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EdKranz

Joined: 29 Dec 2010
Posts: 132
Location: Hastings, MN

Posted: Tue Feb 28, 2012 8:11 am Post subject: Antenna locations

I'm just getting ready to finish up the vertical stab, and I need to make a decision about antenna locations... specifically the Nav antenna(s).



The options I've seen are:

Whiskers on top of the VS (on the rib below the rudder) 
Whiskers below the VS
Wingtip antennaI'm leaning towards whiskers on top of the VS and a NAV2 in a wingtip, as I'm worried about dogs and kids finding the antennas with their eyes (also concerned about the COM antennas on the belly for the same reason, but that's something to worry about further down the line).

 

My question is: is there a performance hit from mounting the whiskers on top of the VS? Do you get any shadowing from the wings and body of the plane? Also, which whiskers (with removable elements) are giving the best performance for your buck?

 



Thanks!

Ed Kranz

41347

edandcolleen.com

  [quote][b]

_________________
Ed Kranz
RV10
Finishing
www.edandcolleen.com

recapen(at)earthlink.net
Guest

Posted: Tue Feb 28, 2012 9:03 am Post subject: Antenna locations

Ed,



For my 6A, I got a set of Comant whiskers on top of my VS - inside the VS top cap.  I don't think they make that one any more.



No reception issues that I've experienced - I'm doing my IFR training in it and having a blast!



Ralph



--

Strasnuts

Joined: 10 Feb 2009
Posts: 502
Location: Salt Lake City, UT

Posted: Tue Feb 28, 2012 9:24 am Post subject: Antenna locations

Mine is up top and out of the way.  It would  have been easier to mount it earlier in construction but it worked out  great.  I made a nutplated doubler to mount the CI-157P and used the  5/16 pneumatic airline to run the coax up the nose of the vertical  ribs.  Best pic of it I found.  Apex is toward the nose.

  

  

  

  

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_________________
40936
RV-10 SB N801VR Flying
780 Hours
SuperSTOL 60 hours

Strasnuts

Joined: 10 Feb 2009
Posts: 502
Location: Salt Lake City, UT

Posted: Tue Feb 28, 2012 9:28 am Post subject: Antenna locations

BTW, I have the bob archer in the wingtip for my  nav two.  A lot of discussion on the reception.  My personal  experience is roughly 20 miles.  The cat whisker will pick up the  signal twenty miles farther than the bob archer.  

 [quote]   ---

_________________
40936
RV-10 SB N801VR Flying
780 Hours
SuperSTOL 60 hours

carl.froehlich(at)verizon
Guest

Posted: Tue Feb 28, 2012 10:17 am Post subject: Antenna locations

Ed,



You are touching on an area close to "primers" as to strong opinions.



Here is what I'm doing:

- VOR antenna; home brew wingtip similar in design to the Bob Archer design, but dimensions changed to take advantage of the larger wingtip dimensions.  I did this on my 8A and consistently get VOR reception at 40+ miles, and ILS/LOC reception way beyond useful range.

- On the eyeball hazard I share your concerns.  I have two bent whip antenna on the bottom of the10.  First thing after it goes back in the hangar I put a hose (with the end capped) over each one.  I don't want my dogs to jam the antenna tips into their eyes - and I also found it a great safety step to preserve my vision when cleaning the belly.

- You mentioned "Nav 2".  If you are striving for bang for the buck, perhaps you consider not having a second VOR receiver.  I find the SL-30 in the 8A provides the "cross bearing to a second VOR" function well using the primary/secondary VOR feature.  If you really need a second VOR, the a single antenna with a splitter works (for all practical purposes) as well as two antennas

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Tue Feb 28, 2012 12:24 pm Post subject: Antenna locations

I don't think finishing the vertical stab is the time to decide on that 

antenna. I just closed off the fiberglass tip with Clickbond #4 

nutplates and #4 flush screws instead of rivets, so I can get in there 

if I ever decide I want something there. Yes, it adds about $20 to 

overall cost, but to me that is easier than having to drill out rivets 

if the need arises.

