Some questions about SM0VPO short antenna

I wasn't refererring to a simple T but to a double T antenna, check the images at my previous post, that antenna is a shortened vertical, fed ad bottom, and using two capacitive hats, one at top, directly connected to the vertical wire, and a second one at bottom, the antenna feedpoint is connected between the bottom of the vertical wire and the bottom horizontal section using a balun followed by a choke; alternatively you may put together a doubled, fed using a run of balanced line

Hi all again


After a long time I've had to do many differnet things from radio world I've be able to go on with my "project" in my balcony and I've applied some of the great ideas you came up to me.


I've attached some pictures of my installation (the wire sports thinny ...). As you can see I've used inexpensive items and I've focused in safety and lightness of them. Also it's folding so I can folded when I need (weather conditions, discretion, ....)


I've still had a few tests with a stainless-steel 2 mm naked wire in T configuration using a CG-3000 remote tuner and using several kind of counter-poises (metal raling, a piece of electrical wire, ...).


In my first test I've seen that CG-3000 isn't very suitable to tune this T-antenna type. However is a fact that I hoped ...


Now I've moved the CG-3000 to feed the wire in an end (with a little piece of insulated wire) and I'm doing test these days with several kind of counter-poises too. However I'm noting RFI in some bands (as I expected) but I'm still testing with differente elements to correct it.


Anyway these supports give me many ideas to make a plenty of wire antenna configurations


I'll tell you my progress.





Thanks. 73.

Tnix wrote:
Yes I had thouhgt in that because I'd like to put in a "long" future other "inventions" like a magnetic loop and the cable to control the capacitor and rotor, but by now this kind of antenna is a bit difficult and expensive to make because air-vacuum capacitors are not cheap and I think the loop couldn't run well with metal railing near.
Maybe I'll also put a miniwhip I have. And for the feeding of CG3000 I save an extra cable with a couple of bias-tee.

Given your ideas for future "expansion", here's my suggestion; make a wider hole and pass a larger pipe, then put two plastic, weatherproof boxes to the inside and outside of the wall to cover the hole, that way the pipe will remain free and you'll be able to easily pass whatever additional cable/wire in a future while, at the same time, keeping the hole "closed" thanks to the boxes, at that point, to pass an additional cable you'll just need to open the inside and outside boxes, pass the cable through the pipe and close the boxes, quick and easy

As for the whip, be careful, being so near to the TX antenna, the whip preamp may get overloaded or even damaged, a way to avoid that would be switching off the whip power before transmitting

Tnix wrote:
By now I'm getting the material to install an outer big loop (or whatever other combination as you tell me like vertical-T) and "play" and test a working multiband antenna for HF from 80 meters  

I'll telling you when I receive and mount the hardware.

That sounds like a plan and, yes, please post here about your updates !! As for feeding the loop (given you'll start with that), the impedance of such a loop at resonance will be around 100...150 Ohm, so, consider that when planning for the feeder balun (if you aren't going to use twin coax... which, if using two 75 Ohm coax would have the right impedance !)

Tnix wrote:
Thank you very much for your interest and help. Regards, 73.

You're welcome, again, let me/us (the forum) know about your progress and results !

Andrew wrote:here's another idea, make the hole a bit wider, and pass a PVC pipe so that there will be room for a twin coax plus a CAT5 cable, pass two runs of RG59 and a CAT5 and seal the pipe with sealing foam, at that point you'll have choice to use single coax (and use the second for another antenna) or twin coax, plus the CAT5 will allow you to bring out power and control signals for antenna switch, preamp, rotator, whatever...

Yes I had thouhgt in that because I'd like to put in a "long" future other "inventions" like a magnetic loop and the cable to control the capacitor and rotor, but by now this kind of antenna is a bit difficult and expensive to make because air-vacuum capacitors are not cheap and I think the loop couldn't run well with metal railing near.
Maybe I'll also put a miniwhip I have. And for the feeding of CG3000 I save an extra cable with a couple of bias-tee.

