10k.Boy was i wrong!

[mrcoily]

SWR meters have no idea what reactance is. Can't measure it, doesn't know when it's there, so can't tell you anything about resonance.

I hear ya Doc. Are saying that if I have a reading of zero reflected power - I can still have reactance in the load at that frequency? It’s my experience that reactance causes a faster rise in swr from the resonant freq. than does a change in resistance alone. Is this wrong? Please advise.

I must disagree about the performance of different metals (skin effect) at very high power levels especially the steel. I know they make broadcast antennas out of plated steel. But I have made steel whips come to a glow with high power. It happens about 2-3ft up from the base! Aluminum does not do that, although the diameter is usually larger on the aluminum. What else would explain that?

73's Wolf

Hi wolf i have to totally agree with you on the steel issues..
That reminds me of mobile tests we did @20kw levels the aluminum itself, shafts and coil up to the tip would stay perfectly cool,But the stainless stinger itself would get warm about 2 inches above the stinger setscrews. i think another 10 thousand may have given us the glow,maybe even a melt down that would have been cool to watch! it was day time so who knows, but the aluminum transfers the heat very well, the stingers not so well,I think the heat just loads up as it drops down from the larger aluminun to the harder 17 - 7 PH 302/304 Aniloy8,steel surface.Its very hard stuff high densisty at a molecular level,There are other things that can also have alot of effects on this like Finishes,Centerless ground, ,Passivated, Electro-polished, Polished Black chrome,Bright drawn ,Black oxide all these finishes can have tremendous affects on how the wattages transfer up the antenna.Anyway aluminum in not compact and breaths alot better on the heat side, I don't want to write a book but you pegged it on steel it sucks litterally as far a wattage tranfer goes.The Mfj it's a great tool for getting it real close everybody should have one i also have several they all read close about the same i even had a guy key up one day and smoke a mfj That sucked :evil: ,I am sure you already know all this stuff been at it longer than me,Even with a perfect score on the mfj of 1.0.1 and .01! i always ended up retuning the antenna{s} for best reflection and sometimes ending up with a 1.2.1 on the mfj and and no reflection on the real deal bird meter?? I wish a person could just tune it for lowest reading and call it good but when you dump the fire in the wire seems to really throw all that out the window, if there running a few hundred not that big an issue, you know how it is if the antenna is not showing a perfect flat 1.0.1 swr with no needle movement well then it's no good,,i know right now on my saburban i have zero reflectioin not even a quiver on the bird meters!But the mfj show 1.1.1 almost 1.2.1 but i can retune it down to 1.0.1 and .01 and get reflect in the birds..LOL ..anyway 73ss..Wolf nice antennas also have a super fine one...Coily

 

[Marconi]

Hey Coily, do you think trying to get that little DC milli-volt current out there to the end of those tree trimmers you build using an MFJ might be why you see that little difference between the analyzer and the bird under fire, to say nothing about tolerances in electronics?

That is one heck of a tune you boys get with them things.

 

[W5LZ]

Wolf,
Yes, that's basically what I'm saying. An SWR meter compares the current or voltage on one side of it with the current or voltage on the other side of it. That current or voltage comparison is directly related to the impedances on the two sides of the SWR meter. And since there can be a number of rectance+resistance points that will produce the same affects as a 'perfect' SWR reading, then there can be reactances present (a definition of resonance is no reactances, right?) indicating nonresonance. One of the properties of reactance is that there is no power developed across it. That sounds good, but it really isn't, since it also means that there are losses associated with the reactances, and that means that all the power just isn't getting ~to~ the antenna to be radiated.

About the continuity of metals. (I'm not disputing that your example with the 20kW and steel getting hot, or that it wouldn't be a 'bad' thing to happen.) I am saying that it's about as relavent as feeding a mouse a ton of sugar, the mouse getting cancer, and saying that sugar causes cancer. Except in very rare instances, ain't many mice that ever eat a ton of sugar. As to why it happened (the antenna thingy, not the mouse), same reason that trying to put 100 amps through a 0.0001 inch diameter wire will make it get hot, too small a conductor for the amount of current present. And remember, I said 'practical' differences in conductivity of metals. Sorry, but 20kW is about as practical as me winning the lottery - lol. What it amounts to is nothing, for the average radio user... same as my lottery winnings...
- 'Doc

PS - I know theres a lot of exageration in the above. But, when you boil it all down, not as much as it might seem.

