#garfield Logs

Dec 17 2022

01:34 AM rue_mohr: https://twitter.com/ZappyZappy7/status/1603953401930579968
01:43 AM rue_mohr: tahts cool
01:43 AM rue_mohr: https://www.youtube.com/watch?v=Kd04quryVPI&feature=youtu.be
01:43 AM rue_mohr: that
04:14 AM Tom_L: .
04:14 AM rue_mohr: .-.
06:15 AM rue_mohr: I woke up, so I'm scanning schematics
06:19 AM rue_mohr: so I started all the numbers with S for schematic
06:19 AM rue_mohr: I realized today I could scan finished projects too, and prefix them P
06:42 AM rue_mohr: 71 schematics scanned in so far
07:02 AM rue_mohr: ok, 82 scanned, I'm gonna take a break
07:06 AM rue_mohr: I need more motor driver circuits
07:06 AM rue_mohr: section is way too shy
08:27 AM Tom_L: P for Pinished?
12:14 PM rue_mohr: trim branches of tree for shipping truck
12:14 PM rue_mohr: Rue, design the gimbal plates
12:37 PM Tom_L: sold?
12:57 PM rue_mohr: no
12:57 PM rue_mohr: I need to go down the list
03:03 PM rue_mohr: https://organforum.com/forums/forum/electronic-organs-midi/leslies-tone-cabinets-speakers-accessories/810866-bench-testing-ao-15-from-jr-20-cabinet?pp=810889#post810919
07:09 PM Tom_L: what's with that?
09:31 PM rue_mohr: oh a fellow I know is trying to fix an organ
09:32 PM rue_mohr: he brought over the amplifier and we tried to figure things out
09:32 PM rue_mohr: but there is a crazy mystery
09:35 PM Tom_L: what crazy mystery?
09:35 PM Tom_L: hammond with a leslie box?
09:37 PM rue_mohr: sorry, distracted
09:37 PM rue_mohr: I severly burned supper and I cant get the smell out
09:37 PM Tom_L: don't burn down the house unless it's well insured
09:37 PM rue_mohr: its not, they dont want to cause its half trailer
09:37 PM rue_mohr: ok
09:38 PM rue_mohr: so in the organ in (middle of nowhere town) he measured B+ and it was about 160V, should be 200
09:38 PM rue_mohr: he packed up the main power amp and brought it over
09:38 PM rue_mohr: but its going over voltage here
09:39 PM rue_mohr: the B+ went for 560V
09:39 PM Tom_L: mmm
09:39 PM rue_mohr: tube limit is like 320
09:39 PM Tom_L: blow the tube?
09:39 PM rue_mohr: one fails test, but
09:40 PM rue_mohr: the sheets say the transformer should have 400V into the rectifier, with 120in
09:40 PM Tom_L: i did very very little with tubes
09:40 PM rue_mohr: I'm on 120, and Its comming out of the transformer at 450V
09:40 PM rue_mohr: so everything is scaled up right on thru
09:40 PM Tom_L: what model is it from?
09:41 PM rue_mohr: I worked out that the tone module (seperate. not included in test) loads B+, but when I worked out by how much, it didn't make a diff to the severe overvoltage thing going on
09:41 PM Tom_L: https://medias.audiofanzine.com/files/m100mm2m3svcman-text-1-470816.pdf
09:41 PM rue_mohr: from a...
09:43 PM rue_mohr: JR-20 ?
09:43 PM Tom_L: newer one?
09:43 PM Tom_L: not the old tone wheels type
09:45 PM rue_mohr: does a tone wheel involve a motor that spins?
09:45 PM Tom_L: yes
09:45 PM Tom_L: synchronous
09:45 PM rue_mohr: yes
09:45 PM rue_mohr: its got that as I understand
09:46 PM Tom_L: https://synthmania.com/wp-content/uploads/2020/05/Hammond-Organ-B3-C3-Service-Manual.pdf
09:46 PM rue_mohr: I think the power transformer has some shorts in the primary, and its otuput voltages are too high
09:47 PM rue_mohr: AO-15 is the amp?
09:48 PM Tom_L: The amp in the JR-20 is the AO-15, and the schematics are in the main Hammond console organ service manual.
09:49 PM Tom_L: https://www.audioservicemanuals.com/h/hammond/hammond-ao/7424773-hammond-ao-15-power-amp-code-c-jr-20-cabinets-schematic
09:49 PM Tom_L: there
09:49 PM rue_mohr: ok
09:49 PM rue_mohr: and its had the reverb removed..
