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Re: 7L13 'Center Frequency' display issue
开云体育Far better analysis than I could have ever doneVernonia Northern Has U2145 (156-0096-00 - LM311H) for $1.20 & U2110 (156-0223-00 - LM308) for $1.10? & U2010 (156-0292-00 – 74L04) @ $0.35 each Chris HJ On 12/03/2013 06:25, David wrote:
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Re: 155-0049-02 for 465 scope
Bob,
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I have a 7B53A with bad switches that I am scraping. I can send you the working 155-0049-02 for $5 plus shipping[$2.06?]. send me your address and it will go out this morning. paypal j_massengale@... $7.10 Jerry Massengale
-----Original Message----- From: Bob To: TekScopes Sent: Mon, Mar 11, 2013 7:59 pm Subject: [TekScopes] 155-0049-02 for 465 scope
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I beleive I need a 155-0049-02 chip to fix the sweep issue with my 465 scope. Anyone know the best place to locate one????
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Re: Tek 214 running without batteries
Mark Wendt
On 03/11/2013 08:34 PM, Scott Harris wrote:
Scott, Do a search on Ebay for "tektronix probe tip" - there's tons of them out there, and most are fairly inexpensive. Mark |
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Re: Found 7854 Boards and more in the big Sphere Storage clear out...
Craig Sawyers
Hi Walter
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A long shot - you don't happen to have a 7854 keyboard lurking in a dusty corner? Kind regards Craig -----Original Message-----lost track of who. I found a big pile of them (when did we get THOSE??? nomode select board, with all the lighted PB switches, one of the first things toget worn out and damaged. this looks very minty. also found some 7094rack mounted storage scope for $50.analyzers. next week Stan and Dennis will be up, so this is the only chance to getthings transported back to the tek museum in oregon for just some gas money. itthese items.really benefit from cheap transport, as they are pretty big and heavy. next weekis the last chance for them. |
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Re: 155-0049-02 for 465 scope
--- On Tue, 3/12/13, David C. Partridge wrote:
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Re: Sony/Tektronix 318 manual with full schematic
--- On Tue, 3/12/13, sbirdasn wrote:
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Re: New here with a 2465 to clean up
Dave, ? This new link does work.??I had already found your file by browsing the group files and was quite impressed.? Very nice professional work.? It looks to me that you have complemented the contours of the U800 to gain maximum thermal transfer to the heat sink.? But I dont have access to a machine shop to?implement your drawing.? And it looks expensive to have it done.? How did you build it? ? Mac? From: Dave C
To: TekScopes@... Sent: Tuesday, March 12, 2013 2:31 AM Subject: Re: [TekScopes] Re: New here with a 2465 to clean up
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This link doesn't seem to be working. Try this one: http://tech.groups.yahoo.com/group/TekScopes/files/U800/ Dave -=-=-=- On Mar 11, 2013, at 11:52 AM, Dave C wrote:
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Re: New here with a 2465 to clean up
Thanks Cslim.? I didnt get much time to work on it today.? But did do some visual inspection.? Many of the caps apear similar in color (copper/gold color) and manufacture.? I believe they are original.? C1101 looks to be?original and is labeled as 100 ufd.? C1102 appears to have been changed (kelly green color)?but is also labeled 100 ufd.? C1116 (original) has been leaking inside its vinyl sleeve.?? C1113 (original) is?bulging at the bottom and will be leaking soon.? C1132 (black) looks to have been replaced at some time.? Also, it looks like diode CR1115 has been replaced at some time.? And diodes CR1103 through CR1106 appear to run hot (the board is slightly discolored under/near them).? Measuring with a miltimeter shows the diodes still
rectify and have similar "resistance" in the conducting direction.? I was surprised to see C1021 and C1022 look?almost like new.? I cant tell if they have been replaced but they are labeled Sprague and I think they sold the capacitor business to Vishay some ten years ago. ? So, I definitely need to replace the electrolytics?in the LVPS which is no surprise.? I will measure their values when I pull them just to see how bad they got.??But that task will have to wait till?I get some?uninterrupted time.? Hopefully later this week.? ? Meantime I plan to look at the fan motor assembly to see why it doesnt run.? I am confused how it works though.? Maybe someone can help me.? I understand the voltage control transistor (Q1698) and the coil dirve transistors (U1690) but I dont understand what
drives the base junctions of U1690.? It looks to me there are burshes or contacts of some kind that connect to motor terminals 2, 4, 6, and 8.? Or are those Hall effect jucntions?? My confusion is "what drives the base junctions of U1690 to commutate the coil drive as the armature turns? ? Again, thanks to all who have helped me on this project.? I hope you are having fun.? I am. ? Mac From: Chin Siang Lim To: "TekScopes@..." Sent: Monday, March 11, 2013 7:16 PM Subject: Re: [TekScopes] New here with a 2465 to clean up
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Not able to access this spreadsheet link using my iPad. There is one capacitor, c1101, which is just above the rows of diodes and beside the transformer, it is a 100uf cap. This must be a 100 uf cap to give the -8volts. Do not change its value.?
