Electronics-free old diesel trucks of the national radio astronomy observatory
61 comments
·March 10, 2025mobilene
Kon-Peki
Ah yes, South Bend is too close to Chicago, too close to Indianapolis, too close to Detroit... No VHF frequency left to allocate! The biggest problem is Chicago. South Bend is on a subcontinental ridge, with an average elevation nearly 300 feet higher than Chicago, and with all the transmitters in Chicago up 1500-1800 feet above ground and close to the lake, overcoming the curvature of the earth limitations on VHF propagation is fairly simple. Anyone in South Bend with a large antenna on their roof would easily receive all the stations.
On the upside, that meant having two versions of CBS and NBC (I don't remember an ABC affiliate in South Bend) plus the couple of other stations. My cousin got his start as a weatherman on NBC in South Bend simply by them needing someone to fill in from time to time and him being essentially the only person they could find that grew up in South Bend but had gone off to study meteorology at a university that was very very good for meteorology.
walrus01
Blonder tongue was a well known vendor for regional cable tv network (analog) operator equipment, supplies, electronics. I think it still exists in some form for video mixing/live studio broadcast equipment.
wolrah
I work in a lot of nursing homes and their in-house "cable" systems are almost universally a rack full of DirecTV receivers connected to a rack full of Blonder Tongue NTSC modulators. I would have to assume similar systems were common in all sorts hospitality environments in the past, and only survive in nursing homes because most of the residents don't care about HD and might not even want it.
panstromek
Since the unwanted interference is from sparkplug, I wonder - assuming it would contain no additional electrincs, could they get some EV? Or does the electric engine itself generate noise by necessity?
genewitch
EV are so noisy they talked about doing away with AM radio in the US because the EV jams it.
I am unsure what would lead to this question...
silisili
The NRAO should kickstarter a new, electronics free diesel fullsize.
Not to build it, just to prove how much demand exists for it. Because this is something every truck guy I know has been asking for forever.
There's even an online rebellion of sorts over the new Hilux not being available here.
genewitch
When has the hilux ever been available here? I've wanted one for over 20 years, but not enough to pay to import...
frompdx
My time to shine! I still own an early square body truck with the 6.2L Detroit Diesel. The thing that stands out to me in this article is that the Suburbans shown are an earlier generation produced from 67-72. Those did not have a Diesel engine, however the 6.2L Detroit Diesel was designed to drop into anything with a Small Block Chevy, so I can see how these may have been retrofitted. In fact, these engines are still produced today in 6.5L form (see the AM General Optimizer) and are used in the HMMWV.
These really are very simplistic engines and simplistic vehicles in general. Mine has power nothing, at least electronically. The shifter really is comically large and very inconvenient to whoever sits in the middle. The highest gear is third gear.
Powerful? No, not really. But surprisingly efficient for the size. Reliable as well.
cellularmitosis
I once swapped an OM617 (the 5-cylinder turbodiesel used in many 80’s Mercedes sedans) into a 67 Chevy pickup.
Once started, the engine would run with no electrical system at all! Even the fuel shutoff operated on vacuum.
By far my favorite hack :)
seabrookmx
The original castings were pretty poor in the 6.2 and 6.5 and lots of them crack at the crank webbings. This is supposedly fixed in the AM General blocks. They were common work trucks in the PNW (forestry, mining) but while you see the old Cummins or Ford IDI's around still the "Detroit"'s (no relation to the 2 stroke Detroit or Series 60) are quite rare. My family still has an early mechanically injected 6.5 that's held up OK though (~300,000km on it).
bluGill
The 6.2/6.5 were gm engines not detroit diesel. very different engenes.
userbinator
Detroit Diesel was a division of GM at the time: https://en.wikipedia.org/wiki/Detroit_Diesel#Origins
defrost
Today, in the Murchison Radio Quiet Zone:
The Power and Signal Distribution (PaSD) SMART boxes (Small Modular Aggregation RFoF Trunk) are an essential component of the Square Kilometre Array Low frequency (SKA-Low) telescope, currently under construction at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory, in Western Australia.
The SMART boxes provide electrical power to the SKA-Low telescope's 131,072 antennas and collect signals received from the sky to go off-site for processing.
[ .. ] “The ‘radio quiet’ results that the ICRAR-designed SMART boxes achieved were to the highest standards in radio astronomy. A mobile phone on the surface of the moon would cause more interference to the antennas than the SMART boxes that sit among them,”
I still haven't found any vehicle guidelines for the Inner Zone ( 70 km radius ), but for anyone with an interest:
* General introduction: https://www.industry.gov.au/science-technology-and-innovatio...
* Restricted airspace: https://www.avsef.gov.au/consultations/restricted-airspace-o...
* Limits of intereference by frequency and distance table: https://www.ursi.org/proceedings/procGA11/ursi/JP2-17.pdf
walrus01
RF over fiber is a fairly well established thing, it's used in two way data satellite earth stations to convert a L or S band signal into something that can go a longer distance from the antenna to a conditioned equipment room at the same place.
toomuchtodo
Very cool. Is there a reason the RF has to be converted back to RF after the fiber link vs processing the RF spectrum data optically?
