Matronics Email Lists :: View topic - Kolb-List: Radio Check â?" Learning

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Kolb-List: Radio Check â?" Learning

Matronics Email Lists Forum Index -> Kolb-List

View previous topic :: View next topic

Author Message

byoungplumbing(at)gmail.c
Guest

Posted: Mon Apr 25, 2011 9:42 am Post subject: Kolb-List: Radio Check â?" Learning

Dear Kolbers,

I wanted to share with you a  learning that I had and may help some of you!

I have an external whip antenna  on my FS-2 and have a Handheld Icom A 22 connected to it. I had a long cable  2.50 meter (RG-5 running from the radio to the external antenna which should  be in multiples of (Half wavelength - 1.25 meters or 2.50 meters) for 121 MHZ  center frequency that we  use.

 	  Quote: 	
		  >>>>>>>>>>>>>>>>>>>>>

  
	


 if the antenna is tuned correctly,,,  the coax  length does not have to be any exact length....  from what I  understand,,,  if the antenna is not tuned, and the coax is an exact  multiple of some magic length / number,,,  then the radio wont  fry....  it may not  work very well but it wont fry.... any length  coax, on a properly tuned antenna, is ok.  the wave length of the frequency  121,000 MHz  is 2.48 meters,,,  but the velocity factor of the coax  will be somewhere about .8  depending on the manufacture /  construction,    I am not sure 1.25  or 2.50 meters is the  magic number to compensate for a badly tuned antenna.  I am just curious,,,  where did you get your information????

  

 boyd young

 ham radio extra class

 N7WFM

  

 kolb mkiii n1225y

   [quote][b]

- The Matronics Kolb-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List

miyer2u

Joined: 19 Nov 2009
Posts: 41
Location: Oregon

Posted: Mon Apr 25, 2011 12:51 pm Post subject: Re: Kolb-List: Radio Check ï¿½?

Hi Boyd,

May be you are right when you say that a tuned antenna will not require the magic figure of 1.25 or 2.50 meters. I have not tried if it does make a difference. I referred to a very good article posted by Bob Kirby - Radio Installations in Ultralights and Homebuilts (Google it)

I had been facing radio problems for quite some and have slowly got improved results. Some of the changes that helped are as follows:



1.Shielding all cables, especially the Kill switch and Hobbs meter

2.Moving to resistor sparkplugs

3.Installing a external whip antenna with a ground plane

4.Connecting the whip antenna to the radio using a RG 58 coax cable.



I am still not done as I have to shield the sparkplug cables. With the current set up, I can hear and transmit clearly until I reach 5900 RPM, but between 5900 RPM and 6400 RPM, its still worse, so the improvement continues. I believe Radio Installation is an art and a science!



Thanks,

Mahesh 

Kolb Firestar 2 â€“ Powered by a Rotax 503 DCDI and driven by a three blade IVO prop

The joy of Flight â€¦â€¦Nothing comes closer, itâ€™s a romance for life!

- The Matronics Kolb-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List

HShack(at)aol.com
Guest

Posted: Mon Apr 25, 2011 4:08 pm Post subject: Kolb-List: Radio Check â?" Learning

A 22,000 microfarad electrolytic capacitor rated at 18 volts should be  considered a minimum.  Connects right where the battery would go.  A  47,000 mfd. cap. is even better.

  

 You can do a google search for "electrolytic capacitors" and find  lots.  No need to spend more than $15.

  

  In a message dated 4/25/2011 6:16:16 P.M. Eastern Daylight Time,  jhauck(at)elmore.rr.com writes:

  	  Quote: 	
		  I    imagine the big ones we use on 912 engines would 

work as well.  They    are 22,000 or 25,000 mfd.  You all correct me if I am 

wrong.  I    am pulling this out of my worn out  memory.



	


 [quote][b]

- The Matronics Kolb-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List

byoungplumbing(at)gmail.c
Guest

Posted: Mon Apr 25, 2011 5:48 pm Post subject: Kolb-List: Radio Check â?" Learning

to all interested parties.

ok     radio installations is 1/3 art  1/3 science  &1/3 magic.....  I say 

this a bit tong in cheek...    some antenna's defy all logic leave you 

scratching your head,  and you are left wondering  WHY  or WHYNOT,,,



 now for clarification,,,  the capacitor should be between the voltage 

regulator and the battery,  if it is an electrolytic capacitor, make sure it 

is installed in the correct polarity,  you could also use one on the power 

buss for the plane,



    one other thing that can help is a set of inductors,,,  if you wind a 

wire around a ferrite ring, and install one on the positive, and one on the 

negative side of an appliance,  it can greatly reduce rf  or pulsed dc 

energy from getting to your devices.  inductors used in conjunction with 

capasitors make a good filter.     I have a gprs tracker in my plane,,,  it 

started out causing interference to my radio, as well as the EIS.   the 

inductors  and a capacitor completely eliminated the interference,   if you 

are running the radio with batteries, they should not be needed,  but if you 

are running off the aircraft power I would find or make some.  the ones I 

used came out of an surplus computer hardware, all mounted on a circuit 

board.



capacitors and inductors do kind of the same thing,,,  but they do it 

differently.   their differences is part of the reason they work so well 

together.



if anyone wants a better description let me know and I will give it a go.



boyd young

mkiii utah



 	  Quote: 	
		  >>>>>>>>>>>>>>>>>>>>>>>>>>>>


	


  I believe Radio Installation is an art and a science!



Thanks,

Mahesh



Mahesh/Gang:



I'm with you, my friend.



However, there are a couple things you can do that will improve your radio

performance in your Kolb.  You already mentioned resistor plugs which help a

lot, but what helped me even more was a capacitor.  On my 447 I used a

10,000 or 15,000 mfd.  I imagine the big ones we use on 912 engines would

work as well.  They are 22,000 or 25,000 mfd.  You all correct me if I am

wrong.  I am pulling this out of my worn out memory.

mkIII

hauck's holler, alabama

- The Matronics Kolb-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List

Display posts from previous:

	Matronics Email Lists Forum Index -> Kolb-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum