“Never do anything to attract enemy fire – It annoys those around you.”
Murphy’s Laws of Combat.
UPDATED 5/8/223 This section will deal with various means to covertly operate radio systems while going unobserved. Any number of situations may call for these measures but the antenna system must still work!
“You can’t have antennas here.” Challenge Accepted!
Like many of us, I live in a neighborhood where now only satellite TV antennas are automatically authorized. (The power of group pressure). However as an individual homeowner I was able to get approval when I first moved here since the original CC&R/HOA documents did not prohibit antennas. In any event, a brief presentation to the HOA Board resulted in approval. However I keep them very low profile to keep the neighbors happy anyway. No towers etc.
“There are no rules here. We are trying to accomplish something.” Thomas Edison.
Some ideas:
Cover, concealment, camouflage – or hidden in plain sight.
Canoe Antenna – N6CC
See that 17 foot aluminum Grumman canoe (hint – mounted on those black plastic rack-mounts)?
I see a quarter wave horizontal mobile antenna for the 20 meter Ham band. It worked fine! (With a little help from impedance matching.) The fun part of antenna experimenting!
Attic Antennas
An obvious solution if you need concealment and have access to a space like an attic. I have several VHF ground plane and discone antennas in my attic. The wood structure is pretty transparent to RF energy. Signal strength from distant VHF repeaters does not seem to be affected even when the roof is wet. Here’s part of my setup:
DIY Discone antenna in attic
This one is a DIY Floppy Discone I made with 1/4″ galvanized screening, suspended from the rafters with paracord. It is fed with RG-213/U 50 ohm coax. Design dimensions of this one allow it to cover approximately 75 – 500 mc with acceptable VSWR so it works well for receiving and transmitting over that range. Simple, cheap, effective, very stealthy.
There is also a commercial discone visible further back towards the vent. These are particularly effective driving scanners or other wide band receivers such as my APR-1 radar surveillance receiver. There are also some wire ground plane antennas for discrete frequencies stapled to the rafters elsewhere.
Spaces like these also work well for suspended dipoles for lower frequency operations. I have also successfully installed fixed-aimed VHF/UHF yagis for reception of TV and FM broadcast signals.
Rain Gutter Antennas:
Below is a photo of a simple, effective and entirely covert HF antenna. It is the rain gutter along the front of a house. It is 80 feet long and off-center fed as a Windom with a single wire lead-in to a tuner. A GRC-109 will drive it directly without the tuner on 80, 40 and 30 meters and it has yielded good results within about 1000 miles at the 10 watt level.
At 10 feet above ground and operated “against” the house wiring/neutral radio ground, it makes for an effective NVIS-type antenna depending upon the freq/time of day. A simple solder lug under a sheet metal screw and then painted over makes the connection. The screw point penetrating the sheet metal is covered with silicone RTV to stop corrosion on that end. This antenna has been in continuous use for the past 15 years. Invisible.
My new gutters are the modern type, formed from a continuous roll of flat sheet aluminum – no seams. Seams? No problem. Sheet metal screws and RTV protection fixes that. Plastic? Just run some insulated wire above, inside or behind them. Simple works.
The covered wood rafters provide adequate “RF insulation”, even when the overlaying roofing itself is wet – I see minimal change in the SWR / complex impedance and any power loss appears to be minimal, certainly in terms of distant field strength “S Units”.
The down spouts, especially at ground level can also part of the system so make sure there can be no RF voltage or possible personal contact there. If there is concern, inserting a short PVC section between the gutter and metal downspout will isolate it. The $2.00 fix; cut to size. Alternatively, make the downspout itself from PVC and run an insulated wire up inside it.
Gutter antenna safety isolation
Hardware stores have a wide variety of standard-size PVC downspout stuff. A simple straight section worked here. Good idea anyway, apply Common Sense. Think it through. SAFETY FIRST!
Rain gutter covert HF antenna
Gutter antenna connection “detail”. See the connection? Simple, effective.
Rain Gutter HF Antenna – N6CC.COM
Above: This gutter antenna is connected via an upper roof-level downspout where no personal contact is possible. This all-aluminum gutter is fed with coax with an unterminated shield (at this end, shield connected to radio ground at the other) to reduce nearby computer hash from inside the house. Experiment.
It is a quiet HF antenna that is untuned but it happens to be resonant in the 60 meter band. With a simple TEE “antenna tuner” the transmitter will feed it power and radiate it anywhere on HF. Produces contacts via NVIS for regional comms and DX out to several thousand miles with a 100 watt transmitter.
It works great and seems to be not affected by rain/wet conditions. Pretty invisible. After you are done testing, apply a blob of RTV to weather proof the connection.
Rain Gutter HF Antenna – N6CC.COM
Above: Another HF rain gutter antenna connection. Also an effective HF performer; this one is used primarily as a shortwave receive antenna. These aluminum gutters are made of 0.032 inch thick material and have an equivalent cross sectional area about the same as size 00 AWG wire. This produces a rugged, high conductivity antenna although not quite as conductive as copper of course. Pretty close. Hint: Big Yagi’s are made of aluminum.
These elevated, isolated gutter antennas do not produce an RF “shock” hazard to someone at ground level since their downspouts do not go all the way to ground level. They spill onto an intermediate roof area. At the low power levels I run on the 80-60-40-30 meter bands they are also RF safe to the building inhabitants.
