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| Ian Jackson <ianREMOVETHISjackson@g3ohx.demon.co.uk>: Oct 29 04:04PM In message <0sd0w.416186$412.141472@fx30.iad>, Scott Lurndal <scott@slp53.sl.home> writes >Have you never boiled water in a styrofoam cup over an open flame? >One can. The water keeps the temperature of the foam below its >melting point. A rather late follow-up..... When I was very young, my uncle had a book that showed you how to make things out of folded paper, One was 'working' kettle, and I remember pestering my mother to help me make it up, then to boil some water in it over a candle flame. -- Ian |
| Paul Drahn <pdrahn@webformixair.com>: Oct 28 12:48PM -0700 On 10/27/2014 9:32 AM, micky wrote: > etc. although WAMU is on a 5 or 10 second delay most of the time. > Because the topic and the voices can be the same it means I can't tell > for a while if I've gotten 88.5 or just another 'instance' of 88.1. If you have the AFC on, the station will pop up at different dial locations depending on which direction you are tuning. At least my old portable does. Paul |
| Michael Black <et472@ncf.ca>: Oct 28 04:39PM -0400 On Tue, 28 Oct 2014, Paul Drahn wrote: >> for a while if I've gotten 88.5 or just another 'instance' of 88.1. > If you have the AFC on, the station will pop up at different dial locations > depending on which direction you are tuning. At least my old portable does. I was thinking along that line, except thinking of pointing out that for whatever reasons, not great selectivity or a noisy synthesizer, a station can be heard on more than one frequency. But, I can't recall that happening when there's an adjacent station, then the first station being received further up. If that second station wasn't there, AFC is a good suggestion, and something we might not think of much anymore, with so many fm receivers digitally tuned. But I'd think it would "lock" to the statino further up, that presumably is stronger at that point than the first station. Michael |
| "Arfa Daily" <arfa.daily@ntlworld.com>: Oct 29 01:40AM > old console FM receiver in the station lobby. 100.1 + 21.4 = 121.5. Radio > row was on the direct approach to Hobby Airport or this old mis-aligned > radio would have never been busted. I can understand the authorities getting a bit ansty about that one. 121.5 is the international aeronautical VHF distress frequency ... :-) Arfa |
| micky <NONONOmisc07@bigfoot.com>: Oct 29 02:11AM -0400 >>> for a while if I've gotten 88.5 or just another 'instance' of 88.1. >> If you have the AFC on, the station will pop up at different dial locations >> depending on which direction you are tuning. At least my old portable does. I think I've noticed this too. But the AFC wasn't on, because that would have made it almost impossible to get a weak station like 88.5. Well, I'm calling it weak because most radios won't get it, but Wikip says that it's 50,000 watts ERF (sp?) but 88.1 is only 15,500 watts. (also ERF? It didnt' say.) So maybe I'm calling it weak because it farther away, in DC, not Baltimore where I live, but actually, there are places north of here, farther from DC, the Westminster, Md. area, where 88.5 comes in well and 88.1 barely comes in. A friend moved to Finksberg and she had to change to 88.5. But maybe the FCC makes them arrange their antennas so that in the city of Baltimore and its populous suburbs, 88.5 doesn't overpower 88.1. But the frequencies are different, and there's no Baltimore 88.5, so why would 88.5's antennas have to avoid the populous part of Baltimore, or any part? |
| "Arfa Daily" <arfa.daily@ntlworld.com>: Oct 29 09:30AM <snip> > Well, I'm calling it weak because most radios won't get it, but Wikip > says that it's 50,000 watts ERF (sp?) but 88.1 is only 15,500 watts. > (also ERF? It didnt' say.) ERP - Effective Radiated Power ? The 'real' transmitter output multiplied by the 'gain' of the transmitting antenna. > So maybe I'm calling it weak because it > farther away, in DC, not Baltimore where I live, There are many many factors that affect the propagation of a VHF signal over a lower frequency one, some of which will degrade that signal, and others of which can, under the right conditions, enhance it. VHF signal reception is a lottery, once you are outside the designed service area of the station. but actually, there are > But the frequencies are different, and there's no Baltimore 88.5, so why > would 88.5's antennas have to avoid the populous part of Baltimore, or > any part? Without seeing a published map of the station's service area, it's impossible to say. However, something as simple as a tall building in the direction of the transmitting site, can be enough to cast a 'radio shadow' across a large swathe of territory on the 'downstream' side Arfa |
