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Re: P6015A HV Probe: Applications?
Geoff Blake
On Sun, 14 Sep 2008, Craig Sawyers wrote:
I don't disagree with you, it is just a consequence of those whoFreon, one of the Ozone layer destroying gasses.This needs to be put in context. The peak of ozone depelting CFC's was in legislate not understanding what they legislate about........ I think that you will find that NiCd batteries are banned in EU, except for certain limited purposes, like replacement in existing equipment.
And those who give them power over us. (somebody should say "Amen" here.) Geoff -- Geoff Blake G8GNZ located near Chelmsford, Essex, U.K. Please reply to: geoff(at)palaemon(dot)demon(dot)co(dot)uk Using Linux on Intel & Linux or NetBSD on Sun Sparc platforms Please avoid sending me Word or PowerPoint attachments. See <> ------------------------------------------------------------------------------ This E-mail and any attachment(s) are strictly confidential and is intended solely for the addressee(s). If you are not the intended recipient please notify <postmaster(at)palaemon.co.uk> and the sender by return and permanently delete the message. You may not disclose, forward or copy this E-mail or any of its attachments to any third party without the prior consent of the sender. ------------------------------------------------------------------------------ |
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Re: Tektronix schematic question
Hi Tom,
The numbers are dates the "R.O.W." are the initials of the guy who drew or updated the schematic. Stan _____ From: TekScopes@... [mailto:TekScopes@...] On Behalf Of tom jobe Sent: Friday, September 12, 2008 5:34 AM To: TekScopes Subject: [TekScopes] Tektronix schematic question Hello Everyone, I tried posting this yesterday, but it did not show up on the Tekscopes message board... Would anyone know what "R.O.W." in the lower right corner of an older Tektronix schematic means? The current discussion of converting a 317's full wave bridge rectifiers from selenium to silicon rectifiers, involved the 317 manual on BAMA and some scans by Kurt from of an early version of the 317's manual's schematics. On the low voltage power supply schematic from BAMA, it says "R.O.W." and below that it has "1264". On the earlier version of the LV schematic from Kurt it says "R.O.W." and below that it says "5-14-59". Are these dates below the "R.O.W." ? The vintage of the 317 scope would certainly fit right in with 5-14-59, or 12-64, as being dates, but what does R.O.W. mean if those are dates? Thanks! tom jobe... |
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Re: selenium rectifiers in a 317
Hi Tom,
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The 10 Ohm resistors you see on the power supply schematics are really fuses to protect the power supplies from shorts in other parts of the scope. The series dropping resistors in a silicon mod kit are generally quite a lot higher in value, like a few hundred Ohms and generally are rated at 10-25 Watts power dissipation. I don't recall ever having a selenium rectifier FIRE, but they definitely have a unique and unpleasant odor when overloaded. Stan _____ From: TekScopes@... [mailto:TekScopes@...] On Behalf Of tom jobe Sent: Friday, September 12, 2008 5:23 AM To: TekScopes; Stan & Patricia Griffiths Subject: Re: [TekScopes] selenium rectifiers in a 317 Hello Stan, Thank you for the explanation of what Tektronix did to make the switch from selenium to silicon rectifiers! This all makes perfect sense now that you tell us about the different transformer for each type of rectifier. The schematics for the two types of rectifiers did not show any difference, and both types used the same value (10 ohm) resistor on the positive output from each of the full wave bridges. I don't think I have anything with a selenium rectifier in it (maybe my 575?) , but it is good to learn about replacing the selenium rectifiers. I did a Google search on "replacing selenium rectifiers", and there was a lot of information to read about on this topic. The consensus seems to be that you want to replace the selenium rectifiers before they fail in a spectacular fashion. On one web page the described the selenium's as selenium rectiFIREs! tom jobe... ----- Original Message -----
From: "Stan & Patricia Griffiths" <w7ni@easystreet. <mailto:w7ni%40easystreet.net> net> To: "'tom jobe'" <tomjobe@dslextreme. <mailto:tomjobe%40dslextreme.com> com> Cc: "TekScopes" <TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com> Sent: Friday, September 12, 2008 1:49 AM Subject: RE: [TekScopes] selenium rectifiers in a 317 Hi Tom and the rest of you guys,gradually increases with time. When the first 317s were produced with seleniums,the power transformer windings were designed to take the larger internalmore turns on each secondary winding than would have been necessary if siliconline, a new power transformer was necessary with slightly lower secondaryvoltages because the silicon diodes had lower internal resistance than theseleniums they replaced. No dropping resistors were necessary because of theredesign of the power transformer.enough to prevent the power supply from regulating properly and eventually thetransformer was designed to provide correct values of AC voltage to power seleniums,but NOT silicon rectifiers. If the manual on BAMA shows silicon diodes, thenit shows the schematic of a later instrument that came from the factory with317 with seleniums to one with silcons.can go through the effort to convert the microfiche images to hardcopy paperand make a copy for you.[mailto:TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com] On Behalf Of tom jobeedebris.com/manuals/tek/317/> edebris.com/manuals/tek/317/need to know, to convert from Selenium rectifiers?org/resources/ I use the "Lizardtech" viewer, and it works great on my Windows machine. |
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7704 tube odd failure - tube examination
I just pulled the CRT from the 7704 to see what I could see inside it.
