#garfield Logs

May 03 2020

02:43 AM rue_mohr: nice, my power converter ideas are working out great
04:19 AM polprog: [05:43] rue_mohr: tea machine is fixed, tea is once again flowing
04:19 AM polprog: are you making tea inna coffee machine?
04:19 AM rue_mohr: NO!, its a tea machine
04:20 AM rue_mohr: and to prove it, everyone who ever tries to make coffee in it dies
04:20 AM rue_mohr: it makes percolated tea
04:20 AM polprog: haha
04:21 AM polprog: nice, i was thinking about putting some tea in a mokka pot, but i would probably never clean it after
04:21 AM rue_mohr: hmm
04:27 AM polprog: i wonder why the phase-lead osc didnt work... hpf in the feedback loop , 3 caps in series with resistors to ground
04:27 AM polprog: just like the one that worked but the R and C are swapped
04:28 AM polprog: i could try putting the "varicaps" in that circuit
04:32 AM polprog: hey, actually, what was the max range on one of those varicaps?
04:33 AM polprog: you could maybe expand it with a PLL
04:33 AM polprog: ah wait.
04:33 AM polprog: pll needs varicaps x_x
07:26 AM polprog: hmm, found a nice broken TV in the ditch while biking
07:26 AM polprog: lots of cool parts
07:26 AM polprog: took all the PCBs
09:22 AM rue_mohr: :)
09:22 AM polprog: lots of power resitors, flyback, some heatsinked transistors
09:22 AM polprog: resistors*
09:22 AM rue_mohr: if it was colour, you have a few really fast transistors
09:22 AM rue_mohr: like 3Ghz
09:22 AM polprog: it was.. it was pretty newish
09:22 AM polprog: "newish"
09:22 AM polprog: lookde like late 1990s
09:22 AM polprog: pretty big as welll
09:23 AM rue_mohr: :)
09:28 AM polprog: Dad is desoldering parts off it
09:29 AM polprog: 5V relays
09:29 AM polprog: nice]
10:22 AM polprog: tda6111q
10:23 AM polprog: k1006, A1535A, C3944A
10:23 AM polprog: neck board is missing
10:23 AM polprog: se130
10:23 AM polprog: c3311
10:25 AM polprog: LA7876 Vertical Deflection Output Circuit.
10:25 AM polprog: looks like it wasnt done discrete.. that one is heavily heatsinked
10:45 AM Tom_L: rue_mohr, can your mill do this?
10:45 AM Tom_L: https://www.youtube.com/watch?v=PtD9w6lp8n8&feature=youtu.be
10:58 AM rue_bed: thats a neat approch to non-round holes for sure
11:08 AM Tom_L: he likes to experiment
11:14 AM rue_mohr: it comes back, for me anyhow
11:15 AM rue_mohr: Almost everything I play with a need like a bit later
11:15 AM rue_mohr: weather I actually DID play with it or I was going to
11:25 AM rue_mohr: well, I'm off to work today
11:25 AM rue_mohr: I need to work out which circuit to work on next
11:26 AM rue_mohr: I think I'll etch another small motor driver for the tilt and pan mirror, then go back to the drivers for the cnc machine
11:26 AM Tom_L: work work or play work?
11:26 AM rue_mohr: work work
11:26 AM rue_mohr: there is an office being rennovated during non working days
11:27 AM Tom_L: oh
11:27 AM Tom_L: looks like i'm back tomorrow
11:27 AM rue_mohr: we need to reconnect a lot of data lines for tommorow
11:27 AM rue_mohr: I'm kinda on and off, as jobs need stuff
11:29 AM polprog: no fast transistors here, maybe two with 300n on/off time
11:29 AM rue_mohr: the ones that drive the RGB grids
11:29 AM rue_mohr: usually quite fast
11:29 AM polprog: everything is one in that la7876
11:29 AM rue_mohr: esp in computer displays
11:29 AM rue_mohr: ah
11:30 AM rue_mohr: 3 channel amp?
11:30 AM rue_mohr: no, that chips deflection
11:31 AM rue_mohr: ... did you grab the board on the back of the tube?
11:32 AM rue_mohr: the tuner will have a local osc
11:32 AM rue_mohr: thats i2c controlled
11:34 AM rue_mohr: there will be a 4 pin (5?) metal can, thats the ceramic filter out of the mixer of the rf and the local osc
11:34 AM rue_mohr: local osc ->
11:34 AM rue_mohr: rf amp ->
11:35 AM rue_mohr: mixer -> filter ->
11:35 AM rue_mohr: might be a TA7xxx PLL chip?
