Do I Really Need to Buy an Antenna?
lou giovannetti (KB2DHG)
on
October 14, 2008
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In my 21+ years as an Amateur Radio Operator the number one topic in this wonderful hobby is antennas...
OH how we can debate of what works and what doesn't... Which antenna is best to buy or build...
I was faced with the unfortunate situation where I had to move from my house to a condo and of course now had to deal with HOA regulations... Long story short I convinced the HOA to allow me one antenna so long as it would not be seen, cause any interference and not be permanently mounted.
I am an HF DXer. I use all modes and bands... So what can I do if I can only have one antenna?
My only real choice is a multi band dipole.
So I purchased a commercial built G5RV dipole.
I tried everything I could to tune this antenna to a fair SWR with very little results, at best my SWR's were 1.8 - 2.1
I could hardly hear any stations and DX was non-existent. I just wrote it off to bad band conditions.
This antenna was a poor radiator and had insulated wire with cheap 300-ohm closed wire. I was getting a lot of RF in the shack and had chokes everywhere.
Obviously this was not a good choice antenna. BUT I needed to have a multi band antenna and had very little options...
One day when I went on the air I could not tune the antenna up at all so I went to the roof and took a look at the antenna. Everything seemed to be ok but then I noticed that some of the insulation on the wire was cracked and it looked like moisture was underneath the insulation?
We had had heavy rains and I figured that the water was altering the performance of the antenna. A few days latter with summer temperatures at a high the antenna started to act normal again. My theory was confirmed.
Still performance of this antenna was poor.
I decided to do research and try another antenna.
I always heard that building your own antenna was better than a store bought one so I decided to try building one my self.
With the aid of the ARRL Antenna book I decided to build my own G5RV.
I cut 2 pieces of bear copper clad stranded #14 wire at 51 feet each making it 102 feet across as prescribed in the book, then got 34 feet of 450 ohm ladder line. I installed it as I had the previous antenna, Only 20 foot up on a mast (the roof is 88 feet off the street level) in an inverted V form.
The coax is directly attached to the ladder line, NO BALUN.
So I turn on my transceiver, I am using an MFJ artificial ground and an MFJ 949 tuner. I start at 80 meters and worked to 10 meters setting all my adjustments. RIGHT AWAY I see a difference. I am able to tune this home built antenna with no more than 1.5 SWR and even flat out 1.1 on some bands. NO MORE RF IN THE SHACK, 20 meters is 1.1 across the band.
I am hearing stations like never before and my very first contact was to Spain!
I have now had this antenna up for 3 weeks now and have been working the world. DX is back and am making tons of state side QSO's. AND the conditions are not good! I can't wait till the solar cycle comes back!
I have concluded that a home built antenna is better than a store purchased one.
In my last home I had a tower with a Mosley beam for 10-15 & 20 meters and several home brew dipoles for 80-40 & 30 meters I never had a problem with those antennas.
So do you really have to buy a commercial built antenna? I don't think so...
Simply build it yourself. There are so many books and Internet sites that give all the formulas and instructions on how to build your own antennas...
I also get a real sense of pride that I built a better antenna!
So my amateur Radio friends build it your self and enjoy!
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Do I Really Need to Buy an Antenna?
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by KA4AQM on October 14, 2008
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Congrats! I agree, there is no better way to go in many cases than to build your own antenna. It gives you a confidence boost like no other. I also build my own antennas due to CCRs. Attic antennas are my forte'. I use a single coaxial feedline into a balun which feeds wire antennas cut for 40, 20, 17, and 15 meters. I spend alot of initial "upfront" time fine tuning (cutting) each antenna leg to ensure the best SWR and to see what effect each antenna has on the previous one as I attach each one to the balun. BENEFITS: SWR stays constant, no need to tuner. No weathering of antennas. DRAWBACKS: Slight RF in house on some appliances if you don't use amp. Satisfaction: PRICELESS!
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Do I Really Need to Buy an Antenna?
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by WW5AA on October 14, 2008
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Your getting close! Now dump the G5RV and build an all band doublet. Have fun.
73 de Lindy
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Do I Really Need to Buy an Antenna?
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by K1CJS on October 14, 2008
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Good job! It will almost always be that homebrew will outdo mass manufactured--when you do the work you take the time to make sure ALL your measurements are correct and precise, and the care to make and waterproof the connections correctly.
Good luck with your operating. 73!
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Do I Really Need to Buy an Antenna?
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by K0EWS on October 14, 2008
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Nice job, Lou.
You mention you have an MFJ 949 tuner. I'd lose the coax completely, and run the ladderline all the way to the back of the tuner. I think there is an input for balanced line on the back. Coax is lossier than ladder-line or twin-lead and if you're not on a resonant frequency, you will notice a big difference from feeding the antenna with twinlead or ladderline to coax. I have owned only 1 pre-built HF antenna in my life, and only because it was given to me. (a pre-made G5RV; it's good on 20 and OK on the other bands) All of the rest, I've made, and they always perform very well.
Another thing, if you want to always know where your signal is going, try a 44 foot doublet (for bands 40 meters and up) or an 88 foot doublet (for 80, 40, and 20 meters.) Your signal will pretty much go the same place every time. G5RV is a good antenna on 20 meters, where it was designed, but can be unpredictable on other bands.
