Photo of the Big Dish radome exterior courtesy of W1MX, the MIT Radio Society
Nomenclature Alert - Dish vs Radome... the DISH is the active element - a 18 foot wide parabolic antenna that's steerable in azimuth and elevation. The RADOME is what you see on the outside - a fiberglass (?) shell that protects the (relatively fragile) dish from the weather. The radome is transparent to radio frequencies - the dish does all the "work".
I've known of the "Big Dish" for several years now since I visited Boston to visit my daughter. We were touring Cambridge and I glanced up and saw the Big Dish's radome on top of a tall building on the MIT campus. I web searched it and found W1MX and learned that it uses the Big Dish for a lot of interesting Amateur Radio activities.
From W1MX: The WR66 radar was once a research prototype for the NEXRAD system. Today, we use the dish for Earth-Moon-Earth communication on the 23cm band and hydrogen line radio astronomy. Getting it up and running was an incredible project involving both complex RF engineering and learning to interface to many different generations of control systems built over the past 55 years.
What makes the Big Dish so unique is a combination of factors:
- It's 18 feet wide - that allows for a great diversity of frequencies and focus points.
- It's steerable in azimuth and elevation.
- The fiberglas (?) radome protects it from weather. That radome must be pretty sturdy considering severe "Nor'easters" that periodically batter the Boston area.
- It's on top of a 22 story building - it has great views to a larger horizon than a similar size dish that's ground mounted.
- It's available for (relatively) unrestricted use by engineering students.
- Because it's not encumbered, it can be used for interesting or "just for fun" activities like Earth-Moon-Earth (EME) or Moonbounce communications during Amateur Radio contests.
Thus, the Big Dish was well worth saving, if possible. But, for one thing, while the Big Dish looks in pretty good shape, the radome as you see it in these photos, especially the one below, looks every bit of those 55 years old.
Photo of the Big Dish and its enclosing radome interior courtesy of W1MX, the MIT Radio Society
But the radome wasn't the biggest problem - the roof of the Green Building was due for repair and refurbishment. As part of that repair, the Big Dish had to be removed. Restoring it back to the rooftop once the roof repairs were complete was another matter. Since "only" W1MX and some academic programs used it (but not a "paying customer" like developing a national weather RADAR prototype), it wasn't (initially) contemplated that the Big Dish would be returned to the rooftop.
From W1MX - Update on Radome Project (March 18th, 2021)
Our perseverance is beginning to pay off! After much discussion and collaboration with MIT Facilities and various contractor groups involved in the Green Building renovations project, we have completed an initial design and project cost for the renewal of our Large Radome.
MIT has informed us that, if we raise $1.9 million before May 1st, 2021, the restoration of the radome can be included in the Green Building renovation project. While this is an enormous challenge, we believe it is not insurmountable.
W1MX conducted a fundraising drive, but raised only a fraction of the $1.9 million that was needed.
Fortunately... Amateur Radio Digital Communications (ARDC) is now up and running and providing grants and gifts for projects involving Amateur Radio, small (like Operation Hamulanche) and now, pretty large, like restoring (saving) the Big Dish. MIT just announced that the Big Dish will be restored with help from an ARDC gift:
To secure the large dish’s future and replace the deteriorating radome, the MIT Radio Society spearheaded a fundraising effort and immediately got to work. Building on the momentum of a previous successful fundraising campaign among Radio Society alumni that helped refurbish their equipment on the roof, they further mobilized the MIT community of alumni and friends by organizing a second campaign. The students also pulled together a successful grant application in record time to Amateur Radio Digital Communications (ARDC), a non-profit private foundation supporting amateur radio and digital communications science, resulting in ARDC’s largest-ever philanthropic contribution, made in memory of the organization’s founder Brian Kantor. This lead gift brought the MIT Radio Society across the finish line to successfully meet their fundraising goal.
Read the rest of MIT's Press Release - Saving the radome - Student-led efforts preserve iconic campus landmark for future generations of education and research.
As one of the volunteers on the ARDC Grants Advisory Committee, I'm proud to have played a small role in this, and I'm very proud of ARDC for stepping up to this challenge (and especially, acting quickly enough to save the Big Dish). That couldn't have been easy. I'm glad that ARDC has proven it's willing to tackle big (and small) challenges in Amateur Radio.
Thanks for reading!
Steve Stroh N8GNJ
Bellingham, Washington, USA
2021-05-09