11:36 AM rue_mohr: the board might have the SDA / SCL lines silk screened on the board
11:36 AM polprog: rue_mohr: no, the tube was totalled, there was no neck board..
11:36 AM rue_mohr: awe, the neck board probably had the final video amps :(
11:36 AM polprog: there was no teletext charset generator either...
11:37 AM rue_mohr: no OSD eh?
11:37 AM rue_mohr: modulated IR reciever?
11:39 AM polprog: there must have been, unless that was integrated in that one SMD ic
11:39 AM polprog: theres an ir receiver but i have some of those
11:48 AM polprog: homework time
01:01 PM Tom_L: blaaa
01:02 PM rue_mohr: ?
01:02 PM rue_mohr: gtg in 30 mins
01:02 PM Tom_L: at least it's not a jam packed week
01:03 PM Tom_L: after 2 months off there might be some re'learning to do :)
01:03 PM rue_mohr: heh
01:03 PM Tom_L: i had taken vacation time right before this
01:03 PM Tom_L: came back early to find i was off some more
03:07 PM polprog: sweet. got two new centretapped transformers
03:07 PM polprog: one has got 4.7 ohms on the centre tapped side and about .4 on the other
03:07 PM polprog: and a flyback transformer ofc
05:00 PM polprog: reading thru old notes/files i remember why i wanted to calculate the RC relax oscillator
05:01 PM polprog: i wanted to have an easier way to determine the capacitance of the dual diodes used in the varicap trick
05:01 PM polprog: so gen with simpler maths than the HCT14 based on is preferable.. although its not very diferent
05:02 PM polprog: that is a relax oscillator as well - but i can set the trip points myself
05:02 PM polprog: something that has a single cap and simpler maths would be even easier
05:08 PM polprog: i wonder if an LC tank circuit plus a BJT would make a nice osc
05:08 PM polprog: on one hand, i could push myself bakc on the chair to the other desk
05:08 PM polprog: on the other, its 0007 and i have to be up at the remote lecture at 1000
05:12 PM polprog: https://www.electronics-tutorials.ws/oscillator/colpitts.html
05:12 PM polprog: this is nice, i havent thought about the phase shift
06:36 PM aandrew: so got my old (like 1950s) drill press going, skinned my knuckle pretty good too which is why it works now
06:37 PM aandrew: I don't know about you guys but I am 100% convinced that technology and old voodoo are a lot closer than people think
06:38 PM aandrew: blood sacrifices are needed
06:39 PM Tom_L: bleeding edge of technology?
06:41 PM aandrew: lol never thought of that
06:41 PM aandrew: but a 1950s drill press is definitely not the bleeding edge of tech
07:16 PM polprog: nice, build a voltage controlled colpitts osc..
07:16 PM polprog: connected a hct14 osc to it and i have an fsk circuit chooching
07:33 PM polprog: goodnight
07:34 PM Tom_L: later
08:43 PM aandrew: do you guys have any reocmmendations on binoculars? nothing fancy, don't want to spend a fortune, maybe something smaller for staring off into the neighb^Wforest
09:17 PM Tom_L: https://www.ebay.com/c/1000614870
09:17 PM Tom_L: i take those to games etc
09:17 PM Tom_L: i'm sure they're are better ones now
09:19 PM Tom_L: i have a larger pair but those are handy
09:20 PM Tom_L: https://www.optics4birding.com/
09:22 PM Tom_L: https://www.optics4birding.com/zeiss-victory-sf-8x32-with-terra-8x42-binocular-bundle.html
09:22 PM Tom_L: on the other end of the spectrum
09:45 PM aandrew: interesting, and cheap too
09:45 PM aandrew: um
09:45 PM aandrew: I said that before the second link
09:45 PM aandrew: lol
09:49 PM Tom_L: :)
10:28 PM aandrew: been getting my funk on with Opiuo
10:28 PM aandrew: not my usual type of music, even when I'm feeling all psy-trancey, but this has something I can't describe
10:28 PM aandrew: good to crank when coding
10:28 PM aandrew: getting my BLE shwerve back on
10:31 PM aandrew: read from 9ECA0002-0EE5-A9E0-93F3-A3B50100406E: 1212121212121212121212121212121212121212
10:31 PM aandrew: reads are working, that was easy. writes don't seem to take yet
11:20 PM aandrew: writing's working now too, helps if you grant write permission
11:31 PM rue_mohr: polprog, by the nature of it, you cant use a varicap on a RC oscillator
11:32 PM rue_mohr: has to be resonance
11:32 PM rue_mohr: polprog, good show btw on the circuit
11:32 PM rue_mohr: post some pics of the transformers maybe I can tell you a bit about them