“dmoore” — Fediverse search results on home.social

Marek McGann @[email protected] · 2023-02-03 · 12:02 UTC

A species is a “way of life” (Gibson, 1979, pp.7, 128, 143; Rietveld & Kiverstein, 2014; Van Dooren, 2014). These ways of life may well be characterized by...genetic resemblance across generations, morphological or anatomical features, or geographical range. ... But with the ecological approach these characterizations are quantifications derived from the way animals live (Gibson, 1979; Oyama, 2000).

#AmReading #VanDijk #EcologicalPsychology #InterSpeciesInteraction

#amreading #vandijk #ecologicalpsychology #interspeciesinteraction

Marek McGann @[email protected] · 2023-02-03 · 12:02 UTC

A species is a “way of life” (Gibson, 1979, pp.7, 128, 143; Rietveld & Kiverstein, 2014; Van Dooren, 2014). These ways of life may well be characterized by...genetic resemblance across generations, morphological or anatomical features, or geographical range. ... But with the ecological approach these characterizations are quantifications derived from the way animals live (Gibson, 1979; Oyama, 2000).

#AmReading #VanDijk #EcologicalPsychology #InterSpeciesInteraction

#interspeciesinteraction #ecologicalpsychology #vandijk #amreading

Marek McGann @[email protected] · 2023-02-03 · 12:02 UTC

A species is a “way of life” (Gibson, 1979, pp.7, 128, 143; Rietveld & Kiverstein, 2014; Van Dooren, 2014). These ways of life may well be characterized by...genetic resemblance across generations, morphological or anatomical features, or geographical range. ... But with the ecological approach these characterizations are quantifications derived from the way animals live (Gibson, 1979; Oyama, 2000).

#AmReading #VanDijk #EcologicalPsychology #InterSpeciesInteraction

#amreading #vandijk #ecologicalpsychology #interspeciesinteraction

Anja @[email protected] · 2021-01-23 · 17:47 UTC

Zelfgemaakte Pizza’s van de BBQ

Met de nieuwe barbecue zijn er weer een heel legio aan andere mogelijkheden. Michel ging vandaag aan de slag met zijn pizzasteen en maakte pizza’s vanaf nul. Dus met zelfgemaakt deeg en zelfgemaakte saus. Voor een eerste keer waren de pizza’s heel goed gelukt. Pizzadeeg Ingrediënten: 1/2 zakje gist, 1/2 theelepel suiker, 150 ml lauwwarm water, 250 gram patentbloem, 1/2 theelepel zout, 2 eetlepels olie, Roer 1/2 zakje gist, 1/2 theelepel suiker en 50 ml lauwwarm water doorelkaar. Roer in een andere kom 250 gram patentbloem en zout door elkaar. Maak een kuiltje in het midden. Giet het gistmengsel er in en roer dit door de bloem. Giet daarna 100 ml lauwwarm water en 2 eetlepels olie erbij. Kneed het deeg goed met je handen tot het niet meer plakt en elastisch begint te worden. Maak een bal van het deeg. Doe het deeg terug in de kom. Dek het af met een iets vochtige schone theedoek en laat 45 min rijzen op een warme plek in het huis. Rol er daarna pizza bodems van. Pizzasaus Ingrediënten: 500 ml gezeefde tomaat, 2 teentjes knoflook, aantal blaadjes verse basilicum, gedroogde oregano, zout, Meng 500 ml gezeefde tomaat met 2 uitgeperste teentjes knoflook, een aantal fijngehakte blaadjes basilicum, wat gedroogde oregano en wat zout. Verwarm de barbecue op 250 graden en verwarm de pizzasteen voor, dit moet zeker een half uur duren. Pizza bouwen Beide pizza’s hebben eenzelfde basis, alleen de ene is met salami gemaakt en de andere met rauwe ham. Bestrijk de pizzabodems met de pizzasaus. Beleg met plakjes champignons, gesnipperde ui en stukjes mozzarella. Doe op de ene pizza salami en op de andere rauwe ham. Bak de pizza’s in een paar minuten op de hete pizzasteen op de barbecue. Eet smakelijk!

#basilicum #champignons #gezeefde-tomaat #gist #knoflook #mozzarella #oregano #patentbloem #suiker #ui

https://www.brutsellog.nl/2021/01/23/zelfgemaakte-pizzas-van-de-bbq/

#basilicum #champignons #gist #knoflook #mozzarella #oregano

Ham Radio Outside the Box @[email protected] · 2025-11-28 · 07:00 UTC

4:1 Balun or 4:1 Unun – how to choose?