However since they are in close proximity to the building (inhabitants) make sure you perform your MPE calculations. SAFETY FIRST!
Below is another HF gutter antenna with a slightly different feed connection at the end of the galvanized steel gutter (antenna). Solder lug is under a sheet metal screw, screwed into the gutter. The lead-in is concealed under the brown flashing strip. The screw/lug is protected by a blob of clear RTV weatherproofing. (Yup, the gutter needs to be repainted..) This antenna has also been in use for over 15 years. I have had no problems with galvanic corrosion or RF rectification but it is something to be mindful of. Simple, effective, invisible.
No gutter access? Just use the aluminum flashing strips as available.
Disclaimer: The NEC Code addresses antennas so follow your local jurisdiction requirements in all cases. Be aware. The ideas presented here are for informational purposes only. Safety First.
Tree Supports/Camouflage:
Below is another simple type of covert receive-only antenna. This time, it’s a 1/4 wave ground plane cut for the local airport tower frequency. It is simply an SO-239 with brazing rod soldered to the center conductor for the vertical whip and 4 radials sloping downward at 45 degrees. That is slipped over a 2 foot piece of 1 inch PVC pipe which conceals and protects the PL-259/SO-239 connection, the internal preamplifier and also provides a mounting capability. The PVC pipe is painted flat olive-drab and is zip-tied to the branches about 30 feet up in the tree.
I am currently using this antenna to drive my AN/APR-1 Radar Surveillance receiver listening to aircraft in the VHF/UHF AM bands. That receiver has inherent low sensitivity so this little preamp helps considerably. Some details here: http://www.n6cc.com/an-apr-1-apr-4-radar-comm-surveillance-receiver
VHF Ground plane receive antenna with preamplifier
The antenna includes an old Radio Shack TV/FM antenna preamplifier (appx 10 db gain, 5-900 MHz supposedly) and protected inside the PVC mounting mast. A notched PVC pipe cap keeps it somewhat weather proof. It drives some RG-6/U 75 ohm “TV” coax that I had on hand, down to the bias tee and receiver. It works very well in the VHF and UHF military AM aircraft bands. It drives my AN/APR-1 Radar/ELINT intercept receiver quite well.
It is very effective and entirely invisible from ground level. The proximity to the branches has no apparent ill effect and the antenna itself is positioned away from the trunk and actual foliage near the support branches. No apparent impedance change or performance loss while wet although at VHF frequencies I am sure there is some loss. I don’t notice it. That 30 foot elevation sure helps with line-of sight radio range though.
The PVC pipe is barely visible, even zoomed up close as in this photo. The antenna vertical element is made from copper alloy brazing rod (from “Harbor Fright”) and the radials are 14 ga copper wire. Sprayed with flat O.D. paint it is all but invisible.
This one is mounted 1/4 wavelength from the main tree trunk. I stapled a vertical, 1/4 wavelength wire to the trunk to act as a reflector element, thus producing a cardioid pattern. Oriented away from the local airport it produces some gain towards the airport and it gives good results.
UPDATE: A new, multi kilowatt FM broadcast station KLVS just set up operation on 107.300 mc. It is about 6 miles away and it completely overloads that little preamp generating intermodulation products. I now hear that FM station all over the VHF aircraft band; what to do?
I put some transmission line theory into practice by installing a quarter wave length open-ended coax stub right at the antenna base (upstream of the preamp.) Correcting for the line 0.66 Velocity Factor. Theory says this will present a “short circuit” at the antenna base-shield connection to (only) 107.300 mc signals before they hit the preamp.
Quarter wave wave trap on VHF Aircraft Band ground plane
The RG-58C/U coax stub exits the rain cap and extends away from the antenna. Some quick work with an antenna analyzer made easy work of cutting the stub to the correct length. I reinstalled the antenna; the stub completely eliminated the problem caused by that overload condition. Presto, Theory becomes practice. The squirrels still like eating the PVC rain cap.
Wire Antennas:
I have found that 26 gauge gray teflon wire works very well for low-contrast dipoles when the backdrop is the sky. If the background is primarily trees, I have found that brown is better than green insulation. Teflon is shiny and will catch the sun, highlighting an otherwise stealthy antenna. Rubbing the wire between 2 sheets of 400 grit sandpaper before launching roughs up the teflon surface, stopping sun glint.
Remote campsite antennas: Here is an 18 AWG 80 meter dipole rigged at a forest camp. Painted coax, thin, non reflective wire, strung close to the trees. Basic stuff..
DIY Dipole insulator, painted coax feedline, low visibility
“Try to look unimportant – they may be low on Ammo.” Murphy’s Laws of Combat
Keeping bush antennas concealed avoids questions. A good (and laid-back) friend of mine was confronted by an irate Park Ranger for putting up a Field Day wire antenna in “his” trees at a State Park. Threatened with a citation, he was ejected from the park and forfeiting his $30 camping fee. Beware. “Hi – I’m just here camping….Nothing to see here, move along.”
Below is one end of an 80 meter “residential” dipole held up by a tree. I usually don’t use end insulators but I did here. 20 pound test monofilament nylon fish line is a better insulator, rides well in the wind and is practically invisible.
