Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- TekScopes
- Messages
Search
|
Re: 067-0502-01 CALIBRATION FIXTURE
On Tue, Dec 21, 2021 at 05:50 PM, Stephen wrote:
The circuit with J115 forms a standard astable multivibrator. R117, R127, C114 and C124 are the main components determining phase length and therefore, together, phase symmetry. Other components have some influence but far less. D112 and D122 certainly do not have to be matched. I'd start by measuring R117, R127, C114 and C124. The relatively low capacitance of C114 and C124 may not be easy to measure. Be aware when measuring that D125 may establish a path across R117 via R118 to the -100V supply, distorting component measurements. Raymond |
|
Re: OT: microwave oven blows fuse
On Monday 20 December 2021 03:15:49 pm Glenn Little wrote:
Do a search for microwave oven parts,This would have been my suggestion too, if you hadn't beat me to it. I've done a number of repairs on assorted appliances around here, and we mostly end up getting parts from third-party vendors. Your best bet is if you can find some sort of a repair manual for the unit (also often available from third-party vendors) and get the exact part numbers to search on. On 12/20/2021 11:47 AM, Jim Ford wrote:Aw, crap!? I just called Kitchen Aid/Whirlpool parts, and no, they -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin |
|
067-0502-01 CALIBRATION FIXTURE
Hi all,
I¡¯ve had this unit for quite a bit now. And while it¡¯s performing quite nicely as far as amplitude, once cleaned, recapped and calibrated, I¡¯m having a small issue that I¡¯d like to address. It¡¯s supposed to have a 50-50 duty cycle, but it¡¯s not the case. The negative side is way thinner than the positive one. Not exactly looking like a negative going pulse, but not far from it either. I¡¯ve checked the diodes D112 and D122 (that are, I think, supposed to be matched), and nothing seems to be wrong with them. Just to see what it would actually do, I even temporarily put 2 (off-the-shelf and unmatched) 1N4007 instead. Surprisingly enough the trace was exactly the same. I even went ahead and put a brand new 6DJ8¡ same results, no change whatsoever. I¡¯d appreciate any input that would help me fix this issue. Thank you all. |
|
TEKTRONIX AM700
Stuart Blacklock
Hello, I wonder if someone can help me?
I have a TEKTRONIX AM700 which I brought dead, originally, it was tripping the mains, this was some RIFA filter caps, once replaced, the AM700 now powers up. But now I have a new issue, the unit powers up, starts to boot with the splash screen, then I get a screen with a number of garbled boxes, then all the lights on the front of the unit turn on and it resets. Things I have tried :- Tried to activate the low level tests (Holding ¡°Menu¡± or ¡°Limit¡±) and to try and go straight into an application but crashes shortly after the splash screen or diags screen Modding the DALLAS DS1286 as the battery was dead, no change 3V second battery OK. Running the processor board on its own with none of the lower boards connected, same outcome. Removing the NVRAM :- Causes the unit to display an error and Continue / Pause / Esc option, no matter which I try, I still cant activate a low level diagnostics Removing the FLASH starts the low level diagnostics, to which it passes Board Program Reg, Board Status Reg, Spurious Interrupts, Dynamic RAM, then it gets to the FLASH which it recognises it¡¯s not present and restarts Checked the + and ¨C 5 and 15V rails, all good, TP1 says its 12V but that¡¯s sat at 4.8V, looking at the diagram, I suspect that the only time this is 12V is if the FLASH RAM is being programmed, I could be wrong but it seems to make sense. Things I have not tried :- Firmware update via the floppy, though I don¡¯t have the disks, there¡¯s no way of doing this as the low level diagnostics screen pops up and then it resets, giving no ability to select that option Reset the NVRAM, for the same reason I cant access the Frimware upgrade screen Recapping, now this is something I haven¡¯t done because I haven¡¯t got the right caps in stock but they are on order, there is clear evidence that the silver SMD types are leaking, but as the fault is persistently the same, I have my doubts the caps are the culprit (But most certainly need replacing). You can see a damp circle around them and there¡¯s some signs of light corrosion, there¡¯s nothing serious looking to suggest corroded tracks. Attempted to flash the boot ROMS ( Not sure if I can as I don¡¯t think I have the correct programmer) Though I plan to replace the suspected caps, I am wondering if anyone may have had the same issue and know some other things to try? Many Thanks |
|
Re: OT: microwave oven blows fuse
I had a microwave that had the opposite problem - it would only work when the door was slammed shut. I found that a flimsy steel bracket holding part of the interlock assembly had deformed over the years, and bending it back into alignment fixed it right up. After that, a gentle push and click was all it took, or slamming was OK too - it just worked like it was supposed to when new. You may want to check out the mechanical alignments of the pieces and mounting structures.
