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Posted: 3/18/2012 9:42:41 AM EDT
The CQ WW WPX SSB contest is this coming weekend... Mar 24th...

Have decided to give this a go...  My current antenna setup isn't adequate below 20m, I need an effective DX antenna on 40m.

Have narrowed my options down to two...

1)  A ZeroFive 12-80m in the front yard with ground radials
  a.   (not a great option for the wife and not really ready to set all those ground radials)
  b.   (not sure I can get it delivered in time to be setup for the weekend., they are in Chicago)

2)  An elevated wire vertical in the back yard  (no room for ground radials)
  a.   (really no place to layout ground radials in the back yard, but an elevated vertical will work)
  b.   (Max-Gain systems sells a 50 ft push up fiberglass mast, they are in GA, I can probably get this in a day or two)

I have every confidence I can get the ZeroFive to work.  Neither me nor the wife are prepared for what that antenna location requries....  but, I can get it to work.

I would rather do the elevated vertical, but it is going to be a home brew project and not sure what pit falls I may run into.

Have any of you guys ever installed an elevated vertical with sloping radials???   Any and all input and suggestions are welcome.

Link Posted: 3/18/2012 9:57:48 AM EDT
[#1]
I have never built an elevated vertical for that low of a band, but I think it's a great idea.

This is coming from someone who has ground radials all over his yard at the moment and knows what a pain they can be while waiting for the grass to absorb and conceal them.

Another option with your mast would be an inverted-V which I believe radiates more like a vertical than a dipole.  Mine does a great job on 40 meter DX.
Link Posted: 3/18/2012 2:13:44 PM EDT
[#2]
Quoted:

This is coming from someone who has ground radials all over his yard at the moment and knows what a pain they can be while waiting for the grass to absorb and conceal them.

Another option with your mast would be an inverted-V which I believe radiates more like a vertical than a dipole.  Mine does a great job on 40 meter DX.

+1 concerning both of the above.  I have radials all over the back yard, but the grass is beginning to cover them up with the early spring temps here lately.  The inverted V would be the easier-to-install option, and the one I had was particularly good with WSPR also.

ETA:  The dog said to tell you hello, Mndless.  



Link Posted: 3/18/2012 3:29:24 PM EDT
[#3]
Quoted:
Quoted:

This is coming from someone who has ground radials all over his yard at the moment and knows what a pain they can be while waiting for the grass to absorb and conceal them.

Another option with your mast would be an inverted-V which I believe radiates more like a vertical than a dipole.  Mine does a great job on 40 meter DX.

+1 concerning both of the above.  I have radials all over the back yard, but the grass is beginning to cover them up with the early spring temps here lately.  The inverted V would be the easier-to-install option, and the one I had was particularly good with WSPR also.

ETA:  The dog said to tell you hello, Mndless.  



It wouldn't be a complete picture without the dog!!    

Have been playing with 4nec2 a bit this afternoon...  part of the complication is I really don't have a target area to plan around...   the contest is points for other countries and other continents...  well... that doesn't help a lot...  with my 100W and 40 meter band I don't think I need to worry much about Europe on 40m... so we're looking at the islands, S. America and Canada, I guess.

I know there is software that will help you determine the best departure angle, height and distance...   but, this is all a toss of the coin right now.

with 4nex2 ..the inverted 'V" on 40m... if I can get it up high enough I can get the departure angle down around 35 to 40 degrees...  

The elevated vertical I can get down to 20 degrees with the 50 ft vertical pole...    So, the question is... do I want 40 degrees or 20 degrees??   not sure yet

So, what I have modeled so far with the vertical...  the top of the antenna is 52 ft above grade and 32.35' long designed around 7.15 Mhz...   I optimized the slope of the four radials and their height for minimum SWR.. they slope from 20' down to around four feet above grade.

It looks like I could plug in a 4:1 balun and feed 15m through this setup as well...  

53 Ohms at the feed point and a SWR of 1.1 at 7.15

So...  will play around a bit more with the Inverted V and will have to make a decision pretty quickly....  have to get parts ordered and this thing tuned up and in the air before the weekend...

Thanks for the comments!
Link Posted: 3/18/2012 3:38:36 PM EDT
[#4]
The great thing about wire antennas is that they're relatively cheap and easy to play experiment with.

I can't even run a modeling program yet though I have the one that comes on the ARRL Antenna Book CD.  Need to learn how to work it.

If you're so inclined, build both and see how they compare to each other and the computer models.  It's just some wire...  

