Urban Rooftop Ham Radio Antenna

Intro: Urban Rooftop Ham Radio Antenna

I recently put a ham radio antenna on my roof, so I could get better signal inside my apartment, which isn't on a high floor.

As an ultra beginner without a lot of investment in the hobby, it was perfectly acceptable to have to climb onto the roof to get any signal on my portable radio's antenna. But the benefit of this larger, roof-mounted antenna is that now we can leave the radio on all the time and listen to it inside, which leads to more opportunistic connections and overall more time spent enjoying.

What follows outlines the process we used. I have previously written a guide about getting started in ham radio, in case you're interested.

The antenna I got is a VHF/UHF antenna that mounts on top of a pole. My friend David, my boyfriend Smokey, and I put up one of these on David's roof and on our own roof, and the two had different mounting situations. At David's place, we used a mounting kit with metal straps and special brackets to hold the pole to a chimney. At our place, there was an unused analog TV antenna pole that we planned to repurpose.

Important note about safety: if you don't know what you're doing, consult someone who does (and who knows your local regulations, too). Putting an antenna on your roof brings the risk of a lightning strike which, if not properly grounded, can cause fire and other damage, as well as loss of life. I'm not an electrician or an expert.

STEP 1: Pole Prep

Starting from scratch at David's place, we attached the pole brackets to the chimney with the kit's included metal straps. It took some adjustments to get the pole straight up and down, then clamped on tightly when we turned the final adjustment nuts.

To prep a previously-used antenna pole, we had to remove what was still left of the old analog TV antenna. Some of its pieces broke off easily, while the final connection was so rusted that it needed to be cut free with an angle grinder.

STEP 2: Assemble Antenna

We put together the antenna by following the included instructions. Basically we needed to screw in all the radials to the center piece, then tighten the nuts against the center piece to help prevent the radials from backing out when they wobble in the wind.

The last step was to add the long radial that sticks off the top of the antenna, at which point the whole thing became difficult to set down anywhere.

STEP 3: Run Cable Up Through Pole

We ran our cable up through the pole, and caught it at the top opening. This was easiest to do with two people. The cable is stiff enough to stay straight in the tube when pushed up from below.

STEP 4: Plug in and Mount the Antenna

We brought the antenna close to its mounting position atop the pole, then plugged in the cable, securing the screw collar tightly. Threading the remaining cable slack back into the pole, then we seated the antenna atop the pole and tightened the set screws.

STEP 5: Test It!

Before running our giant cable all around the building, we tested the antenna to be sure everything was working as expected. We could hear and be heard by the Bronx repeater very clearly.

STEP 6: Run Cable

Then it was time to run the cable where we wanted it to go, and attach it to things. For us that meant going around the roof railing and over the edge, following a bundle of existing cables down to our apartment window.

STEP 7: Ground the Antenna Pole and Cable

The next very important step is to connect both the antenna pole and the signal cable to ground, in case of a lightning strike. I ordered some ground bronze clamps online but got the wrong size. The clamps I ordered were too big for both the antenna pole and the electrical conduit I planned to attach to, so flipped one of the pieces around to allow the clamp to fit a smaller diameter pipe. The downside here is it looks a bit silly and if you overtighten the screws, you could deform the pipe. Electrically, I don't think the flip has any effect (but feel free to explain why that may be wrong in the comments).

The ground clamp has another opening designed for the ground wire to connect. I hooked up some 10 gauge copper wire to the clamp connected to the antenna pole, and routed it to another clamp attached to an electrical conduit for a rooftop appliance, which in theory is all grounded through the building's electric. I'm not an electrician, and I don't have the access to drive my own ground pole into the actual ground, so please consult with a local expert to find the best way to ground your own antenna.

On the other end of the signal wire, I used a grounded coupler to connect another piece of the 10 gauge wire to a ground clamp connected to the same electrical conduit, just a couple floors lower. The coupler then connects to an adapter and wire to my Baofeng radio.

STEP 8: Use It!

I hope you found this guide useful, and thanks for following along! You might be interested in some of my other articles:

• My Experience Getting Licensed in Ham Radio
• What's In My Bag
• Internet Valentine w/ ESP8266

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Comments

[Kshatrya]

Very nice installation!
For VHF (eg 50-54 or 144-148mHz) RG-58 coaxial cable will work well. To fine tune things, changing to a higher grade cable, such as RG-8X or LMR-240, to reduce signal loss at higher frequencies. In the UHF range (440mHz / 70cm) the signal loss gets to be significant. Changing to LMR-400 or RG-8 / -213 / -214 is almost a necessity. My rooftop antenna needs a 30m/75' cable run. Unless I use a thick coaxial type, it's more like a dummy load than an antenna!

