hang loop (optional)
• Two lengths of 20 AWG silicone insulated wire, cut to 8 feet and 1/4" each. You may want to go a little longer and trim to length to adjust SWR as needed.
• Insulators cut from plastic dividers from a plastic parts bin organizer

The build is simple:

1. Cut the wires to length
2. Strip about 1" of the insulation of one end of each wire, twist, and put the stripped end through the hole in the binding post, one to the red and one to the black. Snug down the screw on the binding posts.
3. Cut the wire end insulators and drill two holes large enough for the 20AWG wire near one end. Drill a single hole on the other end.
4. On the end with two holes, thread the end of the wire through the hole closest to the edge then down through the second hole. Tie an overhand knot to prevent it from coming back through, then pull the wire snug. Here's a closeup:

Notes:

• I was going to crimp a ring connector onto the ends of the wires where they attach to the binding posts, but the rings weren't quite large enough. You might be able to drill them out a little with a step drill.
• Depending on what size line I use to hold up the antenna, I may need to add a small loop of bank line to either end. I didn't want to drill the third hole too large because the plastic I used was thin.

I should be able to try this out later in the week and will post a follow up. If by chance I cut the wires too short I can replace them, then repurpose them for use on a 6M dipole.

My First Whack at a Homebrew Jungle Antenna

This afternoon I made a VHF jungle antenna for the first time. 

The jungle antenna is a field expedient ground plane antenna that can be made with limited supplies and tools, under austere conditions, though I built on my dining room table (the XYL is out of town).

This antenna design is featured in military manuals, survivalist videos on YouTube, and @NCScout has a great blog post on them on his site Brushbeater and in his book, The Guerilla's Guide to the Baofeng Radio.

Materials Used:

• 18 AWG wire
• #36 bank line
• A BNC F-to-binding post adapter from Amazon
• Bamboo stakes garden stakes from Lowes, to spread out the ground plane radials.

The only tool I used for the initial build was a SOG PowerAccess multitool, leftmost in the above picture. It is 4.5" long, which I used to measure the wire and bamboo for cuts.

I first cut thee 22" long pieces of bamboo for the spreaders. These were tied into a triangle with bank line.

Three radials were cut to ~20" and one wire for the vertical radiator was cut to 18".

I attached a bank line hang loop to the end of the vertical with a sheet bend. The other end of the vertical was stripped and put into the red binding post. The three radiators were stripped on one end, combined, and attached to the black binding post. The other ends have a small overhand knot tied in them and then were tied to the corners of the triangle.

Unfortunately, SWR (Standing Wave Ratio) came out high on both VHF and UHF, measured with my NanoVNA. On 2M VHF, SWR was 2.29 at 146.5 MHz. On 70cm UHF it was a bit better, 1.86 at 450.2 MHz.

After dinner I made a couple changes. First, I replaced the 18" vertical element with one cut to 19.2", with an overhand knot tied at the top end, with my bank line hang loop tied under that with a couple half hitches.

I have it suspended from an uncut bamboo stake in my second floor home office. Yes, it's a bit cluttered.

I also improved the ground plane part by replacing the bank line securing the ends of the radials and bamboo pieces with a cable tie at each junction. This made the structure much stronger.

After reworking it I remeasured SWR with 29.5 feet of RG-174 coaxial feed line. It's much improved now.

On the 2M calling frequency of 146.52 MHz SWR is now at 1.36, and on the 446 MHz 70cm calling freq it's at 1.06.

Note that SWR will probably change some with the antenna hanging in free space but I cannot test that today because it's been raining off and on outside.

Reception of a couple local repeaters has been very good but I haven't transmitted with it yet.

Measuring SWR on an Ed Fong J-Pole with a NanoVNA

I have an Ed Fong roll up J-Pole antenna for use with 2M/70cm HTs. It's currently hanging from a thumb tack pushed into the wall of my shack up near the ceiling. I thought it would be interesting to measure the SWR (Standing Wave Ratio) on it for 144 Mhz through 446 Mhz, using a NanoVNA. 

After getting the reading I uploaded the picture to Google Gemini, ChatGPT, and Grok for analysis. Here's what Grok had to say:

This is a classic NanoVNA SWR (Standing Wave Ratio) plot of an Ed Fong-style dual-band J-pole antenna (2 m / 70 cm).

What the Graph Shows

• X-axis (horizontal): Frequency sweep from 144.000 MHz (START) to 460.000 MHz (STOP).
  This covers the entire 2-meter band (144–148 MHz) and most of the 70 cm band (430–450 MHz), plus the frequencies in between.
• Y-axis (vertical): SWR, scaled from 1.00 (bottom of the screen) to 1.75 (top of the screen).
  The labels at the top (“CH0 SWR 1.00/ 1.75”) confirm this narrow scale, which zooms in on the good-performance region.
• Blue trace: Measured SWR at each frequency (derived from the reflection measurement on CH0 / S11).

Key rule for reading SWR plots on a NanoVNA:
Lower on the screen = better match (lower SWR).
Higher on the screen = worse match (higher SWR).