And holy cow BigDaddy!   My grass is just starting to turn green, but we haven't got much rain yet either.  You'll be mowing in no time!
Link Posted: 3/19/2012 2:01:31 PM EDT
[#5]
Quoted:
The great thing about wire antennas is that they're relatively cheap and easy to play experiment with.

If you're so inclined, build both and see how they compare to each other and the computer models.  It's just some wire...  


That is what I've decided to do...    got the 50 ft pole ordered, should be here Wed.    Going to rig up with wire and supports for both the vertical and the Inv V....

Think I'm going to start with the vertical...  at some point I'll jump over the the V....

If I put the push up pole on my rear deck, that should get the top of the pole upwards of 59 ft....    we'll see if that is high enough...    The secondary low end supports are going to take a bit more planning....    




Link Posted: 3/21/2012 6:25:40 PM EDT
[#6]
"The Pole" has arrived....   this thing is serious.   very heavy duty fiberglass extendable pole....   clamps and all kind of cool stuff....

This thing is a must have for field day.....  

Will start cutting wire and tuning tomorrow...  have to get the vertical and inverted V up, tuned, trimmed and working before end of day on Friday....

From the late 80's  " I just love it when a plan comes together."

10 extra points to the first who can post where that quote came from... no generic answers, has to be specific with details!!

Link Posted: 3/21/2012 6:45:04 PM EDT
[#7]
The A team.
Link Posted: 3/21/2012 6:49:18 PM EDT
[#8]
Quoted:
The A team.


Yeah, but you have to be more specific. It was Hannibal Smith who used it as his tag line.
Link Posted: 3/21/2012 6:53:39 PM EDT
[#9]
Quoted:
Quoted:
The A team.


Yeah, but you have to be more specific. It was Hannibal Smith who used it as his tag line.


DIng DIng DIng...  you guys are showing your age!!!  

Link Posted: 3/21/2012 8:21:50 PM EDT
[#10]



Quoted:


+1 concerning both of the above.  I have radials all over the back yard, but the grass is beginning to cover them up with the early spring temps here lately.  The inverted V would be the easier-to-install option, and the one I had was particularly good with WSPR also.



ETA:  The dog said to tell you hello, Mndless.  



http://home.comcast.net/~gregbell/Radials merged.jpg





BD, if this is what you were using tonight, then you were probably +20db over where I normally get you.  Granted, that's probably not what OP is looking for.  But, complements on you're new setup nonetheless....





 
Link Posted: 3/22/2012 3:48:40 AM EDT
[#11]
Thats my favorite contest... My bachelor party is this weekend so I will miss it again.
Link Posted: 3/22/2012 1:17:31 PM EDT
[#12]
Quoted:

BD, if this is what you were using tonight, then you were probably +20db over where I normally get you.  Granted, that's probably not what OP is looking for.  But, complements on you're new setup nonetheless....  

Thanks, 'Slice.  Yes, this is the S9V43' vertical antenna I used for the Wed Digi-Net.  Glad it's getting out.  
Link Posted: 3/26/2012 3:05:33 PM EDT
[#13]
Mndless,  what did you build and can you share details?

I'm always interested in building a better DX antenna...
Link Posted: 3/26/2012 3:31:37 PM EDT
[#14]
Man...  this is one of those "best laid plans of mice and men stories..."   I hate to even  open this can of worms until more time has past and wounds have healed.....  

But.. ok...    We know full well, you can't wait until the last min to put up and tune a new antenna...   I have been operating with a 3 band windom for some time (FD3)... 40/20/10,  OC fed dipole fed with 300 ohm window line... 4:1 balun... switch to a 1:1 and you get 15 mtrs...   For a few weeks I have been working on a really nice and 'featured' fan dipole to pick up 80 meters in addition to the above 4 bands.    Had spent many hours building a new mast to be placed up on my roof to get the antenna up another 15 ft in elevation.   Purchased this very cool new 50 ft extendable pole for the vertical, once I finished getting the fan dipole up...   Big WW WPX contest starts Friday night... so, friday afternoon, I have the wife and kids helping me get this new mast and dipole installed...  swetting my butt off on the roof for 3 hours and the mast ends up on the ground, tie downs are nothing but leaks in the roof and the fan dipole is tangled into a wad of wires so far from recoverable that they are cut, bundled and deposited into the awaiting trash bin....    

So...  why is this a problem related to the vertical?   Well... just before starting the install of the new dipole, I take down the mast for the previous working FD3...  upon the realization that the new dipole is now Fubar'd beyond the value of scrap metal... the more shocking realization that I am a few hours away from a contest with nothing that radiates!!   I have the old mast, which was arguably too short and the new extendable pole - which was for the vertical...   I had to draft the service of the pole to get the old FD3 back into service and the vertical was left for another day...

