# Using two VHF antennas vs one because of a large obstruction

1. We have a VHF Omni directional antenna, 2.5 W and 119 MHZ (approximate) mounted on top of a commercial hanger. Access to the antenna is out of the question because of the lack of fall protection. Service personnel have expressed apprehension over accessing the antenna.

2. We’re trying to come up with a solution that minimizes the risk to service personnel

3. One idea is using two VHF antennas mounted at 8 feet elevation at diagonally opposite sides of the hanger with a Wilkinson Power-Divider at the VHF transmitter to ensure that the two antennas are properly phased. The VHF Antennas would be mounted at a much lower elevation (8’) on each side of the Hanger.

4. Two antennas are used because of the obstruction caused by the hanger when mounting them at 10'

a. Do you have any thoughts on this? b. Do we have a reasonable chance of success? c. Is this idea of any merit?

• Please state the problem you're trying to solve. What's wrong with the antenna you already have? What's the obstruction? Is it the hanger?
– mrog
Oct 16 '19 at 16:10
• Technicians are apprehensive of going up there. There are no railings or handholds or tie offs. The surface is deteriorating. Its pretty dangerous. Oct 16 '19 at 16:37
• Possible duplicate of Two antennas on different sides of a building Oct 16 '19 at 17:27
• 6. A major concern is that an unexpected beam pattern would result. a. We don’t know if the ideal result, shown below, would result. b. We could have a beam pattern with some unintended results. Oct 16 '19 at 17:42
• @CofFee yes, but you start of saying you're "looking for a solution" without saying what you're looking for a solution to, and you want to know your "chance of success" without defining what "success" means. What does the existing antenna not do that it should? Why are you contemplating new antennas? How will you know if you succeed? Oct 16 '19 at 20:52

• I guess I should clarify I apologize but I can't believe I didn't add this. We are a State Agency and the building is a Private Property . They let us host a radio advisory system that benefits them. We just can't put in masts, or extensive modifications because its private property and we can't spend hi amounts of taxpayer money on a commercial l building so we are tied to $5K as a limit.$5K these days will buy you a lot of RF cable, fittings, an extra antenna, hardware and that's it. A tilt down tower would be $10 K because we have to follow the code to install it. Oct 18 '19 at 3:00 • I've thought about every workaround I can, including a home made rail system or a hoist or a folding mast, but the bottom line is this is a private property.There is a liability. So we have to keep the signature of what we do light. That's why I am posing the question of 2 antennas. Success would be maybe reaching the same coverage we have now with only a few dead zones, vice huge amounts of dead zones. Oct 18 '19 at 3:12 • Thanks everyone. I am very inexperienced in RF. I am only Google smart/ Oct 18 '19 at 3:12 • @CofFee an appropriate mast will cost less than$20. Example: amazon.com/dp/B07C95LLBT Oct 24 '19 at 17:51