By now I'm getting the material to install an outer big loop (or whatever other combination as you tell me like vertical-T) and "play" and test a working multiband antenna for HF from 80 meters  

I'll telling you when I receive and mount the hardware.

Thank you very much for your interest and help. Regards, 73.

here's another idea, make the hole a bit wider, and pass a PVC pipe so that there will be room for a twin coax plus a CAT5 cable, pass two runs of RG59 and a CAT5 and seal the pipe with sealing foam, at that point you'll have choice to use single coax (and use the second for another antenna) or twin coax, plus the CAT5 will allow you to bring out power and control signals for antenna switch, preamp, rotator, whatever...

Tnix wrote:
- In order to be able to connect and disconnect my future antennas easily I'm going to spread a short coaxials bunch from my shack to the balcony (about 3-4 meters) through a little holes in the outer wall. I'm thinking use RG58 coaxial because the short lenght cannot cause big losses and RG58 is more flexible and thinner.

For such a short run, the RG58 may fit, although to be sincere I'd prefer using RG8, but that's up to you; an approach may be running RG8 from the antenna to the inside and there connect a piece of RG58 going to the rig, but again, up to you

- In regard to the paralell coax (https://i.postimg.cc/xjbrB7vV/balcony-loop3.png) the pict indicates that I should dispose a 20% more than the quarter wavelenght of the lower frequency. If I try to work in 80 meter the lenght is 25 meter or 12.5 meter for 40 meter band. These lenghts are too long to fit in +- 6 meter of balcony. I have a coil of 450 ohm ladder line and a CG3000 available to "play" in a combination to save the construction of the parallel coax. For example, a piece of ladder line from the external RG I had available out of my shack to the loop/vertical T/another antenna using my shack manual tuner (I know ladder line should be have a determined lenght to accomplish tune and I can keep it away from metal) or, another example, using CG3000 in the feed point of the loop/vertical T/another antenna (I know CG3000 is to tune long wires but I don't know if it suitable for a loop, maybe it's a crazy idea).

No need to use that length; it's recommended, sure, but in your case it won't be needed; the idea behind the dual-coax is to be able to run a balanced line even if as in your case the ladder line can't be installed due to nearby obstacles/metal; in such a case the dual coax may run on the floor/ground, near obstacles and through the wall without problems, and even if it presents higher losses than true ladder line, given the short length, losses may be ignored.

If going for such an approach you may run the twin coax from the antenna feedpoint, through the wall and to the inside, there you may decide if run the twin coax all the way to your antenna matching unit (which would be a good idea) or, either, connect the twin coax to a balun and from there run a single coax to the ATU. Then you wrote you have a CG3000 remote ATU, in such a case, you may connect the ATU at the antenna feedpoint and from there run a single coax (add some chokes to it !!) all the way to the shack, the only problem as you wrote is that the CG3000 was designed for endfed antennas, but looking at the infos we see that

"CG-3000 is designed with Pi matching network. It provides more wide tuning range and covers whole HF band. Using 9 solid inductors, the total inductance ranges from 0 to 32 uH. They can give 255 combinations with a resolution of 0.25 uH. 5 capacitors are used at the input side, the total capacitance ranges from 0 to 6300 pF with 31 combinations. Other 5 capacitors are used at the output side, the total capacitance ranges from 0 to 755 pF with 31 combinations. So totally they give 245055 tuning combinations."

so it may be able to deal with a loop antenna too, the alternative is a twin-coax feeder and a manual ATU in the shack, but that's up to you

Oh thank you very much. It's another great idea . I love it!

I'd like to comment you some doubts I have:

- In order to be able to connect and disconnect my future antennas easily I'm going to spread a short coaxials bunch from my shack to the balcony (about 3-4 meters) through a little holes in the outer wall. I'm thinking use RG58 coaxial because the short lenght cannot cause big losses and RG58 is more flexible and thinner.