Note the support for one end of the dipole made with WD-1A/TT field telephone wire and insulator:
Invisible Antenna Support
When held up by this 20 pound test monofilament fish line it is all but invisible relative to the antenna wire.
I use insulated wire whenever possible – it avoids direct contact with wet trees /leaves which helps – although not essential for comms. Also for more permanent wire antennas in the trees insulated wire does not chafe as much as bare stranded wire. Especially with Teflon insulation.
The presence or absence of wire insulation affects both the resonant length and impedance of an antenna. However with HF antennas the effect is minimal and can be ignored relative to other considerations such as height and near-field objects.
Stealthy and therefore lightweight, wire antennas like this are somewhat temporary in nature. Kept slack, they ride well in the wind and accommodate tree swaying but they do occasionally break. I repair mine about once a year where a “permanent” antenna made with 14 Ga wire should hold up longer. Design requirement tradeoffs.
Another stealthy workhorse antenna around here is an Inverted L, the base camouflaged with an inverted flower pot, wire up into the trees. This one is made from paralleled conductors of WD-1A/T infantry telephone wire. Strong, thin, light, hard to see. An initial “breadboard” matching circuit experiment: A 28 microhenry roller inductor, 365 pf air variable and an additional 100 pf ceramic doorknob as needed. The capacitor plate spacing is adequate for my setup.
Initial tests with series/shunt variable mica compression capacitors as I experimented with different wire lengths to get the high-current, radiating segment horizontally and in the clear. “Mr. Smith” (Chart) is my friend!
Inverted L Antenna Feed point Matching
Below: I settled on a final design for this particular antenna: Series, variable inductor with a shunt variable and fixed capacitor on the antenna-end driving a fairly high impedance Inverted L wire antenna. This system includes the important “ground bounce” radial ground wire buried under the antenna to enhance NVIS. It works very well in this dry soil with minimal transmission line losses.
Adjustable L Network for matching wire antennas – N6CC
Here with an adjustable feed point matching circuit to enable occasional frequency/band changes. Designed around a series/shunt variable L/C network protected inside a flower pot. With the coax cable and ground radials buried, pretty innocuous. Nothing to see here, move along.
Inverted L Antenna Camouflaged Feed Point
This antenna is a really good performer for my main interest in 0-400 km “NVIS” regional comms with my buddies using my 10 watt military CW field sets.
Mk1 Mod 0 Antenna Installation System
Above: The Mark 1, Mod 0 Carbon-based, all terrain, night vision capable, 4X4, autonomous, high-altitude HF Wire antenna installation system. I have the highest HF antennas in the neighborhood.
I have found that almost any piece or wire or metal will work as an effective antenna on HF if it is long enough and reasonably in the clear. This isn’t rocket surgery…You certainly don’t need to buy a commercial wire antenna as long as you have any kind of wire, a matching device and a reasonable ground connection on HF. Unless you only work 20 meters, take that G5RV (or at least the coax section) and bury it for your ground system – you don’t need that compromise-complexity to make lots of contacts.
I have made lots of long range contacts on 80-10 meters from the field with a simple 1/4 wavelength wire thrown up in a tree or laying on top of bushes and another 1/4 wave wire laying on the ground for an ” RF return”. You really don’t need much to communicate when the bands are “open”.
I have used the aluminum siding on my house for an antenna when I was a kid, and I used to load my Hallicrafters HT-40 transmitter into my neighbors “grounded” chain link fence. Not such a great plan, but it worked surprisingly well. If you are trying to break a pileup into VQ9 – Land on a contest weekend, you need something much better, but for casual, reliable ops, simple works just fine!
Below is a photo of my portable, non-stealthy 1/2 wave PVC J-Pole antenna sitting on the ground. But that’s not the point of this photo. Can you see the horizontal wire above and behind it? Didn’t think so…Difficult for the camera – or eye to see.
For some more info on temporary “bush antennas”, see Portable Field Antenna Kit elsewhere on this blog. It describes what will come in handy in making stealthy or otherwise useful antennas for Boonie Ops.
Below is a somewhat stealthy (thin, olive drab, no feedline) EFHW antenna. I’m not a fan of EFHW antennas for my purposes but they can work for random contacts. (Take a look here for my experiences and findings regarding the EFHW: N6CC EFHW Antennas )
This 132′ one includes a 49:1 impedance matching transformer for low power portable work on the low HF bands. I still need to field-harden the transformer assembly with a suitable enclosure.
HF Band EFHW Field Expedient Antenna
In a hurry to make your comm window? Try these: Field Expedient Antenna Systems
Speaking of “clandestine comms”, you may need a stealthy, reliable radio to go along with your stealthy antennas…This one is a tried and proven winner.
The RS-6 agent radio
Or for more tactical field ruggedness, this long range Recon set: AN/TRC-77 radio set
Or my personal favorite for covert ops, AN/GRC-109 Special Forces radio set
Another option that takes some equipment and planning is to actually locate the radio and antenna remotely from your operating position: The assistant Radio Operator setting up the AN/PRC-47 in the forest.
AN/PRC-47 LSB setup on 24 volt battery power.
Above: An AN/PRC-47 HF SSB/CW transceiver operated by an AN/GRA-6 remote control set over infantry field telephone wire. The radio can be up to 2 miles from the operator and can be remotely turned on or off without a local operator. On this trip the operating position (campsite) with the remote was about 100 meters from here…That system works great if you can swing it. Easy to conceal if necessary. Also keeps artillery away!
