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Beverage receiving antennas




 
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W0BTU
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« on: August 27, 2011, 07:28:58 PM »


I've been enjoying the amfone.net forums for some time now. However, I have yet to see anyone mention a single thing about using a separate low-noise receiving antenna, such as a Beverage.

Here's what I use at my QTH: http://www.w0btu.com/Beverage_antennas.html

Perhaps not the best on the planet, but they certainly work for me.

How many AM ops use Beverages or other types of separate low-noise receiving antennas?
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73 Mike 
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« Reply #1 on: August 27, 2011, 07:40:27 PM »

Hi Mike,


Very nice beverage website you have! Should be added to the antenna archives here. 

Yes, it's a FB receiving antenna for sure. There's lots of guys using them here.
I had a pair for 75M side by side phased for Europe -  with three others in other directions.

http://amfone.net/Amforum/index.php?topic=6862.0


Go to "Home" here and type "Beverage" into the search box. You will see pages of threads.

Tom, K1JJ     (Still calm with light rain at 7:45 PM)
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« Reply #2 on: August 27, 2011, 08:11:05 PM »

Thanks, Tom. Looks like it's been awhile since there was any discussion about Beverages.

I might try a phased pair someday like that.
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73 Mike 
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Steve - K4HX
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« Reply #3 on: August 27, 2011, 09:21:29 PM »

Lots of discussion on receiving antennas. Here are just a few:

http://amfone.net/Amforum/index.php?topic=21784.0

http://amfone.net/Amforum/index.php?topic=10231.0

http://amfone.net/Amforum/index.php?topic=26477.0

http://amfone.net/Amforum/index.php?topic=18760.0
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k4kyv
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Don
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« Reply #4 on: August 27, 2011, 09:52:34 PM »

Quote
There's a rumor that there is somehow a benefit to sloping the ends down to the earth gradually in, say, the last 60 feet at each end. (The reasoning was that the vertical drop at each end might pick up unwanted signals off the side). Don't do it. That adversely affects the antenna's impedance and could actually hurt performance. And besides, it's a safety hazard.

I think that old wives tale was started by W1WCR (of Liberty Net fame) with his beverage antenna handbook.

One possible advantage to the idea would be to let the ends of the beverage serve as a guy wire for the pole at each end, and allow a slightly longer antenna to fit into a specific limited space. Probably not worth any difference the additional few feet of antenna would make, except that one pole might be eliminated at each end. The vertical slope over 60' would pick up just as much off-to-the-side signal as a straight vertical wire at the very end of the antenna. That's exactly how the Pennant antenna works versus the Flag.

Exactly how did you mount the two-wire line on top of the poles? Looks like you used water pipe or conduit for the supports, but I couldn't tell from the photo how the wire is suspended from the top of the poles. I just finished building a 140' open wire transmission line from shack to tower.  Found heavy duty rigid conduit and water pipe far too expensive, so used 10' galvanised tee-posts with home-made metal cross arms with embedded ceramic stand-off insulators fabricated by cutting 3/4" dia. 6" long open wire line spreaders into two equal pieces using a diamond cutting saw intended for trimming ceramic bathroom tiles.

My single wire beverage uses four poles made from 1 1/2"water pipe I had on hand. The rest of the supports are trees, but I was able to suspend the wire from the lower branches in such a manner as to make the entire length of the wire run in a perfectly straight line. In winter it runs out to 800-900', but in summer I have to reel it in to 400' to get it out of the way of the farmer I lease crop land to. I use #8 copperweld wire stretched tightly enough to get by with a support every 150' or so. Like yours, I run mine at 10' high to keep it out of the way of surface traffic.

Nice site.  I bookmarked it for further reading.

PS: what is the component in the bi-directional schematic shown as circles with the letters "GO" inside, leading from each side of the OWL to ground?
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« Reply #5 on: August 28, 2011, 03:33:43 AM »

Quote
There's a rumor that there is somehow a benefit to sloping the ends down ... That adversely affects the antenna's impedance and could actually hurt performance.

I think that old wives tale was started by W1WCR ... with his beverage antenna handbook.

I think you're exactly right. :-)

Quote
Exactly how did you mount the two-wire line on top of the poles? Looks like you used water pipe or conduit for the supports, but I couldn't tell from the photo how the wire is suspended from the top of the poles.

