View Full Version : A Question for the Antenna Gurus
OK, an idle thought crossed my mind as I was working on the front porch tonight, and I wanted to run it by the antenna gurus out here.
As you may recall from an earlier thread, I am going to be putting up a flag pole vertical sometime this summer, as part of the front porch remodeling project. And it's not a question of "if" but "when" -- the fiberglass flagpole is sitting in the house waiting for the right point in time in the project.
Since it's a fiberglass pole, obviously I'm going to be running a wire up inside it, approx. 21 - 22 feet; the length of the pole is 22 feet, I'm not sure if I'm going to run the feed out above or through the mounting post yet. And it's going to connect to an SGC tuner mounted right at the base, so loading should be relatively easy (famous last words).
Now, the idle thought is simply this... why not run more than one wire inside? That is, run multiple lengths cut for each band (10, 12, 15, 17, 20 & 30 meters) alongside the "main run". This ought to make the flag pole resonant (more or less) on each band; or close enough that the tuner won't have to "work" too hard to match.
For this to work, it would have to be insulated wire. The main length would also be the vertical support. Of course, everything would be tied together at the main feed point. And it should go without saying that there will be a nice radial field laid out underneath the antenna (including underneath the deck that's going to go over the concrete porch) so that shouldn't be a factor.
The theory is that, as implied by Ohm's Law, energy should flow to the most resonant wire on a given band, as the path of least resistance. And I'm confident that this should work, recalling the mobile antenna setup I had on my old van -- 2 Ten-Tec mobile antennas (their short-lived clones of the hamsticks) on 40 & 15, plus a 10 meter whip (OK, a CB whip trimmed), all in parallel on one feed. Three bands, no switching, no tuning (which was nice considering that the TS-120S I ran mobile at the time didn't have a tuner built in!)
And I will try to borrow an antenna analyzer, trying to cut the wires as close to resonance as possible.
Thoughts?
KG4CGC
06-13-2011, 10:14 PM
I've considered similar ideas and some say that the proximity of the wires together may upset the balance of Space Time. Kind of when you use a fan dipole. Why does it have to have spreaders? Why can't the wires just be closer?
Just for your own sanity, make it easy to disassemble so you can get to the insides any time you need to. There may well be quite a bit more experimentation than you are bargaining for.
Is there something you can put on the end of each wire so that it will truly be easier on the tuner? Half wave inductor? I dunno at this point but if a bicycle wheel reflector can work on VHF ..........................
I've seen that done with dipoles ("fan dipoles") but I don't know what will happen with a bunch of 1/4 wave verticals; in such close proximity, I'd expect them to interact with with each other and mess with the tuning/radiation pattern. More typically, one vertical antenna is used with an adjustable loading coil on the bottom. But WTF, it seems like it's worth trying since you're putting the whole thing up anyhow. The worst that could happen is it won't work and you'll have to pull out the extra wires but, who knows? You could end up with something awesome. For instance, a club buddy and I were playing around yesterday and came up a 20m Moxon built out of 1/2" copper plumbing pipe that can be disassembled and tossed in the back of a short-bed pick up for Field Day. No worse than 1:1.5 SWR across the entire band and our first on-air test—with 100 watts and the thing less than six feet off the ground—resulted in a S-9 report from a ham in New Jersey.
I've considered similar ideas and some say that the proximity of the wires together may upset the balance of Space Time. Kind of when you use a fan dipole. Why does it have to have spreaders? Why can't the wires just be closer?< snip >Might be because you can't put bare uninsulated wires too close together?
< snip >More typically, one vertical antenna is used with an adjustable loading coil on the bottom. < snip >Well, that's pretty much what I would have with the SGC tuner.
But hey, it's worth a shot. What do I have to lose, some wire? Anything I pull out can get converted to radials anyway!
WØTKX
06-14-2011, 01:07 AM
Prolly be amusing to play with antenna modelling software, if you do that.
They will interact, but you may find it useful.
What about simply running multiple wires the full length as in a cage dipole?
But you know, like half of one. Fat and tubular to RF.
KG4CGC
06-14-2011, 01:31 AM
Might be because you can't put bare uninsulated wires too close together?
No no no ... has nothing to do with that. To be clear, I use insulated wires on every antenna. My understanding was that it is an issue of resonance and proximity. If there was not an issue there, I would have made a multi-band dipole last year but months of questioning led me away from a non spreader fan dipole.