On the gutter mount antenna are you just using the coax center to attach to the gutter? What about the ground on the coax, is it used? I live in a complex and need to use a gutter mount for antenna.
w9ldv
Hi Larry – With the “gutter antennas” I have shown, the coax shield is not connected to anything at the antenna-end. It is “grounded” at the radio connection. If you have something near the gutter that is “grounded” (like maybe the downspout, a railing, a ground rod etc) that would be generally be better to connect to the shield. But what really matters is the fact that whatever you rig up will have some complex impedance since nothing is likely to be resonant (no reactance). So in that typical case your antenna matching circuit at the radio will need to tune that out so your “50 ohm radio” can transfer power to the system. The main idea is to get transmitter RF current flowing in a metallic conductor up high, and in the clear – even if that’s just a rain gutter. It will work.
But be aware of RF safety issues if the downspouts are accessible to people touching them. I usually run my military gear about 10-15 watts, occasionally 100 watts. Other downspouts could have high RF voltages on them and could produce an RF burn problem with high powered transmitters. The chance of someone touching a downspout or other part while you are transmitting is probably low, but still possible. And that part may-or may not be “hot” at the particular frequency you select for operating…but it needs to be considered.
In a fancy installation one could insert short PVC downspout sections in series with the main metal downspout up high to isolate the ground-level parts. (the parts I have seen are dimensionally-compatible with each other). Probably not do-able in an apartment complex but would work at a private home….Think it through – safety first!!
If you are just using a contraption like this as just a simple “receive” antenna, a single wire down to the radio will work fine, you will hear signals, but probably without optimum efficiency…
Experiment! If it’s all you can get going, it will work and get you contacts….
Have fun with it! A “tuner” is your friend…
73, Tim
Hi Tim,
Fantastic Web site!!!!
I have a few questions regarding my new rain gutter antenna. Should I use 1/4 wave radials on each band or would a single 33 ft work? And second, should I couple the tuner to the gutter directly, or through a pair of parallel 0.01uf, 2kv disks? Seems the gutters show 60ohms to ground on my Fluke.
Tuner is an Icom AH-4 behind an IC-7200 (100w). It’s an L-network type and I’ve received conflicting reports as to float the tuner for RF, or ground it directly.
I have one radial. It is a 4-conductor, twisted pair of 14awg, insulated; running 90 degrees from the 2 story condo. For safety, I buried it 1-2” below the soil. I have another identical radial ready to bury that’s 67 feet. SWR tests indicate 160 meters to 40 meters are ok, but n/g on the higher bands.
Low freq. receiving is insane, but haven’t yet transmitted.
Appreciate your help!
73, Stu Martin, k2qde, Ex CT3 – NAVSECGRU 3-6
Austin, TX
Hi Stu – Thanks for the note…Looks like you have done your homework on this type of antenna…I guess a lot of the answers would depend upon where your antenna tuner is in relation to the antenna feed point – and what kind of transmission line you use. I would certainly “ground” the tuner – especially since it is grounded to the radio via the coax anyway. Keeping the chassis at “ground” is important in a lot of respects. Seems like any number and lengths of “ground radials” will be helpful…Even a single quarter wavelength ground wire, buried, will help keep the RF off your chassis and will be good safety-wise anyway. Looks like your plan is for a quarter wave radial wire for both 40 and 80 meters- should be very helpful in giving the tuner a fixed reference voltage to “work against”..
Also, the (wave)length of your gutter/transmission line at a given frequency of course determines its feedpoint impedance along with height above ground etc. If it is at a voltage null (like the feed point end of a quarter wavelength antenna) the voltage there will be low, the current high. Vice versa if it is n-Halfwaves long… With a “good ground” I would think your tuner should handle most impedances it sees with this configuration.
However a quick look at the AT-4 manual indicates there may be a problem. It may not be the best “tuner” for the job. The manual shows a calculation to determine “undesirable antenna lengths” – and that looks like anything a half wavelength or integer multiple long. That says its design can’t handle “high impedance” antenna loads. So make sure you stay away from those lengths (or corresponding bands with your fixed-length design). They are probably concerned about the very high voltages on the components they chose when driving high impedance levels.
If you have, or can borrow an antenna impedance analyzer that will answer a lot of your questions – they are pretty indispensable for antenna experiments..
I would think a direct tuner-antenna connection is nominal – capacitive coupling it to the gutter doesn’t buy anything that I can see…That might be an issue with a vacuum tube transmitter PA running high voltage – and a failed output coupling cap putting HV on the antenna. Not good, but looks like you are running a solid state transmitter…no worries there.
That 60 ohm resistive as seen by the multimeter is odd. Can you figure out where it comes from? Is one end of the gutter grounded, making the bulk resistance of the gutter metal look like 60 ohms? That 60 ohms will absorb RF power and maybe get hot – may be a problem too…Is the building stucco-lath constructed? Maybe a downspout clamp is nailed into the wall catching the chicken-wire underneath? That could cause a low resistance path to ground…Seems the gutter should be very high resistance above ground…Does that resistance change when everything it wet?
Sounds like you are almost there – reciprocity says that if the receive signal is “insane” the TX signal should do likewise!
