Ham Radio - A 160 meter end fed half wave antenna on 630 meters?

Ham Radio - A 160 meter end fed half wave antenna on 630 meters?

 

Another TBT special. And front page news no less.

 

Why does this guy consider an "Un-Un", usually of silly ratio (obviously guessed!), to be the be-all and end-all of ALL antenna matching issues ? ?
(Will someone please tell?)

In this latest case we are starting with a 1/8th wave radiator, so it just needs the loading coil inductance calculating to go on the end of it (and there are several calculators on the internet which will do that for you), and then, more importantly, you should start racking your brains as to how the heck you are going to achieve the required grounding and/or radials for this very low frequency. (Maybe several linked 4x4 Jeeps plus his camper van buried 10 feet in the ground, could be the initial starter? - given that years ago we used to use things like a couple of old metal double bedsteads and several zinc baths plus loads of chicken wire under the lawn and flower/veg beds, and that was just for 80M and 160M).

Sorry to be nasty, but I now consider this guy to be purely an egotist who only makes these videos for his own notoriety on YouTube
Sadly, his knowledge and technical ability is limited, which makes his videos non-informative.

Most of us old-timers have had superb ideas over the years, some have even gone as far as experimentation, (that's the core of our hobby!) but most are rejected within minutes when we start to look again at the technical basics. If it does end up being built it's usually a case of "well it resonates, it's an acceptable SWR, but the darned thing is as deaf as a plank of wood and it don't radiate even to the end of the street! (And so, back to basics again! It's also a good idea to have a closer look at earlier antenna designs from the 1930's to 1950's. If you have the space, some of these, even compacted slightly, may be worth looking at for this very low frequency. Modified curtain array anyone?))

 

There is a lot of that going on now days....

WQ4G

 

tisk tisk shameful,Your negative and you are nasty...because for some new ones to the new bands needs basic ideas to try..and this is a good one to WORK with.
SO if it works it works. When some thing works who cares how you got there it works..The video is great and informitive and it does work. great idea,super experiment........

 

If someone made a video about "experimenting" with a square wheel, it wouldn't be "shameful", "negative" or "nasty" to point out how obviously ridiculous such an idea would be. The claim could be made that a square wheel "works", but that would ignore the fact that a round wheel works MUCH better.

Ignoring established scientific principles is not "experimenting", it's being ignorant of readily available information. Antenna technology is not an unknown frontier that needs further experimentation, the basics have been well established for many decades. The fact that certain "antennas" seem to work, merely illustrates the fact that it's very difficult to build a perfect dummy load.

Encouraging the posting of unscientific nonsense does a great disservice to those who want to learn about antennas.

We need to quit giving out "gold stars" and "participation trophies" for BS.

 

buried school buses work great too minus the people inside. Bed springs..heh..there ok, not good for mom's tv.

 

word of caution on buried vehicles for ground systems. Some people have used them as a sewer systems and when you have ground system attached to that buried vehicle, you signal may or may not smell or look funny.

 

nice! I live in a 160 room hotel and the metal roof is about 12oo feet long,wonder if loading up the roof would work on 630? It surly would on 160 anyways, but don't think I'd ever try it.

 

Some hams may have a misconception about "ground". Unfortunately, the word "ground" is used in more than one way in ham radio. When used in reference to a vertical antenna, it's really a counterpoise that we're talking about, it is completely different from a DC "ground" or an electrical system safety "ground". The purpose of an antenna counterpoise is to prevent the signal from being absorbed by the lossy Earth, in other words, being absorbed by the "ground". Connecting one side of your antenna feedline to a good DC "ground" does NOT do the same thing as connecting it to a good counterpoise. An effective counterpoise should be AT LEAST two tenths (2/10) of a wavelength long, and you need 16 to 20 of them to even have a mediocre amount of efficiency. 60 to 120 radials, .2 to .25 (1/4 wavelength) long are generally considered to be a decent counterpoise. Substituting ground rods or large amounts of buried metal does not achieve the same results as a counterpoise, they are a good DC ground, but they are NOT an effective counterpoise.

http://www.vias.org/radioanteng/radio_antenna_engineering_02_05_01.html
http://www.vias.org/radioanteng/radio_antenna_engineering_02_05_02.html
http://w8ji.com/counterpoise_systems.htm

 

I agree 100% percent I watch all of Kevins Videos and have learned quite allot. and as for an Antenna working, I'm a big one for "If it works Great, who cares how you got there to get it to work..." My HF Antenna Started of as a 40 Meter Band Antenna usable up thru the bottom part of 10 Meters.....I eventually added another 120 feet onto it by using 2 coils of 90 and 120 turns of RG-58 Coax on one end a 4:1 BALUN at the Appex and another 35 of wire added to the coils end which allows me to tune/match down to the mid 160 range, (1856 - 1999Mhz). the coils are making the Antenna Electrically longer than it actually is....with a tuner it works great contacts all over the world running Barefoot at 100Watts with a Kenwood Ts-430S....so if it works it works, a pieced together antenna is better than NO antenna.....Right?

 

My Rhombics receive pretty good when terminated on the 630 meter band. They're a Traveling wave antenna like a Beverage. I copy a number of the old NDB's navigational beacons that are still active around North and South America.
Each of the rhombics are a half a mile long each and 100 ft high, they might load up on 630 meters but they wouldn't radiate worth a flip.

 

You answered your own question:

A quote from the video: "I had the 49:1 ... um ... transformer, match, unun, whatever you want to call it"

I don't believe you're being nasty. Direct? Yep.

At least he appears to be a nice enough guy and doesn't come across as an arrogant know-it-all - like some folks 'round these parts...

He sure isn't alone in being notoriety-starved: https://tinyurl.com/ycdwxbur

 

Now you've gone and woken up Chip. Time to don the asbestos, friend.

 

Just do the experiment at sea.....and plant your earthing rod in the water....and Bob's your uncle!
I love ideas, experimenting & "pioneers". Keep on going!