| Ian Jackson <ianREMOVETHISjackson@g3ohx.demon.co.uk>: Oct 29 03:51PM In message <4fbddf88-87c7-4b00-bf41-ee38a0c27334@googlegroups.com>, Phil Allison <pallison49@gmail.com> writes > 88.1-10.7 = 77.4 = lowest local osc f > 77.4+20.0 = 97.4 = highest local osc f > 97.4+10.7 = 108.1 = higher f than any station. I'm pretty sure that the local oscillator nearly always runs 10.7MHz HIGHER than the radio signal. -- Ian |
| Oren <Oren@127.0.0.1>: Oct 28 10:37AM -0700 On Mon, 27 Oct 2014 23:46:30 +0000 (UTC), "Danny D." > https://c4.staticflickr.com/4/3935/15025811753_8de1cc2650_b.jpg >Notice we gave up on the lower screw (the one with the longer thread). Those screws are from GRK Fasteners... <http://www.grkfasteners.com/index.php/en/> Videos on Youtube: <http://www.youtube.com/user/grkfasteners/videos> |
| "Danny D." <dannydiamico@gmail.com>: Oct 28 08:48PM dpb wrote, on Tue, 28 Oct 2014 09:21:42 -0500: > that support, it's not necessarily so that the remaining load on the > cable is only half; it depends on the actual geometry of the > configuration. It _might_ be half; could be more, could even be less. Thanks for all the insight. Below is the owner's response to your concerns. BTW, I created an animated GIF of the entire process, as I see it, but I can't get Flickr to show the animations since Flickr turns an animated GIF into a static JPG. I'll post the animation separately, if I can figure out how to preserve the animation, but here is the starting point static JPG: https://c2.staticflickr.com/6/5605/15466740929_084969faac_z.jpg Here is where we are right now: https://c4.staticflickr.com/8/7575/15629669196_d8ed414ac3_z.jpg And here is the penultimate ending point static JPG: https://c2.staticflickr.com/6/5600/15466738719_4866bb66b1_z.jpg Here's the owners response to your valid concerns ... I wonder if they realize how huge the final redwood tree is? The tree probably weighs in excess of 2,000 tons, and has a 30 foot circumference. The smaller set of redwood trees I would estimate weighs 15 tons. In a wind of 50 mph, the small tree experiences 200,000 pounds of force due to the wind. The idea that 28,000 pounds of tension on a cable is more than it encounters in a light wind does not seem tenable. The root structures of both trees routinely handle much larger forces during a typical day. A wind blowing at 100 miles per hour generates 25 pounds of force per square foot. If that wind were blowing straight down on 800 square feet of deck, we'd have 20,000 pounds of force. I consider that unlikely. :-) Edge-on, we have 67 square feet, or 1,666 pounds of force. But that is also somewhat unlikely. Sideways forces will add a little to the cable tension, but will mostly be taken up pushing against the trees and the support posts. The deck will weigh in the neighborhood of 5,000 pounds, and has 800 square feet of maximum surface area. Lifting that, requires 6.25 pounds per square foot, or a wind speed straight up of 50 miles per hour. But the deck is held down at the ends and in the middle by either trees or posts, which also limit the amount it can tilt or twist. The surrounding trees limit the wind considerably. The assumption that the engineering is "seat of the pants", or that the mathematics have not been done is incorrect, but the ideas are all good because I don't want to miss something, by not thinking about it at least. Let them know that I appreciate their advice! (Please invite them to lunch on Wednesdays in Redwood City if they're local.) |
| "Danny D." <dannydiamico@gmail.com>: Oct 28 08:57PM Oren wrote, on Tue, 28 Oct 2014 10:37:43 -0700: > Those screws are from GRK Fasteners... The ones with the longer threads were really stinky because you needed four hands, while suspended on the cable, to screw them in. The ones with the shorter threads only take 3 hands. Here's an animated GIF, I just made, of the suspension bridge... http://i62.tinypic.com/ieeakx.gif |