I sawed four slots in pieces of 1/4" Lucite. Not the best way, but I used what I had at the time. Here's a closeup shot:

https://picasaweb.google.com/100482463989537482519/BeverageAntennas?gsessionid=umUSL5yutWWk7Kkk29aomg#5430777844556191714

The poles are 10' steel Rohn masts. I have some other supports made from treated 10' 2x2s to replace them.

Quote
I just finished building a 140' open wire transmission line ...

I think I saw your photos. Nice workmanship!

Quote
Nice site.  I bookmarked it for further reading.
PS: what is the component in the bi-directional schematic shown as circles with the letters "GO" inside, leading from each side of the OWL to ground?

Thanks, Don. That's "GD". Those are 90 volt Bourns GDTs. They are the blue components in the control box photos on my Beverage page. Sorry about the lousy schematics; I drew those as a preliminary step to an AutoCAD drawing, but never got that far.
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« Reply #6 on: August 28, 2011, 11:41:50 AM »

Mike, fantastic web site you have there.

I have an ~800 footer pointed about 60 degrees. It works terrific on AM BCB and 160, seems almost too long for 80 meters, best for only a limited area of the NE CONUS. W1, W2, it really drops off into Virginia and further south.I need to figure out how to remotely sectionalize it some day. In the direction it points it works remarkably well on 75.

It's made from standard 10' fencing steel T-posts and clip-on electric fence insulators holding the #18 copperweld wire. Has to be that high so ag equipment in the field can drive under it. Not every place stocks 10-footer steel posts, but they are available. It only takes a few minutes to beat the posts in with a fencing tool and the snap-on insulators take a few seconds to snap onto the posts. A two-wire Bev can be done by using two snap-on insulators spaced a foot or two apart.. The wires don't need to be horizontally separated.

My coax feed is about 200' long and only grounded at the receiver end, not at the feedpoint transformer. Have to replace and/or fix it every so often as critters like to chew into it.

Ground conductivity? We don't have any.

Thanks for the posting.

Bill
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k4kyv
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« Reply #7 on: August 28, 2011, 02:52:22 PM »

I assume GDT means gas discharge tube. Sometimes this alphabet soup business drives me crazy. Where did you get yours, and what is the breakdown voltage? After my meter disaster, I could use all the protection I can get.

For the open wire transmission line, I couldn't find any 10' tee posts locally, so I had to have them do a special order. I could have got them a lot cheaper if I had ordered them on line directly from the company, but I would have had to be home to receive them the moment when they arrived (and unloaded them from the truck myself), or else they would have been re-shipped back to the sender at my expense. So I opted for the special order. I got galvanised posts, well worth the added expense. When they arrived, every post was warped into an arc (probably something heavy piled on top of the bundle during transit), like the bow on a bow and arrow.  I didn't notice that when I picked them up, otherwise I would have refused the order. But I managed to bend them all back straight. I never had much luck even with with a fencing tool, driving tee posts in perfectly vertical in a straight line, so I fabricated a tripod jig out of 2 X 3s to serve as a guide to hold them perfectly vertical while I drove them with the tool. Once driven, they still seemed kind of flimsy, swinging to and fro like an old style 8' chicken-band whip, so I poured about 3" of concrete in a shallow excavation round the base of each pole.  That made them much more rigid.

I enclosed my beverage feedpoint transformer in an old rural mail box.  The only critters I have to deal with are ants, which I take care of with bug spray.

Beverages are supposed to be their best with low or non-existent ground conductivity.

Another W1WCR old-wives-tale is that HF beverages work better with a single ground wire, shallowly buried like a ground radial, running directly under the full length of the beverage wire. I tried that, using the braid on a run of crapped out coax, lying on top of the ground under the beverage wire. About all I could hear with the antenna was power line noise. Removing the ground wire improved performance.

The beverage is predominately a vertically-polarised receiving antenna, so it is prone to pick up local electrical noise just like a vertical antenna. Its low-noise reputation is due to its horizontal directivity. Chances are good that the noise source will not be in line with the direction of the wire but in another slice of the pie, so the s/n ratio is improved. But if you are unfortunate enough to have a local noise source in the bore-sight of the antenna, all you will  hear is noise, and the antenna will be useless.
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Don, K4KYV                                       AMI#5
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« Reply #8 on: August 28, 2011, 05:48:43 PM »

Lots of discussion on receiving antennas. Here are just a few: ...