Anyway, nice job! Making antennas is fun, isn't it?
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Do I Really Need to Buy an Antenna?
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by K4QO on October 14, 2008
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A suggestion or two... Run the window line for as far as you can easily, making sure it doesn't lie on the ground or run parallel (within a few inches) to something metal. Window line is less lossy than the best coax you can buy over long runs. Window line is perfect for running through a window, just pad a bit around the wire and close the window on it. Its flat shape will form to the bottom of the window and fit through nicely.
If you can't run the window line all the way to the shack without aesthetics or significant others being offended, then run the last little bit as coax. The least amount of coax the better, say, 20 feet or less.
In any event, I would not recommend hooking up to the balanced input of the MFJ tuners. I suggest a one to one balun/coax (RG8X or RG59) for the last 2 feet to the tuner and use a coax input. The balun part of this is easily made by clamping several (4 or 5)of the clamp on ferrites you can find at RS or other sources like Mouser on the net. BTW, those "european barrier strips" available at RS or other places make a nice transition method at the WL/coax junction.
I wouldn't change your antenna wires unless it is something you would like to do to experiment with a longer antenna for more gain, etc...
Good luck and congrats for stepping out of line and taking things into your own hands. Wire antennas are fun!
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RE: Do I Really Need to Buy an Antenna?
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by WA4UF on October 14, 2008
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"Making antennas is fun!"
And there's the crux of it for me right there. I can save money *AND* have fun at the same time?!?! Sign me up! I've got a 17m dipole made of hamsticks I got cheap at a hamfest, but all the other home antennas up now (40m dipole fed with 300ohm, beams for 6, 2 and 70cm) are homebrew, and the hamstick dipole is going to make way for a small homebuilt beam in the not too distant future. Like the man said, it's FUN! :-)
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Do I Really Need to Buy an Antenna?
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by N2RRA on October 14, 2008
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Lou,
Bravo! You got it unlike some other Amateur operators. I once used to monitor a repeater in New York quite popular where a group of guys about 10 of them just didn't get it. Till today they dont!
The majority would debate how great the G5RV was and it was all you needed so you had to purchase one of these. There were the few experienced operators that would try to explain the theory with pro and cons. Then there were the Hams that didn't know jack, but seemed to know everything. A lot of misinformed individuals as you can imagine.
To avoid this the individuals unsure of what direction they were getting pulled in many times have been suggested to try other antennas and the only way to do that was to build and experiment. Being easy to build you would think that they would even try. It would be the best way to figure out what would be best for you. Rememeber also the antenna your buying has to go through the builder first which is being hand made. How do you know they cut the right length on either side, or their solder joints are satisfactory?
When you build your own wire you can taylor it to your specifications by building it to the resonant frequency of the band you want. Not the compromised version when purchased. "Resonant frequency" is the key word and when ever you have a resonant antenna you just cant beat it.
Keep building Lou and look forward to the next project!
73!
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RE: Do I Really Need to Buy an Antenna?
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by K0BG on October 14, 2008
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While I agree with tossing the coax, and feeding the antenna directly with ladder line, I take exception to the "4 or 5 clip on ferrites from Radio Shack....".
First, the split beads sold by Radio Shack are mix 44, and not suitable for any HF balun, no matter how it's made. Even if it were the correct mix, it would easily take 25 or more to make an effective choke for 80 meters, and even more for 160. And who said the balun in the MFJ wasn't adequate?
Lastly, the G5RV can be "made" all band if you have an adequate tuner. However, on some bands, like 17 meters, the overall losses are very high. Hence the suggestion to dump the coax altogether.
Alan, KØBG
www.k0bg.com
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Do I Really Need to Buy an Antenna?
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by N8AUC on October 14, 2008
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Buy an antenna? For HF? Definintely not.
You've discovered one of the great hidden truths of amateur radio. Many times, what you can build ends up working better than what you could buy. The real benefit of that is, that when something goes wrong, (and eventually it WILL - at the worst possible time in the worst possible way) you will know how to fix it.
Congrats on your new antenna, and keep up the good work!
73 de N8AUC
Eric
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RE: Do I Really Need to Buy an Antenna?
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by NN2X on October 14, 2008
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I like very much the idea of going through the process and making antenna, this is awsome...For me however, it is the mechanics that I am not very good at...
So, folks like Optibeam, (For example)...builds antennas that will last..
But...I love the fact you are going through the process of design, implementation, and testing..!
Best
Tom Wright
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RE: Do I Really Need to Buy an Antenna?
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by AB7E on October 14, 2008
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N2RRA: ""Resonant frequency" is the key word and when ever you have a resonant antenna you just cant beat it."
That erroneous bit of superstition has been debunked and refuted so many times by so many knowledgeable hams on this reflector that I simply don't understand how it keeps popping up. Why spoil an otherwise decent article from the author by polluting it with such nonsense?
Resonance does not equate to efficiency ... I can build a resonant antenna with lossy components (or a lossy ground system) and it will work badly.
Resonance does not equate to pattern ... I can build a resonant antenna with wire that twists around in all directions and it will have a horribly skewed pattern.