The trace shows clear downward dips at the resonant frequencies — these are the “good” spots.

Interpretation of the Dips (Resonances)

J-pole antennas (especially dual-band designs like Ed Fong’s) are not simple dipoles. They consist of a radiating element + a matching stub, so they naturally exhibit multiple resonant modes, including harmonics. This is exactly what you see:

• Left side of the plot (near 144 MHz marker): One or more dips in/near the 2 m band. The marker is placed right at 144.000 MHz (lower edge of the band). The trace near the marker is on the shoulder of a dip, indicating usable (but not necessarily the absolute best) SWR at the very bottom of the band. The main 2 m resonance is likely slightly higher (typical center ~146 MHz).
• Middle of the plot: Several additional dips. These are intermediate/harmonic modes that are normal for this antenna type but usually not used for transmitting.
• Right side of the plot (toward 430–460 MHz): Prominent dip(s) corresponding to the 70 cm band. One of the deeper dips is in this region, showing excellent match where it matters. The trace also trends low again near the right edge (~460 MHz), consistent with another higher-order response.

Between the dips the trace rises high (often off the top of the 1.75 scale) — this is completely normal and expected. You only care about SWR in the actual amateur bands you use.

Overall Performance Assessment

This is a very good result for a dual-band J-pole:

• Multiple deep dips reaching close to the bottom of the scale → SWR very close to 1.0 at the resonant frequencies (excellent match).
• The scale only goes up to 1.75, and the dips are well below that → the antenna is well-tuned for both 2 m and 70 cm.
• Typical real-world Ed Fong J-poles show SWR in the 1.2–1.8 range on both bands when properly built; your scan is right in that ballpark or better.

Quick Summary Table

Frequency Region	Expected Behavior	What You See in the Plot	Quality
144–148 MHz (2 m)	Main resonance	Clear dip(s) near left side	Good to excellent
~200–400 MHz (in between)	High SWR (unused)	Trace high between dips	Normal
430–450 MHz (70 cm)	3rd-harmonic resonance	Prominent dip(s) toward right	Excellent
>450 MHz	Higher-order modes	Trace trending low again	Normal for J-pole

Bottom Line

Your Ed Fong J-pole is performing as designed — it has solid low-SWR resonances in both the 2 m and 70 cm bands. The multiple dips are characteristic of this antenna style and are not a problem.

If you want the exact SWR number at 144 MHz (or any other specific frequency), just move the marker on the NanoVNA and read the value at the top of the screen. You can also narrow the sweep (e.g., 140–150 MHz or 420–450 MHz) for a more detailed view of each band.

~~~

Afterwards, I ran scans but limited the range to 140 - 150 MHz and 450 - 460 MHz, to get more granular views of the 2M and 70cm bands. But this shows how you can use AI to help you understand raw data.

Building a 2M Jungle Antenna

Brett from the Survivalcomms YouTube channel has this nice video on how to build a 2M jungle antenna. The only tool he used to build it was a Leatherman multitool. After he built and hoisted it he measured scanned it with a spectrum analyzer.

This is the same antenna design described by NC Scout on the Brushbeater blog, here. It's a 1/4 wave vertical with three counterpoise elements that create the ground plane.

You might wonder whether a jungle antenna or a roll-up J-pole works better on VHF. Realistically they are very similar but the J-pole is more portable. This archived thread from the Arfcom ham forum goes into some details.

One advantage to the jungle antenna is that some folks (i.e., me) may find it easier to build. When I've tried to strip 300 Ohm TV twinlead to make a J-pole I always mangled the conductors because the wire inside the insulation is so thin. In contrast I find it easier to strip insulation from other slightly thicker wire, like lamp cord. So, for me, if I needed to make an expedient antenna, I'd go with the jungle antenna, assuming I had the BNC-to-banna plug adapter.

Yaesu FT-7800R Programming

Today I found out the hard way not to use CHIRP* to program my Yaesu FT-7800R radio. IIRC, this worked OK for me in the past but not on my current M4 MacBook Air, with a Cable Matters USB-C to RS-232 adapter. I was able to download the pre-existing memory channels fine but when I made some changes and uploaded them to the rig, only the first two memory channels worked.

I wound up doing a factory reset on the radio and trying again with the same result.

So, I bit the bullet and ordered the RT Systems ADMS-2K software plus their USB-29 programming cable. 

The cable will be shipped to me but RT Systems provided me with a download link for the Mac software. I grabbed that and tried it with the aforementioned Cable Matters adapter and the Yaesu RS-232 programming cable, and it worked fine. Once I receive the RT Systems cable I use that, since it'll be a more elegant setup.

My radio is at least 20 years old and while futzing with it I noticed that the microphone cable is fraying on both ends, although it still worked for me to get into a local 2M net this morning. I checked for replacement mics and found a replacement cable only at Amazon, which I should get tomorrow.

*In contrast to the Yaesu rig, CHIRP has never given me a lick of trouble with my Baofeng UV-5Rs or UV-25PRO.