Those look interesting, and I will browse them later. Thanks!

Question: what is the policy in the AMfone forums of replying to an old post? Some forum managers really frown on that. I was thinking I might run across something in those older threads that I might want to comment on. Would that be alright?
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« Reply #9 on: August 28, 2011, 06:18:14 PM »

Thanks, Bill! Glad you like the Beverage page. :-)

... I need to figure out how to remotely sectionalize it some day. In the direction it points it works remarkably well on 75.

Great idea! With a two-wire Beverage, that's very easy. I have often thought about doing the same thing to mine.

With a single-wire Beverage, I've seen people do that with 24 or 48 volt relays. But it sounds like your ground conductivity is so poor that that it may not work. You may have to walk out there and manually switch the extra length in or out when you want to switch bands, or better yet, come up with a radio-controlled switch powered by batteries.


Quote
It's made from standard 10' fencing steel T-posts and clip-on electric fence insulators holding the #18 copperweld wire. ... A two-wire Bev can be done by using two snap-on insulators spaced a foot or two apart.. The wires don't need to be horizontally separated.

Not to pick on you, but I see a real problem with a two wire-Beverage done that way. Here's why I say that.

When we are receiving signals off the feed end of a Beverage, those two wires act as a transmission line that carry the signal from the reflection transformer back to the feed end. The degree of balance of each wire to ground (or each wire to nearby objects) is very critical indeed.

If the balance on that open-wire line is upset just a little tiny bit, we will really kill our F/B ratio. Even small imbalances in the transformers affect this, but a two-wire Beverage with one wire 10' high and the other 9' high is certainly going to make the difference between either hearing some signals and not hearing them at all.

Even if the supports were non-conductive, this would be true. But in the case outlined here, the top wire has less capacitance to the support than the lower wire does. This would further fill in the nulls and degrade the F/B ratio.

Mechanically, your idea is ingenious. But when we think about what it does electrically, that's an entirely different matter.

Having said that, we might be able to get away with that if the spacing was small, especially if we put a slow twist in the open-wire line.

Quote
My coax feed is about 200' long and only grounded at the receiver end, not at the feedpoint transformer.

Exactly the way it should be done.
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« Reply #10 on: August 28, 2011, 06:47:30 PM »

I assume GDT means gas discharge tube. Sometimes this alphabet soup business drives me crazy. Where did you get yours, and what is the breakdown voltage? After my meter disaster, I could use all the protection I can get.

Yes, they are Bourns 90 volt ceramic gas discharge tubes. I just looked on mouser.com. I don't have access to the exact part# right now, but think the ones I used are either # 652-2027-09-BLF or 652-2027-09-B.

The data sheets are on mouser.com;  you should look at the specs, they are pretty impressive, given their small size. I opened one up, and they have a very large and close-spaced gap between the electrodes. That would explain their large current-carrying ability.

Some Beverage antenna transformers that are being peddled to hams that purport to have gas discharge protection actually use NE-2 neon lamps. That is little better than no protection at all. NE-2's are $0.15 and GDTs are $1.03 in the same quantities. Of course, neither the NE-2 nor the much heavier duty GDT will protect against a direct hit; but given the price, I think it's deceptive to sell a unit with NE-2s without telling the buyer.

Quote
Beverages are supposed to be their best with low or non-existent ground conductivity.

They don't work over saltwater, that's for sure!

Generally speaking, the higher the ground conductivity, the longer the Beverage must be.

Quote
Another W1WCR old-wives-tale is that HF beverages work better with a single ground wire, shallowly buried like a ground radial, running directly under the full length of the beverage wire. I tried that, using the braid on a run of crapped out coax, lying on top of the ground under the beverage wire. About all I could hear with the antenna was power line noise. Removing the ground wire improved performance.

I don't know where he got that idea. Since his books don't say how long his Beverage actually is, I thought maybe his antenna was so short that it actually was closer to a loop than an Beverage. Maybe in that case, a wire under the antenna would make some sense. But a ham who lives near him told me that wasn't the case at all.

I was really tempted to say what I really think about W1WCR's design on my Beverage page, but I didn't.

