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Where did you mount your vhf radio antennas?

I am doing a quickpanel from AFS for full IFR and I have so many antennas to mount! Who would have thought building an airplane was so complicated?

Starting to look at mounting my VHF radios antennas.
I have the supertracks so there is limited room on the top deck.
I'm pretty sure the GPS will fit fine just behind the baggage compt.
The ELT antenna is just north of the vertical stabilizer.
I have three more antennas I need to find a home for (look like a small shark fins) and two radio (VHF) to mount.

Thanks in advance for any suggestions.
 
Most common to mount comm antennas on the belly, approx 3ft apart just aft of the spar. One caution of this installation is if your airport ATC are picky, they may call you out on transmissions on the ground as their antenna is higher than your low mounted antennas that may be blanked out by the wings. My solution is stagger the comm antennas, one under the pilot as described above, second aft about 30" and under the passenger side of luggage area (so antenna is aft of wing trailing edge). Any other blade antenna being mounted farther back on tail cone belly. All antennas being the about 3ft spacing.

Others may have other alternate ideas.
 
Under the wings

There's nothing wrong with putting a comm antenna on the bottom surface of the wings. Mount it on an inspection cover if you're hesitant to do something irreversible.

I have a ham APRS antenna mounted that way (outboard inspection cover) and in the vernacular of VAF it "works great".
 
I am doing a quickpanel from AFS for full IFR and I have so many antennas to mount! Who would have thought building an airplane was so complicated?

Starting to look at mounting my VHF radios antennas.
I have the supertracks so there is limited room on the top deck.
I'm pretty sure the GPS will fit fine just behind the baggage compt.
The ELT antenna is just north of the vertical stabilizer.
I have three more antennas I need to find a home for (look like a small shark fins) and two radio (VHF) to mount.

Thanks in advance for any suggestions.

As Ralph said, belly mounted antennas are good for airborne transmissions, but not good at all for ground ops.

Consider the GPS antenna on the glare shield or under the cowl just ahead of the firewall. If anything, it puts it very close to the instrument panel.

Considering that antennas are drag, I put my ELT and nav antenna in the wingtip. (ELT is old 121.5, so not sure if the new ones can mount that distant.) Com whip, xpdr and ADS-B blades on the belly.

ADS-B in a wing inspection cover is an alternative.
 
Forward of Spare Under Gear Weldment

On my RV-9A I mounted two COMANT antennae under the Gear Weldments. They are the required minimum space apart and the weldments prevent anyone's feet from contacting the BNC connectors.
I've never had any complaints from ATC. Not even while inside my hangar facing away from the tower about a mile away. With two GTN-650s, at 3500 feet I am getting about 85 miles of communications.
The ADS-B and XPNDR antennae are mounted just aft of the Firewall, also the required minimum spacing apart. No problems with either of them in the past five years of flying.
 
I put a bent whip on the belly and an Archer in the wingtip. The wingtip antenna was, as Bob Archer warned me, not adequate and I replaced it with a whip on the upper fuselage. I have the Supertraks and was able to get it sufficiently clear of the vertical. It works perfectly. The underbelly antenna has never gotten any complaints on the ground or in the air.

Ed Holyoke
 
Words of wisdom from Garmin:

"The GTR 200/200B COM antenna should be well removed from all projections, engines and propellers.
The ground plane surface directly below the antenna should be a flat plane over as large an area as possible
(18 inch square, minimum). The antenna should be mounted a minimum of six feet from any DME or
other COM antennas, and four feet from any ADF sense antennas. The COM antenna should also be
mounted as far as practical from the ELT antenna. Some ELTs have exhibited re-radiation problems that
cause interference with other radios, including GPS. This can happen when the COM (GTR 200/200B or
any other COM) is transmitting on certain frequencies such as 121.15 or 121.175 MHz, which may cause
the ELT output circuit to oscillate from the signal coming in on the ELT antenna coax.
If simultaneous use of two COM transceivers is desired (split-COM or simul-comm), the COM antennas
should be spaced for maximum isolation. A configuration of one topside antenna and one bottom side
antenna is recommended. The GTR 200/200B requires a transmit interlock.
Simultaneous COM performance varies significantly across installations and is affected by both the
isolation between the COM antennas and the separation of the tuned frequencies. Each installation should
be individually examined to determine the expected performance of simultaneous COM."
 
Halfway along the turtledeck on the centerline. I installed a doubler under the skin to spread the load of the mounting screws. I only have 1 VHF and didn't want to risk poor transmission or reception on the ground.

I certainly understand why folks put them under the fuselage, but being an ugly bugger, I can assure you aesthetics aren't everything! :p

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