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Re: 475 with no Display and no HV
Hi Reed,
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Yes sir working at the Radio Museum is a lot of fun and hard work at the same time but now that I am retired it is a great place to volunteer a few days a week. Between the NTE539 and NTE538 which one would you recommend for the Tektronix 475? Ripley The words are mine but this iPad does what it will with them. On Mar 5, 2019, at 12:08 AM, Reed Dickinson <reed714@...> wrote: |
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Re: Help with 7A18 problem
Thanks for the kudos, it's from one of my own 7A18s.
BTW, the contacts under the board on the other side of the cam switch are for the readout circuits. It's no big deal to remove the board for cleaning but usually not required. For "tricky" cam switch arrangements see the photos at ... Best Peter |
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Re: 7L13, more exact frequency readout
/g/TekScopes/album?id=86278
-----Mensaje original----- De: [email protected] [mailto:[email protected]] En nombre de Gudjon Gudjonsson Enviado el: domingo, 19 de agosto de 2018 21:28 Para: TekScopes Asunto: Re: [TekScopes] 7L13, more exact frequency readout Hi again Now I have done quite a few measurements with my 7L13. I just used a know frequency source to tune it into the frequency I am searching for and then I do the measurement. This works well enough for my zero span measurements with resolution of 300kHz. I did buy a frequency meter for up to 5.8GHz and tried to correlate the frequency of the YIG oscillator with the voltage between pin 6 of U2110 and ground with a more precise voltage measurement than the frequency readout contains. Regarding phase locking of LO1. According to the manual, the span is done in the following way: = 5MHz/div: Main coil of the YIG2MHz/div to 100kHz/div: FM-coil <=50kHz/div: The phase lock loop of LO2, and then the LO1 can be phase locked. I found out that the plugin need through calibration since the center frequency moves quite a lot with changing span. But the nice thing is that I think I have solved the EMC problem the setup was supposed to help solving and my 7L13 is very helpful in my EMC precompliance toolset. Regards Gudjon |
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Re: 2467 restoration: Battery, cleaning
I bought my battery at Mouser a few years ago for my Tek 2465A DV. I also soldered the wires to the battery holder that I used to the board because I was afraid the alligator clips might come loose on me. I wrote an article about it that you can google if you want to.
Robert |
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Re: TM5xx extenders
I've just ordered a set on eBay from John Nery, currently awaiting delivery. These are in kit form so some soldering will be required. He makes custom boards to order using a CNC milling process. I have no affiliation, just passing on the information.
He also included the following note if you want to contact him directly: "In the future please feel free to contact me directly by this e-mail address (WA1ESO@...) for any item you may need and receive a discounted price." |
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Re: 475 with no Display and no HV
Hi Ripley:
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Wiring in a NTE538 is a little different than wiring in an NTE539.? When you get your 3Xer write ma back and I will detail how to do it. Your antique radio setup sounds most interesting.? I would probably be helping you out at that facility if it were on the left coast. Reed On Monday, March 4, 2019, 4:43:02 PM PST, SuddenLink <bob.ripley@...> wrote:
Hello Reed, You just have been reading my mind. I was wondering how to handle the HV lead out to the CRT. What about the Focus Tap on the module. I am guessing that is left unterminated and highly insulated from anything around it. Our plan is to repair the scope so that we can sell it. The Museum of Radio and Technology is a nonprofit all volunteer organization. We don¡¯t charge for admission so our revenue sources are from cash donations, sales from our gift shop , small grants, and the three swap meet/auctions that we host every year. I will keep everyone posted as I bring this repair to completion. Ripley Sent from Mail for Windows 10 From: Reed Dickinson Sent: Monday, March 4, 2019 4:59 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hi Ripley: Good show, a new 3X voltage multiplier will get your 475 back on the air.? If you elect to get an ECG or NTS 538 or 539 you will have to splice the HV lead leaving the new tripler.? I very carefully slip a piece of thick wall plastic tubing over where the splice will be, carefully solder the joint leaving NO sharp points, coat the entire joint with silicone and slip the tubing over the joint.? I put a small tie wrap over each end to keep moisture out.? The 538 or 539 will fit in the space the present tripler is in, you will need to drill two mounting holes for the retainer screws. Reed Dickinson ? ? On Monday, March 4, 2019, 1:40:15 PM PST, SuddenLink <bob.ripley@...