I'd be interested in what changes were made to the Bob Archer design to 

improve the range. If 40+ mile range is possible, I'd much rather have 

antenna in wingtip. OTOH, on other planes I have gotten 100+ mile range 

at 10K cruising alt on H class VORs.

On 2/28/2012 11:14 AM, Carl Froehlich wrote:

[quote] Ed,

 You are touching on an area close to "primers" as to strong opinions.

 Here is what I'm doing:

 - VOR antenna; home brew wingtip similar in design to the Bob Archer 

 design, but dimensions changed to take advantage of the larger wingtip 

 dimensions.  I did this on my 8A and consistently get VOR reception at 

 40+ miles, and ILS/LOC reception way beyond useful range.

 - On the eyeball hazard I share your concerns.  I have two bent whip 

 antenna on the bottom of the10.  First thing after it goes back in the 

 hangar I put a hose (with the end capped) over each one.  I don't want 

 my dogs to jam the antenna tips into their eyes - and I also found it 

 a great safety step to preserve my vision when cleaning the belly.

 - You mentioned "Nav 2".  If you are striving for bang for the buck, 

 perhaps you consider not having a second VOR receiver.  I find the 

 SL-30 in the 8A provides the "cross bearing to a second VOR" function 

 well using the primary/secondary VOR feature.  If you really need a 

 second VOR, the a single antenna with a splitter works (for all 

 practical purposes) as well as two antennas.

 Carl

 On Feb 28, 2012, at 12:27 PM, "Seano" <sean(at)braunandco.com 

 <mailto:sean(at)braunandco.com>> wrote:

> BTW, I have the bob archer in the wingtip for my nav two.  A lot of 

> discussion on the reception.  My personal experience is roughly 20 

> miles.  The cat whisker will pick up the signal twenty miles farther 

> than the bob archer.

>

>     ---

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

bcondrey

Joined: 03 Apr 2006
Posts: 580

Posted: Tue Feb 28, 2012 1:00 pm Post subject: Antenna locations

Kelly,

 Â 

 I don't think he changed the design, it's more that the performance is extremely sensitive to installation.Â  Grounding using the wingtip attach nutplates (not a wire or strap), routing of other wiring along the edge, etc.Â  In fact, I exchanged emails with Bob A. when I did my install in the first -10.Â  I was concerned about the heat protective foil from the halogen landing light kit - he said to make the antenna as close as possible to the foil without touching it.Â  I had one of his antennas in each wingtip (and a GS antenna along with it in one tip) and they worked great.Â  I'd routinely see 50+ miles when I was actually checking distance.Â  I've also heard of really poor performance but without seeing the install hard to say why.Â  FWIW, he will readily admit that his wingtip comm antenna is a poor performer because of the signal polarization.

  Â 

 Bob

 On Tue, Feb 28, 2012 at 3:22 PM, Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)> wrote:

 [quote]--> RV10-List message posted by: Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)>

 

I don't think finishing the vertical stab is the time to decide on that antenna. I just closed off the fiberglass tip with Clickbond #4 nutplates and #4 flush screws instead of rivets, so I can get in there if I ever decide I want something there. Yes, it adds about $20 to overall cost, but to me that is easier than having to drill out rivets if the need arises.

 I'd be interested in what changes were made to the Bob Archer design to improve the range. If 40+ mile range is possible, I'd much rather have antenna in wingtip. OTOH, on other planes I have gotten 100+ mile range at 10K cruising alt on H class VORs.

 

[b]

Strasnuts

Joined: 10 Feb 2009
Posts: 502
Location: Salt Lake City, UT

Posted: Tue Feb 28, 2012 1:44 pm Post subject: Antenna locations

My post made it look like I only got 20 miles of  reception when I meant 20 miles is the difference between my Bob Archer and my  cat whiskers.