If I have misunderstood this particular issue then I might take something down, call it a mulligan and rework it like so much (insert appropriate adjective, noun and adverb)
PA5COR
06-14-2011, 02:25 AM
Known as the "cat whisker" antenna, mostly as dipole.
The several verticals will interact with eachother, but it can work, you need to tune each vertical to the right sweet spot, while they interact that will be a hassle, but it can be done.
Using a coil at the feedpoint you could even cramp 80 in there, though with a smaller bandwidth.
W1GUH
06-14-2011, 07:33 AM
The old Hy-Gain 14AVS (10-40m vertical) used the same idea. 10,15, and 40 were covered by the main antenna with two traps, while 20 m was covered by a smaller diameter tube that ran up beside the main tube, separated by about 3-4".
I added 12 and 17m to a 4-BTV this way. A bit sensitive to tuning, but it works ok.
Prolly be amusing to play with antenna modelling software, if you do that.
They will interact, but you may find it useful.
What about simply running multiple wires the full length as in a cage dipole?
But you know, like half of one. Fat and tubular to RF.Any suggestions on a software app to look for?
Known as the "cat whisker" antenna, mostly as dipole.
The several verticals will interact with eachother, but it can work, you need to tune each vertical to the right sweet spot, while they interact that will be a hassle, but it can be done.
Using a coil at the feedpoint you could even cramp 80 in there, though with a smaller bandwidth.Oh, I'm sure I could. And the thought had occurred to me.
Strictly speaking, you could build a trap vertical that would fit inside, given a little ingenuity... imagine a Butternut HF5V or a Cushcraft AV5 (etc) built on a wire, not aluminum tubing (since the fiberglass pole itself will be the physical support), with thinner diameter coils.
If I wasn't going to mount the SGC tuner at the base, that would be a real consideration. But the tuner will "do the work". I'm just thinking that having resonant wires (after some tweaking) will make the system a little more efficient.
I'm not worried about 80/75 at present. The HF6 and the inverted L cover that with no worries. This will be primarily a "high band" vertical that can also cover 40 & 30; and it will double as an SWL antenna for the Hallicrafters S-108 I just picked up as well.
I should add that if this was going to be my primary antenna, I'd be a little more concerned. I'm certainly taking advantage of the situation to "sneak" another antenna into the mix, and it gives me an excuse to do a little experimenting. If it works out, then I may have some nice suggestions for someone who needs to put up a stealth antenna due to home restrictions (be they CC&R's, HOA's, or XYL's -- or OM's in some cases!)
If I wasn't going to mount the SGC tuner at the base, that would be a real consideration. But the tuner will "do the work". I'm just thinking that having resonant wires (after some tweaking) will make the system a little more efficient.
The efficiency that you would gain is negligible (and possibly non-existent) compared to the amount of work involved. I'd just run one wire and let the SCG tuner figure it out.
You're being anal, IMHO. ;)
Anal? Nah. Just cautious.
I don't like reinventing the wheel; if I'm thinking of doing something, I'd like to know if it's been tried before... so that either I know what works, or just as importantly, what doesn't. Thomas Edison may have had time to discover 200 ways NOT to invent a light bulb before succeeding, but I don't have that luxury.
Anal? Nah. Just cautious.
I've seen this kind of cautious keep people off the air for months and/or years. They tend to let "Perfect" be the enemy of "Good Enough" and never get on the air. I know of one ham who had an IC-746Pro that didn't get on the air for 2 years because he insisted on having an antenna that could do 75m when he did have the room for it.
I don't like reinventing the wheel; if I'm thinking of doing something, I'd like to know if it's been tried before... so that either I know what works, or just as importantly, what doesn't. Thomas Edison may have had time to discover 200 ways NOT to invent a light bulb before succeeding, but I don't have that luxury.
Which is why I say just run the one wire and let the tuner work it out. The labor to benefit ratio is too skewed in the labor direction, IMO.
I've seen this kind of cautious keep people off the air for months and/or years. They tend to let "Perfect" be the enemy of "Good Enough" and never get on the air. I know of one ham who had an IC-746Pro that didn't get on the air for 2 years because he insisted on having an antenna that could do 75m when he did have the room for it.< snip >Oh, not to worry! Like I said, the flag pole is here. And the time frame is "soon" as in "this summer."
This is part of the front porch/small garage rehab project, and it's #1 on the Honey Dew list, so IT WILL get done. Permit me to bore you with explanation:
Part 1 was to seal the concrete surface. Some old cracks needed filled with cement (done), a coat of primer put on the raw & ugly cement (done), followed by a coat of garage paint/sealer (done Saturday, some touch up work last night).