> wrote: Hi Reed, Per your suggestion I disconnected the wire from the secondary of T1320 to the voltage tripler and powered up the scope. The waveform at TP1318 immediately snapped to 32 volts p-p at about 70Khz without any persuasion via the 1K resistor trick. I also checked the oscillator over at the junction of CR1329 an C1326. It measures 320 volts p-p so it looks like I need to order a voltage tripler module. Thank you so much for your help. Obviously, you know your way around these scopes. Ripley Sent from Mail for Windows 10 From: SuddenLink Sent: Sunday, March 3, 2019 8:27 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hello Again, I went back to the circuit around Q1306 and Q1308 this evening. The resistors are all within specs. C1305 was pulled and checked. It is also fine. C1304 is good and so is C1302. By the way I am checking the capacitors with a DE-5000 LCR meter. It was never let me down yet. The only component that I have not replaced or substituted is Q1306. It checks fine on my little Chinse component tester. For whatever that is worth. Enough for today. Ripley Sent from Mail for Windows 10 From: Steph L Sent: Sunday, March 3, 2019 7:05 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hi Ripley, How about C1305 0.1uF. If open, gain of Q1306 (and whole oscillator loop) will be lower and perhaps not enough to maintain oscillation? (Great suggestion from Don re 1K pull up touch on Q1318 base.) Steph PS. Still nubie here and unsure which "Reply" button to click on. I clicked on Ripley's "what the heck?" message "reply" button and see it has been inserted a few messages prior!? That is really confusing. I'm in Melbourne Oz GMT +10 hrs. Is this the reason (i mean time difference guys and not quirky) |
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2213A Repaired and other questions
Hello thanks for some of the advice earlier for my problem. Not sure what did it exactly but the issue is gone. I am thinking that short caused a solder joint to crack on a ground some where. Just re did a lot of joints and everything works great.
So thank you guys. My first scope that I bought and repaired works again. I had a few other questions. I have heard that the capacitors in this thing has to go because they are old. Is there a guide showing the process of which to remove and a list for me to buy replacements? Also the front BNCs are pretty worn that replacements might be needed. Anyone know of what will work well here? I looked up what I could that led me to this. But there is no datasheet or any possible replacement model. Any ideas? |
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Re: 152-0310-00 replacement
On Mon, Mar 4, 2019 at 6:13 PM Sal_rosselli via Groups.Io
<Sal_rosselli@...> wrote: That is not a high failure rate part. I wouldn't worry about it. |
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Re: Tek 577 high collector voltage interlock
Hi Wilson,
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Best solution I have seen, and one I install myself on each 577 I get, is to replace the pushbutton with an ON-OFF-MOMENTARY Miniature SPDT Toggle Switch such as a C&K 7107. In the middle position it is OFF which is the default position and the safety interlock behaves as designed. In the ON position the Safety Interlock is defeated. This position is for "Professionals" who are willing to endure the occasional reminder that the 577 can bite you. The MOMENTARY position is for those who find the safety interlock to be a major annoyance but who prefer it to be there for when they forget. As long as you are holding the toggle in the MOMENTARY position the Safety Interlock is defeated but as soon as you are done checking the transistor and you remove your finger on the switch it enables the Safety Interlock automatically. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
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Re: PG 506
I would like to go back to my original question in my original post about any maint. issues such as changing out the original sprague 300 lytics and also if anyone has any spare parts for one?