Loving your site! Another question for you: How does one ‘program’ the Mark 1 Mod 0 installer? I can’t seem to find an NSN for them either… 😀
It’s classified SECRET SQUIRREL
NSN = No Such Number LOL
73 & TNX for visiting
Just starting in the HAM world. Just ordered a new radio so am working the antenna angle. I too live in a covenant neighborhood. Thanks for your insights and the pictures. Luis
Hi Luis and welcome to a fun hobby! If you keep your antennas stealthy you can “get forgiveness rather than asking for permission”. Hopefully no one even notices. My area has restrictions but luckily my setup was grandfathered in – but I keep it unobtrusive anyway. No hassles…!
Have fun with it & thanks for visiting my website…!
Tim
Hello,
Really like your site and all the engineering that went into these ideas. I have a ham friendly QTH on the weekends (when I can get there), but it seems that all the great DX openings occur when I’m at my apartment during the week.
If you have any ideas for 2nd story apartment dwellers, they would be appreciated. Right now, I’m waiting for the leaves to come back on the trees so I can throw a wire out my bedroom window and have the foliage conceal it.
73, Rob, KC5RET
Hi Rob – Thanks for visiting my site; hope you can get some ideas on how to meet the challenge! It’s almost like that – outsmarting them….
I guess just look for some candidate metal that would be safe for RF and give it a try. But you are on the right track with trying to get some stealthy wire up into the local tree – that would be somewhat high and somewhat in the clear relative to a gutter etc. You might also consider something really thin like 30-35 gauge magnet wire dangling from a window. Pretty invisible, maybe you can also try to figure out a way to just deploy some wire at night and make it easily retrievable when you are done. Also, some guys report running a wire around the apartments, taped to the walls/ceiling. The Special Forces Handbooks from the 1960’s have drawings of just that configuration when used with clandestine GRC-109 sets. On the low HF bands RF exposure for tens of watts + is minimal, just keep it away from contact. It might not be great but better than nothing for sure. The experimenting is the “fun” part! Plus a lot of satisfaction for making contacts with something makeshift like this stuff..
Have fun & 73,
Tim
Tim,
Love the site and this is just what my HOA nazi ruled community drove me too, covert stuff…
My neighbor (who’s father was a ham operator) will allow me to connect to his gutter system which consists of a 50′ horizontal run, and two 20′ + vertical downspouts, and a small 15-20′ horizontal dog leg section…
That’s over a 100′ of gutter…
The feed line run is maybe 20′ to my rig, a kenwood ts-440s with ATU….
Do you think this would be viable for me?
If so, i’m gonna rig it up…
Thanks in advance….
73’s..
Romeo Foxtrot…
Hi RF – A typical situation that is worth a try. A couple of thoughts: First, lash it up and try it on receive only. That is unconditionally safe and it will tell you if all that aluminum is picking up computer hash, light dimmer buzz, flat screen TV garbage etc. If it picks up too much receive noise in close proximity to the building(s) it will be marginally useful as a system. Secondly, if it passes receive tests make sure any personal contact possibility is taken care of. The chances of someone touching an RF-hot downspout, while you are also key-down or on a voice peak are minimal, but the consequences can be high. (you would also want to verify that your RF on the neighbors gutter does not cause RFI problems in his house!). For downspouts, I strongly recommend you decouple them from the RF carrying gutters, probably by an insertable piece of PVC downspout up out of reach someplace. The hardware store may carry compatible parts, mine did..
Yes, it will work and get you lots of contacts and is certainly better than nothing! One hundred feet of aluminum conductor well above ground is a good HF antenna.
Have fun, be safe,,,,Tim
Tim,
Lots of useful practical info here. I’m looking at a gutter antenna with a twist. I have two aluminum gutters, 38′ long on either side of my house. I’m considering connecting them as a horizontal loop with 14 ga wire. They’re 30′ apart and parallel. They’re about 14′ high and I plan to insulate the down spouts (each has one at one end). I have a Micom 2 I plan to run at 60w (half power to start) feeding an SGC tuner. This will be a spring project as the snow is falling and there is a lot of wind until then.
Thank you,
Andrew
Hi Andrew – sounds like a plan! You will have lots of conductor, high enough to be effective and safe. Just verify that the resulting signal does not raise gremlins inside your house with your home gadgets. You’d be surrounded! It should work well for you.
Thanks for visiting my site, hope it is useful.
73, Tim
Hi Tim,
Great info, especially for a new guy like me.
Can you give me some details as to what type of wire you are using to run the rain gutter antenna into the house? It looks just like plain of copper wire, is that right?
If so, do you then connect it to coax inside the house for connection to the radio itself?
Thanks in advance.
Jon Goodson
Hi Jon – Good question! Well it is ordinary “hookup” wire, Something like 20 – 22 gauge insulated stranded wire but almost anything will work. As with all my antennas, the wire or coax comes to a patch panel in the radio room where there is a similar patch panel with connectors to each radio. Then short RG-58/U jumpers which allow me to connect any radio to any antenna. So that panel with its “double female BNC” feedthrough connector is where the wire meets the coax to the radio. I just solder a small pin to the wire and push it into the BNC panel connector in the back to make that connection. Mechanically “flimsy” but it is in a protected area and they don’t fall out or otherwise disconnect.
I have two panels, one for HF systems and the other for VHF/UHF equipment.