 

[The Toolman]

and the beat goes on.....

Wow what a useful post. :roll:

 

[Marconi]

Hey Toolman just tell 1222 that the band left over an hour ago, and they did so because they didn't understand either. Did he miss the buss again?

 

[The Toolman]

Hey Toolman just tell 1222 that the band left over an hour ago, and they did so because they didn't understand either.

Marconi does have a sense of humor. LMAO

 

[WolfRadio.com]

Doc,
I see what you are saying…. I never thought about it quite that way – comparing one side to other, because that’s clearly what is happening in a forward/reverse meter. I guess in that regard there not to reliable, not to mention they will give a different reading depending where they are located in the line if reactance is present. (Right?)

Don’t worry about the exaggeration….proper use of it is a good thing, you can expect some from me as well. And the analogy with the mouse, (lol) I think I have used that one before. Anyway point well taken. There is a significant difference in the diameters. Most aluminum antennas start at half to five-eights and go up from there.

I was curious about the actual amount of current present at 20Kw’s? If I have the right formula:
(I = the square root of P divided by R.)
That’s 20 amps of RF at a potential of 1000 volts! I wonder what the voltage would be at the hi impedance end? I pity the fool that’s standing to close when it’s keyed.

Check this out… FLAME ON with 9000 watts! http://www.wolfradio.com/images/Plasma1a.jpg

One more thing about reactance, I don’t know how many others my have noticed this but the power companies put huge caps in series with the electrical grid in key spots to cancel the reactance caused by large inductive loads – in an effort to correct the power factor. Isn’t that like tuning the swr of the power lines? (lol) I believe a poor power factor causes the watt-hour meter to read slow.

Sorry for derailing so far from the main topic. I believe we were talking about how stainless steel whips are not that good.

Buy the way ….This is what I used to “make her glow”!
http://www.wolfradio.com/images/m5-264a.jpg
http://www.wolfradio.com/images/m5-264b.jpg
http://www.wolfradio.com/images/m5-264c.jpg
http://www.wolfradio.com/images/m5-264d.jpg


Mr. Coily, I’m waving…….

Wolf

 

[fortymobile]

LoneWolf TN i hate to say it but Fords Roofs suck trust me its a floting ground...... please do this test put the magmount on the hood and watch the swr's drop to 1.0 ... the foof is not tuching the rest of the truck it is not a ground... Ford put glue in between the top of the roof .. You have to pull the head liner down and run 4 straps and the 10k will be the best thing you ever seen in you life

 

[mrcoily]

[/quote]
Mr. Coily, I’m waving…….Wolf[/quote]

Hi wolf,,,i was wondering what size if any corna tip you had on the flame on picture,and very nice antenna melting amp!,,when we were playing 20kw i had a massive 1/2x1/2 corna tip to keep the flames at bay.
And the antenna itself was a 1" thick wall shaft with 1/4x1/4 solid square coil with a .200 thick stinger,could have held alot more.High voltages for sure! We had fun a while back cooking hot dogs on the stingers..Even better get a sucker to hold on to the whip "LOL" Now that funny ,,i remember about 7 years ago we used to haev a pizza party and all the locals would hit the round table pizza and meet up and show off there new toys back when The cb was actually fun and not a bunch of tweakers with echos and dead key contest base station"another subject" Anway a guy had a TNT 12pack and he had a light taped to the stinger fish tank light and we were watching it modulate as he talked one of the guys thought he would be cute and hold the stinger for a quick key to see? I stood back and smiled and waited...OOHH My he burt the skin on his fingers when the guy keyed up..tell you what i can;t remeber ever laughing any harded then when i looked at his finger and told him?Whate the hell were you thinking there high voltages running...Its funny how many people call me and also think that only the coil radiates when the entire antenna radiates...Anyway Thats a great pictures of the flame on.
I would love to hear what you think Wolf of flat coils and round coils as i know for a fact a flat coil radiates horizontally even though It is a vertical element it does minipulate the way the signal comes off the antenna and gives it a lower angle of radiation,At least this is what i have come to find.Especaially on my base antenna when i changed over from a small round coil on the base matching system to a large flat coil i had to change the entire feed system to keep the flat coil from working against the coil input vertical stub were it feed to the dc grounded coil..Man That is one beast to build..anyway it was creating a high swr as the Flat coil was throwing more signal horizontal off the large flat surface...I think it is the better way Mobile or base Everything must mirror itself...Anyway i have to run very busy with shipping today,,i have to watch myself as i tend to get burried if i don't keep up with the fun parts boxing and shipping...73ssss Wolf......Coily

