Posts Tagged ‘amateurradio.com’
#POTA Activation of JD Mac Arthur SP in South Florida
This, my second POTA activation, was a much bigger su
ccess (39 qso’s in an hour) than the first (a mere dozen), despite #2 being on a weekday afternoon vs. Sunday for #1. I attribute this to my savvy scheduling to avoid ARRL’s DX Contest and at the same time, ARRL’s respectful consideration for a Big Gun like me in not trying to compete! As the Borg said, “Resistance is Futile.”
The other big factor was getting a few hams to spot me on the clusters. I was quite surprised, and thrilled actually, to be the subject of a pileup for a few minutes. Imagine, lil’ ol’ me, being sought after; I hardly knew how to handle the fame!
Things started kinda slow, my first contact being a ham about two miles away; I’m thinking, oh boy, this’ll be a long afternoon. Will I ever get the requisite ten qso’s to count a POTA activation? I tried to spot myself but on Dxsummit.fi it is so awkward to do on your smartphone. With ten thumbs like me, mistakes are made. I did ask several hams to spot me and soon a few did, and then I was in demand, even at 4pm on a Tuesday afternoon. I never knew there were so many retired or unemployed hams sitting around bored during the day. From South Florida I worked hams in NY, CT, MI, PA, MN, AZ, CA, England and Spain!
I used my link dipole antenna up approx 24′ at the apex, set for 20m. By closing a pair of links, it can be reset for 30 or 40 meters. I built this antenna a while back, and tuned and trimmed it carefully for each of these bands, so no tuner necessary. I’ve tried a PAR EndFedz and a homebrew Buddipole for HF and this is the best for me, thus far.
From left to right: the dipole (made of speaker wire) rolled up on custom deluxe wire winder; middle, the handsomely crafted center SO; and right, the links for 30m, left open so antenna resonates at the shorter 20m cut. Note “stress relief” at the SO and use of safety pins to carry the tension of the dipole when hoisted. Below is pic of my antenna launching tool; it was too heavy at first so I drank half the contents. Also below is a pic of my tie down line, fluorescent builder’s twine. I’ve decided to be stealthier in the future and will change that out for something that’ll blend better.
I want to be stealthier so I don’t draw attention to my station and my suspicious behaviors. Even though I have a right to be there at a picnic table not all Park Rangers got the memo and some may think they should run me off. Last week a Ranger did stop by and I thought “well, here we go,” but actually he just wanted to chat; his Dad had been a ham, so I tried to recruit him. I had another visitor, too; note to self, don’t operate so close to garbage cans!
And finally, a note to the wise for operating out of doors in Florida; bring your bottle!

This is Wayne, k4wk, http://www.hamdom.com. Thanks for listening; you’re in the log.
QST Article – “Live Trees Affect Antenna Performance” – implications for #POTA #SOTA
In February 2018’s QST was a very interesting and scholarly article, the cover story actually, on the effects of live trees on the performance of both vertical and horizontal antennas. Things to ponder:
- Living wood (trees, as opposed to dry dead wood such as boards) absorbs EMF from vertically polarized antennas.
- Living wood resembles human tissue in terms of dielectric properties, so wearing your HT on your belt will greatly reduce your effective antenna power. Presumably, unless you’re a real fathead like me, talking into HT held at your face should not be too bad.
- A single vertical tree has next to no effect on horizontal antennas, such as dipoles.
- A forest, containing lots of vertical trees, is even worse than a single tree like in your backyard, so for us backpackers and hikers, we need to find a clearing when trying to use our HT’s in the woods.
- Worse, a forest will affect both vertical and horizontal antennas so when we’re operating in the field, for POTA or SOTA for example, we should look for a Goldilocks spot with enough trees to launch the, say, dipole, but not too many. Better in Winter after leaves fall, though.
This is Wayne, k4wk, http://www.hamdom.com. Thanks for listening; you’re in the log.
My #POTA Pickle, or How I Learned to Stop Worrying and Love the ARRL #DX Contest
Sunday March 4th was a beautiful and slightly cool (mid-seventies) day in Jupiter, Florida and was the day I selected for my first #POTA activation (parksontheair.com). I picked the 11,000 acre Jonathan Dickinson State Park, KFF-1887, just six m
iles from my Florida QTH. I scouted out locations a few days earlier and chose the picnic area near the river, with cooperating pine trees with handy limbs. Using my unique antenna launch tool (see pic) on only the second try I hit my target limb and hoisted the “high” end of an EndFedz antenna cut for 20 meters. My battery was charged, I had my sandwich, I even had a cushion for the hard picnic table bench seat. Right on time I was ready to spot myself, all settled and happy. Do you hear a “but” coming?
