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VOR/ILS Antena

I can't say enough positives about my Archer antenna in the right wingtip of my -7A. Entirely reliable with great range (60 - 80 nm) with my SL-30. ILS reception (localizer & glide slope) equally reliable.

Mike
 
We have an Archer in the left wing of our 7a. We were flying the melbourne iLS from the south and had very intermittent reception. Once the controller gave us the final heading to intercept it was rock solid. I really thought something was wrong until we figured the signal was blanked by the fuselage. With a moving map this never presents a problem. VOR reception is well over 100 mm at 6k.
Phelps
 
Just one guys opinion...

I'll probably get blasted for saying this... But I'm a bit of a safety nut of sorts. If you are planing on IFR in your experimental, you will probably have a *Ceritified* Garmin 430 or 650. True it, basically loses it cert when installed in an experimental BUT why break the tried & true system by connecting an archer or any other "cheap" antenna to a precision NAV? I'm going with a Comant CI-215 which meets the TSO's out lined in the Garmin GTN 650 Manual (TSO C40,C36 & C34)... Yeah, I'm sure there are non-cert / experimental antennas that "perform" the same. BUT having mating equipement gives me a little more peace of mind. Keep in mind if you install an antenna & your nav checks dont check out, you'll probably end up replacing the el' cheapo. Me & my families butts cruising down an ILS to minimums are worth WAY more to me than saving a few bucks on an antenna or vanity of having a hidden antenna... This is just my opinion & my plan. We're all building experimentals to get what the certified world doesn't provide and forging the way for the certified world. I'm all about experimenting! But with some things, I simply wont. There is a reason that it is required to have a certified nav / gps if filing IFR.
 
I am planing to use the cat whisker type NAV antenna but debating its location, either underneath by the tail or on top of the vertical stab.
 
I have the Archer antenna, and I can report it works great. Flying circles to check reception from the Nodine (ODI) VOR, I get reception in all orientations out to 50+ nm, and head-on/tail-on orientations provide reception to about 85nm from 7500 feet. This is well outside the normal service volume for the VOR, so things are good there.

Localizer and glideslope reception has been excellent as well; I've shot a number of these approaches in both simulated and actual conditions without any reception problems whatsoever. As you know, the localizer isn't as powerful of a signal as a VOR, but I've still have great reception all tested orientations out to about 25 nm at 3000 feet as tested on the KOWA Runway 30 ILS. Head-on reception was good to 35nm.

My testing methodology was to fly a circle centered at the test range at an altitude of 7500ft, checking reception every 45º. For VOR, I started at 100nm and headed directly towards the station until the CDI flag disappeared. At that time, I marked the test point and flew the circle and noted reception every 45º. I then flew 5nm towards the VOR and repeated the test, recording the results on my test card. I repeated this process until I had solid reception for each test heading.

Localizer testing was similar, but done at 3000ft and starting 50nm out.

That said, the installation is key as the instructions state. Follow the directions exactly, and I find it hard to believe you'd have a problem.
 
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BUT having mating equipement gives me a little more peace of mind.

Certified or not, make sure you thoroughly test it. If it doesn't work predictably and reliably, the certified or TSO status of the installation doesn't really matter.
 
I am planing to use the cat whisker type NAV antenna but debating its location, either underneath by the tail or on top of the vertical stab.

Bob- I see you're building a 7A also :D.. I originally made provisions to put the antenna on the top of the VS but I'm still in limbo about the placement simply due to VORs being on their way out. Heck who knows, by they time I'm done with my build, they could be completely extinct & I won't need a VOR/ ILS / GS anyway.



Certified or not, make sure you thoroughly test it. If it doesn't work predictably and reliably, the certified or TSO status of the installation doesn't really matter.

Absolutely! I could not agree more!!! ;)
 
Another opinion

True it, basically loses it cert when installed in an experimental BUT why break the tried & true system by connecting an archer or any other "cheap" antenna to a precision NAV?.

