Marconi's video comparing the Gain Master vs. AstroPlane

[Marconi]

I hope this video comes out clear and OK, I'm still trying to figure the new stuff out. Here and am comparing my Gain Master at 55' feet to the tip to my AstroPlane at 28' feet to the tip.

The difference in height is due to winds Saturday I talk about in the video. My guys setup was not taut enough. I plan to raise it up today and do another similar video with the AP at least 48' to the tip. That's as high as I can get it right now.

YouTube - Marconi Comparing Signals

 

[jazzsinger]

i think the biggest issue you got there Eddie is trying to compare signals on SSB, you'd get much more meaningful results using a constant carrier mode like FM where signals are far more stable.

also with the SGM being almost twice the height, it's gonna see a very different horizon to the astroplane.

 

[gamegetter]

appreciate that

and awaiting the next test at 48'

 

[AudioShockwav]

Eddie,
Do you have someone around you, that even if not involved in radio, that you could put a simple antenna up and a radio of some kind .... temporarily ..... you can put a brick on the key and use it for a solid RX point?

Thinking out-loud here.
73
Jeff

 

[Marconi]

and awaiting the next test at 48'

Thanks gamegetter.

Of course you're right on all counts. I can't get any cooperation to do FM or any other kind of antenna testing in this area with the guys I know. They're all on LSB and are very hard headed about what they like and don't like, and antennas is not one of the subjects they like.

I do go to AM channels and try to get some signals, but on 19 the guys just make comments and are too quick on the key, and this also happens of several of the other popular frequencies that are still around here. Believe it or not, there just isn't much traffic left in the Houston area anymore. The young guys do other things with all the new technology these days.

Here is a picture of my AstroPlane raised up to 48'5" to the tip with the GM @ 56'2" to the tip. The AP is about 36'8" feet to the bottom hoop and the GM is 33'8" to the top of the coil, with the GM about 8' higher at the tip.



I did a video of the AP while I was outside raising it up using the 27.100 mhz beacon. When I got inside I was very surprised that I was just barely hearing the beacon signal at all on the AP...and with it raised up. I was expecting to see a nice signal increases that was about equal or better than the GM, but that didn't happen. I flipped the switch to the GM and there the beacon signal was, just like the earlier video showing a tad bit less than S3.

I took a deep breath and asked myself why is this? Did I pull the coax loose from the antenna while raising? Nope the SWR was great. I switched to channel 19 and the voices and signals on the AP were there and looked and sounded fine. I then switched to the GM, and both signals were very near the same with just about every transmission.

I asked again, what the heck is going on? I've seen some strange things with signals at times, but this beats all.

I don't know what this strange occurrence could be except a polarity difference that would make that strong of a difference. IMO the AP does show a good horizontal response at times, and maybe even all the time, but I can't always notice it with signal or audio. When it happens though, it is pretty obvious on the RX end of the transmission.

I am making another video with the AP at 48' vs. the GM at 55' which I'll post it here as soon as I can get it on YouTube.

 

[Marconi]

Eddie,
Do you have someone around you, that even if not involved in radio, that you could put a simple antenna up and a radio of some kind .... temporarily ..... you can put a brick on the key and use it for a solid RX point?

Thinking out-loud here.
73
Jeff

Probably could Jeff, but that would only give me a short range signal check and I already find that close signals may not be as reliable as those at some distance. The meters do not appear to be very linear, and that may be due to the AGC affects.

Until I saw the video, I was thinking the beacon would be pretty much what you described Jeff, but now I'm not so sure what is happening.

The results I got a few minutes ago, just baffles me and I will post the Video in a bit.

Here is the video of me recording while raising my AstroPlane with the beacon at 27.100 mhz. Boys, it is what it is. I don't understand it, but in order for us to see such a strong signal difference, it might be a polarity thing if the beacon is vertical and the AP responds well to horizontal signals. I have realized this horizontal thing with my AP before and it was remarkable to see, but it happens every seldom.

http://www.youtube.com/watch?v=0m_j8DJze4Q

 

[MrSuburban]

Can anyone do a test with 1 antenna up by itself not effected by another in the near field, then switch antennas using exact same coax and mounting location, otherwise watching these videos of s-meters is really point less. Nothing is the same we aren't comparing anything. Thats why these antenna pages are 48+ pages and counting. Willy go Round in Circles. Not a knock on you Marconi We appreciate the effort but if the effort isn't leading to anything productive why not focus on one. I would go so much as put a antenna up test it for a few hours or days take readings of different scenarios. Then replace the antenna with another test antenna, same coax, same feed point height same mast everything. Now I know the atmosphere changes things but Joe blow up the street gives you a 9 everyday with antenna X how many times has his signal changed during the course of a day? Put up the other antenna and do another day or 2 of testing. You will get better results than antennas at different heights, antennas with different coax, and antennas near each other. Well thats what I would do.