Resonance does not equate to match. I can build a resonant antenna, even one with gain in a particular direction, that has a non-reactive 5 ohm feedpoint (or less) impedance and it will be very difficult to efficiently match.
Resonance is no assurance of anything.
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Do I Really Need to Buy an Antenna?
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by KC2BHE on October 14, 2008
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Having built many antennas over the years and only purchasing one or two I can certainly attest to the fact that building is almost always better than buying. Its a lot more satisfying to do it yourself and if you are careful in paying attention to detail they will usually outlast and quite often outperform the commercial version. I also totally agree with those that suggest running the ladder line all the way to the tuner. With a G5RV the reason for using the ladder line length specified along with some minimum length of coax is only to provide a relatively low SWR on 20 meters at the shack at 50 ohms. Since you need a tuner on the other bands anyways and the ladderline exhibits much less loss you will probably be much better off. The only issue I have with ladder line is that it is sometimes a pain to run if you have obstacles especially conductive ones to get around or through to get to the shack. The thing that makes the G5RV so popular to some is it's touted multiband operation and ease of construction. I used one myself for about a year. It worked adequately but as others have stated there are better multiband antennas. Keep building and enjoy.
73
Russ
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RE: Do I Really Need to Buy an Antenna?
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by W7ETA on October 14, 2008
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Now that you have the wire antenna bug, think of how much more fun you will have during the next 21 years.
Maybe your next project can be to make an antenna for 10 meters out of your call? If I run out of FUN things to do this antenna season, I might try it for my call on 10 meters.
Come to think of it, I might try and make some insulators shaped like my call sign--making vases on a pottery wheel is one of my hobbies. If I add one I'll get 3db gain and the second one on the other side of my dipole should give me another 3 db--6db gain when I send my call by using my call as insulators! better than an amp! Eeer. Maybe only 3 db gain with two call sign insulators since I sign my call at the beginning and end of a transmission?
Now I'll really be able to work everything I can hear!
73
Bob
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RE: Do I Really Need to Buy an Antenna?
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by K4QO on October 14, 2008
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Apologies to the "purist"...
My advice is based on empirical knowledge and observation. You are quite right about the makeup of the clamp on ferrites, however, their practical effectiveness has been observed and verified by scientists and non-scientists.
Even Moxon referred to the "odd piece of ferrite" as suitable for many purposes beyond its designed envelope.
The "problem" with the balun inside the MFJ tuners manifests itself with RF in the shack and losses that were beyond the scope of my advice. This is an observation based on my own experiences which I trust more than theory.
I have found that if you get too particular about some details, the fun of trying things gets lost in the reasons why something shouldn't work. Relax, its only
a hobby.
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RE: Do I Really Need to Buy an Antenna?
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by RADIOROY on October 14, 2008
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Home made antennas, I got a bunch!! Some work better than others, and I keep using them. Location,location,location as the Realtor says is also a big factor. I now have a 40 meter dipole up, and am afraid to take it down and put the "OCF" back up, as it works so well. Have a Mosley beam up 60 feet for 10-15-20, and thats about all I work right now. I just put in a small machine shop for tinkering, and most of it will be for antenna projects for myself and club members here in Clovis,NM. So build that new antenna, and if it doesn't work to your satisfaction find out why, and correct it. Have fun. Alan, Hope to see you in Roswell this weekend, and get an eyeball on you. 73 all W5ROY Roy
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RE: Do I Really Need to Buy an Antenna?
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by N4KC on October 14, 2008
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I know this is not a G5RV thread, but that was probably a good choice for a homebrew antenna project, Lou. When I got back active several years ago and bought a rig, I wanted something quick, easy to install, and multiband. I bought a G5RV kit from The Wireman at a hamfest for about $20...less than the wire, insulators and feedline would have cost me elsewhere...for a quick and dirty antenna. So the thing is still in my arsenal and still gives me a better signal sometimes on 20 and 40 under certain conditions.
As Press, THE wireman, recommended, I did not use a balun either, but very carefully measured the ladder line per the instructions and tied it directly to a short run of coax and it works fine with the internal tuner on several bands and was easy to install. A full-size, long-boom Yagi? Naw!
I know the HOA won't allow more antennas, but hopefully you can figure a way to get them up and down easily so you can experiment. It is rewarding as heck to cobble together something and have it work better than the last thing you cobbled together.
Oh, and ignore all that "gotta be resonant" talk. Ain't true.
Don N4KC
www.n4kc.com
www.n4kc.blogspot.com
www.donkeith.com
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Do I Really Need to Buy an Antenna?
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by N9JFG on October 14, 2008
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Since GR5 #1 didn't work and GR5 #2 did work, wouldn't it be interesting to figure out why #1 didn't work?
e.g. feedline, wire length, connections? That's where the advance knowledge lies -
Anyhow, congrats on making your own good antenna!
73
John
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RE: Do I Really Need to Buy an Antenna?
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by K3AN on October 14, 2008
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OCF, G5RV, fan dipole, inverted L, delta loop- I have built and tried them all. Lots of fun and a good learning experience. Over time you learn the techniques that keep your antennas in the air longer. By this I mean the choice of wire and insulators, along with supporting and strain relief techniques.
