vertical take off angles vs hor 1/4 wave and ground question

[ghutch]

come on gamegetter....fishing is GREAT!!! last trip to this spot a caught 150+ trout and redfish....and thats not a fish story!! really kept a few and released the others.
Beetle.....I thought the radials would need to be close to the radiator!!....problem is the area surrounding the camp is in an area with zero elevation....i mean zero, tallest dune in the area is maybe 6 feet above the water level and it is 100+ yards from the camp site, coax run would be a problem. I feel the rf ground plane should not pose a problem(?) due to the saltwater gulf, bays and the high water table surronding the site for several miles in all directions.
guys would the best solution be a 1\4 wave whip mounted at 1\4 wave or 102 inches off the ground and use some 102 inch wire as guys and supports in a 45 degree angle....could use rope at the ends to terminate to the grond and pegs. that would be simple to do and stop the need for masts radials etc..could use PVC as a mast? this site is a boat/water access only site so simple and light weight is a key. It all has to load on a boat and be brought back out. I just want it to work as good as possible....fish at nite.. DX during the day.

 

[wavrider]

Fabricating CB antennas - Ham Radio Library

113 RSN 025 – 113 Division CB Station

Amateur Quarter Wave Ground Plane Antenna Calculator

several links to help you with the vertical, last link is a 1/4 wl calculator just put in the frequency and it will give you dimensions

 

[gamegetter]

magmount the 102" on the biggest metal cooler you have!

what part of padre or mustang island are you fishing?

 

[Marconi]

ghutch, here are a few models at different heights and a couple of configurations that have been suggested.

I felt that maybe modeling would cast a better light on what might happen near salt water, so these were done over average soil and the soil that is closest to salt water like marshland.

View attachment various antennas.pdf

 

[ghutch]

Thanks for all the input guys....geat help!!
fishing down the ICW about 50 miles south of Corpus, 10 miles or so north of Port Mansfield Jetty. Very remote area....Kennedy Ranch on the west shore and Parde Island to the east....area is due west of "Big Shell Beach Area" of Parde Island. Good fishing, lots of wildlife seen during the day (No People around to spook them), Hope is to "stick a few fish" and work some DX till the battery runs down! keep the power down to 10-20 watts or so and make the battery last a couple days. I have a small solar panel to help keep it charged. We plan to be at camp 3 or 4 days and nites.....Folks are going to need a shower when they return!!!!!

 

[Beetle]

magmount the 102" on the biggest metal cooler you have!

what part of padre or mustang island are you fishing?

Oh, a cooler will be a GREAT counterpoise...:sad:

 

[Beetle]

come on gamegetter....fishing is GREAT!!! last trip to this spot a caught 150+ trout and redfish....and thats not a fish story!! really kept a few and released the others.
Beetle.....I thought the radials would need to be close to the radiator!!....problem is the area surrounding the camp is in an area with zero elevation....i mean zero, tallest dune in the area is maybe 6 feet above the water level and it is 100+ yards from the camp site, coax run would be a problem. I feel the rf ground plane should not pose a problem(?) due to the saltwater gulf, bays and the high water table surronding the site for several miles in all directions.
guys would the best solution be a 1\4 wave whip mounted at 1\4 wave or 102 inches off the ground and use some 102 inch wire as guys and supports in a 45 degree angle....could use rope at the ends to terminate to the grond and pegs. that would be simple to do and stop the need for masts radials etc..could use PVC as a mast? this site is a boat/water access only site so simple and light weight is a key. It all has to load on a boat and be brought back out. I just want it to work as good as possible....fish at nite.. DX during the day.

My advice earlier remains. It really doesn't matter HOW close you are to salt water. It doesn't conduct nearly as well as copper - a LOT of copper (as in "many radials").

 

[ghutch]

Marconi....Thanks for doing the charts!! You guys are the reason for the success of this forum!!
After doing some study on these plots it appears to me the best pattern is the 1/4 wave with radials at 9 ft. with a take off angle of 17 degrees. The 1\4wave at 18 feet has a lower take off but the bulk of the pattern is radiated a too high an angle....not really useable......do you agree??
the antenna design is similar to the old Starduster type antennas.....I think they are 1/4 wave with angle drop radials.
the 1\2 wave design at 18 feet has 10 degree TOA but I do not have a 1\2 wave antenna to haul down to camp. the 1\4 waves are easy and should work as well as my mobile wilson 1000.