Perhaps one of the greatest confusions in the hobby of ham radio is wrapped around the subject of baluns and ununs. What are they, where should they be used and what do they do?

At Ham Radio Outside the Box several antennas that need a 4:1 impedance matching device have been described. Since I had a handy-dandy 4:1 Guanella current balun in the drawer I figured it would get the job done. I applied it to my Rybakov antenna and it worked fine business. I applied it to my Simple, Low Profile, Multiband Antenna and it also worked.

In theory a 4:1 Guanella current balun (properly wound on 2 cores) would also attenuate common mode current and avoid the necessity to add a separate common mode current choke. Like I said – in theory! To be honest, I didn’t experience any common mode current issues using this device. But then I read an article written by Joeri Van Dooren, ON6URE that explained why using a Guanella 4:1 balun is often not a good idea. The reason is quite obvious once it has been explained. If it used with a vertical random length antenna – like a Rybakov – it expects to find balance where there is none. It struggles to do its job and creates a risk of core saturation or overheating. Overheating you say? Maybe that’s another one of the benefits of being a QRP or low power operator, it ain’t gonna happen – at least it’s very unlikely.

What is a Balun?

A balun can be described as a device used to match a balanced antenna to an unbalanced transmission line. Its name derives from BALanced to UNbalanced.

The accompanying schematic diagram here shows an example of a 4:1 balun. This device will match an antenna with an impedance of 200 ohms to coax with a characteristic impedance of 50 ohms. To further complicate matters, the diagram shows a voltage balun, also known as a Ruthroff balun.

It has two separate windings on the same core. The two windings are “bifilar” meaning they are wound together, side by side. Unlike the 4:1 Guanella current balun, there is no expectation that a Ruthroff balun will attenuate common mode current. A separate common mode current choke is needed.

Note that the balun has no ground on the antenna side. The two arms of the balun are balanced. The Ruthroff balun forces equal and opposite voltages on each side of the antenna. A Guanella balun, on the other hand, forces equal currents on each side of the antenna. If we were to need a device to match an antenna that is unbalanced – such as a vertical – we would need a different device called an unun.

What is an Unun?

An Unun can be described as a device used to match an unbalanced antenna to an unbalanced transmission line. Its name derives from UNbalanced to UNbalanced.

The schematic shows how it is wired. A 4:1 unun is shown but it could also be built as a 9:1 by adding a third winding creating a trifilar construction (i.e. 3 wires wound together, side by side).

Note that the configuration is quite different to the 4:1 balun. Instead of the two arms of the antenna being balanced, one side is now at ground potential. This suits a vertical antenna with a system of ground radials.

Isn’t a Balun just a fangle-tangled Unun?

Strangely, considering their different functions, there are a lot of similarities. If we wanted to convert one to the other, a few minutes spent with a soldering iron would get the job done.

Referring to the accompanying diagrams here we can see there are three main components:

The antenna connections – either balanced or with one side grounded
The bifilar (or trifilar in the case of a 9:1 unun) inductor wound on a toroidal core
The coax connector for connection to our transceiver

If we follow the next two diagrams showing how to assemble an Unun or a Balun we can see the similarities in the two devices.

How to choose the correct device?

Once I had made the decision to “do it right” and replace my Guanella current balun with a Ruthroff voltage device, I had to choose between a balun and an unun.

Since I was out of spare toroid cores in my shack component drawers the Guanella balun had to be sacrificed. It had given good service but, in the interest of adhering to good RF physics, it was laid to rest.

The two cores each had a bifilar winding that was identical so I decided to build both a balun and an unun. My intention was to evaluate what would happen if I tried each one. The antenna on which the trials were performed was my wire version of KJ6ER’s Challenger antenna.

The science was telling me that the unun was the correct choice. Call me ‘ornery but I prefer to find out for myself. I like to test the alternatives in the big outdoor lab I call my backyard.

With both devices in my pocket I erected the antenna – clearly not a balanced antenna because the vertical wire is 22 feet long and the counterpoise is only 5.5 feet long with its far end laying on the, as yet, snowless lawn. So, first up was the balun. I didn’t expect this to work at all, but I did want to observe what the result would be. Would it be smoke, rising up into the sky, signaling my ignorant disregard for what the physics was clearly telling me?