So what have I learned? OCF dipoles $UCK. G5RVs are reasonably good on 40 and up. A fan dipole is just too hard to keep in the air for any length of time. A 135 foot inverted L is great on 30 Meters and below, but not that good on the higher bands. Loops are da bomb! Oh, and that black insulated #18 copper-clad "stealth" wire is great stuff-- strong, flexible and easy to work with.
But here's the most important tip I can pass along to anyone interested in antenna experimentation: Sign up for free access to the W4RNL (SK) web site. It is an absolute gold mine of great and useful information and a great dispeller of many of the antenna myths that continue to survive among our ranks.
http://www.cebik.com/radio.html
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RE: Do I Really Need to Buy an Antenna?
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by K1BXI on October 14, 2008
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I call the G5RV design a tri-band dipole. 80, 40 and 20.
Reading up on transmission line theory may help one understand how it works on these 3 bands. And works well.
John
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Do I Really Need to Buy an Antenna?
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by NK2U on October 14, 2008
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YOu did the right thing; it's like making your own sandwich instead of buying one from the deli: YOU KNOW EXACTLY WHAT WENT INTO IT!
The G5RV is a fine antenna, I used one when I was in DU the last four trips. I contacted the US on every band with the exception of 160 which it is not cut for. I use one now in Vermont and it works very well.
73 de NK2U
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Wonders will never cease
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by KASSY on October 14, 2008
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I guess I got the right intro to the hobby.
Here's a fellow who's been a ham for 21+ years who still uses SWR as the first measure of antenna success. And he's a DXer using a low horizontal antenna.
Want real DX success with a simple antenna? Go vertical. You can vertically-orient a homebrew antenna a easily as horizontally orienting it, use the same feeder and tuner and zounds, the DX will come your way.
On any DX contest weekend, I can work 150 countries with my 100watt radio. I could not do that when I tried a dipole...any dipole, whether G5RV or whatever.
Find WB2WIK's various articles here on eham about verticals, tuned radials and mounting them off the ground. Any ham with 21+ years ought to understand the low-angle vertical's benefit for DX.
- k
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RE: Do I Really Need to Buy an Antenna?
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by K0BG on October 14, 2008
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Randy, the losses encountered in most tuners is the fact most folks just don't know how to tune them correctly. The prerequisite is to use as much capacitance consistent with a good match, as you can. The actual losses in the balun are typically small.
I will agree that some tuners don't use well-designed current baluns, and some use 1:4 voltage baluns, both of which can be lossy. This said, when the balun is designed correctly, the loss is practically nil, especially when compared to the rest of the tuner, correct tuning notwithstanding.
Feed line baluns must have an impedance far greater than the circuit they're applied to. Rather than rehash what's already been rehashed far too many times, I suggest you go to www.w8ji.com and read his treatises on baluns. And, you might look here too: http://audiosystemsgroup.com
Lastly, those Radio Shack split beads are nearly worthless at HF frequencies. As I said above, they're mix 44 or something close to mix 44. If you look at the loss tangent data on mix 44, you'd know why they're worthless for constructing a balun for any frequency.
Alan, KØBG
www.k0bg.com
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Me, too!
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by KB4EMF on October 14, 2008
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To this date, I have issues with buying commercially made antennas. I may not know as much as most on this forum and I am probably not even doing it right, but that did not deter me from having my own fun. I used bamboo sticks for Quad spreaders, etc. and just about any wire I can find for elements. An SWR meter was my only instrument.
One of the weirdest one was a dummy load on a stick with element hanging out. Amazing there are commercial products using this idea now.
Looking back, it seems most of my enjoyment in Ham Radio came from making my own antennas. There was something to making something and see it work. (albeit not well sometimes) Actually, I spend more time thinking about and building antennas than actually using them.
I agree with the author of this article.
KB4EMF/JF2DKG
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RE: Me, too!
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by W7ETA on October 14, 2008
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"HOA regulations... Long story short I convinced the HOA to allow me one antenna so long as it would not be seen, cause any interference and not be permanently mounted."
Sorta rules out a vert.
73
Bob
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Do I Really Need to Buy an Antenna?
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by AE1X on October 14, 2008
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Congrads on your new antenna. What you have done is enter into the real world of Amateur Radio. The OT operators all made their own equipment including antennas.
My experience has been with a 180' length of copper over steel wire end feed with an L match network on 80 and 40mtrs. On 160, I set up the roller inductor as a parallel resonant circuit and used the sliding tap to provide a variable impedance match.
The next antenna that I used was a full 40m dipole center feed with a W2AU balun. I was able to use this on 40, 20, and 15m with a Ten-Tec 247 tuner. In addition, used a 90' length of wire with my trusty L match network and had loads of fun running 100w. I was easily able to work the West Coast with the wire. I did try an OCF dipole with a W2AU 4:1 balun at the feed point and got acceptable results on many bands.
My final multi-band antenna has been a short G5RV with the Ten-Tec 247 tuner. This combination has provided me with plenty of interesting contacts. My most prized was a 30m contact running 140mW using a Pixie2 transceiver. I worked W4QBE in Fairmont GA a distance of 821 miles from QTH in Attleboro MA. What a rush to make that distance with flea power.
I wish you all the luck in the world. Isn't this hobby a real rush?