Part 2(a) will be to remove the old painted wood railing (looks like crap & it's falling apart, looks like it's 15 - 20 years old) around the porch. That starts no later than next Saturday, depending on the next few evenings. Then (2b) I start building the frame for a deck right over the old concrete (thus the need to seal it FIRST to prevent leaks into the small garage/storage area underneath). In the process, naturally, radials for the flag pole vertical get run within the frame (deck joists), and I have the wire. Also, holes will be drilled to run coax, electrical power, possibly a spare water line for future use as an outdoor faucet for the front; I'd rather run the pipe and use it later, than try to put it in after the fact. I may also extend the deck further out than the current porch, that depends on some other factors too lengthy to go into now.
Once that's all done, I proceed (2c) to lay down the decking and then (2d) build new railing and a new set of front steps. At this time, the flagpole will be situated -- and the auto tuner place in a sealed container (could be a simple as an old tupperware type container mounted underneath & out of site, but accessible) and everything wired in.
Between time, expenses, material, and unrelated events (like taking a weekend off to go to DC to see the kids), I'm looking at finishing this up, I hope, by the end of July or mid August. I also have to check on whether or not I need a building permit, since I'm putting flooring on the existing porch, not replacing it (some communities require it, some don't). If I do, then I have to do some drawings and such as well, and that will be a delay, but a manageable one.
The boss is a little annoyed that I'm not further along yet, but I pointed out to her that the garden HAD to go in first... can't plant tomatoes in August (in WPa that is) if you want to take advantage of the growing season! She'll get over it.
Incidentally, Phase 3 involves putting a concrete floor in this garage, then dividing it up into three rooms (and cutting a doorway into the basement as well); a front room that will be a combination garden shed/mini workshop, a back room that will be shelving for general purpose storage that's scattered all over the house, and a center room that will become the new shack. You don't really want to hear the details on that phase, do you? :evil:
PA5COR
06-14-2011, 01:21 PM
^looks like you have lots of work to look forward too...
Planning any spare time in there?
^looks like you have lots of work to look forward too...
Planning any spare time in there?Not to worry, I'll manage something!
The biggest problem I'm going to have is figuring out how to get the materials from Point A to Point B. Since I don't have the Subaru Legacy anymore, there are some limits to how much I can haul in the Olds compared to what I used to be able to do. Probably have to rent a truck or van for half a day.
W1GUH
06-15-2011, 07:00 AM
I've seen this kind of cautious keep people off the air for months and/or years. They tend to let "Perfect" be the enemy of "Good Enough" and never get on the air. I know of one ham who had an IC-746Pro that didn't get on the air for 2 years because he insisted on having an antenna that could do 75m when he did have the room for it.
Amen to THAT! If ya can't do what's "the best", do what ya CAN do!
If it works...don't knock it!
PA5COR
06-15-2011, 10:16 AM
I find myself using the Inverted L for 160 also on 80/40/20 with the tuner at the base.
The FD-4 with added coil will work from 160 -10, but at 45 feet high that will work better from 20 and higher.
The other vertical on the roof, Imax 2000 fed with the European counterpart of LMR400 ( all 50 feet of it) works fine from 17 and up.
You put up what you can do, and work what you can work.
The L antenne gets new pipes ( 80 millimeter added to the bottom) so it wil be a lot stronger ending in 30 mm at 23 meters high.
The rest of the L, a wire of 20 meters will go to the front of the house, ending at 8 meters high.
Too long for 160, but the tuner at the feedpoint takes care ofthat, and being longer as a 1/2 wave at 80 it will tune perfectly even running the Heathkit SB-1000.
Our relations with the neighbours is good, they don't mind the antennafarm here.
I hope you get things done quick without problems, i have some work to do here too, the other mast with the 2/70 beams need to be done, removing the 2/70 beams, put the 6 meter beam higher.
I didn't use the 2/70 beams in yeears, so they can go from the roof, including the 1/2 inch coax, that will cost me a day or 2 and some juggling on the roof.....
That setup will have to last me a long time, the masts and fastenings are all 316 stainless steel, i don't have to worry about that, still looking new after 10 years on the roof.
One reason i have the van is for hauling stuff, i can make use of a 21 foot boat trailer to haul masts and other long stuff, the van can do the rest 7 feet long 6 feeet wide and 6 feet high loading space and 1300 kilo load.
Having verticals, you need every foot of counterpoise, i put in 2100 feet now over the years....
