Avidyne Homepage
Forum Home Forum Home > Avidyne General > IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM
  New Posts New Posts RSS Feed - Poor radio reception and transmission IFD540
  FAQ FAQ  Forum Search   Register Register  Login Login

Poor radio reception and transmission IFD540

 Post Reply Post Reply
Author
Message
baldcaldwell View Drop Down
Newbie
Newbie


Joined: 21 Mar 2021
Location: 14A
Status: Offline
Points: 14
Post Options Post Options   Thanks (0) Thanks(0)   Quote baldcaldwell Quote  Post ReplyReply Direct Link To This Post Topic: Poor radio reception and transmission IFD540
    Posted: 25 Apr 2021 at 8:55am
We are almost ready for the first flight of my Bearhawk Model B.  I've been doing some taxi testing as well as calling for radio checks.  Those that can hear me are relatively close.  Near the runway the ASOS antenna is about 2500' away and in my line of sight.  I cannot hear the ASOS unless I have the squelch on.  We did a high speed taxi test down the runway.  The plane behind me on the taxiway heard my call to take the runway.  However when I turned off at about 4,000' he could not hear me when I called to clear the runway.

A friend of mine called his avionics buddy.  He suggested that I install a ground strap to one of the mounting bolts to my belly mounted Comant VHF CI-122 antenna.  Effectively grounding the antenna to the airframe. I did. This did not change anything.  I am still having trouble receiving and transmitting.  

I am using RG400 coaxial cable and RG400 BNC fittings.  

Today Amazon is delivering a SWR meter and I will test the signal at the antenna BNC connection.  

Any thoughts?

Thank you!


Rob Caldwell
Lake Norman Airpark (14A), North Carolina
EAA Chapter 309
Model B Quick Build Kit Serial # 11B-24B / 25B
YouTube Channel: http://bearhawklife.video
1st Flight May 18, 2021
Back to Top
wookie View Drop Down
Groupie
Groupie


Joined: 18 Feb 2015
Location: Colorado
Status: Offline
Points: 56
Post Options Post Options   Thanks (0) Thanks(0)   Quote wookie Quote  Post ReplyReply Direct Link To This Post Posted: 14 May 2021 at 12:54pm
Has to be something in the antenna/connections as both xmit and receive are both affected.   BH
BH
Back to Top
PA23 View Drop Down
Senior Member
Senior Member


Joined: 12 Oct 2019
Location: MMU
Status: Offline
Points: 304
Post Options Post Options   Thanks (0) Thanks(0)   Quote PA23 Quote  Post ReplyReply Direct Link To This Post Posted: 14 May 2021 at 1:45pm
I'm assuming this is in your Bearhawk.  where is the antenna mounted?  I think the fuselage is fabric covered isn't it?  Did you make provisions for a large enough ground plane?  I think you need a ground plane just over 2ft in diameter, on an all aluminum airframe this isn't an issue but on a fabric aircraft this has to be taken into consideration.
Back to Top
baldcaldwell View Drop Down
Newbie
Newbie


Joined: 21 Mar 2021
Location: 14A
Status: Offline
Points: 14
Post Options Post Options   Thanks (0) Thanks(0)   Quote baldcaldwell Quote  Post ReplyReply Direct Link To This Post Posted: 14 May 2021 at 1:54pm
Good stuff everyone!  We have resolved the RX/TX issue and are back up and running!  Move the antenna up the tunnel.  Here's the discussion:  https://youtu.be/GHjPTiy5ViI?t=96

Thanks for the help!


Edited by baldcaldwell - 14 May 2021 at 1:57pm
Rob Caldwell
Lake Norman Airpark (14A), North Carolina
EAA Chapter 309
Model B Quick Build Kit Serial # 11B-24B / 25B
YouTube Channel: http://bearhawklife.video
1st Flight May 18, 2021
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.086 seconds.