MadnessASAP
I would imagine it's because electrical amplifiers, filters, and other such items are cheap and well understood. Whereas optical amplifiers, filters, and other such things, particularly ones that operate at low-GHz frequencies are expensive and kinda wild
walrus01
your typical satellite modem will have an RF interface either somewhere between 70 to 140 MHz (where it's intended to be upconverted/downconverted by the LNB and BUC/SSPA at the antenna), or somewhere between 1100 to 1900 MHz, both intended for attachment to low loss coaxial cables. This works fine if you're putting the modem fairly close to the LNB and BUC/SSPA. If it needs to be a hundred meters away or something, it's a lot of RF loss, and path loss/link budgets in geostationary satellite are already hard enough without introducing any more loss at the ground side.
laurencerowe
> Before retiring from NRAO (years after my interviews with him), Mr. Sizemore outfitted a new Dodge Ram extended cab truck as an RFI vehicle, a feat which was written up in USA Today.
Dead link but luckily archive.org has it.
https://web.archive.org/web/20140725075606/http://usatoday30...
CobaltFire
This is an awesome article. I'm a HAM in an urban area trying to figure out how to operate in the mess that is my EM spectrum with low power gear. It's a fun challenge, but having some quiet would be nice!
I haven't had the pleasure of seeing this site, but I did have the opportunity to visit Sugar Grove Station (not too far away) while it was in operation. I had a friend stationed there while I was nearby, and took a detour to spend the weekend at his house on the base.
Seeing the massive old radio telescopes and the tracks they used for positioning them was something else. The scale is hard to communicate; it's kind of like the first time you get up close with a Navy Aircraft Carrier. It's hard to fathom just how BIG they are until you are next to them.
driggs
Were you allowed on base? What was your experience like and your perception of what was going on?
I had the opportunity to perform a bat survey at Sugar Grove, and a poor guard had to come out to keep an eye on us until 3am because we couldn't be left alone. We noted curious wooden gazebos positioned around a featureless meadow, hinting at significant manned infrastructure underground.
Unlike the Green Bank Observatory from the above article, Sugar Grove was piggybacked on the National Radio Quiet Zone so the NSA could intercept intercontinental telecom traffic as a part of the ECHELON network. The cover story was that it was a run-of-the-mill AT&T site, but was an open secret for all the Pendleton County WV locals that it was a spy site. The base was also home to the best restaurant in the whole county, which isn't saying much for a single-traffic-light county.
CobaltFire
Yes; I was cleared to the level required (but not need to know) and the visit was approved by his (the base) CO. He was stationed there as a Crypto Tech, and though I couldn't see the really neat underground stuff I was mostly free above ground as long as I was chaperoned by him. He gave me quite the tour.
The gazebos are there due to the underground facilities, yes. There is likely a whole lot more than even you realized.
As for my impressions: I was a Security Manager for a more operational side of the Navy for years (later). I informed a lot of my edge case thinking with what I saw of how they handled things there. I don't know that I really want to go into more detail than that.
watersb
I spent two weeks there, during the commissioning of the Green Bank Telescope (GBT). Our team was designing the monitor and control system for an upgrade for another NRAO telescope, the Very Large Array in New Mexico. The team from the GBT led us through their design during the day; our nights sleeping in the on-site dormitory, complete with the break room where Frank Drake came up with his Drake Equation estimating the number of extraterrestrial civilizations...
Those old diesel trucks!
The GBT is so big, it's just wrong. Experiencing the forest moon of Endor, in real life.
(The single-dish GBT is sensitive to near-field RFI, whereas the multi-dish Very Large Array is a bit more tolerant. The VLA isn't restricted to antiquated diesel vehicles. Although they do ask visitors to power off cell phones and refrain from any microwave ovens that RVs might bring in.)
gooseyard
I grew up in this area of West Virginia, it's such a crazy thing that a community of really amazing scientists are nestled in the middle of this incredibly rural area. It's really neat to see the old blue trucks if you take the tour, and the Cass Scenic Railroad is just nearby and gives a really beautiful view of the telescope array. The National Youth Science Academy Camp is also surprisingly located nearby, it was wild as a kid knowing that this batch of future scientists were flying in from all over the country and once I learned of it I wished I'd studied a bit harder. Such a beautiful, strange place.
iancmceachern
One of my favorite parts about the old perkins diesel engine in our boat is that you need to press a button to stop it from running once started. You turn off the ignition and it just runs on physics until you do something to interrupt the fuel or air supply.
doubled112
Diesels diesel (the verb). It keeps them exciting.
I’ve been in a friend’s car while it ran away on motor oil passed by a failed turbo. Turning it off didn’t stop the engine.
johnklos
So there are good reasons, aside from reliability, efficiency and ease of repair, for having a 1981 Diesel Chevette with a 100% mechanical engine :)
rootbear
In 2006 my friend and I decided to stop talking about visiting the NRAO and actually go. We picked a weekend and then discovered that that Sunday was the 50th Anniversary open house! There were special exhibits and more of the facilities were open to tours than on regular visitors days. I can highly recommend visiting if you get the chance.
Coincidentally, my friend's last name is Blonder! And he's related to the Blonder-Tongue founder. According to my friend, all Blonders are related, the family name was originally Gottlieb, but was changed to something more Anglo sounding, to avoid anti-semitic discrimination, probably when they immigrated to the US from Russia.
This was one of the most wicked cool things I've read in a long time.
I grew up in a TV market that was UHF only (South Bend, IN) in the 1970s. TVs from before about 1963(?) didn't have to have UHF dials. So a company named Blonder-Tongue (Blonder was pronounced like blunder) produced UHF receivers you could attach to your TV through the little screw tab things on the back, the predecessor to the coax input. I had never seen Blonder-Tongue referenced anywhere except in nostalgia articles about my hometown.