referring in detail to the drawings , which illustrate the preferred embodiment of the invention , the numeral 1 represents the side wall of a building covered with siding members 3 , having studs 4 , and having an inclined roof 2 . my improved antenna mounting bracket is comprised of two rigid upper fastening plates 5 , and two lower fastening plates 6 , each of which is provided with a plurality of openings 37 adapted to receive screws or like securing means 7 by which the upper fastening plates 5 and lower fastening plates 6 are anchored to the side wall of the building 1 . each of the lower fastening plates 6 , and each of the upper fastening plates 5 , has a pair of extending , laterally spaced ears 9 which are co - axially apertured as at 10 for receiving a bolt 11 with a self tighening nut 12 . four adjustable length arms 14 are rotatably connected to the laterally spaced ears 9 . the adjustable length arms 14 are each comprised of a pair of rigid telescoping members 15 and 16 , and the length of 14 does not change when in a locked position . the locking means consists of a split ring wacher 17 slid between one end of the telescoping member 15 and a threaded end 23 of the telescoping member 16 , and a locking nut 8 received by the threaded end 23 . the locking nut 8 exerts pressure on the split ring 17 when tightened , locking telescoping members 15 and 16 so that the length of the adjustable length arm 14 does not change . rigid telescoping member 15 has an aperture 27 transversely thereof for receiving the bolt 11 , and the rigid telescoping member 16 has an aperture 25 transversely thereof for receiving a bolt 20 . the adjustable length arms 14 are rotatably connected to post 28 made of a standard piece of angle iron . the upper portion of the post 28 has two pairs of extending , laterally spaced ears 18 each coaxially apertured as at 19 for receiving the bolt 20 with a self tighening nut 21 . in like manner the lower portion of the post 28 has two pairs of extending laterally spaced ears 18 which are co - axially apertured as at 19 for receiving the bolt 20 with the self tightening nut 21 . one end of a cable 30 is secured to a flange 31 after passing through an aperture 33 in the upper plate 5 . the cable 30 passes through one end of a turnbuckle 32 , and the opposite end is secured to the other upper plate 5 at flange 31 and is secured by a cable clamp 34 . the turnbuckle 32 is fastened to the post 28 by a hooking part 36 received by an opening 38 in a circular butt plate 35 . the circular butt plate 35 is an integral part of post 28 and has a drain hole 26 . a mast 22 is mounted to the post 28 by u - bolts 41 within which mast 22 is held by means of suitably shaped clamping plates 13 , and nuts 39 , and washers 40 , on the threaded arms of the u - bolt 41 , and rests against the circular butt plate 35 . in the operation of the device the bracket is placed against the exterior wall 1 near the overhang 26 so that the upper fastening plates 5 and lower fastening plates 6 rest against the exterior wall 1 . the upper fastening plates 5 and lower fastening plates 6 are secured to the exterior wall 1 by means of lag screws 7 forced into siding members 3 and studs 4 . the pair of rigid telescoping members 15 and 16 are adjusted so that the post 28 is positioned to support the mast 22 vertically , and to allow clearance from the overhang 26 . locking nut 8 is tightened to prevent rigid telescoping members 15 and 16 against movement relative to one another . tension in the cable 30 is readily increased by turnbuckle 32 to prevent the adjustable length arms from moving . the mast 22 , antenna rotor 29 , and antenna 24 , are mounted to the post 28 by means of u - bolts 41 within which mast 22 is held by means of a suitably shaped clamping plate 13 , nuts 39 , and washers 40 , on the threaded arms of the u - bolts 41 .