POTA station for Ford's Theater

[WA3LTJ]

I am planning a POTA activation at Ford's Theater (511 Tenth Street NW, Washington D.C.). This is truly an urban site with tall buildings. There are no grass areas, just sidewalk in front of the building. Sidewalk traffic is slowest Sunday mornings. SSB is the preferred mode to allow bystanders/spectators an opportunity to eavesdrop. Questions: what type of antenna? how much power? what band? 

My thoughts so far. 
POTA does not allow (land-based) repeaters, so UHF and VHF are not good options.  It seems that NVIS would be the propagation mode of choice. It might be an interesting challenge to string a wire dipole 5 to 15 ft off the ground that is not too long for the available space and does not interfere with foot traffic. I read that 50W is plenty for NVIS, but to some degree that depends upon ground and building wall losses. If I am close to a building, is it NVIS anymore? According to the Australian Space Weather Forecasting center site foF2 map (https://www.sws.bom.gov.au/HF_Systems/6/5), MUF for NVIS is below 7 MHz until around 10am. I cannot imagine setting up a full length 80 m dipole. Does a shortened 80 m dipole work for NVIS, or is the efficiency too low? I hope to get some ideas on how to get a signal out the urban hole.  What about RF exposure to passersby? Do I only transmit when no pedestrians are around?

 

[K3MRI]

Hi Andy. I speak from experience, not scientifically; not in this case anyway.

Before the antenna, let's talk permissions. You may, or may not, want to alert someone 'official' that you are doing this. You're in the heart of D.C.... Second, I would do it as a two- or three-person operation. You need help with antennas, watching over gear, etc.

Now the antenna. I have been successful at NVIS with - I am being serious - multiple metallic coat hangers hooked into one another, sitting 6-inches off the ground. The problem is not getting the signal out, it'll be your SWR. If you can overcome it and get a signal out without frying your TXC, you'll get out; obviously, subject to propagation. Will it be perfect, nope, but you will succeed in activating the site for certain.

One more thought, is there any rule against using a roof? If you can use a roof, ask the Ford Theatre...

Great idea. Depending when you do it, happy to help.

[WA3LTJ]

Jim,

I have already done some research looking at who to contact at the Theater. The plan is for two of us to go, but more is merrier. 

I suspect I can manage SWR, although RF on the case of the radio and into the microphone are yet more potential problems so far from resonance. I would rather not run 100W with people in the area and the added weight of bigger batteries. I would like a bit more elegant solution with enough efficiency to more readily make QSO's and lower the power.

I suspect the roof is precious and is also considered a safety risk. However, there might be something like an attic.