Antennas

[skier]

Never knew that. Saw DJ's photo before but didn't know if that was the real person or just something DJ put up as a photo. Also didn't know it was the forum's owner. (Guess I didn't know much - par for the course.) Thanks, MJ!

 

[skier]

So, I told you that bringing the ends of the G5RV up from six feet AGL to 40 feet has made a tremendous difference, and last night, I was on 15m, a band on which I've never before heard any traffic. Mind you, I realize that we're currently at the nascent stages of solar cycle 25 and some of that could certainly be the reason. But I'm getting a lot more traffic of every band during the night and the day and it all began instantly the day I raised the antenna ends. That also gives me the standard dipole gain that you don't get with an inverted V, so I'm sure that's contributing to all this.

I think the modifications I made to my idea in bringing the ends of the antenna up higher have also now given me some new ideas on how to install the double-size G5RV. I now realize that 4o feet AGL can provide good performance, so I've been assessing how I might be able to install that double-size antenna at that height. It's supposed to rain here every day next week, so I may try putting it up over the weekend. I'm excited that the installation could provide me with a still more effective antenna on most bands of interest PLUS access to the 160m band on which I've been listening for a while and finding great technical conversations that I'd love to join.

 

[skier]

Forgot to mention, I've also been researching other HF rigs with more capabilities for the last 4 or 5 months and I think I'm ready to purchase. It's my B-Day this weekend and that allows me to rationalize a heavy purchase. (Though, I do need to be cautious to keep this feeling in check; like a music studio, it'd be easy to allow oneself to fall into a buying spree that could deleteriously affect future financial security. )

 

[-mjk-]

15m is my favorite band. I've had more contacts and more fun on that band than any other. When it's open you can hear your echo come back around the world on long path. Glad to hear your adjustments to the ends of the G5RV have yielded good results!

 

[skier]

15m? I'd always heard talk through the years before I was a Ham about the 10, 20, 40, and 80m bands, but never about 15m (or 12m or 17m). So I didn't realize it was popular at all.

I've read about LDE recently, but had not heard of that before either. The idea of a transmission taking the long path back to you is very interesting.

 

[-mjk-]

Jerry, in the old days, I use to have (mostly Russian) hams give me the "LP" prompt (Long Path) and I would turn my beam around to the reciprocal bearing and work them long path. Fun times.

I'm not joking: When I wanted to know if a band was open, I would hit my paddle with a couple of CW dits and listen for the LP echo.

 

[skier]

The other night I was listening to some guy in the Carolinas on 20m talking to several others around the country. He was pushing +20dB here and coming in like a ton of bricks, especially when he was aimed at and chatting with a guy in Ohio (giving him a +30dB) and I was likely just getting spill off the side of his pattern. Lots of others were trying to raise him and we had a pileup except when he keyed up. And then he dumps it, he just finished spending $100K on a tower with stacked tribanders, and several other antennas on the same tower. I just couldn’t believe he spent that kind of money on an antenna installation. I thought a person could buy an entire antenna farm for that kind of money. I have seen a couple of videos on YouTube where each of the owners have 6 or 9 towers, some at 200 feet with multiple single band antennas on them – I can only imagine what they spend and never realized one needed to be at least a millionaire for a great antenna system. Guess I’ll continue spreading $50 reels of wire antennas throughout the woods on my property to add more bands and consider it adequate.

 

[-mjk-]

I think the guy is full of it. If he put up a single tower, there isn't anything he could hang on it worth 100 grand. Mosely's most expensive mulitband yagi is around $2k. Towers just don't cost that much to put up. Rhon 25G 10' straight sections are $135. Various top sections can go up to $340 but you only need 1 of those. There is no way he spend $100k on a single tower and many sticks on it, unless he included the house next to it.

 

[skier]

You could be right. I couldn't find any 20m beams and towers expensive enough to come close to that dollar figure. American Tower Company's AME55-20B 200 ft. tower is $10K. Even if we double that, add two of the Mosley multiband yagi you mentioned and throw in extra money for switches, ground radials, etc., the installation still comes in under $30.K

Here's a link to an unbelievable installation. Now, if you want to claim this installation is well over $100K, I completely believe it. In fact, I don't think it's possible to build something like this except for much more, and that doesn't include the shack gear. To me, this is like looking at the homes of the very rich; it's unbelievable, and likely somewhat obscene, but it's still fascinating. Here's the link:

K3LR's installation is even larger, and he has his own multi multi team.