Cslim
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Re: New here with a 2465 to clean up
Dave C
This link doesn't seem to be working. Try this one: Dave -=-=-=- On Mar 11, 2013, at 11:52 AM, Dave C wrote:
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Re: Parallel resistance spreadsheet
I'm bookmarking this. Thanks! -- George Sent from my iPad On Mar 11, 2013, at 1:16 PM, "Dennis Tillman" <dennis@...> wrote:
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Parallel resistance spread sheet
开云体育Since I sent the parallel resistance spreadsheet to the forum many members have responded asking for a version that works in Excel.? I am attaching such a file that works in Excel and it is Parallel.XLS.If you have any enchantments or suggestions please forward them to me. Reed Dickinson reed714@... |
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Re: 7L13 'Center Frequency' display issue
On Mon, 11 Mar 2013 06:35:34 -0000, "Michael" <af7u@...> wrote:
This post is a follow up from post #7360, and my 7L13 with center frequency LED readout all zeros. I am a bit further along with my investigation. I now understand the operation 'somewhat' more. I have looked over the diagrams and taken some voltage readings, I also understand the basic DVM logic and readout operation which sends data to the LCD and the CRT. I have an article from a Jan, 1975 '73' magazine which talks about the Fairchild 3814 digital voltmeter. I must admit I am not too clear on the 'Analog' section of the meter. On board 'A2100', diagram 12, the input to pin 2 of U2110 comes from plug P2540 pin 4. Looking over the A2500 board shows that pin 4 goes to chassis ground. Why would pin 2 from U2110 go all the way back to A2500 to reach chassis ground.U2110 (LM308 style low bias current bipolar operational amplifier) is configured as a differential amplifier. The signal ground that the tuning voltage uses may not be at quite the same potential as the signal ground that the readout uses so the differential amplifier subtracts the difference. The differential amplifier will also subtract low frequency noise between the grounds. Anyway, the A2000 board seems to be working, albeit the frequency of the clock oscillator is not 200kHz as the diagram shows, it is running at 153.7kHz, though amplitude is good at 5 volts, I would think that would affect calibration but not operation. Back on A2100, the tuning control voltage at R2104 is good, it swings from + - 9.6 volts. The output of U2110 swings + - 10.7 volts. The DCPL Supply rails 15, -15, and 5 volts are all good. The reference voltage at the cathode of VR2115 (Zener) is 3.1, not the 3.3 volts is shows. Voltage at TP 2100, (output of U2130) is 11.65, a bit higher than the listed 11.3 volts. The voltages around the N-channel FET (Q2120) is Drain = 3.37 volts, Source = -3.1 volts, and Gate = -3.5 volts, are those in the ball park?Those voltages all sound good to me and they are mostly the ones I would have asked you to measure. In the worst case they add up to a calibration problem and not a complete failure. Needless to say there is NO signals present, waveform, 1, 2, 3, and 4 are all missing. Lines 'E' and 'F' are both quiet, the voltages on 'E' are 7.08 volts, on 'F' the voltage is 5.12 volts which swings a bit higher when I adjust center frequency, up to 5.44 volts. Of course 'E' has no signal as would be expected without drive from U2145 there is nothing to trigger the multivibrator U2030 on board A2000 sending a signal back up line 'F'. I keep thinking of this in terms of a frequency counter, I keep thinking there should be a driving input signal. I try to keep in mind it's a voltmeter, and keep in mind the circuit description given in the manual. It describes a ramp signal coming from the output of U2110, I don't understand that statement. The 'Tune' voltage is just a DC voltage, plus to minus. The minus input of U2120 goes to chassis ground??? What 'RAMP' are they speaking about?E is 7 volts? That is quite a trick since the pull-up resistor (R2149) is connected to +5V and the output of U2145 (LM311 style comparator) is wired open collector (pin 1 is the emitter of the output transistor and wired to ground) so it can only pull down and not pull up. On the receiver side, U2010D is part of a 74L04 and also has a 5 volt supply voltage so even if it failed, it can not pull up to 7 volts U2145 (LM311) is probably bad but you might want to look for a bad socket or open trace. Nothing should be able to make its output go to 7 volts except an open on pin 4 or failed part. The operational amplifiers and comparator are all TO-99 8 pin metal cans which are difficult to find these days. If you can not find metal cans, I would try replacing them with 8 pin DIP parts which conveniently have the same pinout. I have done this before by cutting the DIP leads short and soldering little wires to them. Cutoff 1/4 watt resistor leads work well. Texas Instruments still sells TO-99 LM311 comparators but they are $10 each. U2010 may be damaged as well. I think it can be replaced without problems with a 74LS04 or even a 74HCT04 which are both more common. If you have to order the LM311, pick up an LM308 and 74L04 replacement as well just in case. The LM308 operational amplifiers can be directly replaced with the Linear Technology LT1008. An LT1012 or lots of other devices can be used if you pull the compensation capacitor. JFET or MOSFET input devices should work as well. Lastly the manual's circuit description on page 5-10 talks about a positive going ramp from U2110, aren't these just DC levels, what 'Ramp' are they talking about?I think the ramp they talk about is the output of U2140 (another LM308) which is configured as an integrator. The frequency (and slope) of the ramp is proportional to the measured voltage. Okay, I see there are a lot of questions here. I had better post this and hope for the best. It's a great 7L13, it works well, but without a 'Center' frequency display, it's pretty much just a toy. Also, I do appreciate the feedback~!