Ken - AE1X
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RE: Do I Really Need to Buy an Antenna?
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by W5WSS on October 14, 2008
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The G5RV covers 3.5-30mhz it's natural home is optimized for use on 20m and in that case coaxial cable will work...but An analysis of the antenna's terminal impedance shows there is no length of balanced line of any characteristic impedance that will transform the terminal impedance to the 50 ohm-75 ohm range on ALL bands. A matching network is required for multi band operation. Low swr indications with coaxial cable and NO matching network on bands other than 20m may indicate excessive losses in coaxial line. So best to use lowest loss feedline preferably open wire feeder or ladder line in conjunction with a matching network. The g5rv will then work quite efficiently on multi bands. Glad to see you were able to effect a decent result with your modified doublet. 73
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Do I Really Need to Buy an Antenna?
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by W4WSW on October 15, 2008
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Well I have to say that I had the same problem with my G5RV as well, I never can use it because the SWR always is Up, then I get another one "thinking" that the first one had some "desing/constructions" problems. Guest what..? the same problem I had before & diferent location because it was considered as well, but the same thing happend.
So if I follow your advise I know that I will have beter results...
73's de Luis / W4WSW
And enjoy the Hunting..
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RE: Do I Really Need to Buy an Antenna?
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by KC8TCQ on October 15, 2008
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Having recently upgraded, I wanted to put up an antenna for HF. I already had one for 10m and 2m. I decided to do some experimentation. I had an old 50 ft extension cord that someone had cut the ends off on a construction site, so I stripped off the orange jacket, seperated the 3 conductors and spliced them together giving me 150 ft of wire. hooked one end to my tuner and ran it out the second story window by my desk. It slopes down to an anchor point about 6 ft above ground, and then is folded back up to the end point on the roof of the first floor. I have had great success on 20m with it, and it tunes from 17m through 160m.
Granted not all of the bands are full coverage, and as we all know, you can get a dummy load to tune.
But I am happy with the results so far for an off the wall experiment.
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RE: Do I Really Need to Buy an Antenna?
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by K1BXI on October 15, 2008
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This needs to be said again..........SWR is not a criteria of the efficiency of an antenna. If it were not for standing waves your antenna wouldn't even radiate. Maybe some day the field strength meter will come back in style and that will be the test of how good the antenna really is. I still use one.
John
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Do I Really Need to Buy an Antenna?
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by WA1RNE on October 15, 2008
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I'm glad to hear that all is well now, that you are making contacts and you decided to build your own antenna - all good. However, your approach to solving the problem is probably not the one I would have used.
From your article:
"This antenna was a poor radiator and had insulated wire with cheap 300-ohm closed wire. I was getting a lot of RF in the shack and had chokes everywhere."
"Obviously this was not a good choice antenna."
"One day when I went on the air I could not tune the antenna up at all so I went to the roof and took a look at the antenna. Everything seemed to be ok but then I noticed that some of the insulation on the wire was cracked and it looked like moisture was underneath the insulation?
"We had had heavy rains and I figured that the water was altering the performance of the antenna. A few days latter with summer temperatures at a high the antenna started to act normal again. My theory was confirmed.
"Still performance of this antenna was poor."
"I decided to do research and try another antenna."
>>> STOP RIGHT THERE:
The materials may not have been the best, but many hams use insulated wire and cheap 300 ohm line without any problems. I use insulated wire for my dipoles and verticals and it works absolutely fine. Strength and durability is another matter, compared to copperweld antenna wire, etc.
If you suspected a bad connection due to corrosion from trapped moisture or other resaons, the next step is to run some simple continuity and/or resistance measurements with a DVM or a Simpson style multimeter.
You could start from the antenna elements and work backwards toward the feedpoint in steps, i.e. a resistance check from each side of the dipole to the balun - just disconnect the coax and one side of the 300 ohm line first. (Assuming the typical 4:1 voltage balun)
More than likely you would have found a bad/cold solder joint or a defective balun.
Moving on.....
"I always heard that building your own antenna was better than a store bought one so I decided to try building one my self.".... etc., etc.
>>> It can be better, but not always.
"The coax is directly attached to the ladder line, NO BALUN."
>>> There were some real tip-off's that should have led you to the next step: With or without the balun, there should not have been such a "night and day" change in the ability to receive signals, as well as coupling power into the antenna with the tuner.
What you have to remember is, a low SWR is not a good measure of radiation efficiency. The only thing a low SWR is telling you is that the transmitter is seeing an impedance that's close to 50 ohms - but that doesn't necessarily mean a high percentage of the available power is actually making it to the antenna and being radiated where it will do the most good - which is the goal. Many antennas will radiate efficiently even with an SWR over 2:1 or more - and your antenna is actually one of them. As an example, take a look at the antenna feedpoint impedance of a G5RV on 30 meters. (or for that matter, any band except 20.) The SWR is sky-high, but not at the transmitter using your trusty antenna tuner.
I'm glad to hear you don't have noticeable RF in the shack, but I'm willing to bet that your coaxial feedline still has significant common mode currents on the outer shield, causing the coax to radiate in addition to the dipole. Installing a 1:1 current balun at the connection to the 450 ohm line would be a good idea. You can use a commercial version, build a coaxial balun or use some snap-on ferrites. Just make sure you by ferrites with mix 43, 31 or similar that will work in the HF range.