WIth the gutter antennas I usually use them for receivers or low power transmitters, up to 20 watts, but I have used them with 100 watt transmitters as well. So be careful with having wire with adequate insulation and route it to the equipment with that in mind.
You can see the two panels (green and gray) in the photo posted here; last photo in the post:
http://www.n6cc.com/one-of-many-n6cc-stations
Thanks for stopping by! Tim
I have 191′ of aluminum picket fence that is within 15′ of my condo. It has top and bottom rail that I’m sure would have to be checked for bonding. The post are held to a block wall and set with epoxie.
Do you think this would make a good HF antenna? Just got my general yesterday.
Hi Hugh…Well, give it a try as a receive antenna first – and see how it behaves. If it is metal, it is an antenna…Since it is at ground level in an apparently crowded place, it would not be a good candidate for transmitting however. Safety first!
Congrats on getting your General license..
73, Tim
Tim, with the down spout antenna how do you handle an RF ground? I plan to attach similar to you and the coax shield I was going to attach to a ground rod. I also have an antenna surge protector that I was going to attach about 2 feet away before it heads about 25 feet into the house. I live in the lighting capital of the world and my building has been hit. The coax will then enter into a MFJ 969 TUNER. The inside ground will probably be a cold water pipe. A 30 foot wire to the ground I think would be too long. I am on the second floor of a condo. Condo living is great but…. I don’t have room for counterpoise radials. I have read a lot of article and you make the most sense. just want to make sure I am not on the wrong track. Licensed in 57. Just got back 2 months ago. Between sticker shock and condo living – I hope you can help me and set me straight. Don
Hi Don, thanks for the Comment.. Well you have identified some of the problems and of course, safety first. Operating HF gear from a place (second floor) away from the soil can be tricky due to the impedance of the long “ground” wire. One solution is an “artificial ground”, I think MFJ makes one. It is really just an antenna coupler and its job is to transform the reactance of your long ground wire to a low impedance that keeps RF off your radio chassis. That long wire is now part of your antenna which may help or may not, it will radiate. May be a good solution for you.
Sounds like you plan to feed the gutter downspout near the soil level? That would be good if no personal contact with it is possible. Then terminate the shield with a ground rod there and certainly put your lightning surge arrestor there as well. For RF purposes it would be good to also connect one or more wires to that rod, spread out, probably buried along the foundation which also helps keep them stealthy. If you can.
Also, your equipment AC power ground connects to the building power ground (green wire) and eventually the neutral at your service entrance. Of course, not designed to be a low impedance RF ground it can “help” keep RF off your chassis. That’s what I use for one gutter antenna that is fed up on the roof, coax shield just not connected up there. (my equipment is at ground level with a local ground rod and ground radials nearby). It works fine via a coupler.
In the end, your tuner can probably handle the impedances your antenna presents to the radio and it will work. As you know, with any antenna system, you just want to make sure you are disconnected and otherwise safe from lightning when you are not using the gear. And that there is no RF on the system where personal contact is possible while you are “key down”. It’s a complex problem with lots of variables depending upon the geometry of your station/building. Give it a try, do some experiments, it will probably get you lots of contacts…
Thanks for visiting my site, 73, Tim
Tim, just an update. I have the antenna connected from drain pipe to tuner, MFJ 696,I have a lot of noise on all frequencies . it is so loud I cannot make out stations. The antenna to the first joint of the drain pipe is about 6 ‘. An ohm meter shows a good connection of the coupling 6′ next drain pipe is about 12′, giving me a total of 18’. I know band condx are not good but the “noise” is much louder than my sx101 . Any idea why so much static noise? ideas of eliminating that noise or is that part of the drain pipe? 73, Don
Hi Don – got your note. I tried to PM you but looks like your address does not work..
Well I don’t think the gutter or really any antenna generates its own significant noise. My guess is that the antenna is working OK on receive, but it is *receiving* noise from external sources. I recall you are in a multi unit building and that usually means lots of computers, monitors,TV’s, switching power supplies, wall warts, digital gizmo’s etc. and they all generate a lot of broadband hash. If that’s the case you may not be able to do anything about it. Any antenna near your home will hear the same hash, so it’s probably not related to the gutter per-se.
I have a buddy in San Fran with a similar local noise problem. He can use one of the remote SDR receiver sites on the Web for his HF receiver. You can still transmit locally with your gutters. Take a look on the web for a remote SDR receiver that you can listen in on.
Here’s one in Half Moon Bay CA. It works great and fun to play with. There are probably others closer to you – give it a try. Here is the URL http://69.27.184.62:8901/
RF noise pollution is a real problem on HF, the FCC seems to be unable or uninterested in addressing it…Tim
Hi Tim,
Thanks for the info for those of us in HOA situations! I’m considering running a wire on standoffs above the rain gutters rather than using the rain gutters themselves. I have enough guttering to run 130′, so hopefully I can do 160 or 80 meters. Do you think the gutters will absorb too much of the signal or create spurs? One person I talked to was concerned that the end of the gutter would have high voltage on it which might be a fire hazard. Should I ground the gutter as a counterpoise with the wire only inches above it? I’d appreciate your insight! Currently I have a 40 meter dipole strung from one end of the attic to the other. I’m using an Icom 745 (100 watts) and a Drake MN2000 tuner.
Thanks again for your ideas!