This was
also the weekend ARRL chose, without checking with me, for their hugely popular annual DX Contest. There were a few thousand hams on 20m, most, it seemed, with a kilowatt and a pretty good beam competing with me barefoot with a dipole up all of fifteen feet. I spotted myself on DXSummit.fi but apparently nobody cared. I raised my friend Rick on the local repeater and got him to listen for me at 14.244 a few miles away and we could barely hear one another on ground wave. We were in a wall of sound (and I was learning the value of a filter for sideband.)
So there’s my POTA Pickle; I’m in the right place and all set to operate POTA but cannot compete with a thousand big gun stations. Well golly, let’s join in on the fun then.
First I took down the End Fedz that just doesn’t work that well for me and put up my link dipole made from lamp cord and began to hunt and pounce. Worked a dozen international stations in an hour and called it, after all, a good non-POTA day.
This is Wayne, K4WK, http://www.hamdom.com. Thanks for listening; you’re in the log.
Review – BTech AMP-25 series for Analog & DMR
The AMP-25 series VHF / UHF Amplifiers
The recently announced BTech Digital and Analog amplifier series puts a whole new spin on mobile operation. It performs more like a mobile than it does a power amp. The D series are true TDMA Tier2 DMR amplifiers.
Note: This review was done using an Anytone D868UV on both DMR and analog.
In the Box
Included with the 40W Mobile Amp are:
– Mounting Bracket
– 3′ Interface Control Cable (Kenwood K1 connectors)
– 3′ RF connect cable (SMA-M to SMA-F)
– Microphone and Hanger
– All necessary mounting hardware
– User Guide
General Description
– UHF or VHF Power Amplifier
– 2-6W > 20-40W Output
Modes of operation include:
| V25 U25 | V25D U25D |
| Analog (FM) C4FM (Fusion) P25 (Phase 1) NXDN IDAS dPMR MPT1327 | > DMR Tier II (TDMA) > P25 (Phase 2) Analog (FM) C4FM (Fusion) P25 (Phase 1) NXDN IDAS dPMR MPT1327 |
A Different type of Mobile Amplifier
I found these to be much more than a typical power amplifier. Although they can function as a simple ‘In and Out’ power amp, this is about as close to a full mobile as you can get. Although the driving
force was my DMR handheld sitting in my cup holder, the transmit audio was that of the included hand microphone and the receiver audio out was coming through the built in speaker driven by a four watt audio amplifier.
Transmit Power
I tested the power on two different models. The VHF V25 (non TDMA) and the U25D for UHF DMR. The power was tested using the analog side of both into a calibrated Bird Termaline wattmeter. The maximum current drain from my 13.6V 30A power supply was just under 6A. This is low enough for the amp to be powered by the 10A accessory jack in your vehicle.
Enclosure
The basic frame measures 4.6″W x 1.3″H x 5.5″D (excluding the SO-239) and weighs in at 26oz. I was
curious to see the internal layout of the amp and to no surprise, there was a 5/8″ finned heat sink spanning the entire length and width of the case along with air vent along the back of the enclosure.
Operating Modes
These are single band amplifiers.
V25(D) = VHF 136-174MHz
U25(D) = UHF 400-480MHz.
Note: The V25D and U25D were designed to include DMR Tier II (TDMA) and P25 Phase 2 along with all other modes. Their operation varies slightly.
V25 / U25
To operate VHF through the UHF (U25) amplifier, or UHF through the VHF (V25) amplifier, simply power off the amplifier. This will allow you to run straight through directly to the antenna without power amplification on that band.
V25D / U25D
These amplifiers will only operate within their specified VHF or UHF range. This is due to the circuit switching design of DMR Tier II and P25 Phase 2.
Hook Up
The simplest configuration is using the included RF cable to attach the radio to the amp. You could add a Spkr/Micr to the handheld, but you would still be bypassing some of the best features.
I use the two included cables. The 3′ RF cable to attach the radio to the amp, and the control cable. This
allows me to use the full size hand microphone as well as connecting the four watt audio amp powering the speaker. The power included power cable is compatible with handhelds using the standard two pin Kenwood style connector, such as an MD380, D868, GD77, UV5R, F8HP, UV82, etc.
I use an Anytone D868 on DMR as well as analog with the hookup diagrammed below. Depending on your radios antenna jack, you may need to pickup an SMA-M to SMA-M adapter.
Convenience
All channel selection and volume adjustments are done using the handheld. No duplicate programming or code plugs are necessary. Whatever is in my handheld is what I operate in the mobile
Operating my handheld in the low power position, I still get 22W out on UHF and my handheld’s battery life remains excellent, but high power gives me a solid 39W.
Conclusion
I was glad to see someone finally develop what is a full featured mobile amplifier capable of DMR as well as all other modes including C4FM and D-Star that is small enough to mount in the car, boat, and on top of your computer. This amplifier is Part 90 certified and definitely worth considering.
