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Radio Issue

Posted: Wed Nov 06, 2013 7:30 am
by bobthebuilder
Hi Guys,

I have a MicroAir M760 Panel mount Radio.
In the circuit at Petit (133.20) and Rhino Park (135.6) it functions 5/5.
However! .......

It seems that while on SRE [125.4] and on SRW [125.8], I can hear all incoming transmissions perfectly, but my own transmissions are inaudible to SOME traffic.
When flying with friends, they say that my transmissions are 4/5.

It seems that my transmissions are received well by some aircraft, and poorly by others.

Can anyone advise on how to troubleshoot this problem?

Re: Radio Issue

Posted: Wed Nov 06, 2013 8:14 am
by nicow
Check your antenna...

Re: Radio Issue

Posted: Wed Nov 06, 2013 8:38 am
by ZULU1
Unfortunately Bob, i dont have enough information to help you out ?

When you visit a doctor and advise you have toothache it doesnt help !

So What aircraft
What antenna, where is it mounted and what ground plane if any?
What intercom system or are you using the Microair internal
What headsets are you using

The Microair has a side tone setting and also a power setting. I would advise if used in a trike its redeployed as a rather inefficient wheel chock..

Advise the above and i will see what i can come up with.

Re: Radio Issue

Posted: Wed Nov 06, 2013 11:50 am
by nicow
I also have a Microair on my Cobra,and it works much better than the handhelds on my other trikes...

Re: Radio Issue

Posted: Wed Nov 06, 2013 12:02 pm
by bobthebuilder
Hi Paul,

Aircraft: Super Koala
Antenna: Don't know what make it is. Bee sting type thing mounted on the roof of the aircraft. (Not the swept type)
Antenna Cable: Co-axial cable from the radio (panel mounted) which leads to the roof of the aircraft, more or less aligned with the the tailing edge of the wing. I estimate the cable to be around 1.8m long.
Ground Plane: Wooden airframe.
Intercon: Microair internal.
Headset: Peltor.

I will go out to the field on the weekend and take a photo of the antenna if required.

Many thanks for your assistance.

Re: Radio Issue

Posted: Wed Nov 06, 2013 12:04 pm
by bobthebuilder
Nico, the best setup that I have ever had was a Vertex 220, with an Airmagic intercom and helmets with intergrated headsets. The system also used a V-Rabbit antenna.
Crystal clear transmissions every time.

Re: Radio Issue

Posted: Wed Nov 06, 2013 3:25 pm
by nicow
bobthebuilder wrote:Nico, the best setup that I have ever had was a Vertex 220, with an Airmagic intercom and helmets with intergrated headsets. The system also used a V-Rabbit antenna.
Crystal clear transmissions every time.
I have 4 of them (!!)

Re: Radio Issue

Posted: Wed Nov 06, 2013 6:19 pm
by bobthebuilder
Guess there is a reason for that.....

Re: Radio Issue

Posted: Wed Nov 06, 2013 6:21 pm
by bobthebuilder
Oh Paul, I forgot to mention ......
I use AirNav pro on a Galaxy Note cell phone. There is no GPS antenna.

Re: Radio Issue

Posted: Thu Nov 07, 2013 4:27 pm
by Duck Rogers
bobthebuilder wrote:Hi Paul,

Aircraft: Super Koala
Ground Plane: Wooden airframe.
Byron...on my Koala the interior of the cabin roof had an aluminium plate as a groundplane, stuck/srewed to the interior of the roof lining.

Re: Radio Issue

Posted: Fri Nov 08, 2013 5:03 am
by bobthebuilder
Hi Gerrie,

I don't have an aluminium plate that is visible anywhere.
Could the instrument panel have been used?

Re: Radio Issue

Posted: Fri Nov 08, 2013 8:43 am
by ZULU1
Please take a pic of the interior of the cabin, that ground plane is law!

Re: Radio Issue

Posted: Fri Nov 08, 2013 6:07 pm
by Duck Rogers
bobthebuilder wrote:Hi Gerrie,

I don't have an aluminium plate that is visible anywhere.
Could the instrument panel have been used?
...or maybe the undercarriage....or an empty coke can.......who knows?
You gotta have a groundplane......else she won't work good :shock: ...if at all :?:

Re: Radio Issue

Posted: Fri Nov 08, 2013 6:51 pm
by bobthebuilder
Thanks guys, I now have a place to start. I'll take a look tomorrow and get some pics.

Re: Radio Issue

Posted: Fri Nov 08, 2013 8:25 pm
by ZULU1
I may add that the reason the vee rabbit performs is the fact that it actually doesnt need a ground plane at all. In your application, you may as well use a knitting needle if no ground plane is attached, the plate should be at least the size of half the length of the whip itself. Not getting technical but a dustbin lid is a good start..as long as its metal. No rocket science, as Gerrie says a coke can even works or a few car plates in a cross...