There is nothing "cheap" about an Archer antenna. Mr. Archer is an antenna design engineer and has gone to great lengths to make his antenna perform as well as can be expected. A cheap antenna is one such as a single whip with no antenna impedance matching. You can take all the certified equipment you can find, and if you place it in the wrong place, or have too long a wire run, or make the connections poorly, or use cheap "certified" coax you overcome all that certification testing. Any antenna placed anywhere can be subject to blanking under the proper conditions.

Performance depends upon range, transmitter power, and polarization of the transmitting and receiving antennas. The Archer wingtip nav antenna works well because it is horizontally polarized as nav transmitters are. Altitude helps negate blanking of the antenna when it is on the opposite side of the transmitter (the structure is not in the way). Localizer and glideslope signals are strong at the close ranges involved.

Having said all that, the greatest problem with the Archer Comm antenna is one of polarization. Comm signals are vertically polarized and the Archer antenna is constrained in that dimension by the wingtip height.

For any installation, certified equipment or not, it is a matter of testing and experimentation to expose weaknesses before you need it in a critical situation.

Don
 
I own and intend to install an archer antenna in my wingtip shortly. With that said, the description of cheap is pretty accurate in my mind. It's a few pieces of aluminum scrap. Comparing it to my Commant antennas leaves one word in mind...cheap. It's fine for my mission and I suspect it will be as functional as I need it to be, but it is certainly the most "blue light special" part in my project. The archer may well be as functional as any out there, but everything about it is cheap.
 
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Bill-
Thank you!! EXACTLY!!! There is absolutely NOTHING wrong with Archers or any other experimental antennas. It all depends on the intended use / mission & appropriate testing. Personally, I dont feel comfortable flying an approach relying on a flapping piece of aluminum in the wing tip (yes I know they are glassed in) :D
 
I am planing to use the cat whisker type NAV antenna but debating its location, either underneath by the tail or on top of the vertical stab.

Bob,

I have my nav antennae (v-pole) on the bottom of the emp and it works well there. Mine's a tailwheel so, I would be blind by now if it was on top of the V.S. I seldom fly an ILS in my RV (other than practice), so I am only speaking to the dozen or so approaches that I have used it for.
 
I have two bob archer antennas on my 8, one connected to a GTN650 and the other to a SL30, both work great, but I think SL30 is a better radio than GTN;)
 
It's a few pieces of aluminum scrap.

Using the same analysis, would you agree that the cat whisker antennas are also cheap since they are just a few pieces of steel rod?

Although I went to school for EE, I can't claim to be an RF expert. However, my semi-educated analysis of the archer antenna shows that it is more than just a few pieces of aluminum scrap. They are sized and orientated a particular way, and you'll note the phenolic board and non-conductive hardware that is critical to proper operation. The design is actually clever.
 
Form and Function

Brad, you are exactly correct. The previous posters screaming "cheap" are looking at the antenna with their eye as if it were to be art. The Comants are fine antennas, but are designed to be out in the wind and elements. If you ground off all the composite coating and fairing, you'd find a cheap steel rod (or plate) and an impedance matching circuit... so what's the difference?

The "it looks cheap" crowd might take the time to read about the design theory. It is exceptionally light, is hidden in the wingtip, performs as well (if not better) than an external Comant. The cost is probably 1/2 to 1/3 of the certified ones. Besides that, no drag and you won't bust it off rolling on your creeper under the airplane.

I also am an EE. I can make a functional and safe NAV antenna out of a coat hangar. It'll receive well enough to do the job. Don't make me transmit on it though.

I definitely think a builder should go with what makes him or her comfortable. But I write mostly for the builder who reads this in the future and wants to make an informed decision with facts vice feelings.


Don
 
Nav Antenna

I have also had great luck with the wing tip mounted archer. Is it flimsy? sure. It is your job as a builder to provide the radome (wing tip) to protect it. If you take the fiberglass housing off of a Comant or similar antenna, you will find similar components. It is just that we see the beefy housing and think SOLID.

The whole idea of the RV is light and fast. If you want solid and heavy, get a Bonanza.

Have you looked at the drag of a round rod? The whisker Vor antenna has to have a lot of drag.

I have 3 separate GPS receivers plus my Ipad plus my GNS430W vor. I'm hoping I have nav covered.

