I happened by a consignment antiques shop yesterday while shoe-shopping. My first thought on seeing this item in the window was Captain Nemo has hocked his labs! So I bought it. It’s a Star-Rite Type C heater, made circa 1925 by Fitzgerald Manufacturing Company of Torrington, Connecticut. 630W at 110V, and it even works, not that I left it plugged in for very long. It’s seen some hard use but the paint appears to be original, and only the clips holding the wire cage to the dish are missing. (The cage stays in by spring pressure, and not much of that.)
The parabola seems reasonably accurate, and when I took it out on the deck and pointed it at the Sun it smoked a piece of an advertising flyer in a second or two. It needs a little cleanup, but nothing heroic. Anybody care to guess what I’m going to do with it?
Home brew death ray? 😉
If it has nothing to do with Steampunk I’ll be disappointed!
“Hey, hey, good lookin’, Whatcha got cookin’?” Omelets maybe? 😉
“Wicked Lasers Torch – Scrambled Eggs”
http://www.youtube.com/watch?v=wsIHyRyETKg
I know. You’ll take it apart and use it as a wok to cook stir fry in it 🙂
(either that or you’ll figure out some way to use it as an antenna for your ham radio)
To obtain useful gain as a parabolic reflector antenna, the diameter should be at least 10 wavelengths.
Diameter looks to be about 12 inches, call it 0.3 meters, so minimum useful wavelength to work as a parabolic reflector is 3 cm. I conclude, therefore, plan to excite it with a two element array made from paper clips and an SMA connector and work 3 cm band DX.
What do I win?
Jack
Welllllllll…nothing for now. It’ll be a Wi-Fi range extender when it gets off the bench, with a Linksys AE1000 USB client adapter at the focus. The dish has a useful diameter of 14 inches, and if I were doing anything ambitious and really had to get the gain up, it would be a poor candidate, especially since the f/d ratio is all wrong. The focus is actually inside the bowl. As you suggest, I’d also like a 13 cm band antenna to be about three times the diameter.
However, what I’m doing is basically giving some gain to an omnidirectional antenna, and so any gain is a win, even if the setup is not optimized. I did something similar with a cheap aluminum wok lid in 2004, and got enough gain (even with a crappy parabola) to consider it useful.
I have several range extenders downstairs of various designs, but this one will out-cool them all by a country mile!
Not nearly as cool as a repurposed heater, but perhaps of more general applicability, have you seen the printed circuit board antenna line from WA5VJB? http://www.wa5vjb.com/
Clever idea and makes for a compact antenna.
Jack K8ZOA
Yes, have known about those for a couple of years, and I have sketches for a microwave diode directional Wi-Fi sniffer that would use one of his 2.4 Ghz log periodics. It just hasn’t percolated to the top of the list yet.
I do less in the Wi-Fi world now than when I lived in Arizona because I built a house in Colorado that doesn’t really need Wi-Fi–cat 5E in the walls, to every room–and so I’m not fighting with broadband distribution all the time like I was in Scottsdale. I have an access point that I plug in when I need it, and yank when I don’t. It fills the house nicely with signal, except perhaps the furnace room, where I don’t need it. (Not living in a sprawling 2-level ranch helps.)
It is obvious Jeff. You have there the fine beginnings of a Steampunk long range WiFi antenna.
Bingo! It was obvious to me and obvious to you, but apart from my sister over on LiveJournal, nobody else figured it out. I have a Linksys AE1000 thumb-drive style Wi-Fi adapter sitting on the bench right now as I try to work up a reasonable way to hold it at the dish focus. I did the same thing with a cheap wok lid six or seven years ago and got plenty of useful gain, but it didn’t look nearly as cool.
Aww… I was really hoping you would say “death ray”.
[…] addition to bathroom heaters like the one I bought the other day, the Fitzgerald Manufacturing Company was well-known for making vibrators, albeit not the kind that […]
For some great Wi-Fi I would think one of the old aluminum “Snow Saucers” that were so common in the 60’s would work nicely. Probably hard to find one now that wasn’t buggered up crashing into a tree on many occasions. The f/d would be rather shallow but the gain would be incredible.
When I installed our 1M DirecTv dish the “snow saucer” that thought occurred to me as I was climbing down off the roof.
I had that thought back when I wrote my Wi-Fi book in 2002, but they don’t sell a lot of sleds of any shape in Phoenix, heh. However, even when we moved up here to Colorado in 2003, I was unable to find a metal saucer sled in local stores. They’re plastic now, and generally not round. I did well with a wok lid back in 2004, and it was roughly the same shape as a saucer sled, if about half the size. Because we’re concentrating 10 cm microwaves the focus is fuzzy anyway, and all we’re trying to do is get a little more energy to impinge on the Wi-Fi dongle. I could optimize the hell out of it (and even make my own focus point dipole) but the incremental improvement in gain would not be worth the extra work.
I’ll have more on the project here as I go through it.
[…] who tuned in to my March 18, 2011 entry will recall that I spotted a Star-Rite copper parabolic resistance heater at a consignment […]
I found one of those in the attic of our house—the same model—and with a little rewiring I tured it into—
a heater.
It was actually a working heater when I bought it, though with a naked resistance element at the focus. I needed the gadget for other things, but it made me wonder how we coped with exposed line voltage (and in bathrooms yet!) in our not-too-distant past.
See the details of my rebuild into a Wi-Fi gain antenna here: http://www.contrapositivediary.com/?p=1940