 [quote]   ---

_________________
40936
RV-10 SB N801VR Flying
780 Hours
SuperSTOL 60 hours

EdKranz

Joined: 29 Dec 2010
Posts: 132
Location: Hastings, MN

Posted: Tue Feb 28, 2012 1:55 pm Post subject: Antenna locations

Having flown with both, do you think you'd be comfortable with just the Bob Archer? Do you use it for GS as well as VOR/LOC?



On Tue, Feb 28, 2012 at 3:43 PM, Seano <sean(at)braunandco.com (sean(at)braunandco.com)> wrote:

 [quote]       My post made it look like I only got 20 miles of  reception when I meant 20 miles is the difference between my Bob Archer and my  cat whiskers.

 [quote]   ---

_________________
Ed Kranz
RV10
Finishing
www.edandcolleen.com

Strasnuts

Joined: 10 Feb 2009
Posts: 502
Location: Salt Lake City, UT

Posted: Tue Feb 28, 2012 2:11 pm Post subject: Antenna locations

Personally, no.  I would only install the cat  whiskers if I only had one NAV.  I use the CI-157P for GS/VOR/LOC  and it is ran to the 430W (nav 1) with a Diplexer since the 430w needs the  NAV/LOC separate from the GS.(see link below).  The Bob Archer is ran to my  SL-30 nav portion.  I thought the cat whiskers were easier to install and  it gets a better signal.

  

 http://www.aircraftspruce.com/catalog/avpages/coupler507.php

  

  

 [quote]   ---

_________________
40936
RV-10 SB N801VR Flying
780 Hours
SuperSTOL 60 hours

carl.froehlich(at)verizon
Guest

Posted: Tue Feb 28, 2012 2:17 pm Post subject: Antenna locations

I did modify the design slightly when I made the antenna (a few pieces of scrap aluminum, some hardware and a piece of bakelite or fiberglass to make the gama match).  I did a hard mount (piece of .032 angle) to the outboard wing rib such that the antenna stays on the plane when you pull the wing tip off.  This solves the grounding issues.  I also extended the piece that angles away from the rib such that the piece that runs parallel to the rib is tucked all the way into the outboard edge of the wingtip.  This is a quarter wavelength antenna - which means the part that does most of the work (the high current part) is close to the base.  The end of the antenna (the high voltage part) provides the electrical length to resonate the antenna at the desired frequency.  This is why bent whip antennas work as well as they do.  The part near the base is mostly vertical (communications are vertically polarized, VORs are horizontally polarized).  I use the one antenna for both VOR and GS reception.

As with all antennas, the performance is only as good as the tuning.  I used an MFJ antenna analyzer to adjust the gama match and the overall length to resonance.  Most amateur radio operators have one of these analyzers and for a quick hop will most likely just make the antenna for you.

Someplace I have an old AeroElectric book that provides details for the antenna.

Carl 





On Feb 28, 2012, at 3:59 PM, Bob Condrey <condreyb(at)gmail.com (condreyb(at)gmail.com)> wrote:



[quote]Kelly,

  

 I don't think he changed the design, it's more that the performance is extremely sensitive to installation.  Grounding using the wingtip attach nutplates (not a wire or strap), routing of other wiring along the edge, etc.  In fact, I exchanged emails with Bob A. when I did my install in the first -10.  I was concerned about the heat protective foil from the halogen landing light kit - he said to make the antenna as close as possible to the foil without touching it.  I had one of his antennas in each wingtip (and a GS antenna along with it in one tip) and they worked great.  I'd routinely see 50+ miles when I was actually checking distance.  I've also heard of really poor performance but without seeing the install hard to say why.  FWIW, he will readily admit that his wingtip comm antenna is a poor performer because of the signal polarization.