And the MFJ 269 antenna analyser does help too...
Have fun putting your shack in, i hope we even might make a nice QSO.
;)
I find myself using the Inverted L for 160 also on 80/40/20 with the tuner at the base.
< snip >
Have fun putting your shack in, i hope we even might make a nice QSO.
;)I like my Inverted L (although these days it's vertical leg is more like half a V) especially on 160. It needs more radials. Sad to say, I don't think I'm going to have it for more than another year or two. The tree it's hanging from belongs to a neighbor (which I'm using with permission), but that tree is not in good shape. Last year it got 2 visits from a tree service and looks today to be close to dead, and if that's the case, it will be gone soon.
Even if it's not removed, well, my neighbors are very nice people, but they're both elderly (in their 80's) and not in the best of health. While we don't know when, um, the inevitable will happen, it will happen. Or their kids may place them in a care facility. So the day may come when other circumstances, shall we say, remove my permission to use the tree or what's left of it.
I'm looking into additional options. I have an old Mosley beam in storage, but it needs a lot of TLC before it ever goes in the air again. And that's presuming that I can get a small tower in the back yard at some point; not a zoning issue, but a combination of a wife issue and a wallet issue. I'm also looking at some of the Spiderbeam antennas and similar configuartions (Hex Beams too), and those ought to be light enough to go on my three foot tripod and be placed up on the roof. Shekels again come into play there. But I'll figure something out.
I'm open for skeds, especially on the weekends. How are you fixed for 17 meters?
W1GUH
06-15-2011, 11:25 AM
'WN said:
Even if it's not removed, well, my neighbors are very nice people, but they're both elderly (in their 80's) and not in the best of health. While we don't know when, um, the inevitable will happen, it will happen. Or their kids may place them in a care facility. So the day may come when other circumstances, shall we say, remove my permission to use the tree or what's left of it.
Magnet wire supported with fishing line is invisible. Problem solved.
KG4CGC
06-15-2011, 01:08 PM
'WN said:
Magnet wire supported with fishing line is invisible. Problem solved.
Until the tree comes down.
London Bridges?
'WN said:
Even if it's not removed, well, my neighbors are very nice people, but they're both elderly (in their 80's) and not in the best of health. While we don't know when, um, the inevitable will happen, it will happen. Or their kids may place them in a care facility. So the day may come when other circumstances, shall we say, remove my permission to use the tree or what's left of it.
Magnet wire supported with fishing line is invisible. Problem solved.Ah, no. Nice thought, but what you have to realize is that the inverted L starts at the top of the chain link fence (well, at the end of an insulator attached to the fence actually) which is on the property line. And I mean ON the property line, possibly on the wrong side of it. The people we bought the house from, suffice to say that they were less than careful when putting the fence up (her brother the professional handyman? I've seen his handywork. He can be handy somewhere else).
So, even with magnet wire, it would be very hard to hide. And that's assuming that, if and when the property next door has new residents, I don't have to move the fence. I might be required to (and it needs replacing at some point anyway).
With any luck, this will not be a problem I'll have to face for many years. But you never know.
Magnet wire supported with fishing line is invisible. Problem solved.
Visibility isn't the issue. The tree as a support structure would appear to be in jeopardy.
W1GUH
06-15-2011, 01:49 PM
Ah, no. Nice thought, but what you have to realize is that the inverted L starts at the top of the chain link fence (well, at the end of an insulator attached to the fence actually) which is on the property line. And I mean ON the property line, possibly on the wrong side of it. The people we bought the house from, suffice to say that they were less than careful when putting the fence up (her brother the professional handyman? I've seen his handywork. He can be handy somewhere else).
So, even with magnet wire, it would be very hard to hide. And that's assuming that, if and when the property next door has new residents, I don't have to move the fence. I might be required to (and it needs replacing at some point anyway).
With any luck, this will not be a problem I'll have to face for many years. But you never know.
Can't start it somewhere where you don't have property line issues?
W1GUH
06-15-2011, 01:50 PM
Visibility isn't the issue. The tree as a support structure would appear to be in jeopardy.
But til then....
WØTKX
06-15-2011, 01:58 PM
Any suggestions on a software app to look for?I play around with an earlier free version of EZ-NEC. It's pretty limited, but something of a standard out there. I don't know if the free/trial versions would model what you are trying to do. Might be worth trying.Maybe add a big brass eagle on top as a "capacity hat"?
PA5COR
06-15-2011, 02:03 PM
That sucks....