Ed |
|
Re: Tek 577 restoration -- help needed
The green and white wire is in the main frame of the 577. On the back of the main switch voltage and resister selector control. EXTREME CAUTION is needed here there can be 1,600 Vdc on that switch no matter what the front panel settings are. This gets the 4 voltages off the collector supply regardless of switch position. Make SURE (TRIPPLE CHECK) the variable collector control is at 0% (all the way counter clockwise)
toggle quoted message
Show quoted text
Zen -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Rogerio O Sent: Monday, December 20, 2021 7:30 PM To: [email protected] Subject: Re: [TekScopes] Tek 577 restoration -- help needed Trying to start the calibration of the 177, but there is no voltage reading on the DMM connected as required and I turn the offset Multi. I will have to check if it is present at U350/U360 in the step amplifier. By the way, does anybody know where in the schematics is located this White /Green wire connected to the MAX PEAK VOLTS switch? This location is used in several calibration steps of both the 177 and the 577. I since I am experiencing problems with calibration it would help to diagnose the deviations I am observing if I could follw the procedure on the scematics. Thanks to all, Roger |
|
Re: Tek 577 restoration -- help needed
Trying to start the calibration of the 177, but there is no voltage reading on the DMM connected as required and I turn the offset Multi.
I will have to check if it is present at U350/U360 in the step amplifier. By the way, does anybody know where in the schematics is located this White /Green wire connected to the MAX PEAK VOLTS switch? This location is used in several calibration steps of both the 177 and the 577. I since I am experiencing problems with calibration it would help to diagnose the deviations I am observing if I could follw the procedure on the scematics. Thanks to all, Roger |
|
Re: OT: microwave oven blows fuse
Thanks, Dave.? I'll give it a shot.? ? ? ?JimSent from my Verizon, Samsung Galaxy smartphone
toggle quoted message
Show quoted text
-------- Original message --------From: Dave Daniel <kc0wjn@...> Date: 12/20/21 1:16 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] OT: microwave oven blows fuse is what I have found to be useful more often than not.DaveD> On Dec 20, 2021, at 15:16, Glenn Little <glennmaillist@...> wrote:> > ?Do a search for microwave oven parts,> There are other vendors for parts.> > Glenn> >> On 12/20/2021 11:47 AM, Jim Ford wrote:>> Aw, crap!? I just called Kitchen Aid/Whirlpool parts, and no, they don't stock any parts at all for my "countertop" microwave oven! It's considered a throwaway item...>> >> So I suppose I can either fiddle with the latch to try to keep the timing of the door switches proper or just leave it as-is and hope the fuse doesn't blow for a long time.? Regardless, slamming the door is banned for life!? (Good luck with 2 teenage boys in the house)>> >> Unless somebody has a better idea....>> >> Thanks.>> >> Jim>> >> ------ Original Message ------>> From: "benwetzel via groups.io" <benwetzel@...>>> To: [email protected]>> Sent: 12/18/2021 9:45:17 AM>> Subject: Re: [TekScopes] OT: microwave oven blows fuse>> >>> You will need to replace the plastic bracket that holds all of the switches.? Or easier approach is to>>> get the whole interlock assembly.>>> >>> Good luck sir.>>> Ben>>> >>> >>> >>> >>> >> >> >> >> >> > > -- > -----------------------------------------------------------------------> Glenn Little??????????????? ARRL Technical Specialist?? QCWA? LM 28417> Amateur Callsign:? WB4UIV??????????? wb4uiv@...??? AMSAT LM 2178> QTH:? Goose Creek, SC USA (EM92xx)? USSVI, FRA, NRA-LM??? ARRL TAPR> "It is not the class of license that the Amateur holds but the class> of the Amateur that holds the license"> > > > > >
|
|
Re: Internal Drive Mechanism for 7B53N (et., al.) Sweep Speed Cam
I'm happy to report that the cams are reassembled in the plugin and they are working exactly as they should. Thanks to all who replied.
toggle quoted message
Show quoted text
Thanks, Barry - N4BUQ ----- Original Message -----
From: "Barry" <n4buq@...> The way this works for this particular rear drum is that the two splines drive |
|
Re: OTish: ROM/RAM bank switching in the 2467 et al.