   

 Bob

 On Tue, Feb 28, 2012 at 3:22 PM, Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)> wrote:

  	  Quote: 	
		  --> RV10-List message posted by: Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)>

 

I don't think finishing the vertical stab is the time to decide on that antenna. I just closed off the fiberglass tip with Clickbond #4 nutplates and #4 flush screws instead of rivets, so I can get in there if I ever decide I want something there. Yes, it adds about $20 to overall cost, but to me that is easier than having to drill out rivets if the need arises.

 I'd be interested in what changes were made to the Bob Archer design to improve the range. If 40+ mile range is possible, I'd much rather have antenna in wingtip. OTOH, on other planes I have gotten 100+ mile range at 10K cruising alt on H class VORs.

 





===================================

://www.matronics.com/Navigator?RV10-List

===================================

cs.com

===================================

matronics.com/contribution

===================================



	


[b]

Bob Turner

Joined: 03 Jan 2009
Posts: 885
Location: Castro Valley, CA

Posted: Tue Feb 28, 2012 2:28 pm Post subject: Re: Antenna locations

I have a single Archer in the right wing tip, running to an SL-30, as my only VOR. (As another poster mentioned, if you need to save money, I'd drop the #2 VOR - assuming you have a GPS backup).  I easily pick up good signals at 50 miles (at) 5000', except if the station is 90 degrees left of the aircraft (so the antenna has to look thru the fuselage). I can't say for certain what the range degradation is then. Picking up the localizer and GS signals has never been a problem.

I ignored Bob A's instructions to some extent. I put the antenna fairly far back, away from the landing light, the aluminum foil, and the wiring for the lights (I ran these wires against the wing rib, and brought them out well in front of the antenna.).



I also have a second antenna, an Archer clone slightly modified for slightly higher frequencies, in the left tip which I use for the #2 com (G420). I fastened the ground side of this antenna as high up as I could, under the top side plate nuts,  and ran the element down to the bottom side of the tip, as steeply as I could, to get some vertical polarization. (most of the current flows in the first part of the radiating element). At 10 miles and pointed at the tower, 3000', tower reports the SL-30/belly whip as "5x5"; the G420 and wing tip antenna as "5x4", eg, slightly weaker. This agrees with my reception of the ATIS signal, the Archer/G420 is slightly weaker than the SL-30/external belly whip, although just barely noticeable. Again, I notice that at 15 miles or more I loose the ATIS on #2 if the left wing is pointed directly away from the tower.



If I were doing it again, I would do it exactly the same as it is now.

_________________
Bob Turner
RV-10 QB

jesse(at)saintaviation.co
Guest

Posted: Tue Feb 28, 2012 3:10 pm Post subject: Antenna locations

I have used the Bob Archer Nav antennas in many airplanes and have never been dissatisfied with their performance. In reality, how often do you even tune in a VOR when you have a GPS? I sometimes tune it in to teach someone how they work and how to use them. The range is not as good as the cat whiskers, but the antenna is cheaper and the plane is cleaner that way (and it's easier to install, IMHO). When flying an ILS, the signal is so strong when you are actually using it that the wingtip antenna is more than enough.



I did install one Bob Archer Com antenna and I was very unhappy with the results. The Nav antenna is horizontally polarized so the RV-10 wingtip is ideal. The Com is supposed to be vertically polarized, so the RV-10 wingtip is very far from ideal. 



YMMV, but I will continue to use wingtip Nav antennas whenever I can.



Also, even with dual Nav radios, you can use one antenna with diplexers, triplexers and splitters as necessary.



do not archive



Jesse Saint

Saint Aviation, Inc.

jesse(at)saintaviation.com

C: 352-427-0285

F: 815-377-3694



On Feb 28, 2012, at 5:28 PM, Bob Turner wrote:



 	  Quote: 	
		   

 

 I have a single Archer in the right wing tip, running to an SL-30, as my only VOR. (As another poster mentioned, if you need to save money, I'd drop the #2 VOR - assuming you have a GPS backup).  I easily pick up good signals at 50 miles (at) 5000', except if the station is 90 degrees left of the aircraft (so the antenna has to look thru the fuselage). I can't say for certain what the range degradation is then. Picking up the localizer and GS signals has never been a problem.

