Bottom fuselage antenna

[Flymu2]

 

I have an Eagle with a PM7000 audio panel that allows transmitting on both radios at the same time. I have one comm antenna mounted on the bottom of the fuselage (and one on the top!) supposedly to maximize the separation of the transmitting antennas. The antenna on the bottom is beat up - bent, scratched, etc. I'd like to put a new antenna on it, but the mechanic says that a CI122 (that has the bend on it) scrapes on the ground when the tail skid is close to the ground. Any creative solutions to this issue?

 

[OR75]

move the antenna forward between the 2 wheels ?

Probably good to have an antenna at the top and one at the bottom to maximize reception .... but I am wandering when would you have a need to transmit on both radio (I understand being able to listen)

[Cris]

You might want to check to see if your PM7000 is indeed set up to transmit by both the pilot and co-pilot simultaneously as Mooney did not allow for that as a factory set up. I do not know the reason why since the audio panal seems to be the same standard PS 7000 engineering setup. At least that is what is in my documentation on my Eagle and I can't transmit simultaneously. That bent com antenna might in fact be for an emergency hand held as opposed to simultaneous transmit function on the audio panel.

[danb35]

Whether or not he's set up for simultaneous dual transmitting, it's very likely he has two separate comm antennae.  I don't think it's likely to be a useful feature very often in a piston single, though.

[Jerry 5TJ]

I have #1 comm radio connected to the bottom antenna.   That one is used for airborne communications but when the plane is on its wheels that antenna is very close to the ground and is electrically compromised.

The #2 comm radio is connected to the top antenna.  It works better on the ground than #1 so I use #2 comm for all ground operations.  

Some ADS-B systems have antenna diversity as do some transponders.   Those are intended to have two separate antennas, usually one each on the top and bottom of the fuselage.   Transponders with diversity don't transmit out of both antennas at once, but reply on the antenna which had the stronger interrogation signal.

 

[Flymu2]

There is only one com antenna on the top and the one on the bottom.

Between the wheels sounds interesting, though it would worsen the already limited usefullness on the ground.

I have to check the logs and manuals about the dual transmit. I owned a Baron that had the PM 7000 with dual xmit, though II used it maybe a few times.

 

[jetdriven]

Quote: Flymu2

 

I have an Eagle with a PM7000 audio panel that allows transmitting on both radios at the same time. I have one comm antenna mounted on the bottom of the fuselage (and one on the top!) supposedly to maximize the separation of the transmitting antennas. The antenna on the bottom is beat up - bent, scratched, etc. I'd like to put a new antenna on it, but the mechanic says that a CI122 (that has the bend on it) scrapes on the ground when the tail skid is close to the ground. Any creative solutions to this issue?

 

[Bolter]

Whether or not he's set up for simultaneous dual transmitting, it's very likely he has two separate comm antennae. I don't think it's likely to be a useful feature very often in a piston single, though.

I think there is useful value in the dual, independent transmission with typical GA planes like ours. When flying in my friend's Brand C, we take advantage of the feature to share workload. The PIC handles ATC, while the right seat can check in with flight watch, call ahead to an FBO to have the car ready, transmit onto the CTAF before the handoff from ATC to a non-tower airport, and checking ATIS's. The last one is not a transmit item, but the complete radio separation is handy.

I am not sure the cost difference for the feature, but it is certainly something to consider as useful when upgrading your panel.

-dan