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jim O On March 2, 2019 at 9:18 PM Jim Olson <v_12eng@... mailto:v_12eng@... > wrote: |
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152-0310-00 replacement
Hello everyone. I¡¯m new to electronics. I¡¯m fascinated and overwhelmed with the subject and hoping that I can fit all this information in my brain! I always wanted a Tek scope and I bought a 454 that seems to run ok with nothing more than a quick signal generator test. I¡¯d love to preserve this for as long as possible and restore it but I have a new fear of eventually replacing a tunnel diode. The manual says ¡°part #152-0310-00 similar to 1N3758.¡± NTE claims that the NTE5804 is a replacement for the 1N3758. Is it? Will it work? If that¡¯s my only option, what would be different? Thanks in advance for any help offered.
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Re: 475 with no Display and no HV
Hello Reed,
You just have been reading my mind. I was wondering how to handle the HV lead out to the CRT. What about the Focus Tap on the module. I am guessing that is left unterminated and highly insulated from anything around it. Our plan is to repair the scope so that we can sell it. The Museum of Radio and Technology is a nonprofit all volunteer organization. We don¡¯t charge for admission so our revenue sources are from cash donations, sales from our gift shop , small grants, and the three swap meet/auctions that we host every year. I will keep everyone posted as I bring this repair to completion. Ripley Sent from Mail for Windows 10 From: Reed Dickinson Sent: Monday, March 4, 2019 4:59 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hi Ripley: Good show, a new 3X voltage multiplier will get your 475 back on the air.? If you elect to get an ECG or NTS 538 or 539 you will have to splice the HV lead leaving the new tripler.? I very carefully slip a piece of thick wall plastic tubing over where the splice will be, carefully solder the joint leaving NO sharp points, coat the entire joint with silicone and slip the tubing over the joint.? I put a small tie wrap over each end to keep moisture out.? The 538 or 539 will fit in the space the present tripler is in, you will need to drill two mounting holes for the retainer screws. Reed Dickinson On Monday, March 4, 2019, 1:40:15 PM PST, SuddenLink <bob.ripley@...> wrote: Hi Reed, Per your suggestion I disconnected the wire from the secondary of T1320 to the voltage tripler and powered up the scope. The waveform at TP1318 immediately snapped to 32 volts p-p at about 70Khz without any persuasion via the 1K resistor trick. I also checked the oscillator over at the junction of CR1329 an C1326. It measures 320 volts p-p so it looks like I need to order a voltage tripler module. Thank you so much for your help. Obviously, you know your way around these scopes. Ripley Sent from Mail for Windows 10 From: SuddenLink Sent: Sunday, March 3, 2019 8:27 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hello Again, I went back to the circuit around Q1306 and Q1308 this evening. The resistors are all within specs. C1305 was pulled and checked. It is also fine. C1304 is good and so is C1302. By the way I am checking the capacitors with a DE-5000 LCR meter. It was never let me down yet. The only component that I have not replaced or substituted is Q1306. It checks fine on my little Chinse component tester. For whatever that is worth. Enough for today. Ripley Sent from Mail for Windows 10 From: Steph L Sent: Sunday, March 3, 2019 7:05 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hi Ripley, How about C1305 0.1uF. If open, gain of Q1306 (and whole oscillator loop) will be lower and perhaps not enough to maintain oscillation? (Great suggestion from Don re 1K pull up touch on Q1318 base.) Steph PS. Still nubie here and unsure which "Reply" button to click on. I clicked on Ripley's "what the heck?" message "reply" button and see it has been inserted a few messages prior!? That is really confusing. I'm in Melbourne Oz GMT +10 hrs. Is this the reason (i mean time difference guys and not quirky) |
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Re: 475 with no Display and no HV
Hi Ripley:
toggle quoted message
Show quoted text