 

[WolfRadio.com]

Mr. Coily, I wasn’t using one on that antenna…… I wanted it to arc!!

Wolf

 

[mrcoily]

Mr. Coily, I wasn’t using one on that antenna…… I wanted it to arc!!

Wolf

Have to love them arcs!

 

[WolfRadio.com]

Have to love them arcs!

It's funny you say that....cause I do!! When I was a kid, the only thing that attracted my interest more than radio was High Voltage! Images of: Jacobs ladders, Tesla Coils, and Van De Graffe generators were in my head at all times. I was obsessed with it........Dude!!.......I got some stories. We will talk more about this later.......

Wolf

 

[mrcoily]

Have to love them arcs!

It's funny you say that....cause I do!! When I was a kid, the only thing that attracted my interest more than radio was High Voltage! Images of: Jacobs ladders, Tesla Coils, and Van De Graffe generators were in my head at all times. I was obsessed with it........Dude!!.......I got some stories. We will talk more about this later.......

Wolf

Sound like a blast...I love talking about LARGE exsplosive watts and high voltages...Thats why we do this is to play and in my case do what i love build small and moster Antennas and drop massive wattages!Jacobs ladders are great my buddy has a 3 foot tall one nothing like filling the room with the smell of real electricity in the air...very cool...I have to say that is one nice steel tuber you have very nice..What the output rating? I am not sure if you said i don't really read thru this stuff all the time kinda just surf thru it.

 

[Moleculo]

when i changed over from a small round coil on the base matching system to a large flat coil i had to change the entire feed system to keep the flat coil from working against the coil input vertical stub were it feed to the dc grounded coil..

What else changed when you changed the nature of the coil? Did the diameter or length change? Did the spacing between the turns change? I suspect something else changed, which caused the inductance to change, which would be why you had to retune it. I don't believe that there's not a whole lot of difference between flat or round coils when it comes to radiation angle or any other significant performance factor.

 

[mrcoily]

when i changed over from a small round coil on the base matching system to a large flat coil i had to change the entire feed system to keep the flat coil from working against the coil input vertical stub were it feed to the dc grounded coil..

What else changed when you changed the nature of the coil? Did the diameter or length change? Did the spacing between the turns change? I suspect something else changed, which caused the inductance to change, which would be why you had to retune it. I don't believe that there's not a whole lot of difference between flat or round coils when it comes to radiation angle or any other significant performance factor.

Well you know i kinda thought that at first also.. when i tried changing to the larger flat coil ..Then it went from 1.0.1 to 1.4.1 ..The length of meterials did not change so the actual coil and overall antenna tuned out the same height ..but what i found is the Larger flat surface could see the vertical feed of the connector to the coil ...so i dropped the old feed section off and installed my coil tap jig back on the antenna so i could see if maybe i had it wrong but No, it was on 1.0.1 with the coil tap?..so i made up three differant length arms to move the vertical section out till i found it dropped back to 1.0.1 and thats where it is now.It was simply reflecting off the large flat surface,,telling me it is radiating better horizontally...making me move it out to a point where the reflection dropped off the coil and the 1/4" vertical stub that connects the coil to the coax...i have to run Beer and Pool night...73sss Moleculo :twsted