- In regard to the paralell coax (https://i.postimg.cc/xjbrB7vV/balcony-loop3.png) the pict indicates that I should dispose a 20% more than the quarter wavelenght of the lower frequency. If I try to work in 80 meter the lenght is 25 meter or 12.5 meter for 40 meter band. These lenghts are too long to fit in +- 6 meter of balcony. I have a coil of 450 ohm ladder line and a CG3000 available to "play" in a combination to save the construction of the parallel coax. For example, a piece of ladder line from the external RG I had available out of my shack to the loop/vertical T/another antenna using my shack manual tuner (I know ladder line should be have a determined lenght to accomplish tune and I can keep it away from metal) or, another example, using CG3000 in the feed point of the loop/vertical T/another antenna (I know CG3000 is to tune long wires but I don't know if it suitable for a loop, maybe it's a crazy idea).

What's your opinion?

Thanks in advance. Regards. 73

Here's another idea for your antenna; instead of a loop you may put up a "double t-bar" vertical - basically a vertical dipole fed at base and loaded using capacitive hats, the structure of such an antenna will be like this



that is, the horizontal portion will be the same used for the loop, but the antenna will have a vertical section at the middle connecting the top and bottom sections, the latter will form a capacitive hat, such an antenna will offer low angle of radiation and omnidirectional pattern as shown here



gain isn't "super" but it's compensated by the low radiation angle which allows to send RF "where you need it more", also, it's possible to add switchable coils (e.g. using a relay box) at the feedpoint (bottom of vertical section) so bringing the antenna to resonance on the various bands, and such an antenna will have lower visual impact than the loop

The NEC model for such an antenna is below in case you want to experiment a bit

Code:


CM tbar.nec - double T-Bar antenna
CE

' symbols
SY freq=7.100          ' test frequency
SY hght=10              ' height from ground of top section 
SY horz=10              ' horizontal wires length
SY vert=4              ' vertical wires length
SY wire=0.00075        ' wire radius
SY segm=29              ' segments in wire
SY fwir=5              ' feedpoint wire #
SY fseg=1              ' feedpoint segm #

' calculated values
SY side=(horz/2)        ' half horizontal length
SY base=(hght-vert)    ' bottom wire height

' tag segs    x1  y1    z1    x2    y2    z2  rad

' low sides
GW  1 segm    0    0  base      0  side  base wire
GW  2 segm    0    0  base  -side    0  base wire
         
' high sides         
GW  3 segm    0    0  hght      0  side  hght wire
GW  4 segm    0    0  hght  -side    0  hght wire
           
' vertical segment
GW  5 segm    0    0  base      0    0  hght wire

' ground
GE  -1
GN  2  0  0  0  13  0.005

' material (copper)
LD 5 0 0 0 58000000

' feepoint
EK
EX 0 fwir fseg 0 1 0 0

' test frequency
FR  0  1  0  0  freq  0

' end of model
EN


for further infos about the "Double T-Bar" also see https://sites.google.com/site/lofturj/tf3lj_vertical

Forgot, note to Harry (which I hope by now is ok and same goes for his wife !!)

Let's start from 

https://i.postimg.cc/xjbrB7vV/balcony-loop3.png

and look at the antenna, in your case (Harry) a multiband doublet like that would span about 27ft (each arm) which, if the arms are sloping down (inverted vee) would be reduced

By the way, in your case (Harry again ) running the twin coax all the way to the shack, would result into too high losses, soooo... run the twin coax to ground, and then on ground for a bit, connect the braids to a ground stake and the twin coax to a 4:1 balun (assuming you use two 75 Ohm coax) and to a 1:1 choke and, from there, connect the choke to your existing coax feeder

I believe it may give you a simpler, yet effective 80 to 10 antenna, and pairing it with a LoG (loop on ground) may offer a pretty nice performance

Just some additional thoughts

First of all, consider the idea of adding two loading coils to the vertical sides of the loop to bring it to resonance on the 80m band

Next, if you're going to use the double coax feeder idea, keep in mind that the characteristic impedance of such a feeder will be about two times the one of the single coax, so approx 100 Ohms for a twin 50 Ohm coax and approx 150 Ohms for 75 Ohm twin coax, my suggestion is, if possible, to use 75 Ohm coax cables, then, if connecting them to a tuner which doesn't have a balanced input, use a 4:1 ruthroff balun followed by a 1:1 guanella and, from there a run of RG8 will go to the antenna matching unit, also, since you don't have a good direct ground, leave the twin coax braid unconnected (floating)