No trees here to use for the inverted L, you probably saw the aluminium mast i build behind the house, in the antenna section.
That one will be "grow" a little larger and much stronger, new aramide guy wire etc.
Build originally for 160, the added MFJ 998 tuner has no sweat to tune it flat on the other bands, but on 20 it is or the OCF or the L, depending on conditions etc., higher as 20 it is or the FD-4 OCF from Fritzel, or the Imax 2000 with 15 feet long wire radials on the roof as vertical.
I can chose for all bands between the horizontal FD-4 ( 160-10) or a vertical, L or Imax.
Lets try a frequency there and a time, i can make 800 watts there at ease.
You make the suggestion freq/time, i'll adapt ;)
If you can doctor your Mosley beam back to life, you will have an good edge over my pithy antenna set up ;)
I have only 2 chimney's to use here in the block of 6 houses here, one has the 6/2/70 beams and Diamond X510N, the other the Imax and diamond discone antenna used as antenna for the FT-100 radio.
I like my Inverted L (although these days it's vertical leg is more like half a V) especially on 160. It needs more radials. Sad to say, I don't think I'm going to have it for more than another year or two. The tree it's hanging from belongs to a neighbor (which I'm using with permission), but that tree is not in good shape. Last year it got 2 visits from a tree service and looks today to be close to dead, and if that's the case, it will be gone soon.
Even if it's not removed, well, my neighbors are very nice people, but they're both elderly (in their 80's) and not in the best of health. While we don't know when, um, the inevitable will happen, it will happen. Or their kids may place them in a care facility. So the day may come when other circumstances, shall we say, remove my permission to use the tree or what's left of it.
I'm looking into additional options. I have an old Mosley beam in storage, but it needs a lot of TLC before it ever goes in the air again. And that's presuming that I can get a small tower in the back yard at some point; not a zoning issue, but a combination of a wife issue and a wallet issue. I'm also looking at some of the Spiderbeam antennas and similar configuartions (Hex Beams too), and those ought to be light enough to go on my three foot tripod and be placed up on the roof. Shekels again come into play there. But I'll figure something out.
I'm open for skeds, especially on the weekends. How are you fixed for 17 meters?
w0aew
06-15-2011, 04:48 PM
I've used those 4-foot long, snap-together fiberglass poles to put up a 36-foot-tall support, with a 34-foot long wire taped to the outside of one side of the pole and about a 17-foot wire on the other side. I used around 10 radials of varying random lengths between 10 and 40 feet. I tack-soldered the coax to the ends of the wires and snipped off bits (and re-soldering) the vertical wires until the SWR was around 1:1 in the CW portions of 40 and 20 meters. The whole thing was bungee-corded to a sapling with a few guy wires.
A wind storm finally tore up the fiberglass, and it all came down. But it did work great for a couple years.
KG4CGC
06-15-2011, 06:43 PM
I'm wondering if you could get away with a single top loaded (coil) wire inside the flagpole. Possible have another wire drop from the top to about 1/4th to 1/3rd of the way down.
Then just for fun, a Slinky™ antenna inside the flagpole. Attach a wire to the end with a motor to pull and retract the Slinky™.
Can't start it somewhere where you don't have property line issues?Nope.
There's one Black Walnut tree on the opposite corner of the property, and it's all on my land... but it's a smaller tree, and it's about 20 - 25 feet lower (down slope). Down the road, that might be pressed into service. We'll see; I'm hoping that in a year or two, I'll be able to put a small utility shed down in that area & put a mast or phone pole or something back there, which I'll worry about then.
It's academic right now; the neighbors like us and don't mind the wire at all. And if it has to come down, in the future, well, I'll adapt. There's more than one way to rig an antenna... and I have some other ideas...
I've used those 4-foot long, snap-together fiberglass poles to put up a 36-foot-tall support, with a 34-foot long wire taped to the outside of one side of the pole and about a 17-foot wire on the other side. I used around 10 radials of varying random lengths between 10 and 40 feet. I tack-soldered the coax to the ends of the wires and snipped off bits (and re-soldering) the vertical wires until the SWR was around 1:1 in the CW portions of 40 and 20 meters. The whole thing was bungee-corded to a sapling with a few guy wires.
A wind storm finally tore up the fiberglass, and it all came down. But it did work great for a couple years.A year and a half ago I picked up some of the aluminum poles that match those fiberglass ones (the mil surplus stuff). The original idea was to use the fiberglass piece within the concrete as a base, and use the rest as the actual flag pole vertical. The boss wasn't too thrilled with the esthetics, and I really didn't want to strip the old Army green paint off of the aluminum...
