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jrevens

Joined: 21 Nov 2013
Posts: 34
Location: Arvada, CO

Posted: Mon Feb 23, 2015 8:23 pm Post subject: Handheld transceiver alternate antenna

Is there an efficient, elegant way to connect an external aircraft     comm antenna to a handheld radio in the event of failure of the     panel-mounted radio that the antenna is connected to? I know that I     could run the cable within reach of the pilot, with connectors     inline to break the connection to the panel and connect to the     handheld unit. That's what I did on my first homebuilt. However, I     envision a panel-mounted male BNC connector that could possibly be     used to connect the handheld without physically disconnecting the     failed radio, providing that radio is switched off. If this is     possible, I'm wondering if some kind of antenna switch or splitter     would be necessary. I'm talking about the antenna only serving one     radio at a time. This is very possibly a dumb question.

     

     Thanks in advance for any replies!

     

                                  

            

     

      [quote][b]

_________________
John Evens
Thorp T-18 N71JE (sold)
Kitfox SS7 N27JE (built & flying)

ChasB(at)satx.rr.com
Guest

Posted: Tue Feb 24, 2015 7:47 am Post subject: Handheld transceiver alternate antenna

I installed a second external antenna that matches the one I use for my main radio. The antenna cable terminates at a BNC connection on my panel. I can quickly connect my handheld to the BNC with a patch cord. With the exception of the cost of a second antenna, the installation was quick and simple. Works well. 

Charlie Brame

RV-6A  N11CB

San Antonio

--------------------------------------



[quote]Time: 08:23:42 PM PST US

From: John <jrevens(at)comcast.net (jrevens(at)comcast.net)>

Subject: Handheld transceiver alternate antenna



Is there an efficient, elegant way to connect an external aircraft comm 

antenna to a handheld radio in the event of failure of the panel-mounted 

radio that the antenna is connected to? I know that I could run the 

cable within reach of the pilot, with connectors inline to break the 

connection to the panel and connect to the handheld unit. That's what I 

did on my first homebuilt. However, I envision a panel-mounted male BNC 

connector that could possibly be used to connect the handheld without 

physically disconnecting the failed radio, providing that radio is 

switched off. If this is possible, I'm wondering if some kind of antenna 

switch or splitter would be necessary. I'm talking about the antenna 

only serving one radio at a time. This is very possibly a dumb question.



Thanks in advance for any replies!

[b]

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Feb 24, 2015 8:18 am Post subject: Handheld transceiver alternate antenna

At 22:19 2015-02-23, you wrote:

  	  Quote: 	
		  Is there an efficient, elegant way to connect an external aircraft comm antenna to a handheld radio in the event of failure of the panel-mounted radio that the antenna is connected to? I know that I could run the cable within reach of the pilot, with connectors inline to break the connection to the panel and connect to the handheld unit. That's what I did on my first homebuilt. However, I envision a panel-mounted male BNC connector that could possibly be used to connect the handheld without physically disconnecting the failed radio, providing that radio is switched off. If this is possible, I'm wondering if some kind of antenna switch or splitter would be necessary. I'm talking about the antenna only serving one radio at a time. This is very possibly a dumb question.

 	


    Since the h-h is backup for a failed radio,

    only ONE antenna can be made to service both

    appliances. One of my favorite 'back up' antenna

    arrangements suggests arranging a coiled-up

    excess of comm antenna feed-line to be situated

    in a handy but out of sight location. A BNC cable

    male/female joint on the panel-radio end of the

    coil.  Of course, this excess cable should not

    be retained in a manner requiring more than

    your fingers to access, break the joint and

    uncoil it.



    Should it become necessary to put the h-h

    into service, you can string out the coax

    and hook it to the radio.



 [img]cid:7.1.0.9.0.20150224100526.02004028(at)aeroelectric.com.0[/img] 



 

   Unfortunately, this particular arrangement is a

   bit un-graceful.



   Consider this . . .



 [img]cid:7.1.0.9.0.20150224100526.02004028(at)aeroelectric.com.1[/img] 



   A pair of right angle adapters can be used to

   bring the antenna coax down the back of the

   radio such that the whole becomes more like

   a microphone.  If your BNC cable male on the

   feed-line is already a right-angle connector,

   then you only need one adapter to get the 180

   degree, tight bend.



 

 

   Bob . . .