 

[Marconi]

Last night I was set up to do another video with my GM vs. AP, but someone call me on the radio. I keyed up to returned the call. I was on the AP and transmitting badly thru my computer speaker wire.

That had not been happening with my antennas in a very long while even with power on. I checked my antenna switch again and for sure I was on the AP. I switched to the GM and no problem which was a relief.

If you'll recall in the "raising up" video, I was very surprised when the signal went down instead of going up, maybe stunned is the better word. However, during the process of raising and at some point tugging hard with the last section, I did snag the coax on my ladder and put a tug on the feed line. I recall thinking that I could have pulled the coax loose at the connector, even though I have the cable well taped to the 12' foot mast at several points. I think you can even see the vinyl tape in the image I posted. I checked the SWR immediately and it was fine, so I reasoned the connector was probably OK. However, I'm thinking now that maybe I damaged the feed line when it snagged on the ladder, and such might not show up on SWR.

I won't know about these issues until I get the AP down, which I hope to do later today while checking the coax too.

As old William Benedix used to always say on his TV show, "The Life of Riley, "...what a revolting development." My plans are foiled again.

I'll check this all out and hopefully I'll find something obvious. My AP has always been very well mannered, excepting when everything was not good and tight...and then it made some terrible TVI, similar to what may be going on now.​

I was thinking before this happened, that maybe I should at least put my Imax up and compare it...before I take the GM down and move it back to my new mount. The new mount seems to be a bit quieter in operation and that is good.

 

[Marconi]

Can anyone do a test with 1 antenna up by itself not effected by another in the near field, then switch antennas using exact same coax and mounting location, otherwise watching these videos of s-meters is really point less. Nothing is the same we aren't comparing anything. Thats why these antenna pages are 48+ pages and counting. Willy go Round in Circles. Not a knock on you Marconi We appreciate the effort but if the effort isn't leading to anything productive why not focus on one. I would go so much as put a antenna up test it for a few hours or days take readings of different scenarios. Then replace the antenna with another test antenna, same coax, same feed point height same mast everything. Now I know the atmosphere changes things but Joe blow up the street gives you a 9 everyday with antenna X how many times has his signal changed during the course of a day? Put up the other antenna and do another day or 2 of testing. You will get better results than antennas at different heights, antennas with different coax, and antennas near each other.

Suburban, I think the answer is NO, but I'm waiting for someone to do such testing. I also agree that your idea is probably the best way, and that is why I built my new mount, so I could test using only one system at a time. The reporting will be very boring IMO, but maybe we can get the guys to rehashing all such reports and come up with a really good conclusion like JimBob saying,

"...my Imax with 20/S9 squashed my neighbors A99 with an S9. "​

When I saw the video type reports I was impressed, but in trying my hand at it, I'm amazed at how difficult it is to make the thing short, simple, and effective. More experience will surely help.​

Well thats what I would do.

Thanks for your comments, but I'm waiting and hoping for you and 007 to do some testing and reports for us too.​

 

[MrSuburban]

Suburban, I think the answer is NO, but I'm waiting for someone to do such testing. I also agree that your idea is probably the best way, and that is why I built my new mount, so I could test using only one system at a time. The reporting will be very boring IMO, but maybe we can get the guys to rehashing all such reports and come up with a really good conclusion like JimBob saying,

"...my Imax with 20/S9 squashed my neighbors A99 with an S9. "​

When I saw the video type reports I was impressed, but in trying my hand at it, I'm amazed at how difficult it is to make the thing short, simple, and effective. More experience will surely help.​

Thanks for your comments, but I'm waiting and hoping for you and 007 to do some testing and reports for us too.​

This time of the year is out for me with the snow on the ground, unfortunatly my Vector is mounted on a tower and when I had it down low and compared it to my starduster it had a 2-3 s unit agin , bu since there was nothing the same with each antenna it wasnt worth me giving the results becasue they would be meaningless, it was interesting at the time switching between antennas. I give ya credit for what you are doing it get's to be too much like work, thats why I suggested testing the antenna for a week and doing the same with the other this way it only has to be changed one time. You can actually sit there and enjoy the radio. Thanks for the update. What are you using for mast etc ? Push up poles?