Still have them, plus a could of rings that can be inserted within the system for guy wires. Not as high as the tree has the "L", but I'm thinking that in a pinch, it could be pressed into service as a temporary vertical.
I may just take the whole thing with me to Field Day and see what we can do. Or not.
I'm wondering if you could get away with a single top loaded (coil) wire inside the flagpole. Possible have another wire drop from the top to about 1/4th to 1/3rd of the way down.
Then just for fun, a Slinky™ antenna inside the flagpole. Attach a wire to the end with a motor to pull and retract the Slinky™. Probably, if it was narrow enough. I'm a firm adherent to the KISS principle, though, and I'm thinking that the less futzing I have to do, the better overall.
Physically tying some wires together isn't big deal. But when we start talking about coils or traps, now we're ratcheting up the complexity.
If this was a pure research project, I would give it a try. But this IS going to be a "real" flagpole, and once it's up, I'm hoping to leave it alone.
Again, we'll see. I'm at least a month away from putting it up, I have a lot of deck work to do first. But, that's why I'm enquiring now, so that when the time comes, I have everything ready (he says confidentally).
KG4CGC
06-15-2011, 10:16 PM
You probably already know this. Anyone with black walnut trees on their property should know. They randomly drop large branches with no rhyme or reason. Sometimes dead limbs, sometime living ones. Go figure. I often expect them to break when we get a strong storm but no. Only during a clear still day.
W1GUH
06-16-2011, 07:11 AM
Probably, if it was narrow enough. I'm a firm adherent to the KISS principle, though, and I'm thinking that the less futzing I have to do, the better overall.
Physically tying some wires together isn't big deal. But when we start talking about coils or traps, now we're ratcheting up the complexity.
If this was a pure research project, I would give it a try. But this IS going to be a "real" flagpole, and once it's up, I'm hoping to leave it alone.
Again, we'll see. I'm at least a month away from putting it up, I have a lot of deck work to do first. But, that's why I'm enquiring now, so that when the time comes, I have everything ready (he says confidentally).
The idea of top-loading it sounds intriguing. It's not mentioned much these day, but a top-loaded vertical will be more efficient -- something about current distribution before and after the coil. What's unclear is if the advantage makes up for the extra trouble.
The idea of top-loading it sounds intriguing. It's not mentioned much these day, but a top-loaded vertical will be more efficient -- something about current distribution before and after the coil. What's unclear is if the advantage makes up for the extra trouble.Certainly. And under other circumstances, I'd give it some serious consideration.
But keep in mind that the top sectiion of this fiberglass flag pole is relatively narrow. If I recall the specs correctly, the inside diamater is well under an inch. So I'd have to fabricate a very narrow coil, and then figure out how to snake it into the fiberglass intact, and then rig up a way to attach it. Impossible? No. Just more trouble than it may be worth for THIS experiment. But if it works out, well, there will be others...
KG4CGC
06-16-2011, 12:18 PM
I figured you'd be able to open up both ends. You could always open it up and use a PVC cap. I'm assuming by your last post that the top is not open.
I figured you'd be able to open up both ends. You could always open it up and use a PVC cap. I'm assuming by your last post that the top is not open.Doesn't look like it.
PA5COR
06-17-2011, 03:36 AM
Though you might have no other option as toploading with a coil, add some wire above that.
I don't like (top) loading with coils, i rather use top hats of wire.
Coils lower efficiency, lower bandwidth too.
No possebillety to run a thin wire from the top to a neighbouring structure?, make an inverted L out of it, introduce autotuner at the feeed point with as much radials as you can get in...
Though you might have no other option as toploading with a coil, add some wire above that.
I don't like (top) loading with coils, i rather use top hats of wire.
Coils lower efficiency, lower bandwidth too.
No possebillety to run a thin wire from the top to a neighbouring structure?, make an inverted L out of it, introduce autotuner at the feeed point with as much radials as you can get in...No. The only "neighboring structure" would be the house itself, and believe me, the Boss would not put up with it. That would also run the "stealthy" aspects of it.
Sometime in the next few days, I'll get my hands on some modeling software and try a few things. I'm not ruling anything out, so long as it physically fits inside the fiberglass & isn't overly complicated. Roughly 22 feet of wire inside the flag pole, plus another foot or three (give or take) to get to the SGC tuner, should load just fine on 40 & 30 meters for certain, and a high probability of 20 & 17 without too much difficulty. So the worst that might happen, if 12 & 10 turn out a little flaky on this, is that I retune the Solarcon, or keep using the Butternut on the high bands.