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« Reply #11 on: August 28, 2011, 10:34:16 PM »

Tnx for comments, Mike and Don.

I'm almost read to fire up for the season, but the CBS Volumax died. Need to fix it.  Mike, are you ever on AM?
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k4kyv
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« Reply #12 on: August 29, 2011, 02:47:01 AM »

I have a spool of several thousand feet of 3/16" diameter shielded cable. Not coax, but it looks like similar dielectric material. I have entertained the idea of testing a 1000' piece for rf loss, and if it is satisfactory for rf up to 7 mc/s, to use it in similar fashion to the two wire balanced version for bi-directionality.  I haven't sat down to figure out exactly how to do it that way, but it should work with the proper transformer configuration. Wonder if you ever heard of anyone successfully doing it that way, using the exterior braid as the beverage wire, while using the coax in normal fashion to pipe the signal back to the other end.
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Don, K4KYV                                       AMI#5
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« Reply #13 on: August 29, 2011, 07:23:29 AM »

Mike, are you ever on AM?

I wish, but not presently. All I have right now are a couple of slopbucket Icom transceivers, and I'd almost be ashamed to get on AM with them. :-)

I built an AM transmitter many years ago, but I no longer have it. I do have some 833C's and components that I've been thinking would make a nice legal-limit AM transmitter for 160 through 40.

And after listening to K4KYV in conversation with a couple of others recently, I see that I really need a good receiver and a synchronous detector. I was pointing out some nice vintage receivers to the XYL at the Joplin Hamfest this Friday, but that'll have to wait for another time.
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« Reply #14 on: August 29, 2011, 07:28:27 AM »

I have a spool of several thousand feet of 3/16" diameter shielded cable. ... Wonder if you ever heard of anyone successfully doing it that way, using the exterior braid as the beverage wire, while using the coax in normal fashion to pipe the signal back to the other end.

Oh yes, that's certainly been done. This photo is from the 5th edition of ON4UN's Low Band DXing, page 7-89.

Of course, you would need to have the supports closer together than if you were to use steel-cored wire, since coax can't take a lot of tension. (Or could a non-conductive "messenger" rope be used to support it every 100' or so?)


* LBDX05_07-118-coax_Beverage.PNG (45.51 KB, 574x548 - viewed 957 times.)
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« Reply #15 on: August 29, 2011, 11:36:14 AM »

Not having the room or the inclination to string up several hundred feet of wire for Beverage antennas I'm building a rotatable, orthogonally tuned K9AY loop for low band receiving.   I don't expect it to be quite as good as a Beverage but it should be considerably more versatile and a whole lot easier to build.

The antenna consists of a roughly equilateral triangle, 20 ft on the base and about 20 ft high, with the base about 2 ft off of the ground.  The base is two 10 ft sections of 1/2 inch rigid copper tubing, the sides are copperweld.  It is supported on 5 sections of the common fiberglass military masting and uses an old AR-40 rotator.   The elevation tuning for the null is accomplished with a modified MFJ -956 tuner at the operation position.   The general design is from a QST article a few years back.

IF this antenna works near as well as it models on EZNEC it will allow me to put a 20 to 30db null in any direction and any elevation and should work well from BCB to 20M.

73 Jack KZ5A

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« Reply #16 on: August 29, 2011, 12:11:52 PM »

... I'm building a rotatable, orthogonally tuned K9AY loop for low band receiving.  ... IF this antenna works near as well as it models on EZNEC it will allow me to put a 20 to 30db null in any direction and any elevation and should work well from BCB to 20M.

Jack,

The K9AY is a good antenna. But if you can get a 20-30 db null in any direction and at any elevation from any antenna, you're a better man than me. :-)

I'm not arguing with you, since I'm not real familiar with the K9AY. I've never built one nor have I ever even modeled one before today.

Just glancing at the single K9AY model on http://www.k7tjr.com/rx1comparison.htm, it doesn't look that good. But it was the only K9AY .ez file I could find. I think maybe it's flawed. I would love to see your file.

Take a look at the four square array of K9AYs on that page. May be better than the performance of a one-wavelength Beverage in a lot less space.