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jrevens

Joined: 21 Nov 2013
Posts: 34
Location: Arvada, CO

Posted: Tue Feb 24, 2015 12:07 pm Post subject: Re: Handheld transceiver alternate antenna

To clarify a little, I was thinking of installing a BNC tee in the line between the panel mounted radio and the antenna. Then I would bring a short "branch" from that tee to a panel-mounted male BNC, and possibly close that off with the proper terminating cap until it is used. I would have a short section of antenna cable with connectors already attached to and stored with the handheld. Would this kind of arrangement have shortcomings in the way of signal strength or other losses?



John Evens

Thorp T-18 N71JE (built and flying)

Kitfox SS7 N27JE (building)

_________________
John Evens
Thorp T-18 N71JE (sold)
Kitfox SS7 N27JE (built & flying)

ceengland7(at)gmail.com
Guest

Posted: Tue Feb 24, 2015 2:40 pm Post subject: Handheld transceiver alternate antenna

Don't do it. One radio's transmitter would directly drive the other's receiver; not a good plan for a number of reasons (which might include smoke). 



On February 24, 2015 2:07:15 PM CST, jrevens <jrevens(at)comcast.net> wrote: 	  Quote: 	
		    	  Quote: 	
		  --> AeroElectric-List message posted by: "jrevens" <jrevens(at)comcast.net>To clarify a little, I was thinking of installing a BNC tee in the line between the panel mounted radio and the antenna. Then I would bring a short "branch" from that tee to a panel-mounted male BNC, and possibly close that off with the proper terminating cap until it is used. I would have a short section of antenna cable with connectors already attached to and stored with the handheld. Would this kind of arrangement have shortcomings in the way of signal strength or other losses?John EvensThorp T-18 N71JE (built and flying)Kitfox SS7 N27JE (building)--------John EvensRead this topic online here:http://forums.matronics.com/viewtopic.php?p=438670#438670_

 -=     

/> 	
	




 -- 

 Sent from my Android device with K-9 Mail. Please excuse my brevity.  [quote][b]

john.maccallum(at)bigpond
Guest

Posted: Tue Feb 24, 2015 10:43 pm Post subject: Handheld transceiver alternate antenna

You could install a Coaxial Switch. The output to the Antenna and one port to the Ships Radio and one port to a Socket mounted somewhere convenient that you can plug a Handheld into.

Just remember not transmit into an open port. I.e. donâ€™t leave the ships Radio on if you plan to use the Handheld.

 

Cheers

 

John MacCallum

VH-DUU

RV 10 # 41016

 

 

 

 

From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John

Sent: Tuesday, 24 February 2015 3:19 PM

To: aeroelectric-list(at)matronics.com

Subject: Handheld transceiver alternate antenna

 

Is there an efficient, elegant way to connect an external aircraft comm antenna to a handheld radio in the event of failure of the panel-mounted radio that the antenna is connected to? I know that I could run the cable within reach of the pilot, with connectors inline to break the connection to the panel and connect to the handheld unit. That's what I did on my first homebuilt. However, I envision a panel-mounted male BNC connector that could possibly be used to connect the handheld without physically disconnecting the failed radio, providing that radio is switched off. If this is possible, I'm wondering if some kind of antenna switch or splitter would be necessary. I'm talking about the antenna only serving one radio at a time. This is very possibly a dumb question.



Thanks in advance for any replies!

 

 



 	  Quote: 	
		   Â Â Â Â Â Â Â Â  - List Contribution Web generous  Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  -Matt http://www.matronics.com/c=[/b] 	


 [quote][b]

wrmaxwell(at)bigpond.com
Guest

Posted: Tue Feb 24, 2015 11:05 pm Post subject: Handheld transceiver alternate antenna

That is the only way I         would contemplate sharing a single antenna with two radios.

         Â Apart from avoiding the likelihood of transmitting into an open         port or delivering your transmitter's full output power into the         other radios receiver, potentially with dire       consequences, we should not forget that these radios have a design       antenna impedance of 50 ohms, as does the antenna, giving the       sought after perfect match.

     

     Hook up two radios simultaneously and the apparent radio end       impedance becomes 50/2, or 25 ohms. Immediate mismatch.

     

     Bill

       19-4446

       Jodel D18, also in Oz.