Good show, a new 3X voltage multiplier will get your 475 back on the air.? If you elect to get an ECG or NTS 538 or 539 you will have to splice the HV lead leaving the new tripler.? I very carefully slip a piece of thick wall plastic tubing over where the splice will be, carefully solder the joint leaving NO sharp points, coat the entire joint with silicone and slip the tubing over the joint.? I put a small tie wrap over each end to keep moisture out.? The 538 or 539 will fit in the space the present tripler is in, you will need to drill two mounting holes for the retainer screws. Reed Dickinson On Monday, March 4, 2019, 1:40:15 PM PST, SuddenLink <bob.ripley@...> wrote:
Hi Reed, Per your suggestion I disconnected the wire from the secondary of T1320 to the voltage tripler and powered up the scope. The waveform at TP1318 immediately snapped to 32 volts p-p at about 70Khz without any persuasion via the 1K resistor trick. I also checked the oscillator over at the junction of CR1329 an C1326. It measures 320 volts p-p so it looks like I need to order a voltage tripler module. Thank you so much for your help. Obviously, you know your way around these scopes. Ripley Sent from Mail for Windows 10 From: SuddenLink Sent: Sunday, March 3, 2019 8:27 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hello Again, I went back to the circuit around Q1306 and Q1308 this evening. The resistors are all within specs. C1305 was pulled and checked. It is also fine. C1304 is good and so is C1302. By the way I am checking the capacitors with a DE-5000 LCR meter. It was never let me down yet. The only component that I have not replaced or substituted is Q1306. It checks fine on my little Chinse component tester. For whatever that is worth. Enough for today. Ripley Sent from Mail for Windows 10 From: Steph L Sent: Sunday, March 3, 2019 7:05 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hi Ripley, How about C1305 0.1uF. If open, gain of Q1306 (and whole oscillator loop) will be lower and perhaps not enough to maintain oscillation? (Great suggestion from Don re 1K pull up touch on Q1318 base.) Steph PS. Still nubie here and unsure which "Reply" button to click on. I clicked on Ripley's "what the heck?" message "reply" button and see it has been inserted a few messages prior!? That is really confusing. I'm in Melbourne Oz GMT +10 hrs. Is this the reason (i mean time difference guys and not quirky) |
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Re: 475 with no Display and no HV
Hi Reed,
Per your suggestion I disconnected the wire from the secondary of T1320 to the voltage tripler and powered up the scope. The waveform at TP1318 immediately snapped to 32 volts p-p at about 70Khz without any persuasion via the 1K resistor trick. I also checked the oscillator over at the junction of CR1329 an C1326. It measures 320 volts p-p so it looks like I need to order a voltage tripler module. Thank you so much for your help. Obviously, you know your way around these scopes. Ripley Sent from Mail for Windows 10 From: SuddenLink Sent: Sunday, March 3, 2019 8:27 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hello Again, I went back to the circuit around Q1306 and Q1308 this evening. The resistors are all within specs. C1305 was pulled and checked. It is also fine. C1304 is good and so is C1302. By the way I am checking the capacitors with a DE-5000 LCR meter. It was never let me down yet. The only component that I have not replaced or substituted is Q1306. It checks fine on my little Chinse component tester. For whatever that is worth. Enough for today. Ripley Sent from Mail for Windows 10 From: Steph L Sent: Sunday, March 3, 2019 7:05 PM To: [email protected] Subject: Re: [TekScopes] 475 with no Display and no HV Hi Ripley, How about C1305 0.1uF. If open, gain of Q1306 (and whole oscillator loop) will be lower and perhaps not enough to maintain oscillation? (Great suggestion from Don re 1K pull up touch on Q1318 base.) Steph PS. Still nubie here and unsure which "Reply" button to click on. I clicked on Ripley's "what the heck?" message "reply" button and see it has been inserted a few messages prior! That is really confusing. I'm in Melbourne Oz GMT +10 hrs. Is this the reason (i mean time difference guys and not quirky) |
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Re: Uncooperative 7834
I can totally understand the temptation to get drastic, but recommend not defeating the built-in protection of the PS - it may work, but there's a good chance that the bad part in the mainframe will win out over something in the PS.