For the 1:1 guanella choke/balun follow this

http://vk6ysf.com/balun_choke_balun_hf.htm

but wind 17 turns on. the toroid, and if possible use RG174 for the winding, for the Ruthroff, follow this

http://vk6ysf.com/balun_4-1.htm

but use an FT240-61 core  and twist the two insulated wires together before winding them on the toroid

Andrew wrote:Oh and... while the so-called "ugly balun" is cheap and easy, it isn't exactly the best way to deal with common mode, for a better approach, see here

http://www.karinya.net/g3txq/chokes/

in short, 18 turns of RG174 over an FT240-43 (140 if you're going QRP) will offer MUCH better performance

I'm taking into account . I've never made a balun with ferrites but it will be a challenge for mi

And talking about ugly-baluns this is mine made for me ... It's really heavy and I made it for another antenna for 80 m I haven't complete yet.



Thanks again. Keep in touch. 73.

Tnix wrote:

Ivan wrote:Hi Trix,
IMHO the supports either should be non-metallic (dielectric), or the antenna wire should be separated cca 0,2m from all of them. Just a guess...

VBR from Ivan

Yes, I'm thinking in a kind of wood ant thin poles because the wire is light. Also plastic poles end up shattered by sun.

And also I had thought to put them from 50-75 cm away from metal.

Thanks. 73.

wood will be ok, as long as you paint it with some weatherproofing product, otherwise the pvc pipes certified for outdoor use will be a good choice too and will weight less, the remaining point is the feeder, as I wrote, given the relatively short distance between the antenna and the shack, I believe that using dual coax as I suggested may be a viable idea and will allow to have a balanced feeder for the loop

forgot, opening the loop to make it an endfed or a dipole may work, but the radiation pattern of such an antenna will show higher (NVIS) angles (I simulated that in NEC) so I believe you'll get better performances by going for a loop config

Ivan wrote:Hi Trix,
IMHO the supports either should be non-metallic (dielectric), or the antenna wire should be separated cca 0,2m from all of them. Just a guess...

VBR from Ivan

Yes, I'm thinking in a kind of wood ant thin poles because the wire is light. Also plastic poles end up shattered by sun.

And also I had thought to put them from 50-75 cm away from metal.

Thanks. 73.

Oh and... while the so-called "ugly balun" is cheap and easy, it isn't exactly the best way to deal with common mode, for a better approach, see here

http://www.karinya.net/g3txq/chokes/

in short, 18 turns of RG174 over an FT240-43 (140 if you're going QRP) will offer MUCH better performance

Hi Trix,
IMHO the supports either should be non-metallic (dielectric), or the antenna wire should be separated cca 0,2m from all of them. Just a guess...

VBR from Ivan

Hi Andrew,


thank you very much for your ideas. This week I talked with a ham friend and he just told me the same idea but with a few variations:

1st idea: a big wire loop like the picts you sent but bigger, i.e., covering all the available front and separate about 50 cm from the metal.
With this I get some meters more of wire and metal balcony could act as some type of reflector.
The main difference between this model and yours is the position of the loop (yours on the metal and this in front of the metal).



2nd idea: like the 1st but forming a open long wire and trying to use the metal balcony as a counterpoise.

Regarding the supports and other hardware to hang it and provide security and discrection I'm looking for some kind of folded squares like this: https://www.amazon.es/dp/B09137FY22/?coliid=IE67JKH69J5SX&colid=1ALSCEXJZNIIU&psc=1&ref_=lv_ov_lig_dp_it

I appreciate very much you NEC code too.

I'm very happy because I feel that with your good ideas I'm will be able to put a discrete, secure and performanceful.

I'm telling you my development.

Regards. 73.