 

[GnG8d]

Do near field obstructions effect RX only tests?

 

[Marconi]

This time of the year is out for me with the snow on the ground, unfortunatly my Vector is mounted on a tower and when I had it down low and compared it to my starduster it had a 2-3 s unit agin , bu since there was nothing the same with each antenna it wasnt worth me giving the results becasue they would be meaningless, it was interesting at the time switching between antennas. I give ya credit for what you are doing it get's to be too much like work, thats why I suggested testing the antenna for a week and doing the same with the other this way it only has to be changed one time. You can actually sit there and enjoy the radio. Thanks for the update. What are you using for mast etc ? Push up poles?

I understand MrS, no rush here.

Regarding your meaningless results thought, for which I might agree. My question is; would you expect if you raised the SD up as high to the tip of the Vector...that you would probably see a similar or better signal with that little old SR? That is my only message on the height and comparison matter. I do agree with you...it just is not a practical approach for the typical CB'r to get the SD up higher than the other antenna, so in that case it also makes comparing both at the same feed point meaningless as well and I believe that was your point.

You also might recall in my testing, even when I do set my antennas at the same height to the mount...my results are most often not near as different as you and others have seen at your locations. Except maybe for the soil conditions differences...I can't explain why that is.

At my age and with my desire to do stuff myself, and when I can't, I choose not to do it at all. I also use 40' foot push up poles. I can still work on them buggers with all of my verticals...even from a small ladder when necessary.

Do near field obstructions effect RX only tests?

359, near field may even be worse depending on the obstruction. My experiences have all been far field and I still see it affecting both TX/RX. I use to have a good buddy however, that lived about three blocks behind a high rise building and he could not TX/RX to hardly anyone in that direction.

I can't be for sure, but I believe to a degree stuff that blocks signals and are pretty evenly spaced between the stations has a similar affect on both stations in the far field. If the obstruction is closer to one than the other, it makes sense that there might be some differences to be noted. However, when I talk to guys that seem attenuated to my receiver they tell me that they see the same with my signal we often can figure out that it might be something blocking us in between.

In one case it happens that I'm about 15 miles due south of a tower company with a close group of three 1000'> towers positioned broadside to me and mounted east to west on their property. David is about 3 miles further North on the other side. I can't be for sure, but I figure these towers are the culprit blocking our signals. I hear him a little and he says the same about my signal. Others around him confirm a similar interference and attenuation while others say different regarding his station. I don't seem to hear the same about my station. Yes I think it can affect both TX/RX, and a lot has to do with the angle or reflections in each case. Some reflections may even add to David's direct signal when the angles are just right...and then the guys involved might even see opposite increase in signals.

It's like knowing how to shoot pool well or not, the angles really matter.

 

[MrSuburban]

I understand MrS, no rush here.

Regarding your meaningless results thought, for which I might agree. My question is; would you expect if you raised the SD up as high to the tip of the Vector...that you would probably see a similar or better signal with that little old SR? That is my only message on the height and comparison matter. I do agree with you...it just is not a practical approach for the typical CB'r to get the SD up higher than the other antenna, so in that case it also makes comparing both at the same feed point meaningless as well and I believe that was your point.

Marconi, if I raised up the SD to the same tip height i would be giving the SD a advantage, how much I cant say without a model. Altering the feed point height makes a big difference in ant gain etc, By not testing them at the same feed point you arent comparing them apples for apples. Here is a easy solution to those buying antennas save your money and just raise your antenna up higher, you will get the benefit of free performance. Compare it to mobile antennas a 102" whip normally will have a advantage over a coil antenna if they are mounted properly etc in same location, raise the coil antenna up and it now beats the 102" whip. Is it a better antenna ? NO!

You also might recall in my testing, even when I do set my antennas at the same height to the mount...my results are most often not near as different as you and others have seen at your locations. Except maybe for the soil conditions differences...I can't explain why that is.

