New 40m Dipole

[NQ6U]

Just put up a mast and hung a 40m dipole. It's not nearly as high as I would like to have it but, unlike my G5RV, at least it's actually cut for the band so perhaps the next time we try an Islander net on 40m someone will be able to hear me.

[W1GUH]

Depends. Was the wx inclement? It'll get out like gangbusters. Was the wx pleasant? Won't work for shite.

Just kiddin'...I think. Isn't it great to get a new antenna up? How's it working so far.

[NQ6U]

Depends. Was the wx inclement? It'll get out like gangbusters. Was the wx pleasant? Won't work for shite.

Just kiddin'...I think.

I hope so. The weather in on the Islets of Langerhans is perfect about 88% of the time, which wouldn't leave much of a window for erecting antennas.


Isn't it great to get a new antenna up? How's it working so far.

I haven't had a chance to actually use it yet but it tests out well with the antenna analyzer. Since I do a lot of digital work, I tuned it towards the bottom of the band and it shows less than 1:2 SWR across the lower 2/3 of the band. The upper third is still well within the range of my antenna tuner but I rarely go up there anyhow. The BBC tends to make it kind of pointless.

[NQ6U]

Okay, got on the air with the thing this evening. It's matched well enough at 7037.15 that I can switch out the tuner completely with no reflected power indicated. First QSO was with LU1MGA in Argentina. I think it's working...

ON EDIT: One thing I noticed right away is that it's much quieter than using my G5RV on 40m. I've always had a high noise floor on 40; I assumed that it was just a fact of life, living in southern CA and all. Turns out maybe its not. I wonder if the vertical matching section on the 'RV has something to do with it.

[W1GUH]

Cool!

[KC2UGV]

Okay, got on the air with the thing this evening. It's matched well enough at 7037.15 that I can switch out the tuner completely with no reflected power indicated. First QSO was with LU1MGA in Argentina. I think it's working...

ON EDIT: One thing I noticed right away is that it's much quieter than using my G5RV on 40m. I've always had a high noise floor on 40; I assumed that it was just a fact of life, living in southern CA and all. Turns out maybe its not. I wonder if the vertical matching section on the 'RV has something to do with it.

Most likely the case, as the vertical matching section is part of the antenna, and closer to man-made noise sources (ie, closer to the ground).

[NQ6U]

Most likely the case, as the vertical matching section is part of the antenna, and closer to man-made noise sources (ie, closer to the ground).

That's what I was thinking too—the matching section functions as a vertical antenna element and verticals are known to be noisier than horizontally polarized antennas.

[W1GUH]

Warms my heart to see one of "those" antennas replaced with a real dipole!

And, just for :stirpot:...

Here's how to get the best doublet......

While waiting for one of those GOOD antenna raising wx days....

1) Dust-off, build, or acquire a real truly balanced coupler. Extra points for link coupling

2) Assemble a folded doublet...or maybe better yet, a double extended Zepp using hand made open wire, 600 ohm line.

3) Erect it on a really, really lousy wx day. Could be that where you are "lousy wx" would be extremely hot?

Could gain 1/3 to 1/2 of a dB over a coax-fed dipole!

(Total good-natured jesting....but that's the dipole I'd put up if I could.)

[ki4itv]

Thanks to Carl, it's now readily apparent why the Western Wall of Power may be a necessary (evil :twisted:) for those in Southern California. They don't have any good antenna building weather days.

Damn. The things you miss when you're not really paying attention.

[NQ6U]

Warms my heart to see one of "those" antennas replaced with a real dipole!

It didn't entirely replace the G5RV. I still use that for 20m, for which it works very well.

[W1GUH]

It didn't entirely replace the G5RV. I still use that for 20m, for which it works very well.

I'd love to hear the results of A/B testing of the two on 20.

[KJ3N]

It didn't entirely replace the G5RV. I still use that for 20m, for which it works very well.
I'd love to hear the results of A/B testing of the two on 20.

The 40m dipole would be a full wave length on 20. Very high impedance and a bitch to match, if feeding with coax. Even if you could match it, the patterns are drastically different between the 2 antennas. It would depend on what target you're trying to hit in the first place.

[ki4itv]

My 40m dipole (@55') seems to have some deep nulls on 20.
But,the people who actually do hear me on 20 say I'm really strong for the power I run.

[ki4itv]

The 40m dipole would be a full wave length on 20. Very high impedance and a bitch to match. Even if you could match it, the patterns are drastically different between the 2 antennas. It would depend on what target your trying to hit in the first place.

I have no problems tuning mine with a manual tuner. The nulls are there...no doubt..

If I'm on twenty, it's probably a DX contest day and I have a purpose built vertical end fed zep for that band. Tiring to listen to for long periods of time, yet seems to have a very low take off angle.

[KJ3N]

I have no problems tuning mine with a manual tuner. The nulls are there...no doubt..

Is it fed with coax?

[W1GUH]

Used a 75m dipole for all bands up to 10 for years with no problem. First, fed with coax and then fed with balanced line. Both tuned with no problem using a small MFJ 300w tuner. Eventually home-brewed a coupler with a link. Did no formal comparison, but all cases worked well, despite using coax in the one case.

Only matching difficult I encountered was when I got a Matchbox with its limited range. On that occasion I spent an entire afternoon embedded in the tediom of getting the feedline to a length that would work on all bands.

[ki4itv]

Is it fed with coax?
Yes, and I already know.