Hi "tnix", looking at the pics you posted, I had an idea and quickly sketched it, no masterwork but should give you an idea, here are the pics

https://i.postimg.cc/pdM2yvPv/balcony-loop1.png

https://i.postimg.cc/G2qrMsG3/balcony-loop2.png

basically, my idea is to use all the space you have to setup a loop antenna, the resulting rectangular loop will run from side to side and, seen from the above will have an "L" shape, to support it you may use some PVC pipes or wooden supports in gray or black color and the antenna may use some gray/black wire so that its visual impact will be very limited; I've also tried modeling the antenna in NEC before posting this idea and the radiation pattern from 80 to 10 meters seems pretty good, by the way the antenna will need the use of an ATU (matching unit) but that shouldn't be a big issue, also, given that the antenna feedline will be short, a good idea to feed such an antenna may be the one shown here (discard the antenna shown, focus on the feeder)

https://i.postimg.cc/xjbrB7vV/balcony-loop3.png

that is, two coax lines with the braid bonded together and the center conductors connected to the antenna feedpoints, the two coax will then run all the way to your shack where they'll be connected to a 1:1 BalUn connected to a short coax going to the ATU unit (or, if you have a balanced ATU you may avoid the BalUn), the braid of the coax will be left floating in your case, the resulting antenna, with the help of the ATU should allow you to cover all bands from 80 up to 10 meters, some radiation patterns from my NEC simulation can be seen here

https://i.postimg.cc/WbFMGmcn/balcony-loop4.png

again, it's just an idea, but I believe it may be worth some thought

[edit]

Here's another pic showing the full antenna

https://i.postimg.cc/MHWtdnxD/balcony-loop5.png

[edit #2]

in case you want to fiddle with NEC (https://www.qsl.net/4nec2/) below you'll find the model I used for the loop

Code:


CM qloop.nec - rectangular loop
CE

' symbols
SY freq=7.100          ' test frequency
SY hght=10              ' height from ground of top section 
SY horz=10              ' horizontal wires length
SY vert=2.5            ' vertical wires length
SY wire=0.00075        ' wire radius
SY segm=29              ' segments in wire
SY fwir=1              ' feedpoint wire #
SY fseg=1              ' feedpoint segm #

' calculated values
SY side=(horz/2)        ' half horizontal length
SY base=(hght-vert)    ' bottom wire height


' tag segs    x1  y1    z1    x2    y2    z2  rad

' low sides
GW  1 segm    0    0  base      0  side  base wire
GW  2 segm    0    0  base  -side    0  base wire
         
' high sides         
GW  3 segm    0    0  hght      0  side  hght wire
GW  4 segm    0    0  hght  -side    0  hght wire
           
' vertical sides           
GW  5 segm -side    0  base  -side    0  hght wire
GW  6 segm    0 side  base      0  side  hght wire

' ground
GE  -1
GN  2  0  0  0  13  0.005

' material (copper)
LD 5 0 0 0 58000000

' feepoint
EK
EX 0 fwir fseg 0 1 0 0

' test frequency
FR  0  1  0  0  freq  0

' end of model
EN


nothing special as you can see, but could allow you to run some simulation and see how the model behaves at different frequencies

Hi again.

Thanks for your advices. With your comments I'm taking very good ideas for my next HF balcony antenna implementation and the clother-dryer has gave me a great idea to make. I'll give you some picts when I'll implement it.
By now I've just put the short vertical in the balcon inside metal railing and I take it as a counterpoise. I know that's not the better place to put it but I've tried to put it about 50 cm away from metal railing. For me it's more secure to put inside than outside. The upper whip is a bit slope with a rubber tube I've found. It has a piece of extra wire to connect to upper whip and tune it so it's provisional. The CG-3000 remote tuner attached to the railing doesn't have to do with this antenna 'cos it's from another test installation and it's disconnected.
I have no time to test in deep but the few tests I have done gave me RF in 40 meter band so I've put an air wound choke I have.

I hope to tune and test deeper in a few days.

Thanks again. Regards.

Hi Tnix,
> ... and thanks for let me join to this forum.
You are more than welcome to join us; it is a peasure that you could join.