 I ignored Bob A's instructions to some extent. I put the antenna fairly far back, away from the landing light, the aluminum foil, and the wiring for the lights (I ran these wires against the wing rib, and brought them out well in front of the antenna.).

 

 I also have a second antenna, an Archer clone slightly modified for slightly higher frequencies, in the left tip which I use for the #2 com (G420). I fastened the ground side of this antenna as high up as I could, under the top side plate nuts,  and ran the element down to the bottom side of the tip, as steeply as I could, to get some vertical polarization. (most of the current flows in the first part of the radiating element). At 10 miles and pointed at the tower, 3000', tower reports the SL-30/belly whip as "5x5"; the G420 and wing tip antenna as "5x4", eg, slightly weaker. This agrees with my reception of the ATIS signal, the Archer/G420 is slightly weaker than the SL-30/external belly whip, although just barely noticeable. Again, I notice that at 15 miles or more I loose the ATIS on #2 if the left wing is pointed directly away from the tower.

 

 If I were doing it again, I would do it exactly the same as it is now.

 

 --------

 Bob Turner

 RV-10 QB

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=367479#367479

Mauledriver(at)nc.rr.com
Guest

Posted: Tue Feb 28, 2012 9:00 pm Post subject: Antenna locations

Use a single Bob Archer Nav for 1 or  both NAV radios - it works fine 

for approaches

Don't use a Bob Archer Comm at all - it works okay but not well enough

My limited experience exactly matches everything said below.

On 2/28/2012 6:08 PM, Jesse Saint wrote:

 	  Quote: 	

 I have used the Bob Archer Nav antennas in many airplanes and have never been dissatisfied with their performance. In reality, how often do you even tune in a VOR when you have a GPS? I sometimes tune it in to teach someone how they work and how to use them. The range is not as good as the cat whiskers, but the antenna is cheaper and the plane is cleaner that way (and it's easier to install, IMHO). When flying an ILS, the signal is so strong when you are actually using it that the wingtip antenna is more than enough.

 I did install one Bob Archer Com antenna and I was very unhappy with the results. The Nav antenna is horizontally polarized so the RV-10 wingtip is ideal. The Com is supposed to be vertically polarized, so the RV-10 wingtip is very far from ideal.

 YMMV, but I will continue to use wingtip Nav antennas whenever I can.

 Also, even with dual Nav radios, you can use one antenna with diplexers, triplexers and splitters as necessary.

 do not archive

 Jesse Saint

 Saint Aviation, Inc.

 jesse(at)saintaviation.com

 C: 352-427-0285

 F: 815-377-3694

 On Feb 28, 2012, at 5:28 PM, Bob Turner wrote:

> 

>

> I have a single Archer in the right wing tip, running to an SL-30, as my only VOR. (As another poster mentioned, if you need to save money, I'd drop the #2 VOR - assuming you have a GPS backup).  I easily pick up good signals at 50 miles (at) 5000', except if the station is 90 degrees left of the aircraft (so the antenna has to look thru the fuselage). I can't say for certain what the range degradation is then. Picking up the localizer and GS signals has never been a problem.

> I ignored Bob A's instructions to some extent. I put the antenna fairly far back, away from the landing light, the aluminum foil, and the wiring for the lights (I ran these wires against the wing rib, and brought them out well in front of the antenna.).

>

> I also have a second antenna, an Archer clone slightly modified for slightly higher frequencies, in the left tip which I use for the #2 com (G420). I fastened the ground side of this antenna as high up as I could, under the top side plate nuts,  and ran the element down to the bottom side of the tip, as steeply as I could, to get some vertical polarization. (most of the current flows in the first part of the radiating element). At 10 miles and pointed at the tower, 3000', tower reports the SL-30/belly whip as "5x5"; the G420 and wing tip antenna as "5x4", eg, slightly weaker. This agrees with my reception of the ATIS signal, the Archer/G420 is slightly weaker than the SL-30/external belly whip, although just barely noticeable. Again, I notice that at 15 miles or more I loose the ATIS on #2 if the left wing is pointed directly away from the tower.