[Jerry]

KJ3N seems to be a very intelligent person.
I Have gotten in so many internet arguments with internet idiots about G5RV antenna's that I stopped counting them.

Since there is all different models of G5RV there is no way for sure to make any assumptions but the one comment I will make is that I know of a guy who uses a NVIS antenna on his receive side of the radio and a 40 meters di pole on the transmit side and claimed to have good results in both directions.

The NVIS antenna only needs to be a couple of feet or less off the ground.
It ignores the local noise and is much quieter then a Di Pole.

I hate di pole antenna's because they have no gain.
Good for anyone with limited space - ( me included) but a poor performer for things such as field days where you have 30 idiots on one frequency, all demanding to be heard, and each person - other then you, using some type of amplifier to talk over every one else.

That is what I like about 20 and 10 meters.
Give me a 100 watt radio and a 20 meter beam and I will talk all day, all night, all weekend, and the only problems I will have is from other hams, trying to steal the frequency away from me - with more power and a closer location to the receive side of the conversation.

10 meters is great - because most of the idiots stays away from 10 meters because it is too hard to predict when it is going to be open, or for how long.
Give me a 25 watt radio and a Antron 99 antenna and I will talk clear across the US in any direction.

The problem is - most of the idiots comes down for their 10 - 10 contests or what have you, with their amplifiers and their beam antenna's and they try to scream and yell over each other as close as possible to 28.400 mhz because they don't know no better.

If a person wants to work a contest, let them move up or down.
If a person wants to participate in a contest, they will look for you and will meet you just about anywhere.

The other half of the idiots is the inconsiderate hams - the ones who thinks that in order to be heard, has to tune up their radio right on the call channel, then tunes up their amplifiers the same way.

I don't know what it is about some idiots, but they either buy their ham license, or they figure once they get it, they can do as they please and don't care who they offend, as long as they get to do what they want to do, and they brag about how educated they are or how much they know or how long they been a ham, but most of them don't know how to talk on the radio.

I guess that is what probably attracts so many of them to contesting, because they don't have to talk, just collect call signs.

All I am going to say is Good Luck with your 40 meter di pole antenna, hope it works for you.

[ki4itv]

Welcome to The Island Jerry!
Our esteemed bartender should be along shortly with the libation of your choice.
Me, I'm just going to put up a hammock right here and await 3N's return.
I wouldn't want to miss that.

[KJ3N]

KJ3N seems to be a very intelligent person.

Appearances are sometimes deceiving. ;)


I hate di pole antenna's because they have no gain.

Really? :chin:

Ever use an 80m dipole (fed with ladder line) on 20m? I do. It has 4 gain lobes. Those lobes have about as much gain as a 4-element 20m beam.

Ever use EZNEC? Model an 80m dipole @ 60 feet above ground and see the "no gain".

Dipoles in free space have no gain. Dipoles over real ground have gain due to ground reflections.

[N8YX]

Ever use an 80m dipole (fed with ladder line) on 20m? I do. It has 4 gain lobes. Those lobes have about as much gain as a 4-element 20m beam.
Yes - I have.

It's called a 'G5RV'. The 102-foot version.

Mine employs a current balun at the feedline transition point and exhibits a VSWR of under 2:1 up to around 14.300. It also nets a lot of unsolicited commentary regarding signal strength. Works good on 12M, and about as well on 75 and 40 as the dipoles I have up for those bands.

The other bands? Forget it. Might as well be using a dummy load.

One day I'm going to install an array of multiband (160-30M) slopers for grins and see how that works out for lower HF usage.

[KG4CGC]

Welcome to The Island Jerry!
Our esteemed bartender should be along shortly with the libation of your choice.
Me, I'm just going to put up a hammock right here and await 3N's return.
I wouldn't want to miss that.
Whoa! How'd I miss that?

http://i25.photobucket.com/albums/c79/bebop5/drinks/9dde7c13.jpg

[KJ3N]

Whoa! How'd I miss that?

http://i25.photobucket.com/albums/c79/bebop5/drinks/9dde7c13.jpg

Too much "sampling" behind the bar last night. :lol:

[KG4CGC]

Too much "sampling" behind the bar last night. :lol:
Well, you guys are always demanding that I come up with new specialty concoctions. A new one for every occasion.
Last night I was trying to get the balance right for a drink that was requested to celebrate the loss of one's virginity. I call it the Coitus Boiler. It's a mixture of Sex on the Beach and a Slippery Nipple mixed into one shot and dropped in a tall frosty glass of Guinness Stout.
I wanted to used Dixie Blacked Voo Doo beer but that stuff is getting very hard to get a hold of and where it is available, it just isn't the same recipe.

[ki4itv]

Too much "sampling" behind the bar last night. :lol:

You must have been fairly mellow yourself, without taking the contest bait.
First time I've seen that happen.:lol:

[KJ3N]

You must have been fairly mellow yourself, without taking the contest bait.
First time I've seen that happen.:lol:

Anti-contest people aren't going to listen anyway, and it's too fscking hot to bother talking sense into them. ;)

[K7SGJ]

Besides, the Mahi are bitting. See at the secret cove. Don't forget the anchovies.

[KG4CGC]

Besides, the Mahi are bitting. See at the secret cove. Don't forget the anchovies.
I've captured some squid this morning and it's been cut and soaking in fish oil and hoisin since 10am. It should make excellent bait. Change it up a bit from the little fishes.

[K7SGJ]

Works for me.