Dean
Hi Dean – A few thoughts. Running your wire antenna very close to, and parallel to your gutter will certainly induce RF currents to flow in the gutter. I think that in that geometry the gutter will just re-radiate most of that absorbed energy (less metallic and support losses). Your attic dipole is probably also inducing RF current into those gutters anyway..
“Spurs”?, no, you need non-linear rectification to cause that kind of harmonic generation problem. You should be OK in that regard unless the gutter is rusty or if there are dissimilar metals in corroded contact involved. But something to be aware of.
As to high voltage at the ends of the gutter – yes. The far end of any wire (conductor) antenna will exhibit “high” voltage since the impedance there is very high. The resulting voltage being a function of your TX power etc. This is why beefy insulators are used at the ends of wire antennas. Whether that HV will be a problem depends upon the structure and possibility of personnel contact. Be conservative with safety!
Grounding the gutter might help safety-wise but the downlead to the “ground” will have inductance and this will keep some level of voltage on the gutter ends anyway. I think that using it as a “counterpoise” that close to your wire probably won’t do anything useful for you.
That’s what I’m thinking…..
73, Tim
Just wanted let you know that i have using a rain gutter antenna for years with an alligator clip to gutter support a few feet off the ground then 16 gauge wire though window to antenna tuner works very well on 40 meters with my military tcs-12 transmitter and my johnson ranger and my ten triton iv though does not like 20m. I get good reports people are always surprised thanks for the fine site greg wa2oro
Hi Greg – Thanks for checking in – always great to get “field reports” from users. Yes, unconventional antennas can work quite well. Especially cool that you are using it with your Navy TCS PT Boat radio!
73, Tim
Hi Tim,
I hope you get this question, not sure how often you look at this page. I’m in an apartment situation with 10 floors, and, I’m on the 8th floor, 64 feet off the ground, and I have a 39 feet long balcony, 39 feet! I love that length. I have an MFJ 902 6 through 80 meter antenna tuner. Right now, I currently have, a dipole with a 1 to 1 balun between the 2 legs, and each leg is 19 and 1 half feet long. It works fantastic on 6 through 20 meters!!! However, I would like to also get on 40 and 80 meters.
I thought about doing any of 3 things:
1. Buying 2 coils of single strand copper wire, which the dipole is also made out of, and connecting those 2 coils (not unwound, but still in coils, to the dipole, 1 coil on each leg. or
2. Taking down the dipole, and instead, I’ve got a 10 feet long piece of sheet metal that is used on a car body, and thought about using an 80 meter mag mount, placed in the middle of that sheet metal, with 2 18 and a half feet wire radials, going in each direction, and trying to tune that up on all bands. or
3. Take down the dipole, and instead, I can also get chain length fencing and stretch it 39 feet from one end of the balcony to the other, with a 1 to 1 balun, in the middle of that 39 feet balcony. So, which one would you do?
Please email me, or, just leave your reply here. I will bookmark this wonderful page!
73,
Trippy
Hi – Sounds like you already have the hardest part worked out – the ability to experiment with the space you have available. It’s hard to zero in on specifics, but if your dipole works well on 20-6 meters it sounds like your “tuner” can’t then transform that impedance to something that will work on the lower bands as well. So your instinct is probably good – add some inductance in each dipole leg, maybe halfway or more towards the ends. Just experiment until you find something (stealthy) that your tuner can handle and that works for you. Interaction with the metal in the building structure will be a dominant factor I think. Chain link fence on the balcony sounds interesting but it is not a continuous metallic conductor so a simple wire might work better and be easier, less “obvious”… A (lossy) mobile vertical can also work but the “ground plane” will be very important. Nothing magic about sheet metal that a few radial wires can’t also do and be easier to work with. Just an educated guess. Try to use insulated conductors – safer and results will be more predictable.
Thanks for visiting my website – have fun, sounds like you are on your way…
Tim
Howdy!…..
Back many years ago, I seem to remember that someone wrote an article about building a clandestine bird house vertical antenna that was capable of being remotely tuned………..I have been trying to find that article as I am now residing in an HOA and would like to ry something else other than just my raingutter antenna on HF.
TNX for any help /suggestions that you have to offer…….
Best regards,
Val L. Erwin / W5PUT
Hi Val – I seem to remember that article as well but I don’t remember where or when I saw it. Sorry I can’t nail that one down for you..
QST has had some articles on remotely tuned antennas in the past. Several were for verticals/flagpoles but the “camouflage” could be adapted to your particular situation..
Have fun with it – I look at this as a challenge!! Tim
Now temporarily located on Holidays Deep in HOA Occupied Territory in the “Sunshine State” (where it is raining most of the time) but always on Covert Antenna Projects Assignment…I wanted to pass on this suggestion, based on my observation of the general construction techniques observed here:
If you live in one of those Gawd Awful Condos, Radials would go nicely in the the little decorative rock and shell “Garden” next to your place.
No Problem there….
The Vertical?
Got a tall section of wood moulding as part of the “decorative” part of the dwelling?
Well, you MIGHT consider placing a wire right in the corner of where it joins the outside wall, and you might just caulk it in place.
You might be able to temporarily affix it easily with superglue or something from near the top most window until the caulking sets.
If the insulation on the wire is white, it’s going to stay mostly hidden as the caulking ages..