     On 25/02/2015 5:41 PM, John MacCallum       wrote:

     

     [quote]                       <![endif]-->   <![endif]-->                

You             could install a Coaxial Switch. The output to the Antenna             and one port to the Ships Radio and one port to a Socket             mounted somewhere convenient that you can plug a Handheld             into.         

Just             remember not transmit into an open port. I.e. donâ€™t leave             the ships Radio on if you plan to use the Handheld.         

Â          

Cheers         

Â          

John             MacCallum         

VH-DUU         

RV             10 # 41016         

Â          

Â          

Â          

Â                                  

From:                 owner-aeroelectric-list-server(at)matronics.com (owner-aeroelectric-list-server(at)matronics.com)                 [mailto:owner-aeroelectric-list-server(at)matronics.com (owner-aeroelectric-list-server(at)matronics.com)] On                   Behalf Of John

                 Sent: Tuesday, 24 February 2015 3:19 PM

                 To: aeroelectric-list(at)matronics.com (aeroelectric-list(at)matronics.com)

                 Subject: Handheld transceiver                 alternate antenna           

         

         

Â          

Is there an efficient, elegant way to           connect an external aircraft comm antenna to a handheld radio           in the event of failure of the panel-mounted radio that the           antenna is connected to? I know that I could run the cable           within reach of the pilot, with connectors inline to break the           connection to the panel and connect to the handheld unit.           That's what I did on my first homebuilt. However, I envision a           panel-mounted male BNC connector that could possibly be used           to connect the handheld without physically disconnecting the           failed radio, providing that radio is switched off. If this is           possible, I'm wondering if some kind of antenna switch or           splitter would be necessary. I'm talking about the antenna           only serving one radio at a time. This is very possibly a dumb           question.

           

           Thanks in advance for any replies!                    

Â                         

Â            

         

          	  Quote: 	
		  Â http://www.matronics.com/Navigator?AeroElectric-Listhttp://forums.matronics.comÂ Â Â Â Â Â Â Â  - List Contribution Web generous ï¿½Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  -Matt http://www.matronics.com/c=Â  	
       

                      	  Quote: 	
		  

	
     [b]

dlj04(at)josephson.com
Guest

Posted: Wed Feb 25, 2015 12:38 am Post subject: Handheld transceiver alternate antenna

On Feb 25, 2015, at 12:00 AM, jrevens(at)comcast.net wrote:



 	  Quote: 	
		   To clarify a little, I was thinking of installing a BNC tee in the line between

 the panel mounted radio and the antenna. Then I would bring a short "branch"

 from that tee to a panel-mounted male BNC, and possibly close that off with the

 proper terminating cap until it is used. I would have a short section of antenna

 cable with connectors already attached to and stored with the handheld. Would

 this kind of arrangement have shortcomings in the way of signal strength

 or other losses?


	


Yes, many. It won't work. RF is not like water pipe. Besides damaging whichever radio was not transmitting, the impedance mismatch would badly compromise receive and transmit range.

john.maccallum(at)bigpond
Guest

Posted: Wed Feb 25, 2015 3:47 am Post subject: Handheld transceiver alternate antenna

Yes RF is not like water. It's far more fickle and you can't use a

terminating cap because of the power involved during transmit. You would fry

a terminating resistor that was plugged into the free port plus the

impedance would be halved. Hence an SWR of 2:1 before it even gets to the

antenna. 

A tee in the feedline is not a good idea. It will work but there are a lot

of things that can go wrong with that setup. Up to and including 

accidently transmitting into your HH with the ships radio or visa versa.



It is best to use a Coaxial switch or have a patch panel.



To make a Patch panel you will need one BNC socket (female) and one

Connector (male) mounted on a small bracket and a Jumper Lead with one

Connector and one socket. The Jumper plugs into the Ships Radio via a socket

and a socket on the other end goes to the Antenna via the from the

connector. You disconnect the Ships Radio end of the jumper and plug into

the hand held. The reason for making the jumper male and female is so you

don't accidently plug into the Ships radio with the

Hand Held. Don't laugh it is easy done!  I still vote for a coaxial switch

it's a lot easier. They can be bought for not much money from a Ham Radio

supplier.

Cheers



John MacCallum

VH-DUU

RV 10 # 41016



	

--

BobsV35B(at)aol.com
Guest

Posted: Wed Feb 25, 2015 6:01 am Post subject: Handheld transceiver alternate antenna

Good Morning All, 

  

 Just to jump in on a message already well answered, I would like to add my  thoughts. 