As a test of your logic from start to finish: If you were willing to build the entire antenna from scratch, why weren't you willing to run some simple troubleshooting steps on the store-bought version? Your new homebrew antenna may suffer the same failure in a couple of years and you could be faced with the same problem.
In advance of the "why are you picking on him, you should be glad he decided to wing his own" posts, my criticism is meant to be constructive, as well as providing some insight to others - especially new hams.
Part of being a radio amateur includes good diagnostics and repair methods to maintain your station and antenna system.
....WA1RNE
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RE: Do I Really Need to Buy an Antenna?
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by K9FON on October 15, 2008
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The best antenna i have so far is my trusty old homebrew 270' 160-40 meter doublet. I run it to my tuner and it works GREAT! NO rf anywere in the shack and it works great with 1200 watts. I have used it on 17 and 20 meters but i have a triband beam for 10 15 and 20. I also have a home made 4 element quad with wide spaced elements for 10 meters that works very well too. Very tight beamwidth, good forward gain and great F/B. IMHO id much rather build my own antennas as i enjoy homebrewing very much, and there is nothing like building something on your own and the self satisfaction of seeing it work, and work well!!!
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RE: Do I Really Need to Buy an Antenna?
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by WB3T on October 15, 2008
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re: "HOA regulations... Long story short I convinced the HOA to allow me one antenna so long as it would not be seen, cause any interference and not be permanently mounted."
Sorta rules out a vert.
------------------------
I live in an antenna-restricted HOA neighborhood, and I did get a variance for one antenna. I installed a Gap Eagle multiband vertical on the ground behind a pine tree six years ago and it's been working DX for me ever since.
Now, on the "build-your-own" topic, the Eagle is great on bands 14 MHz and up, but poor on 40 and does not accomodate 75/80 or 30, some of my favorite bands. So last summer I build a homebrew base loaded ground-mounted vertical with 27 feet of wire run a couple of feet from the tree trunk and a tappable loading coil at the base to change bands to whatever I want. Being inside the tree, nobody knows it's there. I buried 16 ground radials during the day when everyone in the neighborhood is at work. I nicknamed the homebrew vertical "BLT." Base Loaded Tree.
My first two 75 meter contacts were London and Amsterdam, and it shreds the Eagle on 40 meters. I work a lot of QRP and I make easy QSO's with less than a watt. Sure you can get a variance for a vertical. I would think that would be easier since if it's installed behind a tree, it won't show as much. Small footprint.
BTW, the pine tree has grown a lot over the six years and the Eagle is now also inside the tree. I know this compromises performance somewhat, but the antenna, counterpoises and all, barely shows at all any more and worldwide DX on the high bands is routine at QRP or 100 Watts, automatic when I fire up the amp. I bought a used HW-8 last year and worked DX all afternoon on 15 during a sunspot drought with 1.5 Watts. I figure I've got good ground conductivity, a prerequisite for a ground mounted vertical.
I also experiment profusely with wire antennas and have found (shhhhhh!) that magnet wire doesn't show until you're right next to it. I have three wire dipoles up 30 feet, and a 75' random wire antenna up now that nobody can see, and a G5RV running along the top of a 7-foot fence in between the slats. Being so close to the ground, the G5RV shoots almost straight up and does well for those close-in contacts on the low bands, up to a 200-300 hundred miles or so. I have a few friends in that range so concentrating the energy this way is a plus. If I want farther out, I have several antennas to choose from, and yes - the farther out I want the more I'm prone to firing up one of the verticals. I love the empowered feeling I got when I saw how well they work for DX, and this was especially gratifying in the case of the homebrew $10 BLT.
I never figured on a bona-fide antenna farm when I moved in to a restricted neighborhood, but I worked it out. I am confident now that wherever I may move, no matter what the restrictions, I'll come up with something. Yes! I love to try new ideas and I have a great time with it.
Thanks Lou for starting this very interesting thread.
72/73,
Bob, WB3T
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RE: Do I Really Need to Buy an Antenna?
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by K9MHZ on October 15, 2008
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"Artificial ground..." Just wondering about that, especially since it's made by MFJ. How does it work, and is it better than snake oil?
Thanks, just curious.
Brad
K9MHZ
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RE: Do I Really Need to Buy an Antenna?
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by KB2DHG on October 15, 2008
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WA1RNE,
I want to THAK YOU for your constructive remarks...
Your advice and ideas are well taken and appreciated...
This is a wonderful hobby and anyone who thinks they know it all in this hobby is truly kidding themselves. The main reason for my post is to feed off of fine amateurs as yourself to gain more information and ideas...
Thank you and I will try more experaments.
Hope to meet you on the air!
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Do I Really Need to Buy an Antenna?
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by G0GQK on October 15, 2008
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It always makes me smile when I read the comments about the G5RV. Louis Varney copied his antenna from a design which was originally designed by Collins, which I believe, if I recall correctly, was a couple of feet longer He produced his 20 metre aerial in 1946 which he called the G5RV. It was 102 feet long and fed with open wire feeder 10.3 metres long into 75 ohms at the transmitter. He did re-design it a few times but it was never intended as a multiband dipole, and it wasn't designed for coax feed.