>

> If I were doing it again, I would do it exactly the same as it is now.

>

> --------

> Bob Turner

> RV-10 QB

>

>

> Read this topic online here:

>

> http://forums.matronics.com/viewtopic.php?p=367479#367479

>

>

bill.peyton

Joined: 19 Sep 2010
Posts: 198
Location: St. Louis, MO

Posted: Wed Feb 29, 2012 5:35 am Post subject: Re: Antenna locations

I installed 2 Archer nav antennas in each wing tip, one for each radio.  My rationale was that you will loose 3.5db through a splitter, which is around 50% signal strength.  As an earlier post stated, you can tune the antenna for your installation using a piece of test equipment that  most hams have.  I have not flown the aircraft as of yet, but based on most reports, I think this should work fine.  In today's environment, only real use for a VOR antenna is to receive the localizer and GS.  Normally the distance on this is less than 7nm.



I also installed an Archer MB antenna in the wingtip on the top surface above and outside of the Archer antenna.

_________________
Bill
WA0SYV
Aviation Partners, LLC

Bob Turner

Joined: 03 Jan 2009
Posts: 885
Location: Castro Valley, CA

Posted: Wed Feb 29, 2012 10:17 am Post subject: Re: Antenna locations

True, a matched signal splitter will knock your signal strength down by a factor of two. But it also will knock down any external noise coming down the coax by a factor of two as well. What counts is the signal to noise ratio - the receivers always have plenty of gain.

If you have a good receiver which generates little internal noise, then the splitter doesn't hurt at all - just turn up the volume.

If your background noise is dominated by noise generated by the electronics of the receiver itself, then you lose the 2x.

So the answer is, "it depends".

_________________
Bob Turner
RV-10 QB

bill.peyton

Joined: 19 Sep 2010
Posts: 198
Location: St. Louis, MO

Posted: Wed Feb 29, 2012 1:13 pm Post subject: Re: Antenna locations

Bob,

You have it incorrect.  The signal to noise ratio is just that.  More gain at the antenna given the same amount of internally generated receiver noise will yield a higher S/N ratio through the entire system.  Cutting the gain of the antenna  also cuts out externally received, (through the antenna) noise, thus the S/N is unchanged due to the fact that you not only decreased the wanted signal, but decreased the unwanted signal at the same time.  As long as the noise comes in prior to the radio's antenna connector, inserting a splitter does just that.  It decreases the signal AND the noise by the same exact amount.

I will agree that for the most part, especially when using an externally mounted antenna, such as a cat wiskers, you have plenty of signal to split between two VOR receivers.  The issue that the Archer antennas present is, they do not have the gain nor are they mounted in an optimum location on the aircraft.  In addition,  with the Archer antenna, you do not have an omnidirectional pattern due to the mounting location. So having one antenna in each wing tip, connected to separate receivers is good insurance.  So in this instance, maximizing the signal coming down the coax is a good idea.

Bill

_________________
Bill
WA0SYV
Aviation Partners, LLC

Bob Turner

Joined: 03 Jan 2009
Posts: 885
Location: Castro Valley, CA

Posted: Wed Feb 29, 2012 10:04 pm Post subject: Re: Antenna locations

Bill, I think we both said the same thing about S/N ratios...



You left out another small advantage of 2 wing tip antennas, over one split 2 ways: given the cost of splitters, 2 antennas may be cheaper than 1+splitter!

_________________
Bob Turner
RV-10 QB

bill.peyton

Joined: 19 Sep 2010
Posts: 198
Location: St. Louis, MO

Posted: Thu Mar 01, 2012 5:25 am Post subject: Re: Antenna locations

Good point Bob.  The Archer antennas are a bargain compared to the signal splitters.  Having said all this, I still ran a spare coax back to the tail in case the Archer's don't work out as planned!