You probably already know this. Anyone with black walnut trees on their property should know. They randomly drop large branches with no rhyme or reason. Sometimes dead limbs, sometime living ones. Go figure. I often expect them to break when we get a strong storm but no. Only during a clear still day.Yup. Which reminds me, I need to trim some branches on the small one growing behind the house.
< snip >Lets try a frequency there and a time, i can make 800 watts there at ease.
You make the suggestion freq/time, i'll adapt ;)
< snip >
How's tomorrow afternoon (your local) look? I'll be up in the neighborhood of 1200 Z anyway; the ladies have a Miracle League game to be at around 1330 Z, and they need at least 45 minutes to get there (plus they have to allow for PennDOT road construction). So I'll have a few hours to myself, although there's plenty to do around here.
17 meters around 18140 kHz ought to be good. If the band is open, we can even try 12 meters, but I think 17 is a better candidate.
PA5COR
06-17-2011, 10:48 AM
17 meters at 18.140 it is.
I'll put the transceiver to that frequency from 12.00 Zulu till 00.00 Zulu ( GMT) tomorrow.
Lets hope cndx will do some magic ( and the SB-1000) ;)
17 meters at 18.140 it is.
I'll put the transceiver to that frequency from 12.00 Zulu till 00.00 Zulu ( GMT) tomorrow.
Lets hope cndx will do some magic ( and the SB-1000) ;)Sounds good. 1200 is the EARLIEST I would be in the shack, that's assuming that the ladies will leave that early. Knowing my wife, well, 1230 may be more practical. And of course, this will be +/- QRM and other stations, but I'm hopeful.
And it should go without saying (but I'll say it anyway) that any other Islanders who happen to be around or up at the time are welcome to chime in! Gives me an excuse to use one of my "new" Island-themed QSL cards...
I do want to give 12 a crack at some point in the morning as well. I'm standing at about 74 confirmed to date on the band, so if it opens, I want to see if I can pick up anyone else.
Currently (18:04 UCT) monitoring 18.140.
Currently (18:04 UCT) monitoring 18.140.Wish I could. Sure beats parsing the corporate database looking for school districts.
(Tomorrow!)
PA5COR
06-18-2011, 09:48 AM
Lots of europeans on 18.140 had a few try's, nothing from the USA, running 600 watts here in the FD-4.
Will try again in 10 minutes 16.00 Zulu, but on 18.139, UK qso going on at 18.141.500 dang.
I don't think it's going to work today. I'm not hearing any EU stations; seeing some spots (mainly from the left coast) but nothing actually heard.
PA5COR
06-18-2011, 03:23 PM
Just European stations and Africa...
We will have to try it again later when the bands are better.
;)
W1GUH
06-22-2011, 07:06 AM
There must be some sort of force in the ether that dooms many Island hook-ups on the radio. I tried a few times last year & everytime I did condx really sucked & there was nothing doing. The best (and it was pretty good) was 'bny and I could hear each other, but barely. Enough to exchange reports, but not nearly enough for a rag chew.
And, usualy a couple of days later the bands were wide open to where they were deader than a doorknob when we were trying. Go figure.
We had reasonable success on 75m some months ago. :dunno:
KG4CGC
06-22-2011, 11:23 AM
There must be some sort of force in the ether that dooms many Island hook-ups on the radio. I tried a few times last year & everytime I did condx really sucked & there was nothing doing. The best (and it was pretty good) was 'bny and I could hear each other, but barely. Enough to exchange reports, but not nearly enough for a rag chew.
And, usualy a couple of days later the bands were wide open to where they were deader than a doorknob when we were trying. Go figure.
It's called the egg shaped circle of event. Eventually it will oscillate in your favor.
Conditions have been a little strange lately.
Almost worked FO8RH on 17 meters last night. At about 11:30 PM local (0330 Z). I say "almost" because he copied my call as W3WH; and Bill was not QRV at the time (I asked him).
Conditions have been a little strange lately.
I worked a guy in Italy Monday night, which is not as easy for me here on the Left Coast as it is for you guys over there on the other side of the map. And, just in time for Field Day: A CME headed our way with a possible geomagnetic storm, projected to arrive at 07:00 UCT on Friday. Woo-hoo!
W1GUH
06-23-2011, 07:21 AM
It's called the egg shaped circle of event. Eventually it will oscillate in your favor.