*BOTH* the connections for a vertical plate were disconnected! Each one is clearly separated from the neck contact pin and bouncing around with any tube movement. And I don't just mean disconnected, but each like a quarter inch away! This explains why I didn't get usable performance when I jumpered across both plate terminals. I wonder what could have caused such a failure? Vibration? Shock? Or just poor welds? |
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Re: Thanks to all (P6015A)
Craig Sawyers
After due consideration, and considering it's one ofThat is entirely the correct decision! If you had said otherwise, I would have offered to take it off your hands ;-) My P6015 came with a half full can of freon, which has been in the fridge for the last couple of years to keep the vapour pressure in the can to about atmospheric and eliminate slow leakage. If I ever need to use the full capability of the probe, I will top it up. Craig |
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Re: P6015A HV Probe: Applications?
Craig Sawyers
If you can use it with a DMM it gives a very high input resistance'cept it is not intended for the purpose and will give a wierd result dependent on the input R of the DMM (which often changes between ranges). The correct division ratio only happens with a scope input R of 1M. The only way to go is to buy a high voltage probe for the DMM - which is designed for the purpose, like the Fluke 80K-40. Craig |
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Re: P6015A HV Probe: Applications?
Craig Sawyers
Freon, one of the Ozone layer destroying gasses.This needs to be put in context. The peak of ozone depelting CFC's was in the mid 80's, when R12 was used in all domestic and automotive refrigerators worldwide. In addition, other CFC's were used as degreasing solvents in the electronics industry (and others) in truly huge quantities (Freon TF). In total the global annual production of ozone depeting CFC's was the high hundred thousand tons during the decade before the Montreal Protocol (and later Kyoto agreement). Production of these materials is now down to truly tiny quantities - a few hundred tons per annum - largely for scientific purposes (such as spectroscopic applications) and very expensive and paperwork laden. In any event, the quantity of the rather specialised freon used in P6015 probes was entirely insignificant as compared with R12 and TF. Now that I'm started, it is kind of like the elimination of mercury batteries. Sure, in general mercury in batteries was a bad idea since it is leached out in landfills - but it means that the tiny market for replacement mercury cells for our Tek gear were likewise banned. Also, the entirely irresponsible banning of lead in solder - in which form the lead is not leachable and poses no environmental hazard. This is triply nonsensical when cadmium (a far more poisonous element, easily leachable) is still allowed in NiCd batteries, produced in the billions per annum, and lead is still used by the megaton globally in automotive batteries! Heaven save us from the thought police bureaucrats. <rant mode> = off Craig |
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Thanks to all (P6015A)
Thanks to all who provided insight on the P6015A HV probe.
After due consideration, and considering it's one of the newer type that uses a no-refill-required silicone compound instead of fluorocarbon liquid, I have decided to hang on to it. Happy tweaking. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- kyrrin (at) bluefeathertech do/t c=o=m "Quid Malmborg in Plano..." |
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Re: P6015A HV Probe: Applications?
Don Black
If you can use it with a DMM it gives a very high input resistance (probably about a Gigohm?) and with the sensitivity of even basic DMMs will measure 200 volts full scale with resolution down to 0.1 volt. This gives very low loading on high impedance circuits for minimum error apart from any high voltage applications.
