What Should You Look For In A Helium Antenna?

“Will this anten­na work?” I get that ques­tion a lot, usu­al­ly about some anten­na that was dis­cov­ered after hours of search­ing and sift­ing through Google results. Anten­nas are one of the most con­fus­ing parts of Heli­um, most­ly because RF is fair­ly com­pli­cat­ed and the aver­age hotspot own­er has as much expe­ri­ence with anten­na design and the­o­ry as a warthog does with wear­ing Kiton tuxedos. 

Hot tip up front: Anten­nas have very lit­tle to do with your earn­ings. Most of your earn­ings come from your place­ment, most of the rest comes from how high you can get in that place­ment, and the final lit­tle sliv­er comes from anten­na choice. If you want to go deep into the best anten­na for your Heli­um hotspot, read up on it here.

My rec­om­men­da­tions for most instances is two-fold: If you have extra cash, try the HNTen­na, either indoor or out­door, for what­ev­er set­up you’ve got.
If you are deploy­ing a fleet and have to watch costs, use any of the McGill anten­nas, the 6 dBi is a sol­id mid­dle-ground applic­a­ble to almost all installs.

For those of you who don’t want to spend that much, here’s what to look for in a Heli­um hotspot antenna:

• Over­all, you want an anten­na with a fair­ly nar­row range. What is a nar­row range? Ide­al­ly, less than 30MHz of band (15 on either side of cen­ter). In the US, 915 is our cen­ter, and 902–928 is what usu­al­ly I look for.
• In that same vein, Wide Band and Ultra Wide Band should be avoid­ed. While they sound like they might be great because they “cov­er a wide band”, that’s like say­ing a Ford Fal­con should fly because it has “Fal­con” in the name.
• An anten­na for Heli­um should be either ver­ti­cal­ly polar­ized or mul­ti-polar­ized. I’ve writ­ten about anten­na polar­iza­tion in this post on anten­na radi­a­tion pat­terns.
• Any anten­na you buy should have a datasheet. That’s the thing that shows you its pat­tern from the top and sides. If it does­n’t, con­sid­er it exper­i­men­tal and usu­al­ly a waste of money. 
• If the anten­na is high gain (say above 6 dBi), you want elec­tri­cal down­tilt of 1–3 degrees. This helps you to not over­shoot near­by hotspots.

Ok, so that’s how to assess what you should buy. The next step is actu­al­ly test­ing the thing. We’re going to go a lit­tle into geek land here, be ready. I’ll step up the cost slow­ly, from zero to, oh, more than you want to spend.

We’ve got 3 gen­er­al things to check:

• Is it actu­al­ly work­ing in “the real world”?
• Does the anten­na per­form the way it’s sup­posed to?
• Is our hotspot actu­al­ly putting out any RF energy?

Is It Working In The Real World? — Discovery Mode

• Equip­ment Need­ed: Hotspot and the Heli­um phone app
• Cost: 0. Well, it will even­tu­al­ly cost a few data cred­its, but if that’s a bur­den then you’ve got big­ger prob­lems than your anten­na working.
• Use­ful­ness: Rea­son­ably use­ful. There’s no rea­son you should­n’t do this.

The cheap­est way to see if your anten­na is work­ing is to jump into Dis­cov­ery Mode on the Heli­um app. You need to have a hotspot con­nect­ed to a wal­let you con­trol for this step. 

Here are good exam­ples of what you might want to see. Keep in mind that the visu­als may change over time, so you’re see­ing some vari­a­tion here. Yes, I’m choos­ing hotspots that have an unusu­al num­ber of witnesses. 🙂

Here’s what you don’t want to see:

Obvi­ous­ly, if you see some­thing like this, that’s an indi­ca­tion that some­thing might be wrong with 

• Your anten­na
• The Heli­um app 
• The chain itself. 

You should­n’t imme­di­ate­ly freak out if you see that, but you should dive a lit­tle deeper. 

What do I mean by that? I’d check activ­i­ty and rewards on either the app or Explor­er. If those are recent (with­in the past 24 hours), you’re prob­a­bly fine as far as your hotspot and anten­na work­ing. Here’s a screen­shot from Explor­er for the above Dis­cov­ery (failed) attempt. This hotspot is doing fine, there was just some­thing wonky with either Dis­cov­ery or the chain.

Of course, you might want to scroll back to your most recent bea­con and make sure you’re being wit­nessed, although with all the bea­cons being wit­nessed in the above case, you’re prob­a­bly fine. Anten­nas trans­mit & receive at the same “lev­el”. I had to scroll back a day or so to see the most recent bea­con, but there it was, com­plete with witnesses. 