Have you ever seen Dallas Lankford's work with small phased loops? Looks pretty interesting to me. http://groups.yahoo.com/group/thedallasfiles/ He claims a 50 dB F/B ratio and a very clean pattern with his best loop array.
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« Reply #17 on: August 30, 2011, 11:09:29 AM »

Mike,

I attached the .ez file.  To get this performance from the model you have to use a complex termination, rather than the simple resistive termination used in most published K9AY plans.

The new idea in the QST plan was remoting the termination to the shack  so it can be better manipulated.  So the antenna is connected to the shack via 4 to 1 transformers and RG-6. At the shack I plan to use a MFJ-956 tuner which is a simple L and C in  series, modified with the addition of a variable R to provide the necessary variable complex termination.

No telling if the real world antenna will match the model until I get it built.

This was done in an older version of EZNEC, as I haven't coughed up the $$ for a new version in several years.

I had to rename the file extension ".txt" because the web site would allow uploading a ".ez" file so it will have to be changed back to ".ez".

73 Jack KZ5A

* Tyler K9AY.txt (6.68 KB - downloaded 190 times.)
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« Reply #18 on: August 30, 2011, 11:54:44 AM »

If the post contains good info, no problem.


Lots of discussion on receiving antennas. Here are just a few: ...

Those look interesting, and I will browse them later. Thanks!

Question: what is the policy in the AMfone forums of replying to an old post? Some forum managers really frown on that. I was thinking I might run across something in those older threads that I might want to comment on. Would that be alright?
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« Reply #19 on: August 30, 2011, 12:18:48 PM »

Dallas has a phasing configuration that only works over a small frequency range since he is only interested in MF. Last night I found a phasing configuration that works 160 through 40M with 1 delay line length. I will be testing it soon. The loaded delta loops work quite well. I had a phased pair facing East last winter but phasing wasn't right for more than one band. I put up a pair broadside yesterday. I was playing with HPSDR beam steering but this antenna configuration in broadside mode is not the way to go. Simulation and tests agree it doesn't work that well. Steering the beam only gives a couple dB of gain.  I'll put up the end fire next to verify simulation.
I will be comparing it to simulation of W8JI dxengineering 4 square performance.
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Steve - K4HX
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« Reply #20 on: August 30, 2011, 12:42:33 PM »

Quote
Quote
Beverages are supposed to be their best with low or non-existent ground conductivity.

They don't work over saltwater, that's for sure!

Generally speaking, the higher the ground conductivity, the longer the Beverage must be.

Mostly irrelevant at HF. The incoming wave is not at zero degrees elevation angle, so the lossy earth is not required to induce phase delay. Differences in ground conductivity just mean the termination resistance will need to be different and/or the height can be different for a given amount of gain.

Nulls (on the K9AY or any other directional antenna) are mostly a sideshow. Big numbers sound good but mean little in the real world (assuming they even exist in the real world). For amateur radio work at HF, the amount of the rejection off the entire backside of the antenna is what counts, especially if you have noise on a broad front from that direction (e.g.  An east coast station wishing to work Europe can do well with good broad rejection to the Southwest. This reduces all the electrical noise from a large population of the country, QRM from those directions and T-storm static too). Another important factor is how narrow the front lobe is. The more narrow, the less noise is picked up. The front side and back side performance can be compared across antennas using RDF (Relative Directivity Factor) and DMF (Directivity Merit Figure).

The K9AY is a terminated loop. It's in the same family as the EWE, Flag, and Pennant. All of these terminated loops produce a cardioid pattern with a broad forward lobe and fairly deep but narrow null off the back. The position of the null off the back can be varied by changing the shape of the loop and to some extent the termination resistance. The RDF and DMF are about the same for all of them: an RDF of about 7 and a DMF of about 11. A vertical has an RDF of 4.  A properly terminated one-wavelength Beverage has an RDF of about 10 and a DMF of 19.

There are times when a deep but narrow null is important or useful.  One is when you are trying to null out local noise. A phasing box and two antennas (one optimized to pick up the noise) is a better way to go than a K9AY. Another is when you are doing BC band DX. Here you want to null out other stations on the same frequency and/or adjacent frequencies to pull out a rare one in a different direction. For both of these applications, the null should be maximum at or very near zero degrees elevation. The null on a K9AY is maximum in 20-30 degree range. These angles are not optimum of local noise rejection or BC DXing but better for amateur radio work where incoming noise and QRM is likely be at higher angles.
 

