Zero Retries Guide to Neil's Night

The complete Neil's Night article, previously serialized in Zero Retries.

Mention the issues…

Thought Experiment - Neil’s Night

By Steve Stroh N8GNJ

One of my most profound joys is to have conversations with people much brighter, more experienced, and more talented than I am. Such conversations often lodge in my mind for a time, and are brought forward by other conversations or experiences in a synthesis of combined thoughts. This idea / story is an example of that.

This is a thought experiment (a specialty of Zero Retries, where I air out, rather than self-censor some of my "irrationally exuberant" ideas¹ about creating an annual event on July 20th to:

• Commemorate, via Amateur Radio, the anniversary of humanity’s first steps on the Moon in 1969;

• Encourage Amateur Radio Earth Moon Earth - EME (“Moonbounce”) communications especially to those that haven’t tried it;

• Expose the fun of Amateur Radio to the public and especially techies (hopefully, young techies) by staying up late on a summer evening pointing antennas (and computers) at the Moon.

This article was previously serialized in:

• Zero Retries 0097 - Thought Experiment - Neil’s Night - Part 1 (2023-05-05)

• Zero Retries 0098 - Thought Experiment - Neil’s Night - Part 2 (2023-05-12)

• Zero Retries 0099 - Thought Experiment - Neil’s Night - Part 3 (2023-05-19)

This article is updated and lightly edited (not necessarily a verbatim compilation of those serialized articles).

EME Background

For those unfamiliar with EME operation… EME is tough. Not only is the round trip path of one’s radio signal nearly a half-million miles (769 kilometers), but the Moon is a lousy, lossy barely-a-reflector for radio signals. Combining the path loss and the very low reflectivity of the Moon makes it amazing that it’s possible to do EME at all. For those interested in the history of EME, I recommend the Project Diana Wikipedia page, the book To the Moon and Back: The Life and Times of Project Diana, and the original site of Project Diana that was operated by an Amateur Radio club (but that no longer seems to be the case per the club’s current website).

My Interest in EME

I’ve been interested in EME since shortly after becoming an Amateur Radio Operator in the mid-1980s. An Amateur Radio friend took me along to a visit to an Amateur Radio friend of his who enjoyed EME. The EME operator was a farmer who, of course, was busy farming during the summer, but had ample time available in the winter - his “tinkering” time. The EME operator had an impressive antenna array of either yagi beams or circularly polarized antennas. The part I remember vividly about the EME operator was that his array was built on a frame at ground level (he was also a good welder) and the method he used to aim his array as the Moon changed position in the sky was to use a hydraulic system that used the Power Take Off (PTO) capability of one of his tractors.

At that time, having an EME station was rare in Amateur Radio because it required high transmit power (1000 watts on VHF or UHF), an antenna array (or large dish antenna), and sensitive receivers (often putting receiver preamplifiers right at the base of the antenna to minimize feedline loss of the very weak signals). Plus one needed to understand the physics of EME, knowing what the schedules were for other EME operators, frequencies, modes, etc. And patience… lots of patience.

Fast forward two decades from my initial encounter with EME to the 2005 release of the WSJT-X suite of weak signal modes. My admiration for (Nobel Prize Laureate) Joe Taylor K1JT is beyond the scope of this article, but this video is a good introduction to the WSJT-X suite of modes by K1JT himself. Suffice it to say that K1JT applied his considerable expertise in signal processing of radio signals to some common situations in Amateur Radio, and created an entirely new class of data modes, including JT-4 and JT-65 for EME. JT-4 and JT-65 enabled a modest (comparatively, vs the traditional EME station) Amateur Radio station (11 element beam, 100 watts power) to reliably work EME. JT-4 and JT-65 opened up the possibility of EME operation to many more Amateur Radio Operators. I include myself in this category as building a “conventional” EME station (such as the farmer’s EME station) isn’t a reasonable possibility for me, but a “JT-4 / JT-65” EME station is possible for me.

My Very Bright Friend

The idea for “Neil’s Night” really begins that I’m friends with an Amateur Radio Operator who is a very bright and talented engineer who is involved in the radio technology industry. I’m not in good enough touch with my friend to discuss their part in this story, thus I’m keeping my friend’s details vague.

My friend enjoys putting their considerable radio technology (and software) talents to use in personal Amateur Radio projects. Because my friend’s capabilities are so far ahead of most Amateur Radio Operators (and Amateur Radio in general), my friend generally keeps their projects to themselves except for a few confidants. Simply put, my friend wants to enjoy their Amateur Radio activities, not put their project out into public and open themselves up to providing defacto technical support. I don’t blame my friend for this perspective - such a defacto technical support burden has happened to a number of folks who’ve “made public” projects of similar scope. Thus my friend works on their Amateur Radio projects in stealth mode.

My friend has gotten interested in doing Earth Moon Earth (EME) communications and has put together their own unique EME system. (From memory…) my friend’s EME system automatically aims the antenna and tracks the progression of the Moon across the sky, and uses their own variant of the open source JT-4 and/or JT-65 protocols for EME communication. In our last conversation (more than a year ago) about their EME system, my friend’s system was receiving EME transmissions from the Moon and they were confident that milestone meant that their concept was sound and EME transmit capability would likely succeed with a bit more development.

My friend’s EME system rekindled my latent interest in possibly doing my own EME system.

EME Receive-only

Despite the profoundly sad loss of the Arecibo dish in Puerto Rico which once was used for Amateur Radio EME communications, there are a number of large dish antennas accessible to Amateur Radio Operators for EME communications. One of them is “The Big Dish” at W1MX, the MIT Amateur Radio station in Cambridge, Massachusetts. Another one is an even bigger dish on the original site of Project Diana (mentioned above).

Large dish antennas such as these can focus transmit power, and receive weak signals much, much better than a modest “JT-4 / JT-65” Amateur Radio station. If a dish antenna such as these “big dishes” are in operation, working EME for the average Amateur Radio Operator is a lot more feasible… and a lot more fun. The “big dishes” also enable (I think…) receive-only EME which, of course, doesn’t require an Amateur Radio license. That’s a key aspect of “Neil’s Night”, and more on that later in this article.

The key to such a scenario is to arrange schedules² with those large dish antennas. What if there was an annual event for “show off to the public” EME operation on, say, each July 20th, the anniversary of humanity's first steps on the Moon?

1. Especially, like this one, for promoting Amateur Radio as a license to experiment with radio technology.

2. Yes, I’m aware of the ARRL EME Contest, but as I’ll discuss later in the article, “Neil’s Night” isn’t quite compatible with the EME Contest.