  

 We have a Piper Pacer equipped with just one radio. A Garmin 430W.   The aircraft is flown IFR regularly. 

  

 In order to add a bit of reliable back up, we do carry a handheld and have  installed a separate external antenna just for that radio. It is a bit of extra  drag and a bit more weight, but when a back up is actually needed, it is nice to  know that the unit has an antenna all of it's own. Just my idea of a full backup  totally separated from the primary radio system.

  

 Decisions, decisions. All the time decisions! <G>

  

 Happy Skies,

  

 Old Bob

 AKA

 Bob Siegfried

 Ancient Aviator

 PA-20

 Brookeridge Air Park LL22

 Downers Grove, IL

  

  

 [quote][b]

john.maccallum(at)bigpond
Guest

Posted: Wed Feb 25, 2015 2:02 pm Post subject: Handheld transceiver alternate antenna

Probably a little bit of overkill for what you want it for. That particular one has a relay so that you can remote switch it. You can get good 

quality manual ones for a lot less than what that will cost although of course not quite as neat and tidy as a remote mounted switch such as that.

 

A quick search around I can find some N type connector switches for around $50. You would need to terminate the Antenna Feedline with and N connector

for the one in the link below but thatâ€™s actually a better specification than BNC. If you look around a bit you could probably find a BNC terminated type.

 

http://www.hamradio.com/detail.cfm?pid=H0-003421

 

 

Cheers

 

John MacCallum

VH-DUU

RV 10 # 41016

 

 

 

 

From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Ken Ryan

Sent: Thursday, 26 February 2015 3:58 AM

To: aeroelectric-list(at)matronics.com

Subject: Re: Re: Handheld transceiver alternate antenna



 

Attached is a pdf data sheet for a coaxial switch. Question: would this switch be a good choice?



 

On Wed, Feb 25, 2015 at 2:46 AM, John MacCallum <john.maccallum(at)bigpond.com (john.maccallum(at)bigpond.com)> wrote:

--> AeroElectric-List message posted by: John MacCallum <john.maccallum(at)bigpond.com (john.maccallum(at)bigpond.com)>



Yes RF is not like water. It's far more fickle and you can't use a

terminating cap because of the power involved during transmit. You would fry

a terminating resistor that was plugged into the free port plus the

impedance would be halved. Hence an SWR of 2:1 before it even gets to the

antenna.

A tee in the feedline is not a good idea. It will work but there are a lot

of things that can go wrong with that setup. Up to and including

accidently transmitting into your HH with the ships radio or visa versa.



It is best to use a Coaxial switch or have a patch panel.



To make a Patch panel you will need one BNC socket (female) and one

Connector (male) mounted on a small bracket and a Jumper Lead with one

Connector and one socket. The Jumper plugs into the Ships Radio via a socket

and a socket on the other end goes to the Antenna via the from the

connector. You disconnect the Ships Radio end of the jumper and plug into

the hand held. The reason for making the jumper male and female is so you

don't accidently plug into the Ships radio with the

Hand Held. Don't laugh it is easy done!  I still vote for a coaxial switch

it's a lot easier. They can be bought for not much money from a Ham Radio

supplier.

Cheers



John MacCallum

VH-DUU

RV 10 # 41016

--

john.maccallum(at)bigpond
Guest

Posted: Wed Feb 25, 2015 2:14 pm Post subject: Handheld transceiver alternate antenna

Yes Bob that was something else I thought about to suggest. If the extra drag is not an issue a dedicated antenna is a good solution.

 

Cheers

 

John MacCallum

VH-DUU

RV 10 # 41016

 

 

 

From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of BobsV35B(at)aol.com

Sent: Thursday, 26 February 2015 1:00 AM

To: aeroelectric-list(at)matronics.com

Subject: Re: Re: Handheld transceiver alternate antenna

 

Good Morning All, 



 



Just to jump in on a message already well answered, I would like to add my thoughts. 



 



We have a Piper Pacer equipped with just one radio. A Garmin 430W.  The aircraft is flown IFR regularly. 



