I think this boils down to a question re. 'Exclusive Use' and/or 'Exclusive Control'. If you have either or both of those over the wall surface in question, you likely have the full support of the FCC. If you lack both of those, you will likely want to make nice promptly.
I would be a bit surprised if you or another individual condo owner 'own' the exterior surface of the building. In most condominiums I would expect the exterior roof and walls to be owned by the entire group of owners, because they all depend on the roof and walls to protect their individual units. If the condo association owns the exterior of the building, a rule that prevents an individual owner from making holes in it seem reasonable.
http://www.fcc.gov/guides/over-air-r...n-devices-rule
Q:* Whose antenna restrictions are prohibited?
A:* The rule applies to restrictions imposed by local governments, including zoning, land-use or building regulations; by homeowner, townhome, condominium or cooperative association rules, including deed restrictions, covenants, by-laws and similar restrictions; and by manufactured housing (mobile home) park owners and landlords, including lease restrictions.*
The rule only applies to restrictions on property where the viewer has an ownership or leasehold interest and exclusive use or control.
Q:* If I live in a condominium or an apartment building, does this rule apply to me?
A:* The rule applies to antenna users who live in a multiple dwelling unit building, such as a condominium or apartment building,
if the antenna user has an exclusive use area in which to install the antenna.* "Exclusive use" means an area of the property that only you, and persons you permit, may enter and use to the exclusion of other residents.* For example, your condominium or apartment may include a balcony, terrace, deck or patio that only you can use, and the rule applies to these areas.*
The rule does not apply to common areas, such as the roof, the hallways, the walkways or the exterior walls of a condominium or apartment building.* Restrictions on antennas installed in these common areas are not covered by the Commission's rule.* For example, the rule would not apply to restrictions that prevent drilling through the exterior wall of a condominium or rental unit and thus restrictions may prohibit installation that requires such drilling.
Q:* Does the rule apply to condominiums or apartment buildings if the antenna is installed so that it hangs over or protrudes beyond the balcony railing or patio wall?
A:* No.* The rule does not prohibit restrictions on antennas installed beyond the balcony or patio of a condominium or apartment unit if such installation is in, on, or over a common area.* An antenna that extends out beyond the balcony or patio is usually considered to be in a common area that is not within the scope of the rule.* Therefore, the rule does not apply to a condominium or rental apartment unit unless the antenna is installed wholly within the exclusive use area, such as the balcony or patio.
Q:* Does the fact that management or the association has the right to enter these areas mean that the resident does not have exclusive use?
A:* No.* The fact that the building management or the association may enter an area for the purpose of inspection and/or repair does not mean that the resident does not have exclusive use of that area.* Likewise, if the landlord or association regulates other uses of the exclusive use area (e.g., banning grills on balconies), that does not affect the viewer's rights under the Commission's rule.* This rule permits persons to install antennas on property over which the person has either exclusive use or exclusive control.* Note, too, that nothing in this rule changes the landlord's or association's right to regulate use of exclusive use areas for other purposes.* For example, if the lease prohibits antennas and flags on balconies, only the prohibition of antennas is eliminated by this rule; flags would still be prohibited.