Update on the Longwire


Figure 1: Nicely wound transformers (not my doing tho LOL)

So, I’ve been using the 75.5 foot (23m) longwire for a couple weeks (the length of the wire was picked by the analysis conducted by VK6YSF on his site, with the goal being to find a wire that was not too long (<100 ft) and could be an easy POTA Qrp antenna).  On forty meters and lower, I guess it’d qualify as a shortwire antenna hihi.


After some fussing I settled on a 60 foot counterpoise to go along with the antenna. Then I added a triple rod earth ground on top of that (driven down at the antenna feed point). The photo shows the 1:1 current balun that I added to the 9:1 unun already in the box).  IMO the 1:1 current balun was needed to reduce mantle radiation and RF coming back into the shack.  According to my understanding, current baluns can perform dual service as ununs). Before adding the 1:1 balun, I had mantle radiation and some noise in the receivers. Afterwards, both seem to be gone.

Even with my dipole and its choke balun, I usually have at least a couple hundred milli-watts of reflected power. With the balun/unun combination on the longwire, the tuner is able to make the SWR absolutely flat: zilch, nada reflected power, and no receiver noise. It works a treat IMO. However; the radiation pattern is pretty high when the wire end is low to the ground. VK6YSF has the antenna a few meters off the ground, because he was trying to emulate POTA conditions where one might not have a high anchor point for the end of the wire. Raising the end of the wire (to maybe 30 degrees) – lowers the radiation angle, and gives better results.

Note that, due to the high voltage nodes, I’d never run the wire with more than QRP levels of power. So, a lot of hams are using EFHW antennas, which would seem to be limiting in the number of bands that could be used. The only band this antenna will not tune is 17m, and I have a nice loop for that band.

Man, I love the balun winding. I didn’t do it myself. A nice Ebay store owner did it for me, and wow did he ever to a good job of it. Both of the transformers are double core – good for big power on another antenna (but not the end-fed longwire we’re discussing here tho, LOL).

I absolutely love the hybrid (1:1 balun + 4:1 unun) from BalunDesigns that I put on the 17m loop. It works a treat. I wish I could post photos of the windings, but the thing is too high to reach at the moment hihi. With the hybrid setup, I seem to be able to tune a number of bands (other than the 17m target band) to a flat SWR on the loop. The performance is pretty miserable on other bands though, and I suspect that all my power is heating the cores. They tell you NOT to do this sort of thing on their site LOL.  As usual, none of this is advice, since I could be entirely full of it.  Best 73’s – Ron/WB8LZR

Triton and Me: Back together Again

Figure 1The Ten Tec 540 is playing love songs again

Four times I courted her.  Three times I dropped her.  This time it’s forever.  Over the years, I’d managed to find myself paired with the one whose songs were so delightful, whose voice stuck in my memory for the whole day long.

Impressionable and easily infatuated, my young mind learned of the CW siren, that seductress of the airwaves.  Long into the night, I listened to her soft messages, sometimes drifting off to sleep with my hand on the key, eventually slipping into one of those sweet dreams of hamdom.

Read more of the Ten tec 540 …

Junk or Joy? Heathkit GR-78 Amateur / Shortwave

Figure 1:  The venerable? Heathkit GR-78 receiver, as it was found in flea market.  

What ham can resist the allure of a piece of vintage gear, sans cover, knob, and a part or three, looking ever like the cartoon character with sprigs of pointy hair wires protruding from it, and connected to nothing?  When we go to ham swap ‘n shops, we brace ourselves ahead of time, lest we not load our trunks with the contents of theirs.  We have time in such cases to revisit the vision of our junk corners at home, and the XYL’s displeasure of same.

But …

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Unboxing a Forty One year old Ham Radio

Figure 1: Unboxing another Alda 103

Another Alda?  I’ll admit to having an affinity for them.  The one I already have is the 80-40-15 tribander (the 103A) – and the one I’m unboxing is the 80-40-20 tribander (the 103).  The package came in a solid little Home Depot box, and no shaking or rattling could be heard during a shake-test next to my ear.  The question on my mind?  Would I hear more from the speaker of the actual 103 when I finished opening the package and plugging the little gem-from-the-past into my supply?

Read More about the Unboxing …

Ham Radio on a Pi2

quiskplussdrhardwareplusraspberry-1Figure 1: Quisk running on the second “homemade” tablet, which use a Pi2 SoC SBC board. (Click to enlarge).

Some of the other posts on this site refer to my “homemade” tablet, which I subsequently outfitted with components for ham radio usage.  I recently built another “homemade” tablet, this time using a Raspberry Pi2 board for the computing power.

Read More …

Note: This author is not affiliated with the Raspberry Pi/Pi2. For information about those projects visit http://www.raspberrypi.org. “Raspberry Pi is a trademark of the Raspberry Pi Foundation.  Figure 1 contains elements of a desktop system and associated programs that have been released under a free software license (Copyright: LXDE team: http://lxde.org). As a derivative work, the respective part of the screenshot in Figure 2 falls under that same license. The full text of the licences may be found at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html.  Fig1 contains another program that has been released under a free software license (Quisk). As a derivative work of that program, the respective part of the screenshot in Figure 1 falls under the same license (GNU GPL). This site/author has no affiliation with the author of the Quisk program. The code and full text license for Quisk may be found at https://pypi.python.org/pypi/quisk/.

New (For Me) Omni-A (Analog)


I have always been a Ten Tec fan. As a kid I dreamed about the PM-1, but had to settle for home brew and (eventually) an old (even then) DX-40 transmitter / Lafayette-HA350 RX combo. When I was older, I purchased a Triton 4, and fell in love with the quietness of its noise blanker assisted audio, its filters, and its fabulous QSK. Some time ago, I decided to find another Triton (I’ve had and subsequently sold several, when I wish I’d kept them all!) The prices have crept up, as the numbers dwindle, and Ebay resellers have ascertained that hams will give blood for these units. They are made primarily of discrete transistors, with a smattering of commodity ICs, and so are relatively easy to fix in a pinch.

Read more …