1. Getting Started On 144 MHZ EME
Two-Way radio communication on VHF using the Moon as a reflector.
Commonly know as “Moon Bounce”.

2. EME history – military purposes
The use of the Moon as a passive communications satellite - was proposed by W.J. Bray.
It was calculated that with the available microwave transmission power of the day and low noise receivers, it would be possible to beam signals from Earth and reflect them off the Moon.
The “moon bounce” technique was developed by the United States Military in the years after World War II, with the first successful reception of echoes off the Moon being carried out at Fort Monmouth, New Jersey on January 10, 1946 by John H. DeWitt as part of Project Diana.
The “Communication Moon Relay” project that followed led to more practical uses, including a teletype link between the naval base at Pearl Harbor, Hawaii and United States Navy headquarters in Washington, DC.

3. Project Diana facts 50 kilowatts at 111.5 MHZ in ​1⁄4- second pulses.
The first successful echo detection came on 10 January 1946 at 11:58am local time.
The Project Diana array was later used to map Venus and other nearby planets.

4. Project Diana array

5. Diana special event- n2mo https://www.youtube.com/watch?v=CdrtnFlIKRI

6. Eme for the radio amateur

7. In theory……..
If two stations have adequate equipment and can simultaneously see the moon, they should be able to make a contact via EME.
Several attempts may be required to achieve success.
Signals are very weak echoes reflected from the moon’s surface.
Typically, they are usually at the noise level, or even beneath the noise, occasionally rising from the noise for brief periods

8. IT’s A Long Trip
The moon is an average of 238,855 miles away from earth.

9. Challenges - Polarization
Spatial Polarization Offset – “Your Horizontal Isn’t My Horizontal”

10. Challenges – Path loss
During the lunar month, the moon travels in a slightly elliptical orbit with a distance to earth of approximately 221,500 miles at perigee (point closest to earth) and about 252,700 miles at apogee (point furthest from earth).
This distance results in about a 2.5 second delay on 2 meters, the round trip path loss is about dB at perigee and dB at apogee and the path loss increases with frequency.

11. RF noise

12. Local noise

13. In house noise - Plasma TV

14. Kitchen noise – old dishwasher

16. EME then!

17. Eme now

18. Eme then

19. Eme now

20. Then….

21. Now….

22. The digital age arrives

23. 2003 - something “wonderful” happens

24. K1jt “joe taylor” miracle worker

25. Professor joe taylor
Joseph Hooton Taylor Jr. is an American astrophysicist and Nobel Prize in Physics laureate for his discovery with Russell Alan Hulse of a "new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation.

26. https://physics.princeton.edu/pulsar/k1jt/
WSJT

27. Why jt65 digital for eme
Can decode signals to <-31 dB relative to the noise floor on VHF.
CW is only copyable to about -12 dB with “Good Ears”.
The program is very stable – does not need an expensive processor to execute.
It is all open source – many developers are out there working on the product.
There are new builds and updates coming through almost monthly.
Oh Yes – IT IS FREE!

28. Survey says -> jt65B
The by far most used and most reliable mode of operation is JT65B, due to the readability of signals with respect to noise.
I’d would to say that 95% of all EME QSO's on 2m are performed in JT65B mode (not taking into account EME contest situations etc.).

29. http://physics. princeton. edu/pulsar/k1jt/wsjtx-doc/wsjtx-main-1. 7

30. Let’s begin – the shack!

31. The transceiver

32. Multimode transceiver
VFO Stability for digital EME is very important. What ever radio you choose, make sure it is very stable at 144 mhz.
An all mode transceiver is required – a radio that is capable of SSB / CW.
The better the filtering and stability, things will work more in your favor!

33. Interfacing radio / computer

34. Cables and connections

35. Clean Signals are a must!
In order to participate in 2m EME communication, you absolutely need to enable your equipment to run digital modes flawlessly (no audio "hum“).
Avoid interfacing that requires you to use your microphone connector if possible!
Most radios offer a “Data Port” on the back of the radio – this is the best way to keep noise down.
Use “Snap On” chokes – take the RF of the cabling.