[favoritefruit2020]

good

[adityadeb9462]

Hi!! I am very I am impressed with your project. Hope you will continue with your good work.

[gmendez3]

Very cool!

[jgeepers]

Check with your insurance agent to make sure your insurance will cover a lightning strike. One thing you can be sure of, when it comes to lightning strikes: You can be sure of nothing. It's very unpredictable. I'm talking from experience. I had a lightning strike on a 65' building I manage recently. It hit a piece of concrete and found it's way through the rebar of the concrete of the parapet wall, went through the flashing, hit the roof, and damaged lots of electronics in the building. The parapet wall had to be repaired. Lots of broken pieces concrete thrown everywhere, including about a 10 pound piece that fell to the street level. Thank God nobody was out during the storm. It was a $12,000 bill by then end. $1,500 deductible. Anyhow, not discouraging you from using an antennae, just make sure your insurance will cover damage and liability you if there is a strike!

[brianchadorourke]

Nice Becky (and crew) I've been a ham over 25 years (K4UL). I have had the same discone antennas and it's great omnidirectional. I also have several of the Baofengs. Starting out, it will look messy and you will learn the best way to make things work. You'll learn the difference between RF ground and electrical ground. If you are pinging the Brooklyn Repeater without a problem, your cable is fine, no matter the decibel loss over the long distance. It is after all your first antenna. The only issue with the discone antenna is the need to re-tighten the radials every once in awhile. If you continue as a ham radio operator and pursue HF privileges, you'll definitely need to worry about RF and electrical ground (there are ways around that even if you are in an apartment), RFI, neighbors, lightning, etc, etc. Welcome aboard!

PS - Nice call sign too!

[themakotohd]

es un poco con pérdidas a 144 (abajo 4 db / 100 pies) y bastante perdido (abajo 8db / 100 pies) a 440

[phlurim]

I'm a licenced HAM (novice) with Baofeng DM-5R. My condo doesn't allow the addition of exterior structures of any kind (antennas, satellite dishes, et. al.) I have no problem contacting my HAM club's local repeater from inside my home. But to boost the non-repeater range of my Baofeng, a club member presented suggestions for stringing antenna wire throughout the attic crawl space, such as at my 2 story condo. Would the rooftop configuration work if installed inside an attic - just the array with little or no support pole? If so, would it still need lightning protection given that it would be inside the roof structure?

[Locomiguel]

I don't know about using that particular antenna in an attic or crawl space but you might want to check out KK4ICE's $35 J-pole at this link: http://www.kk4ice.com/?page_id=20
Grant it it is a J-pole and all the idiosyncrasies of that type of antenna, But it is cheap, easy to build and tune, works well in a crawl space and has no lightning problems. I put one in my daughter's house so I could hook up either an HT or the radio out of my truck and use it when I visit her, as her area has a fairly restrictive group of HOA nazi's. I do recommend using low loss cable. It is expensive but well worth the added money for anything permanent.

[mtnredhed]

I hate to be "that guy" but let me add two things. The coax you used (the white thin stuff which I'm assuming/hoping is RG8X) is a bit lossy at 144 (down 4 db/100ft) and quite lossy (down 8db/100ft) at 440. If the run isn't long it may not matter, but using a HT means you're not starting out with much (may not take much if you're close to the repeater). The other thing is draping the coax over the concrete edge will not make for happy coax over time as the center conductor will deform through the foam dialectric and the jacket will chafe on the concrete. Best to see if you can add something to cause a nice smooth 2.5-3 inch bend radius.

[bekathwia]

Y'all didn't see the roof edge but it's terra cotta edge tile with a rounded edge and big radius. Link to the cable I used is in the supplies list. David used the beefier cable and is saying "I told you so" about it now. I figure it's not hard to replace if needed.

[francisc8000]

nice set up but should have started with a small base unit which gives you a better reception and transmit capability.

[gsmith57]

I don't think this is very helpful advice. Thousands of new hams have started with Baofengs lately and it's an excellent way to hit a local repeater. Suggesting people hold off until they have much more to spend is liable to blunt interest in the hobby than encourage it.