Gadzooks!

To minimize the size of any potential mushroom cloud arising from my scientific folly, I chose a very low level of RF – you could call it “QRPpp” perhaps. The source was my antenna analyzer. To my astonishment, hitting the big button that sent milliwatts of RF coursing through the balun into the antenna produced no fireworks. Instead, with a little minor adjustment of the length of the radiator and counterpoise, the antenna analyzer showed a surprisingly good SWR. Hitting another button on the analyzer showed the antenna was resonant just below the 20m band. I like to operate CW near the bottom of the band so that would be just fine.

Next up was the scientifically anointed device, the Chosen One, the device whose destiny was ordained to become part of my field kit – the Unun. Of course it worked too.

Now let’s summarize the experimental results here. The Guanella 4:1 current balun worked – but it shouldn’t have. The Ruthroff 4:1 balun worked – but it shouldn’t have. The Ruthroff 4:1 unun worked as expected. I earned my physics degree a long, long time ago but studying for it gave me a lifelong habit of following the scientific method – as verified by my own experiments.

Of course a low SWR tells us nothing about the efficiency of the antenna system. It only indicates that it won’t drive the magic smoke out of our transceiver. The wrong matching device may result in less of our transmitted signal being radiated.

So the end of the story is I will be using the unun, confident that it is backed up by antenna physics – and my own, white lab coat wearing independent verification!

The final image shows the unun mounted on my wire Challenger antenna during its backyard trial. The larger toroid is a common mode current choke. The small one is the unun.

Note I used an FT140-43 ferrite toroid core even though many sources recommend a powdered iron core such as type 2 material. Type 43 ferrite material is not the optimum mix for the 20m band and up but it is what I had. I may have wound too many turns on the core, risking core saturation. When I tidy up the construction I may reduce the number of turns from 10 down to 8.

NB: I have been unable to find a source for type-2 powdered iron toroids. Can anybody tell me where to buy them, preferably in North America?

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#amateurRadio #antennas #counterpoise #cw #portable

#amateurradio #antennas #counterpoise #cw #portable

joene 🏴 @[email protected] · 2025-09-24 · 21:19 UTC

Dit wil ik nog even hier kwijt voor het slapen gaan. Must watch video van Tofik Dibi over de extreem schandalige Israël lobby met het #CIDI in de hoofdrol. Tofik geeft een zeer goed overzicht van hoe de lijntjes lopen, en de medeplichtigheid van bepaalde media en politieke partijen.

https://geenwoordenmaardaden.nu

De captions van Tofik's Instagram:

"De pro-Israëllobby probeert mij al jaren tot zwijgen te brengen. Het is een signaal naar iedereen die meekijkt: ‘Dit is wat er met je gebeurt als je Israël publiek bekritiseert.’ De lange arm van Israël heeft aardig wat littekens achtergelaten - bij mij en velen voor en na mij.

Deze video die begin juni is opgenomen als sluitstuk van de Geen woorden maar daden campagne is ook een duidelijk signaal. Wij weigeren in te binden, buigen of bukken voor de waakhonden van Israëlische fascisten in Nederland.

Dit is hun playbook voor íédéréén om in te zien. Iedere keer dat zij die activeren om antigenocidestemmen te onderdrukken, zijn wij er om hun handelswijze bloot te leggen en te bestrijden.

Ik dank de strijders die vanaf dag 1 tot nu naast me staan: Kauthar Bouchallikht en Joel van Dooren. …"

[verder in de alt-tekst]

#TofikDibi #IsraëlLobby #Israël #zionisme #Gaza #genocide #BIJ1

#cidi #tofikdibi #israellobby #israel #zionisme #gaza

Karen van Dooren @[email protected] · 2025-04-27 · 13:30 UTC

Zoals altijd, meer werk dan gedacht. Na het wikkelen, nu al naaiende patroon maken en zorgen dat het geen halfuit bontjas wordt, maar een diermeisje blijft. #art #contemporarysculpture #contemporaryart #taxidermyart #beverratmeisje

#art #contemporarysculpture #contemporaryart #taxidermyart #beverratmeisje

Derek @[email protected] · 2026-04-29 · 17:25 UTC

It’s the little things #smiley #smile #photography

#smiley #smile #photography