K9AY. Info at the link below.

http://amfone.net/Amforum/index.php?topic=26477.0


I also have up a pair of offset, end-fire phased Beverages. The Bevs of course are superior. But they only work in one direction. The K9AY is very simple and easy to put up  and covers four directions. More info on comparing my Bevs and K9AY at the link below.

http://www.amwindow.org/misc/huzantennas/antennas.htm


One other thing to consider are dimensions of the K9AY loops. As designed by Gary Breed, K9AY, the loops are too large be effective on 40 meters and for sure on 20 meters. He actually optimized the system for 160 meters. It works reasonably well on 80 meters too. If you aren't going to operate on 160 meters and want directivity on 40 meters, make the loops smaller - something around 50 feet total wire instead of the 80-85 feet used in the original design.
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Steve - K4HX
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« Reply #21 on: August 30, 2011, 12:50:39 PM »

Some audio clips showing how the K9AY works for AM amateur radio purposes.


The first is Ken-K8TV on 3875 kHz at 2PM ET. Reception is rather noisy on the dipole (you'll hear it first) but much less so on the K9AY. Ken is about 390 miles northwest of my location.

The second is Tron/WA1HLR on 160 meters, 26 February at about 10PM ET. The band is quite noisy and his signal isn't all that good on the dipole. Switching to the K9AY cleans it right up. On the clip, it's hard to hear when I switch the antennas (there is no audible click). Instead you will hear what sounds like Timmy fading and the static coming up. He wasn't fading. That was me switching to the dipole. Tron is 600 miles from my location, but I've seen similar results on stations as close as 250 miles, depending on band conditions and/or time of day.




* k8tv28feb091902z3875.mp3 (426.22 KB - downloaded 418 times.)
* wa1hlr27feb090250z1885.mp3 (493.72 KB - downloaded 394 times.)
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« Reply #22 on: August 30, 2011, 01:02:49 PM »

I attached the .ez file.  ... I had to rename the file extension ".txt" ... so it will have to be changed back to ".ez".

EZNEC+ 5.0 choked on it. It displayed a run-time division by zero error and quit. Thanks anyway, though.
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« Reply #23 on: August 30, 2011, 01:44:16 PM »

Some audio clips showing how a Beverage antenna can improve receiving conditions even relatively local AM signals on 75-meters.

The first is of Kerri - KC2UFU on 3872 kHz in the fall of 2009. She is located 211 miles from me. The static is not terrible but you can hear the noise drop when I switch from the dipole to the Beverage. The clip starts out on the dipole, then switches to the Beverage at about 12 seconds, then back to the dipole at 27 seconds and then back to the Beverage at 32 seconds. She was running about 30 Watts.

The second clip has Kerri and Bob - K1KBW. Bob is located 352 miles from me. Here you can hear the reduction of some SSB QRM. Both Kerri and Bob are located Northeast of me, right in the main lobe of my Beverage. The SSB stations were all to the South of me. Some were in Florida. Notice the drop off in the SSB when switching from the dipole to the Beverage at 8 seconds. Then the SSB comes back up at 22 seconds when I switch back to the dipole and drops again at 30 seconds when I switch to the Beverage. Then it's back to the dipole at 44 seconds and back to the Beverage at 52 seconds. The drop off in the SSB is completely due to the back and side rejection of the Beverage. I'm not changing IF bandwidths at all.

* kc2ufu29oct090255z3872.mp3 (796.64 KB - downloaded 417 times.)
* k1kbwkc2ufu29oct090252z3872.mp3 (988.46 KB - downloaded 392 times.)
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Todd, KA1KAQ
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« Reply #24 on: August 30, 2011, 02:47:54 PM »

I'm still not sure which is more impressive - the overall performance or actually seeing the two systems you use, Steve. The K9AY is at least discernible in the trees and brush, but the beverage has to be hunted for. Hard to believe you can get such results from something so....simple? I'd think you were yanking our collective chain if I hadn't seen it myself. I remember thinking it would somehow make the signal hugely louder, which it doesn't; it just takes away all that noise and makes it appear louder as a result.

A beverage is next on the antenna project list here. Trenching the feedline will be the worst part here. It's always interesting to read of others' experiences and learn new tricks.
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