[JimG50]

I add my comments as a 64 year ham. By all means disconnect the coax at the window when a storm arises and get some distance. Only a slight chance of a lightning hit with surrounding buildings there, and your pictures didn't show all the building profile(s) but it can be devastating. I'm speaking from experience and 15K$ loss even though in Texas where everything is big, had 3, 8 foot ground rods at the tower base but it still got in the house. Second hit went within 4 feet of my 80 meter dipole to hit the TV antenna on chimney sure took out the coax and cable TV box! Same storm, Ham up the street took a hit blowing screws out of the walls so hard it deeply dented his refrigerator, set all the globes on the wagon wheel light fixture at a 45 Degree angle. Couple months later a fire from his burned wiring in the attic caused lots of damage. Not to worry about RFI. With everyone's systems above 1200 MHz your Baofeng power is nothing to them. Maybe at 200-300 Watts VHF/UHF using China designed rigs might be an issue?

[wa8ycd]

There is also something on the market called a NON-PENETRATING BASE PEDESTAL. You can place it on a flat roof and weight it down with cement blocks and/or sandbags. You can use it as a base to mount this or somewhat larger antennas.

About being relatively new to Ham Radio: There is always something new to learn. I have been licensed since 1967, and I still like to learn new stuff whenever I can. Thanks for sharing your project.

[Guyp]

nice work.. I wish I had a flat roof to put antennas on!

One point about grounding. Really you should setup an RF ground rather than using the electrics ground. By using the building electrics earth there is a greater possibility of RF interference with other equipment, and as this is a shared building that might cause tension.

To setup an RF earth is really easy.. Just find a patch of earth and bang most of a 2-3meter Copper rod in the ground and attach your earth wires from the antenna to it.

Next stop DMR..

All the best

Guy (M7GUY)

[bekathwia]

"Really easy" if you have access to the earth in your urban oasis, but I do not. Even if the shop downstairs let me into their back yard, it's completely paved.

I do care about being a good neighbor, can you elaborate with examples of the interference I could cause through the electrical conduit that runs the vertical exterior height of the building-- would my neighbors' speakers make funny noises, or their FM radios reception quality decrease? Fortunately (or unfortunately?), none of them are ham operators. What proximity to the conduit would be affected? My desk is really close to it (other side of the exterior wall), and I haven't had any issues with my radio or anything else yet.

[LarryG7]

First, check to see if that electrical conduit connects to the ground. It probably doesn't and would be worthless as a ground. VHF and UHF radios seldom cause interference with the neighbors. If you get a licence upgrade and operate HF then you'll need to start worrying about interference. By then you would likely know what to do. Just use a good antenna with good coax and the interference mentioned by others is a non-issue. If you buy a good antenna with certified ham radio equipment VHF and UHF radio should present no problem with rf. It should operate just the same as the bare radio with an attached antenna. Those warning you about rf with VHF and UHF are just exercising their typing fingers.

[Guyp]

Yes sorry, not always "easy". Doesn't have to be big patch of ground 10x10cm square would do.. but as you say not possible if it's all paved.

It's possible that RF leaks, maybe due to a short and the metal then acts as another antenna, and it's directly feeding into other equipment. Now the other equipment should be well shielded from it, most modem equipment is...but...:)

The interference could manifest its self in a number of ways from noise on public radio stations, loss of signal on a TV (Specially Digital TV) or buzzing on speakers, They'll only see it while you're transmitting, and of course your on a handheld which is only putting out 5Watts, however now you have an antenna, you might look for a more powerful set.

It's also possible you'll pick up extra noise on your radio too which is coming in from other peoples equipment which again isn't working right.

You could put an RF choke around the coax at the bottom of the antenna.

To be fair it's not too likely so carry on, but if someone comments, that's were to start focusing your investigation.

[LarryG7]

I have been a ham radio operator for 50 years. A copper rod driven into the ground is NOT an RF ground unless the ground is perpetually damp. Period. A copper rod driven into the ground with an antenna on the roof is especially not an RF ground. The best thing one can do to prevent stray RF is to connect the grounds of all equipment together and at a common point. i.e. run a braided wire from each piece of equipment to a common point. Ground that point if possible. That antenna used in this instructable has it's own RF ground and doesn't need anything else to work well with the Baofeng. The Baofeng is pretty stripped down electronically and may present RF crosstalk and interference of its own. All the man needs, in this case, is the antenna well mounted with coax to the radio. No other grounds unless he starts adding more equipment then connect them together. He already has the RF ground and a ground against lightning is useless. He could run a copper wire from the antenna down to the ground, for static discharges, but I would just disconnect the antenna when not in use. The Baofend costs about $25.00 and the copper wire and getting permission to run it down to the ground would be more than that.