 



In order to add a bit of reliable back up, we do carry a handheld and have installed a separate external antenna just for that radio. It is a bit of extra drag and a bit more weight, but when a back up is actually needed, it is nice to know that the unit has an antenna all of it's own. Just my idea of a full backup totally separated from the primary radio system.



 



Decisions, decisions. All the time decisions! <G>



 



Happy Skies,



 



Old Bob



AKA



Bob Siegfried



Ancient Aviator



PA-20



Brookeridge Air Park LL22



Downers Grove, IL



 



 

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 [quote][b]

kenryan

Joined: 20 Oct 2009
Posts: 426

Posted: Wed Feb 25, 2015 2:22 pm Post subject: Handheld transceiver alternate antenna

Not considering price, are the specs what they should be? And to those

suggesting the switch is the best solution, wouldn't there exist the danger

of the switch being in the wrong position, and then trying to transmit with

the equivalent of "no antenna" attached? I've heard that's not a smart

thing to do.



On Wed, Feb 25, 2015 at 12:59 PM, John MacCallum <john.maccallum(at)bigpond.com

 	  Quote: 	
		   wrote:


	


[quote] Probably a little bit of overkill for what you want it for. That

 particular one has a relay so that you can remote switch it. You can get

 good



 quality manual ones for a lot less than what that will cost although of

 course not quite as neat and tidy as a remote mounted switch such as that

wrmaxwell(at)bigpond.com
Guest

Posted: Wed Feb 25, 2015 2:34 pm Post subject: Handheld transceiver alternate antenna

It could be made to         work Ken but it is more complicated than necessary. It also         needs a 12 volt supply and utilises SMA connectors. I suggest         you look for a much simpler mechanical switch type.       They are commonly available from ham radio suppliers and usually       are fitted with SO-239 connectors. Connection is selected by       simply turning a knob or flicking a switch. Better reliability.

       

       Bill

     

     On 26/02/2015 3:58 AM, Ken Ryan wrote:

     

     [quote]       Attached is a pdf data sheet for a coaxial switch.         Question: would this switch be a good choice?

       

         On Wed, Feb 25, 2015 at 2:46 AM, John           MacCallum <john.maccallum(at)bigpond.com (john.maccallum(at)bigpond.com)>           wrote:

           [quote]-->             AeroElectric-List message posted by: John MacCallum <john.maccallum(at)bigpond.com (john.maccallum(at)bigpond.com)>

             

             Yes RF is not like water. It's far more fickle and you can't             use a

             terminating cap because of the power involved during             transmit. You would fry

             a terminating resistor that was plugged into the free port             plus the

             impedance would be halved. Hence an SWR of 2:1 before it             even gets to the

             antenna.

             A tee in the feedline is not a good idea. It will work but             there are a lot

             of things that can go wrong with that setup. Up to and             including

             accidently transmitting into your HH with the ships radio or             visa versa.

             

             It is best to use a Coaxial switch or have a patch panel.

             

             To make a Patch panel you will need one BNC socket (female)             and one

             Connector (male) mounted on a small bracket and a Jumper             Lead with one

             Connector and one socket. The Jumper plugs into the Ships             Radio via a socket

             and a socket on the other end goes to the Antenna via the             from the

             connector. You disconnect the Ships Radio end of the jumper             and plug into

             the hand held. The reason for making the jumper male and             female is so you

             don't accidently plug into the Ships radio with the

             Hand Held. Don't laugh it is easy done!Â  I still vote for a             coaxial switch

             it's a lot easier. They can be bought for not much money             from a Ham Radio

             supplier.

             

             

             Cheers

             

             John MacCallum

             VH-DUU

             RV 10 # 41016

             

               

               

               

               

               

               --

rv7a.builder(at)yahoo.com
Guest

Posted: Wed Feb 25, 2015 3:04 pm Post subject: Handheld transceiver alternate antenna

deej(at)deej.net
Guest

Posted: Wed Feb 25, 2015 6:28 pm Post subject: Handheld transceiver alternate antenna

I have a Narco VP-16 antenna switch that I will sell for $25 including 

shipping in the continental US.  It uses BNC connectors, and switches 

one antenna between two radios.  It is essentially an electrical relay 

that switches with 12v.  Wiring connector included.



Pic on my website

http://deej.net/forsale/



-Dj



-- 

Dj Merrill - N1JOV - EAA Chapter 87

Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/

Glastar Flyer N866RH - http://deej.net/glastar/

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