_________________
Bill
WA0SYV
Aviation Partners, LLC

EdKranz

Joined: 29 Dec 2010
Posts: 132
Location: Hastings, MN

Posted: Thu Mar 01, 2012 5:33 am Post subject: Antenna locations

Thanks for the input everyone!



Although I think I now have more questions than when I started, I've decided to not decide, but provision for different possibilities while the VS is still open... mostly with conduit runs and using nutplates for the tips like Kelly suggested.

 



Ed



On Tue, Feb 28, 2012 at 4:16 PM, Carl Froehlich <carl.froehlich(at)verizon.net (carl.froehlich(at)verizon.net)> wrote:

[quote] I did modify the design slightly when I made the antenna (a few pieces of scrap aluminum, some hardware and a piece of bakelite or fiberglass to make the gama match).  I did a hard mount (piece of .032 angle) to the outboard wing rib such that the antenna stays on the plane when you pull the wing tip off.  This solves the grounding issues.  I also extended the piece that angles away from the rib such that the piece that runs parallel to the rib is tucked all the way into the outboard edge of the wingtip.  This is a quarter wavelength antenna - which means the part that does most of the work (the high current part) is close to the base.  The end of the antenna (the high voltage part) provides the electrical length to resonate the antenna at the desired frequency.  This is why bent whip antennas work as well as they do.  The part near the base is mostly vertical (communications are vertically polarized, VORs are horizontally polarized).  I use the one antenna for both VOR and GS reception.

 



As with all antennas, the performance is only as good as the tuning.  I used an MFJ antenna analyzer to adjust the gama match and the overall length to resonance.  Most amateur radio operators have one of these analyzers and for a quick hop will most likely just make the antenna for you.

 



Someplace I have an old AeroElectric book that provides details for the antenna.

Carl 





On Feb 28, 2012, at 3:59 PM, Bob Condrey <condreyb(at)gmail.com (condreyb(at)gmail.com)> wrote:

 



 	  Quote: 	
		  Kelly,

  

 I don't think he changed the design, it's more that the performance is extremely sensitive to installation.  Grounding using the wingtip attach nutplates (not a wire or strap), routing of other wiring along the edge, etc.  In fact, I exchanged emails with Bob A. when I did my install in the first -10.  I was concerned about the heat protective foil from the halogen landing light kit - he said to make the antenna as close as possible to the foil without touching it.  I had one of his antennas in each wingtip (and a GS antenna along with it in one tip) and they worked great.  I'd routinely see 50+ miles when I was actually checking distance.  I've also heard of really poor performance but without seeing the install hard to say why.  FWIW, he will readily admit that his wingtip comm antenna is a poor performer because of the signal polarization.

    

 Bob

 On Tue, Feb 28, 2012 at 3:22 PM, Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)> wrote:

  	  Quote: 	
		  --> RV10-List message posted by: Kelly McMullen <kellym(at)aviating.com (kellym(at)aviating.com)>

  

I don't think finishing the vertical stab is the time to decide on that antenna. I just closed off the fiberglass tip with Clickbond #4 nutplates and #4 flush screws instead of rivets, so I can get in there if I ever decide I want something there. Yes, it adds about $20 to overall cost, but to me that is easier than having to drill out rivets if the need arises.

  I'd be interested in what changes were made to the Bob Archer design to improve the range. If 40+ mile range is possible, I'd much rather have antenna in wingtip. OTOH, on other planes I have gotten 100+ mile range at 10K cruising alt on H class VORs.

  





==========

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==========

cs.com

==========

matronics.com/contribution

==========



	






get="_blank">http://www.matronics.com/Navigator?RV10-List

tp://forums.matronics.com

_blank">http://www.matronics.com/contribution



	


[b]

_________________
Ed Kranz
RV10
Finishing
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