~ I am not accustom to working on test equipment, my experience has been mostly all in Hi-Fi, but this has been very interesting.I had to add a few pages of the 7L13 manual to my book of stuff I do not have so it took a bit longer to respond to your post. The 7000 series spectrum analyzers look like fun. I will have to keep an eye out for one. |
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Re: New (ugly) 134 Current Probe Power Supply (015-0058-02)
Thanks Dennis,
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I will change my setup and remove the 7815 so it get ?> 16V unregulated. I will use a 1000 uF buffer. That should keep the lowest voltage in the ripple above 16V, but that is easy to test on a mini-dynamic ( 0-1.5A 100Hz to 50 kHz pulsed with adjustable 0-1.5A bias) load I made for testing small ( < 3A ) PSUs that can be easy set at f.i. excact 40 mA and then pulse 20 mA extra? Very handy for these sort of things Fred PA4TIM --- In TekScopes@..., "Dennis Tillman" <dennis@...> wrote:
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Re: Found 7854 Boards and more in the big Sphere Storage clear out...
开云体育Hi Walter, I recently acquired a “regular” Tek 465 scope. Would the 465M front cover fit the 465? Thx, Al ? From: TekScopes@... [mailto:TekScopes@...] On Behalf Of wshawlee2
Sent: Monday, March 11, 2013 6:20 PM To: TekScopes@... Subject: [TekScopes] Found 7854 Boards and more in the big Sphere Storage clear out... ? ? …… No virus found in this message. |
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Re: Sony/Tektronix 318 manual with full schematic
sbirdasn
Try www.ebaman.com.
It contains a copy of the army version service manual, it is complete and a good scan. You have to register to get access to the files, but it's free. You will find it in the Test Equipment-> Tektronix-> Logic Analyzers section. It's a direct copy from the original Tektronix service manual, complete with typographical errors, etc. that exist in the Tektronix service manual. I'm curious as to the full symptoms of your 318 other than being unable to select 20nS clock rate. I don't see how it could limit the clock sample rate, and not show some other indication that it thinks it's a 338, like incorrect setup menus such as the Setup menu being populated with 4 pods of signals (318 only populates Groups 1 & 2 w/ signal names for pods A & B, respectively). Or, not fail numerous tests of the hardware in respect to ACQ/Glitch capture SRAM. Either in the normal startup diagnostics, or any of the manual diagnostic tests. Keep us posted on your progress. Sbirdasn. |
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New (ugly) 134 Current Probe Power Supply (015-0058-02)
开云体育I just received a type 134 current probe amplifier with a newer power supply I hadn’t seen before. (see attached picture) Instead of the classic power supply, Tek used a power cube (model 3310) that came from Engineering Design and Sales. Tek had their logo and part number (015-0058-02) engraved on the front. Tek completely changed the power connector to the 134. They are now using a 2 prong power connector like you would find in automobiles. ? It is a very big ugly thing. The power cube is 3 ?” x 2 ?” x 2”. ? Here is the important part: Input: 120V, 50 to 400Hz, 10Watts Output 26.5VDC @ 200mA ? This is clearly way over rated for what the 134 requires (>16V @ 40ma) so that tells me that just about any power cube that outputs >16V will work. |
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Re: 155-0049-02 for 465 scope
7B80, and therefore also very likely in any of 7B50A, 7B85, 7B87 (but please don't steal one from a working 7B87).
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Dave -----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Bob Sent: 12 March 2013 00:59 To: TekScopes@... Subject: [TekScopes] 155-0049-02 for 465 scope I beleive I need a 155-0049-02 chip to fix the sweep issue with my 465 scope. Anyone know the best place to locate one???? ------------------------------------ Yahoo! Groups Links |
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Re: Tek 214 running without batteries
开云体育I built some new packs and installed them in my Tex 214: It now works like champ.?Getting the boards aligned up and stuffed back in that little case took a few tries, but it's working again. Now I just need to find some replacement probe tips. Any suggestions? Should I just buy some cheap probes and replace the ones I have? -Scott ? On Mar 5, 2013, at 5:50 PM, Steve <ditter2@...> wrote:
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Re: Parallel resistance spreadsheet
Derward Myrick
开云体育Dennis
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Here is another calculator that does
a good job.
Serial or parallel
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Derward Myrick?
KD5WWI
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