 

[Marconi]

Well these are just models, but I would agree. You need to move around a little and see if you detect any difference in reception and take advantage of that too. I find this range can sometimes be within less than a city block.

You might get by with an L shaped mirror mount, a pair of vice grips, and two 102" whips in an L shape like this. You may need to turn it a little for best reception.



Good luck,

 

[BJ radionut]

"After doing some study on these plots it appears to me the best pattern is the 1/4 wave with radials at 9 ft. with a take off angle of 17 degrees. The 1\4wave at 18 feet has a lower take off but the bulk of the pattern is radiated a too high an angle....not really useable......do you agree??
the antenna design is similar to the old Starduster type antennas.....I think they are 1/4 wave with angle drop radials.
the 1\2 wave design at 18 feet has 10 degree TOA but I do not have a 1\2 wave antenna to haul down to camp."

I really think this TOA gets way overdone...The difference in 3 to 5 degrees really gets over played. Everyone gives so much credence to these modeling programs (IMHO) These models are for "Perfect" eviroments...
I would take the whip with a mirror bracket...hook the radials (4) to the bracket with bolts and nuts...tie some 30-40 lb test line over the tip of the whip and through that thing over the highest tree and pull it up!!!
Stretch the radials out so you don't cloths line anyone...and see what happens...actually the whip without a spring is going to be short(I think)...I would take some scrap ALM tubing(telescoping) about 9 ft long...hook the center of the coax to that...hook the radials to the shield with a small hose clamp...Pull it up...see what goes...
I have worked the world with a ground mounted Vert and 5 watts...Don't over think this...
I have done it MANY TIMES on many different bands!...It's not rocket science and your not building a watch either
Have Fun
All the Best
BJ

 

[Marconi]

I tend to agree with you BJ, but it doesn't do much good, because most guys use it as a measure of maximum gain, which it is.

Personally any pattern with a wide wavefront between about 0* - 30* degrees toward the horizon is probably better at snatching useful signals, and the 1/2 wave tends to do that better in many cases than the higher gain types...with those sharp lobes and nulls.

That's another idea that is not discussed very much either. I'm a firm believer that more is not always better.

 

[Robb]

i'm planning a beach trip during the next couple weeks.....been setting around think up antennas to take and setup as a portable DX antenna. The antenna must very portable (due to size) and the mast can be no more than 20feet. My plan is to take a 102 whips and a couple 10 foot fence top rails to use as a mast, some wire to use as radials(if needed).
thought about taking two 102 whips and making a hor. 1/4 wave dipole that can be rotated? or may just use the 102 on top as a vertical. I think the take off angle would be better for the vertical for DX as all the mast we can take is 20 feet of top rail....what do you guys think would be the better antenna with these limitations?? My question about grounding is, if the grounded end of the mast (top rails ) are buried into the sand a foot or so(wet sand) to stablize the base,(using rope as guys) will i need to run a ground wire from the 102 whip down the mast and attach to a ground rod or will the mast act as my ground?
second question is can anyone tell me the take off angle on such an antenna?

setup will be on the sand, at the beach feet from the gulf of mexico around 60 miles south of corpus christi tx
i'll post before we go and see if any members can make contacts the plan to work the station for 3 days.

First of all, some people define 'DX' a couple of different ways. I consider it any country outside of the US. Some define it as longer than 1,000 miles. If on the Gulf Coast; it is a fair chance that you may get both outside and inside the US. Probably South America, the Caribbean Islands, and Central America too. Maybe more; hard to say with skip.

Skip conditions haven't been the greatest in the mornings and early afternoons lately. Late afternoons and early evenings have been a little bit busy. Timing is everything with DX - IMO.

Height of the antenna makes a big difference for my kind of DX. 36 ft to the feed point or a bit more is the rule. But you may get some just the same at 20 ft. You could use a vertical antenna; but then radials are necessary - as already mentioned. If it were me trying to do what you are asking; I'm sure I would build a cheap horizontal dipole. They are horizontally polarized, bi-directional, need no ground planes, quieter receive, and easy to build. Better for long distances; if that is what you are after.

