earth moon earth communications the challenge to build a very large antenna by mike melum presented...
TRANSCRIPT
![Page 1: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/1.jpg)
Earth Moon Earth Communications
The challenge to build a very large Antenna
By Mike MelumPresented to ASPE June 13, 2013
![Page 2: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/2.jpg)
Contents
• How I got hooked• The steps
– Design– Procure– The Tower– The Mechanics – Electrical/Electronic
![Page 3: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/3.jpg)
MOTIVATION
• The Moon on a clear night is beautiful to behold• Typically about 0.5 degree of arc• Average 238,000 miles from Earth• The thought of reflecting a signal off the moon is
seemingly absurd, not quite as absurd as the thought of ‘going there’ but nevertheless not a normal quest
• Therein lies the challenge
![Page 4: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/4.jpg)
How I got Hooked
• Ham Radio – since age 14• Amateur Satellites • The Ultimate ham radio challenge – EME
![Page 5: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/5.jpg)
Hooked
• EME Attracts all kinds of people from carpenters to Nobel Prize winners (~2-3000 world-wide)
• Technology “Sport”– Civil, Mechanical, Electrical, Electronic– Astrophysics – Moon dynamics are complicated– Control systems– High Power Amplifiers– Low noise, high sensitivity receivers
![Page 6: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/6.jpg)
The Steps
• Acquire the Dish• Design• Procure parts, materials, services• The mounting structure (Tower)• The Mechanics
![Page 7: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/7.jpg)
Structural Design
• Tower Requirements – Strength– Height – Cheap
• Mechanical concepts• Make Drawings• Ask everyone!
![Page 8: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/8.jpg)
Acquire a Dish
![Page 9: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/9.jpg)
Original Dish
9.2 METER TRANSPORTABLE PARABOLIC DISH ANTENNA
50"
![Page 10: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/10.jpg)
Modifications
![Page 11: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/11.jpg)
DesignWINDLOADING AND FOUNDATION CALCULATIONS The following assumptions were used in the calculations: 1. Design windspeed = 50 lbs/sq.ft. (approx. 120 mph)2. Two legs of the tower face away from maximum wind direction to reduce potential for buckling of the tower.3. Total weight = 15 to 20,000 pounds4. Dish area = 700 sq. ft. 5. Overturning moment = 875,000 pounds ?6. Decision: Design for worst case in parked position7. Design is with antenna parked (EL = 90; AZ = 150 +/-10) (Historically most winds in excess of 30 mph are from this direction)
![Page 12: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/12.jpg)
Alternatives
![Page 13: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/13.jpg)
Tower (Pilings)
![Page 14: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/14.jpg)
Tower TopTOWER TOP FABRICATION
AUGUST 31, 2000
18.0in.
VERSION 4
26 in. DIAM x 8 in. X 1/2 in. CYLINDER
(51.25 in.)
(56.5 in.)
18.0in.
28 in. DIAMETER x 3/4 in. DRILLED PLATE TO BE
MOUNTED ON TOP, WELDED TO CYLINDER (SHOWN HERE ON
BOTTOM TO CLARIFY POSITIONING OF CYLINDER
BETWEEN EDGE AND HOLES)
10.5in.
26 in. OD x 8 in. X 1/2 in. CYLINDER
(DIAGONALS NOT SHOWN)
4x8x1/4 in. TUBULAR STEEL
BOTTOM VIEW
65.5in.71.0in.
66.0in.
2EA. 6:1 SPROCKET SETS AND BAND BRAKE
![Page 15: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/15.jpg)
Rotating Platform
75.0
in.
85.5
in.
8.0
in.
4.0i
n.
5.0
in.
36.1
in.
65.0
in.
29.7
in.
`
1.5in.
36.0in.
AUGUST 4, 2000
PLATES 10" X 28" X 1/2" STEEL
SCHED 40 3/4" PIPE SLEEVE REINFORCEMENT
SQ. X 1/2" STEEL
22 EA. 3/4" - 10 X 10 1/2" GRADE A325
4 EA. 3/4" - 10 X 2 1/2" GRADE 8
WELD
4 EA. 3/4" - 10 X 2" GRADE 8
REMOVE
MAX
BEARING
![Page 16: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/16.jpg)
Rotating Platform (Part 2)
![Page 17: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/17.jpg)
Elevation Actuator
![Page 18: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/18.jpg)
Dish Assembly
![Page 19: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/19.jpg)
Lift Frame
![Page 20: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/20.jpg)
Crane
![Page 21: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/21.jpg)
Mounting the FeedPhase 1
![Page 22: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/22.jpg)
Mounting the Feed Phase 2 (First Attempt)
![Page 23: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/23.jpg)
Mounting the Feed Phase 2 (Final Solution)
DISH SURFACE
TO WINCH
HINGE HINGE
TOP PIVOT
2.00
2.00 2.00
FEEDCONEMAY 22,2003
![Page 24: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/24.jpg)
Mounting the Feed Phase 2 (First Attempt) (Continued)
![Page 25: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/25.jpg)
DIY
![Page 26: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/26.jpg)
Operating Console
![Page 27: Earth Moon Earth Communications The challenge to build a very large Antenna By Mike Melum Presented to ASPE June 13, 2013](https://reader036.vdocuments.net/reader036/viewer/2022062805/5697bfe31a28abf838cb4b84/html5/thumbnails/27.jpg)
Test Bench