 

[-mjk-]

I'm with you Jerry. Now these high dollar antenna farms are great but I would feel some personal pressure to use it a lot. I would have to justify it and, tbh, I'd rather put the cash in the studio. But 1 tower? Of course. I had a 3 ele yagi on the roof of my home in Lynn, MA, for over a decade. My landlord was very understanding of my ham radio hobby.

 

[skier]

I, too, would like to have a tower to get above the terrain. Or just live on a large hill or mountain top. Once one has a tower, it then becomes the central support for several other inexpensive wire antennas that can be very efficient providing a great signal. Also, the tower itself, if isolated from the ground or shunt fed, can be used as an antenna, and add a beam or stack on the top and that'll act as a capacitive hat electrically extending the tower to radiate lower frequencies than its actual length would otherwise allow - lots of options!

 

[-mjk-]

Or, slant-wire fed for 160!

 

[skier]

Exactly! The only thing I don't like about a slant wire antenna is that it has directionality. (Unless, of course, I need a slant wire for directionality. )

 

[-mjk-]

Hmmm, it's considered an omni-directional feed system.

 

[skier]

Yes; it is considered that, but I'm not sure why. Most of what I've read about it is that it favors the direction of the slant, as opposed to a vertical which is truly omni-directional.

 

[-mjk-]

It's just offset but there isn't any gain. It's not like a lobe at the feedline.

 

[skier]

I agree. Perhaps I have been unclear in my communications, for which I apologize. My only assertion, and this is based on my reading - I have no experience with this antenna design, is that a slant wire or sloper antenna has a pattern determined by the angle of the slope. While a vertical antenna is truly omnidirectional (the effect of nearby metallic objects notwithstanding for the purposes of this discussion), a slant wire has a slight directional advantage in the direction of the slope.

 

[-mjk-]

Oh, now I see the confusion! I was not paying attention well enough. My apologies, Jerry.

Previously, @skier said:

Also, the tower itself, if isolated from the ground or shunt fed, can be used as an antenna

Then, @-mjk- said:

Or, slant-wire fed for 160!

I was talking about feeding the tower with a slant wire feed (transmission line) to use on 160m, not a slant wire antenna.

Any kind of slanting wire antenna is directional, so I can see why you must have thought I was nuts, lol.

Slant wire feeding a tower is something completely different, and the really cool part is the tower doesn't need to be insulated. You can put up your tower in a normal manner, with a solid concrete base, securely bolted with grounding system and guy wires. You don't need johnny balls on the guys either.

To slant wire feed an antenna, you have the climber run up the tower with a feeder and have them bolt it onto the tower at various points until you find the 50 ohm resistive point (typically these are used with a skirt, but you get the point). Then you add a variable capacitor at the bottom of the feeder to cancel out the inductive reactance and there you have it.

This is a worthwhile read: https://forums.qrz.com/index.php?attachments/dawson_slant_wire_shunt_fed_ieee_bts_2010-pdf.596316/

 

[skier]

Ha! Both of us saying the same thing. While you missed "shunt-fed" in my post, I missed that you were referring to the feed system several times - the fact I missed them all confirms that I'm the dumber one - a dubious distinction I have to admit.

My problem now is that the double-size does well up to the 18m band and occasionally the 15m. So I need to put up something to better grab 15m and to also get 12m, 10m, and 6m. Mind you, I may not actually need access to all of these bands - there may be little traffic on some of them around here. But until I know, I don't know. I will be asking other Hams this week about them. Based on what I've read, I likely will want 10m as the Solar Cycle winds up and I suspect 6m also. And you mentioned liking 15m a lot. Any insight you can offer on these other bands is appreciated.

 

[skier]

I'm thinking of trimming the original G5RV for access to one or more of these other bands. I don't think I can grab them all - perhaps I can, but all I know for sure is that a dipole can usually also get odd harmonic bands above the fundamental. I need to get EZNEC to try some modeling.