Available from Amazon: V25 V25D U25 U25D
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VHF /UHF
Digital / Analog
Mobile Power Amplifiers
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On the Air – SOTA, POTA, BOTA, IOTA and now, COTA
The newest OTA I’ve discovered is the World Castles Award, or COTA – Castles on the Air. Not sure if COTA is official or not, but let’s call it that for now, since it rhymes so well with SOTA, POTA and BOTA. (IOTA is only a half-rhyme).
You might think “We Americans don’t have any castles here; we were settled after the period of castle-building, so how is this relevant to me?” Well, you can think that if you want to, but you might be wrongish. True, we have no castles in North America (or do we? – see below), but we do have other structures that the wise men and women of WCA have recognized as eligible structures of note. Happy Dance! Here’s a new game we can play once we’re all worn out activating all the mountains in SOTA, parks in POTA, and beaches in BOTA.
Here in the Southeast that I inhabit, there are scores of eligible structures. In my own tiny hometown of Decatur, GA, pop. 18,000, I find that we, too, have a castle called Oakhurst Castle. I need to find out what that is, and of course, activate it. Look for me on Dxsummit some day.
Forts, even if not fortified, can qualify, such as Fort Jackson, SC, where I spent three happy months one summer and most if not all other military bases with “Fort” in their title. Also, historic forts like Castillo de San Marcos in St. Augustine, Florida qualifies but the towns of Fort Lauderdale, Fort Myers and Fort Pierce where we can imagine forts once stood, are sadly excluded. However, don’t despair – you can still go to the beach in those towns and activate your suntan via BOTA!
Mansions, or “Stately Homes,” also seem to qualify, such as the indisputably stately Biltmore House in Asheville (raise your hand if you’ve been there). The WCA styles it as “Biltmore Castle.”
Scanning the list I see others in my haunts I can consider activating and some that raise questions such as one on Marco Island known only as “Unknown Castle.”
But there is one I expected to see that has been overlooked – probably the only purpose-build Castle in the United States, and it’s certainly not unknown; of course I’m talking about Cinderella’s Castle at the Magic Kingdom (raise your hand again if you’ve been there). If you are as hurt as I am at this (rather slight) slight, please join me in a letter-writing campaign to the WCA to help right this wrong. We’re Americans – we fought for our freedom, now we must fight for Cinderella’s honor!
Signing off for now, de k4wk, www.hamdom.com. Thanks for listening; you’re in the log.
A Personal Self Defense Weapon, a Utility Hammer, and a DMR #Hamradio, All-in-One
My first impression of my new TYT MD-380 (and Steve, KA4RSZ, felt the same way), was the solid, sturdy feel of the thing. Not at all what you’d expect from an $88 plastic cased electronic device of any sort. We were both quite impressed, and the reason has become clearer as I’ve learned more. This radio or its kin, were built for non-ham, heavy-duty use by folks like security guards and retail store personnel, not dainty and refined hams such as ourselves.
Reading the User’s Manual has been fun, and incidentally makes the bizarre Icom manuals seem lucid. Filled with handy tips, I love where it cautions me on page one “Do not transmit too long, for the radio may heat and hurt the user.” Also advising “if the radio appears smelly or smoke, please shut off…” Great tips for us all.
On page six it is reassuring to be told “wearing the radio in your waist will not make you feel uncomfortable.” I just love Chinglish!
Signing off for now, de k4wk, www.hamdon.com. Thanks for listening; you’re in the log.
Not so "oldies".
You may remember a few years ago (I think it was just a few years ago - maybe 10 years?, or maybe I'm having a "senior moment"?) Icom released a series of comics entitled "The Adventures of Zack and Max". These were anime style comic books intended (I guess) to get the youngsters curious about Amateur Radio.
Max was a strange little pig companion to Zack - a boy and his pig - go figure.
Anyway, here are their links - both as comic books or as coloring books. If you have any kids or grandkids who are curious about what it is that you do - these may be helpful to explain it to them in a more contemporary fashion.
The Adventures of Zack and Max, Vol 1-7
http://www.icomamerica.com/en/amateur/comic_book/Books/v1/ComicBookV1color.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v2/ComicBookV2color.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v3/ComicBookV3color.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v4/ComicBookV4color.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v5/ComicBookV5color.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v6/ComicBookV6color.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v7/ComicBookV7_Color.pdf
Accompanying coloring books of The Adventures of Zack and Max.
http://www.icomamerica.com/en/amateur/comic_book/Books/v1/ComicBookV1BW.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v2/ComicBookV2BW.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v3/ComicBookV3BW.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v4/ComicBookV4BW.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v5/ComicBookV5BW.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v6/ComicBookV6BW.pdf
http://www.icomamerica.com/en/amateur/comic_book/Books/v7/ComicBookV7_BW.pdf
72 de Larry W2LJ
QRP - When you care to send the very least!






