From the pictures you provided I can see that you re very fortunate. You have loads of possibilities. Working for you are:

1 - you have that metal fence (counterpoise)
2 - corner balcony - poking out pole would only have 25% obstruction to radiation
3 - height - a good distance off the ground
4 - two balconies facing different directions - more than one antenna array?

I have seen some of those clothes-drier racks that hang on balcony rails, over the edge. They are long wires that clothes are hung over. You could make a folded antenna element with that technique. Just put a couple of pairs of socks on it to disguise the real purpose.

Do the same on both balconies for different bands.

The antena array you have on the floor looks good. I would bre really interested to hear about performance. Remember that if you can get it to protrude outside the balcony are to the air i front of the building then your radiation will become better - more efficient. If you can just hang it 25cm outside the balcony then you could see as much as a 30% increase in performance.

One other suggestion, loops are always good performers. You can use fishing line from each corner of the opening to support a wire loop.

Stupid questions: at the corner of the two handrails, are they bolted and painted at the junction? Are the metal rails grounded? Are the vertical supports just bolted to the handrail? It could be that the handrail/fence itself may be insulated and used as an off-center-fed antenna. Perhaps you could be lucky if the rail/fence can be unscrewed and re-mounted on insulators. Just a thought!!

Very best regards Harry - SM0VPO

Hello Harry and all others and thanks for let me join to this forum.

I'm glad to read your good ideas to make HF antennas in restricted spaces and I'm taking into account for future reviews in my home.

Regarding the short vertical, as I said, I have a limited space and I priorize security and discrete. Next I show a very schematic picture where I'm putting the antenna inside the balcony using the metal railing as counterpoise (note that upper whip should be slightly slope to fit inside). Also I show a picture with the antenna made for 3.5 MHz in default of installing and tuning.




Thanks in advance. Regards.

Hello Tnix,

I have previously been forced to install covert antennas, and thre are loads of things you can do.

I was once asked to get a blind amateur in Cambridge (UK) on the air and he had exactly the same problem. He lived in a three-storey apartment block, luckily on second floor. One night there magically appeared another drai-pipe fixed to the wall of the building, with a sewage vent grille at the top. Nobody ever noticed. The drainpipe was a plastic tube containing a vertical half-wave antenna for 14 MHz.

When I lived in Upplands Väsby I used an electrical conduit in the ceiling of an apartment using "coathanger traps"to electrically cut the length to 1/2-wave. It was a bit noisy, but it worked. I tried a plastic tube flagpole with a nice Swedish flag, pointing out of the balcony at 45 degrees from the vertical. I had wrapped about 5m of enamelled magnet-wire around the pole to form some form of helical 1/4-wave antenna. That was very succesful.

Later I tried a full-length 1/4-wave using aluminium tubes. The base sat on a widow-ledge, and two nylon ropes from the top of the window allowed the pole to lean out to about 30 degrees from the vertical. A tapped loading-coil allowed the same pole to be used for 10MHz, 7MHz and 3.5MHz. A 5m pole is quite large, but three floors up it looked quite small from outside and I got away with it. The groundplane was the metal cladding on the wall of the building.

Later on I ran a 20m long wire antenna using 0.8mm Dia. magnet wire from the same window to a tree in the woodland behind the building. That was the best antenna I had in that building. From the ground outside it was totally invisible, even if you knew it was there.

Look at my homepages for the "packing crate antenna" ( http://85.226.187.247/antennas/crate.htm ). It was just a plywood panel, so I hung a dartboard on it (with the metal band removed) and used the edging of the panel as a magnetic loop antenna. I just had to use some frigolit (expanded polystyrene) blocks to lift the panel about 10cm from the wall. That antenna covered nearly all the HF bands.