09:50 PM rue_mohr: V1/V2
09:51 PM rue_mohr: oh, wow, did they use magnets/gears and a synchronous motor to actually generate the frequencies?
09:52 PM Tom_L: uh huh
09:52 PM rue_mohr: that would explian the lack of oscillators I see here
09:52 PM Tom_L: cores
09:52 PM Tom_L: :)
09:52 PM Tom_L: they made an electronic replacement for the tone wheels but i never ran across one
09:53 PM rue_mohr: I cant see a mechanical one would ever really stop working?
09:53 PM rue_mohr: might start to squeak
09:53 PM Tom_L: they had oil threads all over the place
09:53 PM Tom_L: and you would oil them every so often as part of the service
09:54 PM rue_mohr: like to distribute oil?
09:54 PM Tom_L: yes
09:54 PM rue_mohr: that move?
09:54 PM Tom_L: https://www.google.com/search?client=firefox-b-1-d&q=hammond+tone+wheel+oilers#fpstate=ive&vld=cid:1574689b,vid:ZSuKIEWkT-4
09:54 PM Tom_L: no
09:55 PM Tom_L: about halfway in
09:55 PM rue_mohr: ah the organ is a hammond CV
09:55 PM Tom_L: fill the oil reservoirs once maybe a year or 6 mo
09:56 PM rue_mohr: it conducts thru the threads?
09:56 PM Tom_L: yup
09:56 PM rue_mohr: huh
09:56 PM Tom_L: pretty sure
09:56 PM rue_mohr: sure
09:56 PM Tom_L: it's been a long long time
09:57 PM rue_mohr: sure
09:58 PM Tom_L: https://www.google.com/search?client=firefox-b-1-d&q=hammond+tone+wheel+oiler+threads#fpstate=ive&vld=cid:da392f2d,vid:7Qqmr6IiFLE
09:58 PM Tom_L: better i think
09:58 PM Tom_L: there's an oil trough
09:59 PM Tom_L: 3:21 shows the thread
10:00 PM Tom_L: had a start and run switch
10:00 PM rue_mohr: I'm just digging thru the pdf's for power supply anything
10:00 PM Tom_L: one to get it up to speed then keep it there
10:06 PM Tom_L: https://el34world.com/schematics.htm#Transformer%20wiring%20diagrams
10:06 PM Tom_L: https://el34world.com/schematics.htm
10:06 PM Tom_L: https://el34world.com/charts/TubeAmpSchematics.htm
10:08 PM Tom_L: nothing directly related
10:09 PM rue_mohr: mmm
10:09 PM Tom_L: maybe they were made by hoffman?
10:09 PM rue_mohr: see, in the days of 20% precision, I'm not sure whats out or not
10:09 PM Tom_L: nothing is out :)
10:09 PM rue_mohr: the transfoerms?
10:09 PM Tom_L: the amps
10:10 PM rue_mohr: oh, I'm not sure
10:10 PM rue_mohr: I dont know how reliable transformer production was back then
10:11 PM Tom_L: monday's were good, friday's were questionable
10:12 PM rue_mohr: oh dear...
10:12 PM Tom_L: get a wednesday and it will outlive you
10:13 PM Tom_L: i bet they were pretty good. most workers then took pride in their work
10:14 PM Tom_L: now you're lucky to find someone that is even willing to work
10:15 PM Tom_L: https://el34world.com/Forum/index.php?topic=22585.0
10:15 PM rue_mohr: ssh
10:15 PM rue_mohr: :]
10:17 PM rue_mohr: one of these leads I have will come thru sooner
10:17 PM Tom_L: https://www.worthpoint.com/worthopedia/hammond-organ-tube-amp-amplifier-power-supply-7591
10:19 PM Tom_L: gnite
10:20 PM rue_mohr: https://thumbs.worthpoint.com/zoom/images1/1/1211/13/hammond-ao-15-stereo-tube-amplifier_1_0c908656e3145db84966fccef9b67ef7.jpg
10:20 PM rue_mohr: thats the amp
10:20 PM rue_mohr: gnight
10:20 PM Tom_L: 403
10:20 PM rue_mohr: stupid sire
10:20 PM rue_mohr: well I lost the google results now
10:22 PM rue_mohr: it made it verify I was human 4 times