I will get this vertical up and running and properly evaluated a week or more before I need it next time...   wife said I "had a fit on the roof"... well...   she and I have disagreed before..  

Thanks for asking... I think this has been somewhat therapeutic for me to vent in written form...   and, looking to the bright side... over the weekend the old FD3 gave me 2 Austrailia contacts, one in Alaska and a not so impressive list of countries and islands that were new to my log, so... all was not lost....

Vertical is in the works... as far as the 50 ft pole...   50 ft is freeken tall!!!   You don't realize the importance of guy wires until you get past 30 ft... that last 20 ft, in fiberglass, is stinkn' crazy... everybody needs one of these....   way cool!!
Link Posted: 3/26/2012 3:47:46 PM EDT
[#15]
Thanks for sharing, I'm seriously laughing out loud here after reading that!  Not laughing at you, laughing WITH you!  

Any of us that have put up more than a simple antenna have been there and can relate.

It's hard for me to get an antenna support just 25' up in a tree so you have my sincere sympathy
Link Posted: 3/26/2012 4:11:13 PM EDT
[#16]
Wow, Mndless.  Sorry for the bad luck with that one.  I feel your pain, too, having done about the same thing before!  That whole scenario is a lot more entertaining when it happens to someone else.  
Link Posted: 3/26/2012 4:52:52 PM EDT
[#17]
Thanks...  I have been so 'moved' and 'motivated' by this experience that today, I have found material  and labor sources to fabricate, weld and install three aluminum masts at oposing locations on my property, aligned of course...   the material costs for two 30 ft end supports and a center 50 ft mast is not as bad as you would think....  yes, the last bit will be non-conducting, but not ready to think rationally about this just yet...

Did you know there is a difference in Aluminum pipe and Aluminum tube???    yep... and don't confuse the two !!

but yes...   there is nothing more motivating than shear frustration bordering on humor... as BD said...  if it were someone else!!  

Discussions of this afternoon... with the local City Building official, who responded like he thinks I'm planning a 200 ft cell tower project....  regarding my proposed grid to metal poles is a subject for another day....  there we go...    dragging up those supressed emotions again.....

Serenity Now...   Serenity now...   (159th episode)...






Link Posted: 3/26/2012 5:44:22 PM EDT
[#18]
Penninger Radio
Link Posted: 3/26/2012 6:03:15 PM EDT
[#19]
Quoted:
Penninger Radio


good stuff right there ... thanks!!

Link Posted: 3/29/2012 8:41:45 AM EDT
[#20]
Was doing some reading last night, and learned something that was a surprise...

When building/using ground plane antenna, verticals with radials elevated above ground, you can have high voltages at the ends of the radials.

For example, when running 1500W your can generate voltages at the radial ends upwards of 2000V...   But, I'm barefoot at 100W, so I figured no big deal for me.

As it turns out, that is not the case.   Even with 100W you can get voltages  upwards of 400 to 500V at the ends..   that is a significant concern if you have these radials within reach...

The ARRL antenna book goes so far as to recommend placing a small ball of solder at the end of the wire to help prevent/minimize cronal discharge...

So,  if operating a ground plane antenna, you really have to be very carefull to have the readials sufficient high and/or protected....
Link Posted: 3/29/2012 10:15:41 AM EDT
[#21]
Sounds like the safe thing to do is to bury the radials.
Link Posted: 3/29/2012 10:17:16 AM EDT
[#22]
I wonder if the dog would find it when transmitting.....
Link Posted: 3/29/2012 10:21:22 AM EDT
[#23]
Quoted:
Was doing some reading last night, and learned something that was a surprise...

When building/using ground plane antenna, verticals with radials elevated above ground, you can have high voltages at the ends of the radials.

For example, when running 1500W your can generate voltages at the radial ends upwards of 2000V...   But, I'm barefoot at 100W, so I figured no big deal for me.

As it turns out, that is not the case.   Even with 100W you can get voltages  upwards of 400 to 500V at the ends..   that is a significant concern if you have these radials within reach...

The ARRL antenna book goes so far as to recommend placing a small ball of solder at the end of the wire to help prevent/minimize cronal discharge...

So,  if operating a ground plane antenna, you really have to be very carefull to have the readials sufficient high and/or protected....


If you want to have fun with someone walk near the raised radials with a tube type fluorescent light while transmitting!  Just remember it is RF energy!!!
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