Murphy will dictate that it's "in your favor" when it doesn't matter! :lol:
KG4CGC
06-23-2011, 09:13 AM
Murphy will dictate that it's "in your favor" when it doesn't matter! :lol:yep :)
We had reasonable success on 75m some months ago. :dunno:
We'll have even better luck with future attempts. I haz fire in wire now. :yes:
KA9MOT
01-01-2012, 03:09 AM
They will interact with each other and make initial tuning a little difficult. I see no reason why it wont work. That said, the best antenna I ever owned was my Fan Dipole..............
ab1ga
01-01-2012, 02:30 PM
...
Now, the idle thought is simply this... why not run more than one wire inside? That is, run multiple lengths cut for each band (10, 12, 15, 17, 20 & 30 meters) alongside the "main run". This ought to make the flag pole resonant (more or less) on each band; or close enough that the tuner won't have to "work" too hard to match.
...
It has been done, although not within the relatively tight confines of a flagpole.
"WA5ABR's Homebrew Seven-Band Vertical", in "Simple and Fun Antennas for Hams", First Edition, ARRL. This book may no longer be in print, but I think it was replaced by another title within the past two years, and the article may be in there.
The article also appeared in the ARRL Antenna Compendium, Volume 5.
The antenna covers from 10 to 40 meters, and looks to be about 23 feet tall, with the 40 meter radiator being 16' of tubing, a loading coil, and a whip. It's made of telescoping tubing using 15-inch diameter acrylic disks as spacers.
Just brainstorming here: Use aluminum tubing as the 40 meter element right down the middle of the interior of the flagpole. Put the loading coil right at the top, drill a small hole in the top for the whip portion to attach through. Attach acylic spacer disks to that center element at intervals, maintaining as snug a fit as practical. Use bare wire, or perhaps brazing rod for rigidity. Rigid small-diameter copper tubing would also work, but might be pricey. Assemble the unit, do preliminary tuning outside the pole, then slide it in from the bottom.
You may have the books on your shelf, but if not, send me a PM with email address and I'll send you a copy of the article. No guarantees, either about the quality of the scans or the performance of the antenna, though. :)
73,
PA5COR
01-01-2012, 03:59 PM
I worked a few guy's now here, 10 15 meter, east coast USA too with 100 watts.
If it was too easy, what would be the fun?
ki4itv
01-01-2012, 04:27 PM
Hey Ron...looks like that perfect antenna building weather is on its way!
5103
Hey Ron...looks like that perfect antenna building weather is on its way!
5103
Just started raining here.
It has been done, although not within the relatively tight confines of a flagpole.
"WA5ABR's Homebrew Seven-Band Vertical", in "Simple and Fun Antennas for Hams", First Edition, ARRL. This book may no longer be in print, but I think it was replaced by another title within the past two years, and the article may be in there.
The article also appeared in the ARRL Antenna Compendium, Volume 5.
The antenna covers from 10 to 40 meters, and looks to be about 23 feet tall, with the 40 meter radiator being 16' of tubing, a loading coil, and a whip. It's made of telescoping tubing using 15-inch diameter acrylic disks as spacers.
Just brainstorming here: Use aluminum tubing as the 40 meter element right down the middle of the interior of the flagpole. Put the loading coil right at the top, drill a small hole in the top for the whip portion to attach through. Attach acylic spacer disks to that center element at intervals, maintaining as snug a fit as practical. Use bare wire, or perhaps brazing rod for rigidity. Rigid small-diameter copper tubing would also work, but might be pricey. Assemble the unit, do preliminary tuning outside the pole, then slide it in from the bottom.
You may have the books on your shelf, but if not, send me a PM with email address and I'll send you a copy of the article. No guarantees, either about the quality of the scans or the performance of the antenna, though. :)
73,
Actually, I found a vendor at the WACOM hamfest who's selling a 31 foot fiberglass antenna that could double, in a stealth environment, as a flag pole. If I didn't already have everything I need...
It's called the Eagle One Vertical Antenna from S&G Engineering in Proctorville OH. The ham behind it is W8AFX. I was trying to get him to come to WASHFest, we shall see...
And, well, I don't think I have the first edition, but I have a lot of ARRL antenna books on the shelf. I'll go take a look through them...
Hey Ron...looks like that perfect antenna building weather is on its way!
5103Yeah, but I have to build the deck first. And it looks like my surface sealant may have sprung a leak, we have moisture under the porch again...
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