Now how about a high performance internally mounted com antenna?
 
The facts

Hi All,

I wanted to wade into the debate as I feel that the thread has missed the focus and some in this thread are being less than helpful.

I reviewed the Comant antenna range, among others, and and the Bob Archer antenna.

I also did some research on Bob and his antennas, and also looked at making the antenna like the one Bob makes.

My first thought was that given it was only a "few pieces of metal and some screws etc.." it would be easy. I quickly established that this is not the case.

There is a lot of KNOWLEDGE and EXPERIENCE in each of these "few bits and pieces".

I researched what he did with each antenna. How they are tuned and tested. I compared the detailed information with the other ranges of antenna and their performance.

In the end, after much research I established that Bob was more than qualified in designing and producing antenna that matched and/or exceeded the PERFORMANCE of many antenna on the market, be they "certified" or not.

Most things are cheap if you look at the materials. The true cost is in the knowledge behind them and their performance. From my research, the Archer antenna was a lower cost and performed equally or better than many on the market. This is due to Bob and the approach he has taken to his antennas.

BTW: I did not say I purchased his antenna...

To me, making sure that my daughter and wife and anyone else who flies with me is safe is also paramount. To indicate that if you don't do as some have suggested here that you are in effect reckless, dangerous and stupid, is blatantly offensive.

Personally the zealot is the last person I would trust for an opinion as they are least likely to ask for help as they already know the answer. To resort to the need to make others feel small to "win" a discussion that could help everyone, tells me a lot about them and their character.

Therefore, lets help each other with information, facts, calculations and unbiased observation, not derogatory opinions and statements.

Do your research, make your own choice. Don't belittle others for the choices they make. And, in short, try not to make an idiot of yourself.

Now I will get off my moral soapbox and back to work....

BTW: Did I buy an Archer or a Comant, or both, or neither... hmmmm...
 
Archer is very well done.

We flew our -6A all over the Southeast and across the Mississippi with an Archer driving an older Garmin radio and never worried about range.

We installed one in the -10's wingtip when I added the Garmin 430W. On a trip to Pensacola, I dialed in a VOR..one with the cat's whisker under the tail, driving my SL30 and the Archer driving the 430W. Guess what...no difference at 100 miles out, from the same VOR, so why have outside antennae that may poke someone in the eye when you can have a much cleaner installation.

We routinely fly approaches with the 430..LPV's and a few ILS's...it's totally dependable when you install it just like Bob's instructions.

Best,
 
phase I - impressed with archer antenna

phase I testing - I am very impressed with the archer antenna reception. Radio is SL-30.
 
Bob,
While not flying yet I copied a location that a buddy has on his RV6 which he flies IFR all the time, we both but the antenna on the aft bottom fuselage with the cat whiskers just behind the horizontal Stab so you don't run into them while walking around the plane
Jack
 
I've been using a Bob Archer VOR antenna in left wingtip, connected to a Micro Circuits 3-way splitter; ZFSC-3-4+ (similar to COMANT CI-505) thence into a Garmin 430W and SL30. ILS, VOR works flawlessly...

Cheers,

Brian
 
Comant removable elements on VS

This has come up several times I believe. When building the plane I considered one of the "in the wingtip" NAV antennas and called the company direct. The man that answered said their antenna was designed for sport type flying and was not recommended fro IFR. That was the end of its consideration by me. I bought an antenna with removable "legs" and mounted the central element under the vertical stabilizer cap for minimum drag exposure. Typically I unscrew and remove the "legs" for racing but not always (like this past Sunday) because I need a fast getaway and the drag is small. It works very well and I drive two NAV radios (SL-30 and a Terra NAV) through a special splitter.

Bob Axsom
 
I've been using a Bob Archer VOR antenna in left wingtip, connected to a Micro Circuits 3-way splitter; ZFSC-3-4+ (similar to COMANT CI-505) thence into a Garmin 430W and SL30. ILS, VOR works flawlessly...

Cheers,

Brian

If anyone can make it work flawlessly... Decker can!! :D
 
vor antenna

What do you guys think is a decent nav antenna. I may not even use a nav radio but would like to install an antenna just in case.
 
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