I think he would be astonished to find that the most popular dipole sold in a plastic bag at every hamfest, hamvention or even hamorama was a dipole he named after his call sign. There have been dozens of re-invented dipoles, all claiming to be improved versions, from all over the world.
G0GQK
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RE: Do I Really Need to Buy an Antenna?
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by K0BG on October 15, 2008
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Mel, isn't it the truth! There are so many variations, you'd think that's all Varney did was mess with the design. Some had baluns, some didn't. The length of the ladder line varied, the length of the coax varied, and the characteristics (50 to 75 ohm) varied. There were at least 4 versions published under his name which were published in QST!
Then there are the other guys who came up with a junior version, a senior version (what the hell is that!), and at least one version which used 93 ohm coax.
If that wasn't enough, some had the balun at the junction of the ladder and and coax, some at the tuner, and some at the radiating end. To call all of these G5RVs, is a stretch of the truth!
I agree with you! Old Jim is turning over in his grave! God! Won't he ever rest in peace?
Alan, KØBG
www.k0bg.com
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BOB IS SIMPLE
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by PLANKEYE on October 15, 2008
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BOB WB3T:
I live in an antenna-restricted HOA neighborhood, and I did get a variance for one antenna. I installed a Gap Eagle multiband vertical on the ground behind a pine tree six years ago and it's been working DX for me ever since.
Now, on the "build-your-own" topic, the Eagle is great on bands 14 MHz and up, but poor on 40 and does not accomodate 75/80 or 30, some of my favorite bands. So last summer I build a homebrew base loaded ground-mounted vertical with 27 feet of wire run a couple of feet from the tree trunk and a tappable loading coil at the base to change bands to whatever I want. Being inside the tree, nobody knows it's there. I buried 16 ground radials during the day when everyone in the neighborhood is at work. I nicknamed the homebrew vertical "BLT." Base Loaded Tree.
My first two 75 meter contacts were London and Amsterdam, and it shreds the Eagle on 40 meters. I work a lot of QRP and I make easy QSO's with less than a watt. Sure you can get a variance for a vertical. I would think that would be easier since if it's installed behind a tree, it won't show as much. Small footprint.
BTW, the pine tree has grown a lot over the six years and the Eagle is now also inside the tree. I know this compromises performance somewhat, but the antenna, counterpoises and all, barely shows at all any more and worldwide DX on the high bands is routine at QRP or 100 Watts, automatic when I fire up the amp. I bought a used HW-8 last year and worked DX all afternoon on 15 during a sunspot drought with 1.5 Watts. I figure I've got good ground conductivity, a prerequisite for a ground mounted vertical.
I also experiment profusely with wire antennas and have found (shhhhhh!) that magnet wire doesn't show until you're right next to it. I have three wire dipoles up 30 feet, and a 75' random wire antenna up now that nobody can see, and a G5RV running along the top of a 7-foot fence in between the slats. Being so close to the ground, the G5RV shoots almost straight up and does well for those close-in contacts on the low bands, up to a 200-300 hundred miles or so. I have a few friends in that range so concentrating the energy this way is a plus. If I want farther out, I have several antennas to choose from, and yes - the farther out I want the more I'm prone to firing up one of the verticals. I love the empowered feeling I got when I saw how well they work for DX, and this was especially gratifying in the case of the homebrew $10 BLT.
I never figured on a bona-fide antenna farm when I moved in to a restricted neighborhood, but I worked it out. I am confident now that wherever I may move, no matter what the restrictions, I'll come up with something. Yes! I love to try new ideas and I have a great time with it.
Thanks Lou for starting this very interesting thread.
72/73,
Bob, WB3T
__________________________________________________
PLANKEYE:
Thanks Bob, that was kick ASS!!
For all you guys that know everything, and know nothing works, don't read this.
PLANKEYE
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Do I Really Need to Buy an Antenna?
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by K1DA on October 15, 2008
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I say build your own simple hf wire and vertical antennas and buy commecial grade antennas from public service suppliers for vhf and uhf. They may cost more than Bob's Backyard J Pole Company but at least they probably have seen an antenna range and will stay up all winter.
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RE: Do I Really Need to Buy an Antenna?
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by KC2SUO on October 16, 2008
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I'm a firm believer in homebrew antennas, In part due to budget limitations, but also for some real satisfaction. When I first got on the air I adapted my endfed swl antenna. It was 130ft of wire with a 25ft vertical section near the house that went through some windings on a toroid and then to ground. The coax feedline terminated in windings making up the other half of an impedance matching transformer. Not too much real science involved, just some stuff I found online. I had under 1.5:1 from 80 through 20. The core would get a bit warm after Tx, not sure how much signal I was losing. But my second day on the air I made a qso into Czech republic. I was pretty thrilled, to say the least! After a time and a little more learning I made myself an 80m OCF dipole and a home made 4:1 balun. Got me 80, 40, 20, 17, 12 and 10 without a tuner. It was originally made with 14awg THHN, but I had a couple big surplus spools of 16awg enameled belden stuff so I switched to that. I eventually got a tuner. Needed it for 75m. In the recent Texas qso party, I had just retuned and forgot to put the power back up. I still got through a pileup with 25w from NY. Stoked the satisfaction level up some more! Well, yesterday I took it down and put up a 135ft doublet fed with twinlead. Been reading about the losses being significantly lower with balanced feedline. Seems like it picks up less noise, but can't really tell yet. I hope to get talking tonight, didn't really have time last night. We'll see how it works.