Let’s say your Explor­er page does­n’t look like that, and you have zero wit­ness­es on your bea­con. There is the pos­si­bil­i­ty that your hotspot is work­ing fine BUT one of the wit­ness­es was on a relay, so despite the bea­con actu­al­ly going out, it is report­ed as (basi­cal­ly) incorrect/not work­ing as intend­ed. Still, let’s not get too far into the weeds on that. Let’s stick with anten­nas for now. How do you test your antenna?

Is The Antenna Performing The Way It’s Supposed To? 

• Equip­ment Need­ed: Vec­tor Imped­ance Ana­lyz­er or NanoV­NA
• Cost: $70–150
• Use­ful­ness: Very use­ful for mak­ing sure your anten­na is good. This is more impor­tant if you’re buy­ing an anten­na from less rep­utable sources. Most­ly this is use­ful for mid-lev­el geeks who just want to know what’s going on. 

In the image below, the VIA is the lit­tle black box between the long grey anten­na (a Nebra) and the short white one (an eBay spe­cial.) The black anten­na on the top is the HNTen­na, my go-to for most deploy­ments. A VIA is used to test the effi­cien­cy of an anten­na. If you’re see­ing a low VSWR at your fre­quen­cy, you’ve prob­a­bly got a great anten­na. More on that in the Spiess video below.

I bought my VIA from Bang­good, you can get ’em on Ama­zon. Those links aren’t exact­ly what I bought, there seem to be 4 or 5 vari­a­tions of this thing that are all sim­i­lar enough to work for you. You’ll need to get a pack of adap­tors as well, pick those up on A‑zon.

Pro-tip: Make a “con­nec­tor saver” cable that attach­es to the con­nec­tor of the VNA. That way, when you’re attach­ing your anten­nas you don’t risk dam­ag­ing the con­nec­tor direct­ly on the VIA. 

So far most of the anten­nas do just fine, although I have seen a few duds.

Andreas Spiess has a great video on how to use this VIA, check it out start­ing at 7:30.

I use one to test any anten­na that comes through the shop. You may find some RF snobs that turn their nose up at it. Yes, it’s not the high­est end device, but I don’t see a rea­son for every­one with a Heli­um hotspot to buy (and learn how to use) far fanci­er equip­ment. This is a great quick and easy check.

Is The Hotspot Putting Out The Correct Amount Of Energy?

• Equip­ment Need­ed: Bird Mod­el 43 RF Wattmeter
• Cost: $300–500
• Use­ful­ness: Almost total­ly use­less for the aver­age Heli­um Hotspot own­er, but a very cool piece of kit, and it reas­sures you that your hotspot IS actu­al­ly beaconing. 

When I went out to vis­it the HNTen­na folks a few weeks back, Adam pulled out a device so well designed that it has­n’t been changed since the 1950s! It’s a Bird Mod­el 43P Wattmeter, and it tells you how much ener­gy is being pushed out from a device (your hotspot) and into an anten­na. I’m kind of a suck­er for old school badass things, so I imme­di­ate­ly bought one on eBay. I’ll tell you right now: You don’t need to. They are SUPER cool, but so far into geek-land that for 99% of Heli­um peeps it’s just not the right fit. Still, I bring it up in case you want to see what’s one lay­er deep­er when it comes to RF investigations. 

Here’s what it looks like in use. You plug the hotspot into the left side, the anten­na into the right, then fire up Dis­cov­ery mode so the hotspot bea­cons. When it does, you can mea­sure the ener­gy of that bea­con. For US hotspots, it should hit 1 watt. Using the bot­tom scale and divid­ing by 10 gives you the 1 watt. Yes, I know, dif­fer­ent scales, divid­ing by ten…that’s just stan­dard RF geek­ery. This thing is doing what it’s sup­posed to do.

But, But, But…What Else Can I Test?

I’ll leave you with what you should do if all that HNT is just burn­ing a hole in your pock­et and you’re des­per­ate to know even more about the RF waves all around you. Here’s the HNten­na crew walk­ing me through test­ing the Heli­um Tab using a device called a Hand­held Microwave Analyzer. 

See that lit­tle spike every time we press the but­ton on the Tab? Yep, it’s work­ing. No, you don’t want to know how much that HMA costs. Or maybe you do.

In any event, we can see the Tab work­ing it’s tiny lit­tle elec­tron­ic but off to push out sig­nals. Magic!

So now you know way more about how to choose and test an anten­na for Helium. 

If you’d like fur­ther help with Heli­um, whether it’s under­stand­ing the net­work or opti­miz­ing your place­ment, con­sid­er hir­ing me or tak­ing the Heli­um Basic Course, which you can find here.

Rock on!