Re: Coupling Radio antennae

Del Schier

The splitter would screw up the radiation pattern and if one antenna shorted it would cause a mismatch and work even worse.


I agree that the radio is much more likely to die than the antenna.  I think a good idea, which I should do, is put a jack in the cockpit for the spare antenna to connect my handheld to.


Del Schier

Cozy IV N197DL

Cannon Creek Airpark 15FL






From: canard-aviators@...
Sent: Saturday, June 29, 2019 1:54 PM
To: canard-aviators@...
Subject: RE: [c-a] Coupling Radio antennae



Thanks for all the responses.  I sort of guessed that, trying to avoid a communication loss by doubling my antenna, might cause problems beyond my expertise. 

That I why I invoked my Canard Aviators’ card. 

Good move.


OK.  I will not try and couple the two antennae, but, at least, I have a backup in the event that one goes bad.  What will I do, if I lose my antenna due to something weird?


I have been using a KX99, panel-mounted, hand-held for 33 years.  With the winglet antennae, I can obtain good communication for greater than 50 miles.  For that reason, I will be able to use my rubber ducky antenna in the event of antenna loss.  I just have to remember to make it accessible.  I will do that today.


Thanks again for the rapid responses.  This is a great group.


Marc Borom


From: <canard-aviators@...>
Sent: Saturday, June 29, 2019 9:58 AM
To: canard-aviators@...
Subject: Re: [c-a] Coupling Radio antennae


In case you still want to try something, this phasing harness should combine the antennas.   The distance between the antennas is a factor, but at ~28', might be at an optimal 1/4 wave distance.   The VSWR would change if one antenna were shorted or opened, but could easily be checked with a meter.

For someone doing an around the world flight, increasing fore and aft coverage might be desired.  OTOH, the tower might not be able to hear you sporadically when you're in the pattern..

Mike Satchell

On 6/29/2019 10:02 AM, Phillip Johnson cozy.cgple@... [canard-aviators] wrote:


Agreed Tim,


BTW if you use any form of splitter/combiner you would be transmitting/receiving on two antenna’s.  There would be interaction between the two antenna’s resulting in a horrible azimuthal beam pattern.  Additionally the impedance matching would only be good with both antenna’s connected. I.e you have just doubled the probability of failure.  Kind of like having twin engines on an aircraft.


Phillip Johnson


Phillip Johnson (From iPad)
Cozy MKIV RG Powered by Subaru IO-200 (SN 0030)

On Jun 29, 2019, at 10:52 AM, Tim Andres tim2542@... [canard-aviators] <canard-aviators@...> wrote:


I think you're far more likely to need a back up radio than a back up antenna. 

Tim Andres

On Jun 29, 2019, at 10:47 AM, 'Del Schier' cozypilot@... [canard-aviators] <canard-aviators@...> wrote:


Mike that would not work, it splits the signal into two different bands. It is made so if you had a dual band antenna and two radios, or a dual band radio, (VHF and UHF), it would work on one antenna.


Del Schier

Cozy IV N197DL

Cannon Creek Airpark 15FL




From: canard-aviators@... <canard-aviators@...>
Sent: Friday, June 28, 2019 3:41 PM
Subject: Re: [c-a] Coupling Radio antennae



Congrats on getting back in the air Marc!

A "diplexor" might work for you (one radio/two antennas).   Might check with them to be sure you get the type of connectors you want and matches your application.

Mike Satchell / Cozy #1537

On 6/28/2019 12:18 PM, 'Marcus Borom' borommarc@... [canard-aviators] wrote:


Since I had my mid-air, in which I lost my left winglet and associated radio antenna, I want to avoid the possible loss of radio contact, if this ever (very unlikely) happens again.  It was fortunate that my radio was connected through my right winglet, so I maintained radio contact with the tower.


I have now rebuilt my left winglet and associated radio antenna.  It works.  Is it possible to connect both antennae to the radio through a splitter (or combiner??) so that, if one antenna goes bad, or is knocked off by an errant airplane, radio contact is maintained?


Anxious to know.


Marc Borom


Ryan Field

Tucson, AZ




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