| "Danny D." <dannydiamico@gmail.com>: Oct 28 09:18PM Danny D. wrote, on Tue, 28 Oct 2014 20:48:36 +0000: > BTW, I created an animated GIF of the entire process, as I see it, but I > can't get Flickr to show the animations since Flickr turns an animated > GIF into a static JPG. Flickr turned the animated GIF into a JPG but tinypic seems to keep it as an animated GIF ... Here's my rendition, as I understand the plans so far ... http://i62.tinypic.com/ieeakx.gif I am omitting the actual building structure, but what you see here are the following: 1. The starting point, on a steep slope, with a path near the top: https://c2.staticflickr.com/6/5605/15466740929_084969faac_z.jpg 2. All brown lines are 16-foot long lengths of lumber: https://c2.staticflickr.com/6/5610/15467815060_5471646329_z.jpg 3. This approximates the "ladder network" you've seen in the photos: https://c4.staticflickr.com/8/7580/15467423737_a9ec2183b7_z.jpg 4. This was the first (thin) cable that went from tree to tree: https://c4.staticflickr.com/8/7572/15654210442_007a87f618_z.jpg 5. From that thin cable, we hung two large safety cargo nets: https://c2.staticflickr.com/6/5614/15467236098_ffe03d5577_z.jpg 6. Then we hung the thick cable, which was initially 250 feet long: https://c4.staticflickr.com/8/7554/15650701911_a8bc487651_z.jpg 7. We sunk two fenceposts, so that the platform rested on the ground: https://c2.staticflickr.com/6/5611/15467814730_6b9ae30e5e_z.jpg 8. Then we built & suspended the first 16-foot by 10-foot section: https://c4.staticflickr.com/8/7583/15653383255_8ab43e6304_z.jpg 9. Yesterday, we hung the second 16-foot-long section which is a foot or two shy of the smaller redwood pair of trees: https://c4.staticflickr.com/8/7575/15629669196_d8ed414ac3_z.jpg 10. The plan is to add successive 16-foot sections, one by one: https://c4.staticflickr.com/4/3955/15654209272_22de5c06a0_z.jpg 11. We keep that up until we finally reach the big redwood tree: https://c2.staticflickr.com/6/5600/15466738719_4866bb66b1_z.jpg 12. And, finally, we'll add 8'x4' sheets of plywood as a railing: https://c4.staticflickr.com/8/7467/15653381675_a674bb6d59_z.jpg After that, we begin to build the actual treehouse, complete with WiFi, refrigerator, bar, running water, and heating (no kidding). It will take time, of course, so, I'm not sure if I should continue to update this thread, but, since we've never done this before, any and all advice is welcome. PS: Jeff Liebermann and SMS are both welcome to attend the Internet WiFI setup party since they both live in the area! https://c4.staticflickr.com/4/3953/15460990220_5b1f28763d_b.jpg |
| Oren <Oren@127.0.0.1>: Oct 28 02:27PM -0700 On Tue, 28 Oct 2014 20:57:49 +0000 (UTC), "Danny D." >you needed four hands, while suspended on the cable, to >screw them in. >The ones with the shorter threads only take 3 hands. The GRK screws are self-tapping, self-pulling and self-counter sinking. From videos they will drive into a wood knot - generally with just a hand held impact drill/driver. _Screws that Practically Drive Themselves _ <http://www.youtube.com/watch?v=tWFf4IOuAnI&list=PL1szv0FP8dUthzyAv88t3sQzhxFLWMXRF> <https://tinyurl.com/mza8hmp> |
| Oren <Oren@127.0.0.1>: Oct 28 03:22PM -0700 On Tue, 28 Oct 2014 21:18:32 +0000 (UTC), "Danny D." >> GIF into a static JPG. >Flickr turned the animated GIF into a JPG but tinypic seems to keep >it as an animated GIF ... Tinypic showed it just fine: <http://tinypic.com/view.php?pic=ieeakx&s=8#.VFAWF2dqE2N> What software did you use to make it? |
| "Danny D." <dannydiamico@gmail.com>: Oct 29 05:05AM Oren wrote, on Tue, 28 Oct 2014 15:22:29 -0700: > What software did you use to make it? > http://i62.tinypic.com/ieeakx.gif I drew it, by hand, with Kolourpaint, on Linux, which, according to Wikipedia, is a Microsoft-Paint like drawing app: http://en.wikipedia.org/wiki/KolourPaint After drawing each line, I just saved the file to a new name, e.g., drawing01.jpg, drawing02.jpg, drawing03.jpg, etc. Then, I slapped it all together with this Linux command: $ convert -delay 50 -loop 0 *.jpg animatedplans.gif That created this: http://i62.tinypic.com/ieeakx.gif The "loop 0" just means loop forever; and the delay is something like 50 milliseconds between images, I think. I use this method only because it's trivially simple to do, so, I'm sure there are *better* ways to make animated drawings. For example, on Windows, I'd just draw using "Paint.NET" or even Microsoft Paint. Then, I'd slap it together using one of the programs described here: How to make animated GIFs, by PC Magazine http://www.pcmag.com/article2/0,2817,2392701,00.asp |
| "Danny D." <dannydiamico@gmail.com>: Oct 29 06:03AM Danny D. wrote, on Wed, 29 Oct 2014 05:04:53 +0000: > There's almost no way you would have known how absolutely huge the big > redwood tree is downslope. I found only one picture of the big redwood, but it doesn't show how massive the trunk is (measured at 30 feet in circumference). https://c2.staticflickr.com/6/5607/15498557171_df86936bcb_b.jpg There's actually a person, close to the tree trunk up there, in the cargo net, setting up the blocks of wood for the cable to go around (this picture was taken a few weeks ago). |
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