Cable hangers are commonly used to secure cables to structural members of antenna towers and or along tunnel walls.  Generally, each cable is attached to a structural member by cable hangers mounted at periodically-spaced attachment points. 
Antenna towers and/or tunnels may be crowded due to the large numbers of cables required for signal-carrying.  Over time, as systems are added, upgraded and/or expanded, installation of additional cables may be required.  To conserve space, it may be desirable for each set of cable hangers to secure more than a single cable.  Certain cable hangers have been constructed to secure multiple cables; other cable hangers have a stackable construction that permits multiple cable hangers to be interlocked extending outwardly from each mounting point/structural member.  Stacked and multiple-cable-type cable hangers significantly increase the number of cables mountable to a single attachment point. 
One popular stackable cable hanger is discussed in U.S. Pat.  No.  8,191,836 to Korczak, the disclosure of which is hereby incorporated herein in its entirety.  Hangers disclosed therein have generally a U- or C-shaped profile with rounded arms.  A locking projection extends from the free end of each arm, and the “root” of the hanger that spans the fixed ends of the arms has a large aperture.  The hanger can hold a cable between the arms; gripping of the cable is enhanced by short fingers that extend inwardly from the arms to engage the cable.  The locking projections of a hanger are inserted into a hole in the antenna tower (typically in the leg of the antenna tower) to secure the hanger to the tower.  Hangers can be “stacked” onto each other by inserting the locking projections of one hanger into the large aperture of the next hanger.  One variety of cable hanger of this type is the SNAP-STAK® hanger, available from CommScope, Inc. (Joliet, Ill.).  Other cable hangers are shown in U.S. patent application Ser.  No.  15/081,177, filed Mar. 25, 2016, Ser.  No.  15/081,240, filed Mar. 25, 2016, and Ser.  No.  15/335,614, filed Oct. 27, 2016, the disclosures of each of which are hereby incorporated herein by reference in full. 
In some instances, it may be desirable to mount multiple stacks of cable hangers in close proximity.  In such instances, it may be desirable to employ an adapter, such as that shown at 10 in FIG.  1.  The adapter 10 has a trapezoidal profile, with a base panel 12 and three serially attached mounting panels 14.  Each of the mounting panels 14 includes a mounting hole 16 (typically a nominal ¾ inch hole) that can receive a cable hanger such as those described above, one of which is designated 20 in FIG.  2.  The base panel 12 of the adapter 10 has a hole 18 that can be used to mount the adapter 10 to a mounting structure via a bolt.  The base panel 12 also includes slots 22 on either side of the hole 18 that can receive a hose clamp 26 or the like to mount the adapter 10 to a pole 24, as shown in FIG.  3.  This mounting approach may be desirable when the pole 24 has no pre-formed holes to receive a typical cable hanger. 
It may be desirable to provide additional configurations for mounting cable hangers.