I'm great at making the short story long! I enjoy stories like this that bring radio back to basics and keep the "experimenter" in there with the "operator".
Thanks
Bill
KC2SUO
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Do You Really Need to Buy an Antenna?
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by KG6WLS on October 16, 2008
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Do YOU really need to buy an antenna??
Heck no!!
Just read the next article and see why. :D
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Do I Really Need to Buy an Antenna?
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by K8YZK on October 17, 2008
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Welcome to the fun world of building antennas and congraduations on making the G5RV.
Now to really make it work, it needed to be done in the middle of the worse snow storm in a century with the temps so cold that it freeze's your .......off
Again congrads.
73
Kurt
K8YZK
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Do I Really Need to Buy an Antenna?
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by KN4LF on October 17, 2008
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A G5RV horizontal doublet antenna is fine if it is used as a single band antenna. I have one up on 6 meters and works well. However as a multiband HF antenna the G5RV is an air cooled dummy load on several bands.
If you do not have the room for a dedicated antenna for every band then a 1/2 wave (at the lowest operating frequency) horizontal doublet fed with 300-600 ohm window/ladder line to a balanced antenna tuner will work much better as a multiband antenna. Even better is a A 1/2 wave (at the lowest operating frequency) horizontal loop fed with 300-600 ohm window/ladder line to a balanced antenna tuner will work much better as a multiband antenna.
In 43 years as an SWL and 20 years as a ham I have never bought a commercially made antenna, with the exception of the 6 meter G5RV that I purchased from K4TR Wire Antenna Mfg. and Sales at http://kk4tr.tripod.com/index-10.html.
Just my .22 cents due to inflation.
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RE: Do I Really Need to Buy an Antenna?
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by G3LBS on October 18, 2008
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KN4LF - I disagree with this. My 102 ft G5RV works fine all bands 20 to 6 meters and I have worked all recent DXpeditions with it. Of course I don't add coax to it - I use 450 ohm ladder line all the way to a Johnson Matchbox true differential tuner - no baluns of course. It also gives 5/9 USA on 40.
Does your horizontal loop give low-angle radiation?
Gil
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RE: Do I Really Need to Buy an Antenna?
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by KD8JCH on October 19, 2008
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I saw your post advising to build a doublet. Do you mean a folded dipole? I'm just starting out getting my Technician licence several months ago and am working on my General now. I have a ft 840 and I liked what I read about the Baker and Wiliamson 90 ft folded diapole.
Do you know where I could go to find plans to build one?
Thanks a lot and I look forward to hearing back from you.
73
KD8JCH
bktraveler2007@yahoo.com
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Do I Really Need to Buy an Antenna?
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by DH5JBR on October 21, 2008
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Both sides now.
My commercial Antenna is a genuine Fritzel FD-4 windom and in no extra-ordinary height. I like to work SSTV and have worked LU and JA from DL on 20 and 10 meters. Even 15 works although it is not supposed to.
One night, I only had the FT-817 working on it and VK4CAT (now SK) was calling CQ Europe SSTV on 20. Well. what the heck, I thought and answered in Scottyie DX mode. Any 100-W station would suppress me. Since nobody else was there, VK4 heard me and there was an exchange of a few pictures with my 5 Watts.
The FD-4 windom is just great, especially for the "817" because it will also work on 144 and 430 MHz with a better SWR than the supplied rubber antenna.
So: not a mean antenna.
The other side:
I go on DXpeditions (Google Earth Community and my call). The antenna I am using there is a bit of wire that I have matched with both manual and automatic tuners (MFJ and LDG) and a 1:4 balun. The cost of the antenna itself was below $1. The length of insulated braid was 25m and cost 2.80 Deutschmarks which is 1.40 Euros and I only used half of it.
If you are on an island and a rare DX, literally anything will do.
The wire goes up a 30 ft fiber glass rod.
This year, I was working VK4 from GM on 20.
I doubt very much that any of the two antennas described is up to cracking a pile-up of any description. The secret is to make yourself a rare station and you will get away with any antenna.
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RE: Do I Really Need to Buy an Antenna?
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by G3LBS on October 22, 2008
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50 years experience led me to the Spider multi-band quad.
Lightweight, wideband, hang it from a rope between the trees if you are too old to maintain tower. Cheap rotator. If you like - one ladderline feeder, no multicore cables. No coax, no baluns, no traps. Differential Johnson Matchbox tuner. Antenna is cheap. Quiet. Low-angle radiation.
Make it in a morning with 6 bands 20 to 6 .
Most important SteppIR fans please note my quad has optimum SPACING all bands!
See reviews of GEM quad on eHam, unfortunately GEM is no longer produced. To fill overwhelming demand, I make Aluminum spiders now for hams and can also sell them fiberglass spreaders. Sold them all over Europe 100% positive feedback on ebay.
Gil W2/G3LBS Allegany Western New York. gcleeton@hotmail.com
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