36. Pc / transceiver connections

37. Eme array

38. In order to perform 2m EME QSOs on a regular base - you need to provide a minimum of a 15 db of antenna gain on 2 meters. 
This amount of gain can be achieved e.g. by two horizontally stacked yagi’s with about 4 to 5 meters of boom length.
A single Yagi would require a boom length of about 10m in order to achieve about 15 db of gain.
The antennas

39. Faraday rotation / antennas
Many times during an EME session there are effects like "Faraday Rotation" which basically turns the polarization of an EME signal around by up to 90 degrees
This results in a degradation of the received signal - if the polarization cannot be switched – needless to say that under such circumstances the received EME signal is completely lost.
The bad news with Faraday is that this situation can last for hours!
Being able to switch the polarization of the antennas by 90 degrees is a very efficient way to getting around this polarization change issue.
Cross Polarization Yagi’s (Horizontal/Vertical - Switchable)

40. Switching polarity can make a huge difference

41. X-pol antennas

42. rotating the antennas

43. Up and down side to side

44. Manual pointing

45. Manual elevation

46. Nice and cozy inside operation

47. Moon tracking hardware

48. Homebrew setup

49. Inexpensive video camera

50. Several freeware programs for pc http://www.f1ehn.org/

51. Cabling the array

52. Transmission line – hard line / lmr 400

53. feedlines
Get the “Best” (lowest attenuation) feedline you can get for feeding your EME antenna and make your feedline is as short as possible!
This is especially true if you don't have an RX preamp close to the antenna!
Don't be shy of investing into a "good" feeding line. It will definitely pay-off!

54. The numbers do not lie!

55. Getting the signal to the moon!!! We need an amplifier!

56. Plug and play solid state amp

57. K1fo – 2 tube amplifier rip Steve! / An eme pioneer!

58. Ldmos “Pallet” amplifier the best bang for your dollar!

59. Amplifiers – Give you the punch!
For JT65B EME communication a TX power level of 300 Watts minimum needs to be considered.
Under better than good conditions – you might get away with 150 watts.
The TX periods are 1 minute sequences with JT65B, this amount of output power needs to be delivered at a continuous duty level (similar to FM operation). 
Your antenna relay, TRX, Final Amp plus PSU's need to cope with this amount of power and run time!
COOLING IS KEY!!!

60. Your station’s output is your responsibility!!!

61. spurious signals are not good!

62. Low pass filter - Keep your signal clean

63. Let’s help kitty hear better!!!!

64. What is a Low noise preamp…
A low-noise amplifier (LNA) is an electronic amplifier that amplifies a very low-power signal without significantly degrading its signal-to- noise ratio.
An amplifier increases the power of both the signal and the noise present at its input. 
LNAs are designed to minimize additional noise.

65. An effective Lna for “EME”
A low noise preamp with a noise figure of less than 1.5 dB is needed.
At 2m, it can be mounted in the radio room as long as good low loss feedline is used. The shorter the length of feedline, the better.
Up at the antenna will give you better results – but there are considerations.

66. Small but effective!

67. Mast mounted preamp
Ideally, the preamp should be mast mounted at the antenna. It needs to be protected from transmitting into it either via internal RF sensing and relays when lower power levels are being used or with a sequencer when running higher power levels.

68. “best” set up for an lna

69. Mast mounted lna’s need some supporting items

70. Sequencing for safety!
Sequencing the change-over from receive to transmit and vice versa is a *very* important subject. Not only for EME-operation but also for any kind of switch-over of receiving and transmitting devices. The purpose of "sequencing" is to avoid damage to the equipment/components caused by RF energy hitting a device at a non-appropriate point in time. In an EME station - The "sequencer" takes care of the proper switching in the time domain of components like: Pre-amplifier for RX Antenna relay Power amplifier for TX Transceiver

71. Yep – it blow’d up!!!

72. They do not like static!

74. Where is the moon?

75. EA6VQ – Thank You!!!! https://www.dxmaps.com/emecalendar.html

76. Can we work via eme?

77. Let’s find out!!! https://www.dxmaps.com/moon.php

78. Who’s around to try eme?

79. Ping jockey https://www.pingjockey.net/cgi-bin/pingtalk

80. Let’s be realistic……

81. The challenge - noise
Galactic Noise - Moon is in front of Milky Way for 3-4 days every Lunar month.
Background noise rises ~6-8 dB.
SOLUTION: Work on your station and don’t operate on those days.

82. The challenge – doppler shift
Occurs because of relative motion between Earth and Moon
Maximum ~300 Hz at 144
Operating procedures have been developed to mitigate the “missed QSO” problem due to not tuning correctly

83. The challenge - Faraday Rotation
Random polarization shift, variable (and unpredictable) rate of change.
Different for stations at different locations around the globe.
XPOL Array can help solve this issue.

84. It all takes time

85. A multi part series!!!

86. Antenna Design and Building
EME Array Assembly
Mast Mounting Preamps
Amps Amps Amps
Operating with JT65
Station Setup and Sequencing
Some Live EME QSO's