On Mon, Nov 29, 2021 at 1:06 PM Sigur?ur ?sgeirsson <siggi@...> wrote:
On Sun, Nov 28, 2021 at 4:40 PM Mark Litwack <mlitwack@...>So I started writing a MAME driver for the 2465, since it's "uncomplicated" in terms of memory accesses. I discovered that there are actually several tek device drivers in MAME already, notably Driver tek4051 (Tektronix 4051): Driver tek4052a (Tektronix 4052A): Driver tek4107a (Tektronix 4107A): Driver tek4109a (Tektronix 4109A): I don't know to what level of completion or accuracy these devices are emulated. In any case, my embryonic emulator is currently stuck in initialization, where it appears the firmware is wiggling DAC levels while polling the display sequencer for trigger status. Presumably this is the self-test that validates triggering against the line input. I have a vague recollection of a power-up hang in these scopes when the display sequencer or the trigger hybrid are bad. Does anyone here remember this sort of powerup hang? |
|
Re: OT: microwave oven blows fuse
Don't ignore ebay for appliance parts. Easy to search and with pictures. Made in Asia and zero cost to advertise has done wonders for consumer replacement parts availability.
toggle quoted message
Show quoted text
Eric WB6KCN -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Randy.AB9GO Sent: Monday, December 20, 2021 2:37 PM To: [email protected] Subject: Re: [TekScopes] OT: microwave oven blows fuse Go on the internet and look up Dayton appliance parts or Cincinnati appliance parts.com. They've been very good about having parts for anything I've needed over the years. Take anything you receive from a 1-800 number for Whirlpool with a boxcar full of salt. They usually don't know what they're talking about. -- Thanks, Randy. randy.ab9go@... |
|
Re: OT: microwave oven blows fuse
Go on the internet and look up Dayton appliance parts or Cincinnati appliance parts.com. They've been very good about having parts for anything I've needed over the years. Take anything you receive from a 1-800 number for Whirlpool with a boxcar full of salt. They usually don't know what they're talking about.
-- Thanks, Randy. randy.ab9go@... |
|
Re: OT: microwave oven blows fuse
My dim memory is that U.S. manufacturers are required to support products for five years. We certainly live in a throw away world.
toggle quoted message
Show quoted text
On 12/20/2021 2:05 PM, Geoffrey Thomas via groups.io wrote:
As posted elsewhere, manufacturers in Europe have to hold spare parts for 7-10 years after product purchase, and not before time. --
Richard Knoppow dickburk@... WB6KBL |
|
Re: OT: microwave oven blows fuse
As posted elsewhere, manufacturers in Europe have to hold spare parts for 7-10 years after product purchase, and not before time.
toggle quoted message
Show quoted text
Geoff. On 20/12/2021 16:47, Jim Ford wrote:
Aw, crap!? I just called Kitchen Aid/Whirlpool parts, and no, they don't stock any parts at all for my "countertop" microwave oven!? It's considered a throwaway item... |
|
TDS520A horizontal hold
#chat-notice
David Collier
My TDS520A lost its horizontal hold recently. Half of its SMD electrolytics are still OK, incidentally.
Cause: a small 39Kohm resistor had gone high, in the megohm range. There are only two on the CRT board. The guilty one reduced the SYNC. The same resistor was pointed to on an EEV blog notice. Regards. |
|
Re: OT: microwave oven blows fuse
Greetings,
toggle quoted message
Show quoted text
Of course, I don¡¯t know the details and having only loosely followed this interesting conversation, but two things came to mind. My first reaction is that Kitchen aid/Whirlpool calling an appliance a ¡°throw-away¡± item is callous and obscene - let¡¯s just keep filling the planet with ¡°throw-away¡± trash. Then, on perhaps a more productive and helpful note - can you reverse engineer the needed parts and have them 3D printed? Wishing you a good solution, wonderful holiday, and that 2022 becomes you best year thus far and a better year for us all. Regards, Ken On 20Dec, 2021, at 9:47 AM, Jim Ford <james.ford@...> wrote: |
|
Re: OT: microwave oven blows fuse
is what I have found to be useful more often than not.