Like this one:

http://www.youtube.com/watch?v=eVbuH1Av0Vk

 

[Captain Kilowatt]

"After doing some study on these plots it appears to me the best pattern is the 1/4 wave with radials at 9 ft. with a take off angle of 17 degrees. The 1\4wave at 18 feet has a lower take off but the bulk of the pattern is radiated a too high an angle....not really useable......do you agree??
the antenna design is similar to the old Starduster type antennas.....I think they are 1/4 wave with angle drop radials.
the 1\2 wave design at 18 feet has 10 degree TOA but I do not have a 1\2 wave antenna to haul down to camp."

I really think this TOA gets way overdone...The difference in 3 to 5 degrees really gets over played. Everyone gives so much credence to these modeling programs (IMHO) These models are for "Perfect" eviroments...
I would take the whip with a mirror bracket...hook the radials (4) to the bracket with bolts and nuts...tie some 30-40 lb test line over the tip of the whip and through that thing over the highest tree and pull it up!!!
Stretch the radials out so you don't cloths line anyone...and see what happens...actually the whip without a spring is going to be short(I think)...I would take some scrap ALM tubing(telescoping) about 9 ft long...hook the center of the coax to that...hook the radials to the shield with a small hose clamp...Pull it up...see what goes...
I have worked the world with a ground mounted Vert and 5 watts...Don't over think this...
I have done it MANY TIMES on many different bands!...It's not rocket science and your not building a watch either
Have Fun
All the Best
BJ

Nice to see someone thinking the same way I do. It has often been said that a little knowledge can be a dangerous thing and I believe it. Antenna gains and take off angles seem to be the worry of those that are inexperienced as they do not seen to fully realize what they REALLY mean and get too caught up in the numbers not realizing what difference those numbers really mean when translated into on air performance. The reality is that any antenna transmitting any TOA will work DX. Maybe not as often as a different antenna in less than ideal conditions but it will work DX. I can't even begin to tell you the crappy antennas I have used to work a couple thousand miles. What do you suppose the TOA is on a 20m Hamstick mounted on the trunk of a car a couple feet off the ground? Hell if I know but what I do know is it allowed me to work 3B9C via longpath for a distance of 15,000 miles with just 100 watts. I also worked all over Europe and southern Africa as well consistently. If that isn't DX on a crappy antenna then what is?

 

[2RT307]

It would be nice to throw one in the trees, but the beaches I've been to where he is going don't have any. Not Oak, not Palm, not even Mesquite trees! :laugh:

Take a pole along, stick it in the sand, mount a cheapo dipole to it as an inverted vee, and call it done. Or, take two poles, stick them in the sand, mount a cheapo dipole as a horizontal dipole, and call it done. Tada!

Australia has been coming in during the afternoon/evenings in North Central Texas. Maybe you'll have the same on the coast.

73 and have fun!
RT307

 

[BJ radionut]

Robb said:"Height of the antenna makes a big difference for my kind of DX. 36 ft to the feed point or a bit more is the rule. But you may get some just the same at 20 ft. You could use a vertical antenna; but then radials are necessary - as already mentioned."

Robb....not beating you up Bro....but all the math in the world...All the Hype "It's got to be this way or that way or your wasting your time"
It ain't so Bro! Remember seeing this from FD 2010

BJ/Gary-W9FNB said:
What a great weekend...if you remove the 100 deg index heat! The temperature stayed above 80+ till after midnight...brutal!
We operated 3A:
Xcvrs: FTdx 9000D contest special Yaesu
TS-2000 Kenwood
IC -703 ICON

I've posted just a couple of pages of my log...nothing special to note other than these contacts were made using the TS-2000 Kenwood with the kicker being the antenna.
ANTENNA: DOUBLE ZEPP/ 40m / 3/4 wave long (3/8 th's each side)
/w 60ft of 450 ohm Ladder Line at 30ft....
Who says you got to have beams and resonant antennas to make good contacts...We had a blast!
Can not wait till next year! Thanks to Rodger and Troy for being great hosts.
All the Best
BJ
Attached Thumbnails

CK said:" I also worked all over Europe and southern Africa as well consistently. If that isn't DX on a crappy antenna then what is?"
I can't even begin to tell you the crappy antennas I have used to work a couple thousand miles.
Ck that is so true!!!...If the masses only knew the Truth!:w00t:
All the Best
BJ