Caveat Emptor….this is just a suggestion based on my observations. Try at your own risk… Your mileage may vary…
73 DE W8LV BILL
Hi William – I like your thinking! It’s a challenge, there’s always a way…
Illegitimus Non Carborundum!
Tim
Two more observations here on Special Secret Squirrel Assigment from deep in HOT…
(HOA Occupied Territory)
Someone mentioned using their car antenna in the driveway.
Or using your car as a Mobile Repeater…
Well… Your “Car” could also be your BOAT!
Just in the yard here, right outside of the sliding back door,
there is a slip. Affixed to the slip, a sailboat..
You could easily use your sailboat in lieu of the car…
After all, you should equip it for HF Amateur Radio, anyway.
So why not slip in a UHF/VHF and do the Mobile Repeater thing?
Certainly you could cross link: And use UHF/VHF hand-held from your dwelling to activate your HF Rig on the boat! Or: you could just run a temporary feedline over to the boat.
You could run off if an isolated secondary marine battery for hours or more. And then, there’s also Shore Power! And the boat wouldn’t necessarily have to be that close by, either. It could even be in dry dock miles away.
So There You Have It: Several Ways to use a boat.
I also see: Leftover Modular Telco plug indoors. There would be a lot of existing wire conected to that. I wonder if it has been abandoned?
You could find out..
Or, if it is still connected to “something” on the far end, but not in use?
Well… You just might trace it down to a more distant location, say 80 metres or so,.and REALLY Cut the Cord!
Remember, Ham Radio is the Next Best Thing to Being There!
Abandoned CATV wires might also be a possibility…
These could be used for just lead ins from ohhh say a Caulked Vertical,
or in some cases, as actual antennas themselves… Caveat Emptor.
73 DE W8LV BILL
It’s all good! When I was kid I hooked my Heathkit Crystal Radio to the metal “finger stop” on our rotary dial telephone – for the antenna. It worked! Lots of wire connected to that thing… Tim
I have a long length (120+ft) of gutter around my house…. But I was thinking instead of using the gutter as the conductor, has anyone ever ran wire in the gutter. Maybe along the brackets… The gutter then becomes a reflector.
Is this too vertical of an NVIS? We’re talking about few inches spacing to the gutter metal. Im in a strict HOA environment…. (:-(
Hi Phil – Is your gutter metallic or PVC? In either case a wire mounted as you stated should work fine. If the gutter is metal, it will not work as a “reflector” on HF frequencies due to the long wavelengths – but it will just absorb and then re-rediate the RF signal in the wire. With adequate safety considerations it should work well on HF, even with decent “upwards” radiation for NVIS work depending upon the freq and time of course. Experiment! It should work pretty well.
Hi Tim,
My house has straight gutters on three of the four sides that are each about 40 feet in length. I could add a wire along the fourth side of the house to complete the loop. Do you see any issues with that? Or would it be best to run wire all the way around with the wire near the three gutters? I would like to use the antenna for both transmit and receive. Seems like the antenna would detune with rain or snow in the gutters as well.
Hi Scott. My best advise is to try whatever you can get up. A loop makes sense since you can easily feed it without a “ground” at the feed point. That could be mechanically tricky. The main issue might be local noise inside the house – digital garbage from all the computers etc… Maybe first try just using the existing gutters with a wire to your receiver – and give it a listen. If you can’t hear anything over the noise, game over. Also, be aware of RF exposure in the house if running anything “big”.
I wouldn’t worry about anything de-tuning the antenna. You will need a “tuner” anyway so if anything changes, you just re-tune it slightly. I doubt rain or snow would have any tuning effects..Have fun experimenting give something a try – that’s the best part. Wire (conductors) in the air work on HF…even if part of your house… Tim
Thanks, Tim. I’ll try it in receive first using the downspout. I was originally thinking of isolating the downspouts with PVC sections. It looks like you don’t connect the coax shield at the antenna end. Wouldn’t it be best to use an unun with coubterpoise, similar to an end fed antenna to keep common mode current off the coax shield?
Hi – Well it depends upon how and where you feed the antenna. If you are thinking of a downspout, near the ground, then I would use a counterpoise/ground radial system of some kind nearby. The more the better. Tie the coax shield to that. If the feed point is elevated, tying the shield to “ground” becomes difficult since you don’t want a long ground line to ground. (Inductance that would have to be tuned out). Your idea of a continuous Loop is good, feed it at a break point so it is semi-balanced. A Balun might help there. But again, best to do a receive noise test first to see it your location is even viable…If it’s quiet, then get serious!
My tip: buy a cheap weather station that has clearly visible wind measurement scoops on top that turn, and preferably a rain gauge. Apart from that you may actually use the weather station, neighbours have no issues with such a stealth pole on your premises and it worked great for me. I extended it after a few months with wires coming from the 15 feet tole. Never heard the neighbours. They just kept asking me about windspeed and I became the street weather guru, stealth HAM.
Hi Johan – I like your thinking! Reminds me of the early 1980’s when HBO, Showtime and others transmitted program OTA on UHF to home systems. Smart people figured out how to decode the “scrambling” (reinsertion of horizontal sync pulses) and used very small antennas to receive it without a subscription. The giveaway was a forest of poles sporting “birdhouses” all around town; when I was working in Las Vegas they were everywhere. Thanks for visiting! Cheers…