IMHO, You arent seeing a big difference because you(along with everyone else) are tesing them using a S meter, everyones smeter is different, you are using better radio's than they are from what I have seen in video, typical S meter is who knows what but lets use 4-6 db per s unit. The difference in antennas is supposed to be what 1-2 db? thats a half of a S unit if you are lucky. Throw in a loosely calibrated meter and you will see more signal. As long as you see an improvement thats all that matters, readings are all relative as you cant compare your 2 S unit gain or decrease to mine or anyone else's, were not working with the same test parameters. I dont wanna blame your soil either because it is the same for both antennas.

http://www.seed-solutions.com/gregordy/Amateur Radio/Experimentation/SMeterBlues.htm#Introduction

 

[HomerBB]

I think:

1. Practically speaking, most folks will just mount an antenna on the present mast/pole. So comparing antennas in that way is valid with respect to how someone who can't/won't change their mount can benefit from this testing.

2. Testing antennas at the same total top height is also a valid test because some people will adjust their mast/pole height if an advantage to a given design is indicated by this kind of test. This is information they would like to know before they purchase additional antennas.

3. I think the test of antennas at the same feed/mount point is valid because it is in most cases virtually the same as #1.

4. I think testing antennas by setting each at the point where they radiate their peak RF to the same elevation is the most reasonably accurate way of comparing the designs of each antenna, as this is where the rubber actually meets the road. However, given different antennas exhibit different properties at different elevations/heights, things like TOA, influences of earth effects, etc. there will rarely if ever be an absolute understanding of which antenna is superior to the other except in the particular locations they are mounted and operated.

SO, although I am enjoying the discussions and the information I am learning, and particularly the fun I am having building and raising antennas to try out, I know the eventual real test of an antennas efficacy will be which one gives me (or you) the best results at my/your QTH.

So pick either of the scenarios, and consider which fits, and then have the imagination to encompass the variety of results being experienced by different folks. That's the way it really works.

I think.

 

[Henry HPSD]

Homer Quote:
4. I think testing antennas by setting each at the point where they radiate their peak RF to the same elevation is the most reasonably accurate way of comparing the designs of each antenna, as this is where the rubber actually meets the road. However, given different antennas exhibit different properties at different elevations/heights, things like TOA, influences of earth effects, etc. there will rarely if ever be an absolute understanding of which antenna is superior to the other except in the particular locations they are mounted and operated.
End of Quote:.


Hello Homer,

I would like to add to that.

Say you would like to compare a Quad with a Yagi. You must place the yagi at the center heigth of the Quad. As that would be "fair" in regards to how much they where radiate, so i would say your correct!

The problem lies with verticals in two things:
Antennas wich use the buttom part to "gain" heigth and are used for "matching". A J-pole is a famous example. In such a case the physical center of the antenna wouldnt be the physical electrical heigth.
The second problem is those "DX" tests wich include different electrical length antennas (1/2 wave versus 5/8 wave) those are just notas usefull..as we are speaking off different antennas.
The TOA are different. It wouldnt be fair to compare a car to a airplane though theyre both "ways" of transport.

In aspect to the rest, im not to afraid about it.
The direct Groundeffects influence the antenna upto many wavelengths away from the antenna.
That means that is equal to the ones under tetst. They are both seeing the same "ground".

We all know that vertical antennas perform worse when groundconductivity gets worse.
And we also all know that the higher one placeses a antenne the less significant these ground influence become.
But again, those influence are equal to the antennas under test.
So no mather where you place two verticals if the tests are done correct, results will be equal.

It is the difference in "test" methode witch will give different results.
For example a test with a station say 10 miles away is wrong. This is cause everything between those two stations will have influence as it is a "direct" line of sigth communication. Buildings/trees/mountains/cars etc, will change the signal.

As mentioned before any test with a fieldstrength measurment direct near the antenna is meaningless, as the Farfield hasnt esthablished yet.
In the nearfield things happen to a antenna in such a way the real "guru's" still dont agree.

So that leaves only two options open for fair "no laboratory" testing.
1- Direct line of sigth without anything in between. several wavelength away.
2- Real DX. (granted you have a a clear spot to put your antenna preverbly upto about 330 feet around..)

And ofcourse the antennas under test at least 1 preferebly 2 wl apart. Using two identical receivers at the same time. and switching them...just in case

Now, since most of us dont have such a beatifulll spot...there alway will be different results. Those who do and give therefor the most accurate results, will always be under fire...
As the next door neighbour who doenst understand a thing, thinks differently...
Sadly it turns out neighbour is always on the air and spreading "the word" ...

A never ending story m8....

Kind regards,

Henry

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