On one occasion I had a particularly nasty neighbour. He contacted the kommun several times about me "jamming" his TV set. I put a wooden cane in the end of a long broom handle, painted it all white and poked that off the balcony. When he called about the interference I told him precisely where he should go. The following day a very angry official from the kommun came and told me that I had to remove the antenna or be evicted. So I showed him the wooden pole (that was NOT an antenna) and suddenly he changed, and laughed. There was no way the wooden pole was interfering with the neighbours telly, so he sa that the neighbour was lying through his teeth. All further complaints were ignored, even after I changed the wooden pole for the flag/pole/coil antenna.

So do not despair. There is ALWAYS a solution for getting an antenna, and even shutting up complaints. It is only your imagination that restricts your antenna possibilities.

Throw a few adeas at us and watch the response. Remember that a retractable antenna is always allowed, just like my pole on the window ledge.

Very best regards from Harry - SM0VPO

Tnix_ wrote:Thank you for your answer. Yesterday I signed up in the forum but I don't receive the activation mail from the admin yet so I cannot post any picture yet.

Regards.

Sorry for the delay, but your account HAS now been activated.

BR Harry

I removed the spaces of course, but the link still directs me to instructions how to sign up and upload my files.  

VBR from Ivan

Hi again,

the link is public reachable (it contains two blank spaces 'cos the forum doesn't let me post links).

I'm afraid that cannot mount it in my environment ... but I'll try to fit and tune it.

Thank you very much for your help. Regards.

Hi,
the link cannot be opened for some reason. Probably it requires the proper login.

I understand your effort to hide the antenna, but if you shield it inside the balcony, its efficiency may drop to almost nothing. I am unsure about your idea mounting it horizontally. If it was perpendicular to the railing and sticking horizontally into apace, high enough from the ground, it might act as a half of a dipole (the other half built by its mirroring in the railing and in the house facade). You would get horizontal polarization of the waves, which is not significant on HF. The plane of the wire cage is irrelevant. If you mounted it in parralel with the railing, it would be no good.

VBR from Ivan OK1SIP

I wish Harry will be better soon.

I've shared a quick picture of the terminated antenna with the unmounted upper stick at side in the environment I'd like to mount it inside the balcony. (Please edit this post to accommodate the link to be able to view the picture).

https:// drive.google .com/file/d/13nQ196xcxsSDFWBTjjIfTNeQviW-qjnu/view?usp=sharing

Also I have a "crazy" idea of an alternate position: could I put it in horizontal position with the wires in a vertical plane and the stick in vertical or horizontal position, and all in the upper plane of the metal handrail? What's your opinion?

My priority is as far as possible the antenna not be indiscrete and fit it inside the balcony or show it outside the less.

Thanks in advance. Regards.

Hi,
Harry has some health issues now, so be patient please. I cannot activate your membership.

VBR from Ivan

Thank you for your answer. Yesterday I signed up in the forum but I don't receive the activation mail from the admin yet so I cannot post any picture yet.

Regards.

Hi,
yes, this is exactly the right place for your questions and comments.

Keep in mind that the railing serves as the counterpoise and so it is a part of the whole antenna. If you place the radiating part inside the balcony, the metal railing and the concrete around will shield it. Placing it outside seems therefore better.
You can bend the upper whip by 90 deg or less if you need. The radiation pattern will be affected slightly.

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VBR from Ivan OK1SIP, co-moderator.

Hi all. I'm new at this forum.
First of all congratulations to Harry for his web site and sorry if this forum isn't the right place to ask my question.

I'd like to ask you for some help about the construction and placement of the short antenna that can be found here I have restricted space in a balcony with an about 11 m metal handrail and about 1 m width and 2.62 m high. Following instructions I have constructed the 3.5 MHz version with 4 turns of wire. I'd like to put it inside the balcony because I feel more secure than outside and it stays a quite away from metal railing. Also outside it not be discrete.
I haven't tune it yet but the first problem is the 3 m height. Which options could I have to fit in the 2.62 m height? Could I slope the entire antenna slightly from inside to outside or only the B pole? Could some of these slopes affect the radiation angle?
Does it change substantially the behaviour if the antenna be inside or outside the balcony?

I'll try to attach a picture of my constructed antenna and the place where I'd like to put it.

Thanks in advance. Regards.