toggle quoted message
Show quoted text
DaveD On Dec 20, 2021, at 15:16, Glenn Little <glennmaillist@...> wrote: |
|
Re: OT: microwave oven blows fuse
This is why the ¡°Right to repair¡± movement is important. I can understand a
toggle quoted message
Show quoted text
manufacturer that no longer has parts for something 20+ years old (like the old Tek 500-series!) and is the reason why groups like this are so useful. I knew there was an interlock system in the microwave. I fixed one before myself - the pivot bolt for the moving part of the latch was too short and would loosen so the latch would not activate the switch. I wound up replacing it with a NAS (aircraft) standard bolt because it was the right size and I could hold it in place with a matching nut - and I had it in my hardware bin. The microwave gave out long before that bolt did. What bugs me is manufacturers who won¡¯t even sell you a manual for a current product. I had this experience with a Miele dishwasher. Very well engineered - they had a smart design. The main water valve was at the end of the hose that connected to the water supply. It was a normally-closed valve of course but unlike the usual design with that valve inside the dishwasher, if this one failed, the water would be shut off at the supply. You don¡¯t have water at pressure inside the supply hose. The problem was a failure in that valve. I contacted the local Miele customer support and asked about buying a service manual and parts list. They would not sell it to me - ¡°only for our authorized factory repair personnel¡±. I asked if I could get it serviced - sure, but I just had to tell them from which distributor I purchased it. I couldn¡¯t. It was bought by the contractor who re-did our kitchen and it had been fifteen years since then. I had no idea from whom he bought the dishwasher and they would NOT service it unless I could prove it was purchased from one of their ¡°authorized¡± dealers. I was not asking for warranty service - I said I¡¯d be happy to pay for it. Nope. They ¡°protected¡± their dealers as well as their service people. A lot of the reason I like to have service manuals for stuff I own is not only to do simple fixes or maintenance myself, but I can quickly determine if it is something I cannot do - either out of my capability range or requiring specialized (and expensive!) tools. Wound up scrapping that $1000 Miele dishwasher. I replaced it with a Kenmore after I determined that they would sell me a service manual. I¡¯m not trying to put service folks out of work - I think it¡¯s a minority of folks like those on this group who are willing to put hours of work into fixing something, so we¡¯re not a threat to repair and maintenance folks. I did figure out that I could not repair that Miele myself even with the manual - that valve was attached to the pipe nipple with a specialized crimp connector; that would need the proper crimp Here¡¯s a link to ¡°right to repair¡± legislation: Steve Horii On Mon, Dec 20, 2021 at 13:47 Jim Ford <james.ford@...> wrote:
Aw, crap! I just called Kitchen Aid/Whirlpool parts, and no, they don't |
|
Re: OT: microwave oven blows fuse
Do a search for microwave oven parts,
toggle quoted message
Show quoted text
There are other vendors for parts. Glenn On 12/20/2021 11:47 AM, Jim Ford wrote:
Aw, crap!? I just called Kitchen Aid/Whirlpool parts, and no, they don't stock any parts at all for my "countertop" microwave oven! It's considered a throwaway item... --
----------------------------------------------------------------------- Glenn Little ARRL Technical Specialist QCWA LM 28417 Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178 QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA-LM ARRL TAPR "It is not the class of license that the Amateur holds but the class of the Amateur that holds the license" |
|
Re: OT: microwave oven blows fuse
Aw, crap! I just called Kitchen Aid/Whirlpool parts, and no, they don't stock any parts at all for my "countertop" microwave oven! It's considered a throwaway item...
toggle quoted message
Show quoted text
So I suppose I can either fiddle with the latch to try to keep the timing of the door switches proper or just leave it as-is and hope the fuse doesn't blow for a long time. Regardless, slamming the door is banned for life! (Good luck with 2 teenage boys in the house) Unless somebody has a better idea.... Thanks. Jim ------ Original Message ------
From: "benwetzel via groups.io" <benwetzel@...> To: [email protected] Sent: 12/18/2021 9:45:17 AM Subject: Re: [TekScopes] OT: microwave oven blows fuse You will need to replace the plastic bracket that holds all of the switches. Or easier approach is to |
Raymond Domp Frank
Eric Schumacher
Randy.AB9GO
to navigate to use esc to dismiss