I have a similar situation, with three 7904s out of commission, all tickers. I have done all sorts of swapping and unhooking, and testing combinations, and know that in one it's the PS itself, and in others it's something definite, but not readily found, in the mainframe. In these cases, there is no obvious near or dead short, which would be preferable - I can see all the supplies come up to nearly the right voltage, but then it shuts down. I have fixed a lot of 7Ks over the years - sometimes it's easy, and sometimes very, very not. It can be very frustrating. This recent predicament has motivated me to finally get going on building my super-duper 7K maintenance box, a project I envisioned years ago, but didn't pursue. A few weeks ago, I started piecing it together and gathering up the parts, and figuring out the design requirements and features. It's a work in progress, and not nearly ready for prime time, but I can share some of the design concepts developed so far. It's nothing that can't be done with the right assortment of other gear, but this unit consolidates the functions needed to test the PS unit, and the mainframe, separately, or combined, to view all of the supplies, including the high voltage CRT stuff. Here are the major components, and the associated functions: Scope AC powering and monitoring. A 700 VA variac, 0-100% V line, with PT and CT signals via BNC outputs for monitoring line input waveforms, and DC outs to metering circuit for rough V line and I line measurement. Switchable test load resistor bank to test or run the PS low voltage supplies while unhooked from mainframe, and measure their voltages. Forcing/running supply. A modified 7603 linear PS that provides the nominal 7K low voltages: +130, +50, +15, +5, -15, -50. The circuits are to be modified so that each supply can be faulted independently, without affecting the others. Supplies the voltages (except the +130) to front panel binding posts for experimenting and developing plug-in circuits. Also provides various DC for internal control circuitry. Metering section, two 3-1/2 digit DPMs and signal switching, for selecting and measuring voltage and current on all LV supplies and line, and CRT HV section anode, cathode, and heater voltages. Also routes the selected supply voltage signal to a BNC for monitoring with a scope. High voltage interface box. This function was originally going to be built in, but the practicalities of the HV interconnections warranted making it an external unit. This box contains the HV dividers for Va and Vk, and load R and HF current transformer for monitoring Vh. The results are at low voltage, sent via cable to the main unit. I/O interface, two DB-25 connectors, one inputs from the PSUT, the other outputs to the MFUT. Corresponding DB-25 connectors will be rigged up as adapters to route the various PS voltages in and out, via Tek ribbon cables and harmonica connectors, according to the particular mainframe type. The basic overall operation: For PS unit testing, the adapter goes to the various connections on the PS, then to the test load, and the supply voltages can be measured if it's operational. If the mainframe has a fault, an output adapter can connect the PS to the mainframe via the metering circuit (loop-through mode), and the load currents can be measured. The test load resistors are turned off. If necessary, the force mode can be used, running the mainframe from the built in linear supply. The voltages and currents can all be monitored, and there will be no difficulties as with transient ticking. The power situation will be constant, and clear, and the parts (usually Ta caps) that don't necessarily show bad when not powered, will have the full, normal voltage applied, or have to take whatever (measurable) fault current is needed to lug down the supply. If the low voltage supplies all seem OK, the HV box may then be used for investigation into possible HV faults. If the PS unit has internal problems on its primary side, the variac and line signals can be used. Problems like bad line rectifiers or main caps, or startup circuit issues, can be detected by looking at the waveforms as voltage is applied and increased. That's all for now. Ed |
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still trying to track down 2216 manuals
I've search through the archives here and saw the 2014(?) discussion on the 2216 service manual. I have copies of the partial manuals for the 2216 and 2212. Alas, no schematics. Yet.
I am surmising that the manuals' unavailability is related to the fact that both the 2212 and the 2216 were designed in Heerenveen. I would guess that they were only manufactured in Holland and repaired at the Benelux Repair Center. Since Benelux was closed in 2000 as part of the Tek breakup, who knows what happened to the stock of manuals? I am hoping that they all didn't end up in the tip. Unfortunately, I am now in "dog chasing bone" mode now wrt to finding documentation. Does anyone know if there's a European-based Tek fan or alumni club? I want to see if I can track down anyone that worked in Benelux. So as not to inflict my obsession on others, I can be contacted off list, my call sign at arrl dot net. |
Robert Calk Jr.
Peter Mulvey
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