#garfield Logs

Aug 09 2015

19:59 zhanx nice pdf
20:19 rue_school writing gear software
20:20 rue_school but I have to detour and write a geometry solver
20:42 rue_school detour and write a simotanious equation solver
20:42 rue_school lib
20:42 any99956329 if you put a 'o' for every 'l' sound, then "lib" becomes "oib"
20:43 rue_school hi kat!
20:43 any99956329 lo rue!
20:43 rue_school I'm fixing up a scope at home thats a 1976 heathkit
20:43 rue_school so far I'v replaced 2 resistors and a transistor
20:43 any99956329 ok
20:43 rue_school mostly up on its feet, looks like its got a number of bad caps
20:44 rue_school gonna start with the osc that does the ch1/2 muxing
20:44 any99956329 prolly do, caps tend to not last 40 years
20:44 rue_school its an IO-4550
20:44 any99956329 i
20:44 any99956329 d bypass the mux and just see if you can get a dispayon the crt first
20:45 rue_school yea, I was trying to look up a 10-4550 and it wasn't to be found
20:45 rue_school yea, it only shows channel 1
20:45 rue_school the osc is stuck
20:45 rue_school its just a transistor flipflop
20:45 any99956329 typically 500khz - 1mhz, prolly 555 will do fine
20:46 rue_school 10Mhz scope
20:46 rue_school I have an old tube scope with white phosphor I want to do something with
20:47 rue_school the chassis is wrecked
20:47 rue_school I think it worked enough for me to get the operating voltages before it crumbled
20:49 any99956329 i dunno why you didn't want that working Tektronix
20:49 any99956329 but, whatevers
20:49 rue_school because of the $50 chipping and the $50 border fee
20:50 any99956329 how do they know to charge you $50 at the border? you don't live at the border, and they have never see you
20:50 rue_school I'm only fixing up the 4550 cause one of my buddies would like a scope
20:50 rue_school any package I get from the states is dutied
20:50 rue_school if the duty is $0, there is still the $50 duty processing fee
20:51 any99956329 you need to make a robot that sites in the top of a tree during the day, with pv panels, and comes down at night to travel around delivering packages to you
20:51 rue_school :)
20:51 any99956329 that smells like duty :-|
20:52 any99956329 send me some canadian stamps, i box up something, put the canadian stamps on it, and write "return to sender"
20:53 rue_school :) that idea I like
20:54 any99956329 wel, we can try it
20:55 rue_school I have too many projects :/
20:56 rue_school do you have a scope looking for a new home?
20:56 rue_school do yo uhave a shelf of them?
20:56 any99956329 a ahelf of them,, umm, yeas
20:56 rue_school what do you have that you would suggest sending me?
20:57 any99956329 depends on what you'd return to me
20:57 rue_school I'm working on a math problem
20:58 any99956329 i have a hitachi 65mhz , i tend to use the Tenma 20Mhz more
20:58 rue_school I have 3 points, and i'm looking for the raduis that will reach them all
20:58 rue_school 8-|
20:58 rue_school 65M
20:58 rue_school my good scope is 25M
20:58 any99956329 i have 4 7603 and a 7903 in this room
20:59 rue_school dont know the specs
20:59 any99956329 there's at least 10 scopes in the den
20:59 rue_school I sitll have the input modules to make a digital storage with
20:59 rue_school oh and I got 2 digital tuners to search for adc's in
21:00 rue_school so far I'v only popped the lids
21:00 any99956329 not all my scopes work, a few are parts, two 7603 have ntsc vectorscope graticule crts
21:00 any99956329 the mainframes work, but the display isn't the typical scope display
21:01 rue_school electrostatic def?
21:01 any99956329 yeas
21:01 rue_school cant be too different then
21:01 any99956329 i don't think Tek made any magnetic deflections
21:01 any99956329 :-/
21:02 rue_school I have one off a medical machine iirc
21:02 rue_school square 6" tube
21:02 rue_school but I have this old round one thats got white phosphor!
21:04 rue_school how do you take 3 points and find the radius that hits them all witout trying to find the point hte radius is at
21:04 any99956329 i don't
21:04 rue_school if I put it all in vectors
21:04 rue_school then , no
21:08 any99956329 locate the two outermost point, calculate the arc segment that includes the middle point, from that arc, you calculate the radius
21:09 any99956329 the defelecton of the segment is based off the str8 line between the 2 outer points
21:10 any99956329 this should work in 2D space
21:11 any99956329 else, you make 3 equations, assign each the same radius variable, but to the different points, then make all equal (since equal radius), and solve the unknowns
21:12 any99956329 if you draw a line between the two outer points, their common radius point will fall on a line perpendicular and centered on that first line
21:12 any99956329 where on that first line depends on the distance the middle point is off the first line
21:13 any99956329 but half the solution is knowing the restricted set (that perpendicular line) the final radius must be on
21:42 any99956329 ...
21:44 any99956329 if you move the xy grid so that line is the x axis, then the radius of the 3 points has a y value of zero, because it's the x axis
21:44 any99956329 so you are now solving for only one value
22:12 any99956329 .
22:13 any99956329 it's been 3 half hours
22:16 rue_school i'm back
22:17 zhanx- So is me
22:18 rue_school you have 3 points in cartesian space, work out a radius that reaches them all
22:19 zhanx- R=>c1
22:21 rue_school hmm?
22:22 zhanx- Well c1,c2c,3
22:26 rue_school you talking maxtries?
22:27 zhanx- Thought that's what you meant
22:27 rue_school I dislike matrixies
22:36 zhanx- Think I might start making a canoe tomorrow