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Don Black. Bruce Lane wrote: Fellow tekkies, |
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TDS380 CH1 Module
normanshanks
Does anyone out there have a front end channel module for a TDS380
scope??? The schematic shows a AT206/B2565 module. It's a hybrid part. The input channel will measure -5.3vdc on the most sensititive ranges as measured by a DVM. The other channel is 0vdc when measured. Would be glad to pay a nominal fee +postage. Thanks......Norman |
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FREE PART!
Paul Kraemer
Tek group
I have a transformer pn 120-169 Recollection is that it was changed out of a small scope 30 or so years ago and didn't fix the problem. Don't remember what scope. This transformer is potted in a rectangular can. One winding was to filament of hv rectifier tube. There are 7 other wires arranged in two sets of windings. I drove the highest z winding with my audio generator at 10khz and got indications it is good. FREE for several dollars cost of postage. Paul |
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Re: P6015A HV Probe: Applications?
Geoff Blake
On Sat, 13 Sep 2008, ken chalfant wrote:
Hi ALL,Freon, one of the Ozone layer destroying gasses. There were two of the P6015 series probes, one designed for 25kV and the other designed for 40kV. I say designed because I know from personal experience that the 25kV probe arced at around 35kV, and that caused my boss to throw coffee all over his brand new suit. I kept out of his way for a week or two...... As I recall the new price was about USD 1,500.00. I use mine to evaluate the performance of gas laser charging andRadar Magnetron PFN's in my case. I don't think they have a very high frequency response - butI think that they were good enough for their day. I certainly suggest holding on to it. If you need it nothingThe P6015 series did no de-rate with frequency anything like as fast as the DMM probes. Geoff -- Geoff Blake G8GNZ located near Chelmsford, Essex, U.K. Please reply to: geoff(at)palaemon(dot)demon(dot)co(dot)uk Using Linux on Intel & Linux or NetBSD on Sun Sparc platforms Please avoid sending me Word or PowerPoint attachments. See <> ------------------------------------------------------------------------------ This E-mail and any attachment(s) are strictly confidential and is intended solely for the addressee(s). If you are not the intended recipient please notify <postmaster(at)palaemon.co.uk> and the sender by return and permanently delete the message. You may not disclose, forward or copy this E-mail or any of its attachments to any third party without the prior consent of the sender. ------------------------------------------------------------------------------ |
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Re: More Tek 494P GPIB help needed
John Miles
If the talk-only and listen-only switches are both off, and address 0 is
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reported by the analyzer even though the address switches are set to (say) address 31, then I'd look at the other end of the cable harness next. Someone may have damaged the cable or one of its header pins when R&R'ing the power supply. One thing you can try is temporarily shorting either side of R2034 (430 ohms) to ground on the GPIB board. See if the analyzer then reports address 1. Also, attach temporary test jumpers to R2038, R2032, and R2031 that you can use to verify that the talk-only and listen-only switches are open (R2031, 2032 both=TTL high), and that LF-or-EOI is closed (R2038 low). If it now reports address 1, the problem is the cable harness or one of its connectors, or an intermittent DIP switch. If it still reports address 0, and the other three switch lines are OK, then you have an addressing problem. Hang a scope on U2027 pin 1 to verify that the CPU actually tries to read the DIP switch at some point. No pulse activity here would call U1035 into question. Try to avoid manipulating the key on the sandwich connector while the power is on. On a 494P I was repairing recently, I realized I'd forgotten to close the connector after reinstalling the GPIB board. I turned the key to close the connector without bothering to power the analyzer down first, which seemed harmless enough since both endpoints already had power. It damaged the 40-pin TMS9914 interface chip and I had to buy a new one from the UK on eBay. I still don't see how that happened, looking at the schematic. -- john, KE5FX -----Original Message----- |
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Re: P6015A HV Probe: Applications?
Hi ALL,
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Actually I have several P-6015A HV probes. The older ones came with a can of some Fluorocarbon solution which could be put into the probe allowing for measurement of even higher voltages. I don't exactly remember how or why because I haven't used that feature in a long while. My newer P-6015's I believe will handle 40 KV and of course do not rely upon a Fluorocarbon solution to extend their range. As I recall the new price was about USD 1,500.00. I use mine to evaluate the performance of gas laser charging and pulse forming circuits as well as pre-ionizer circuits. Additionally, they are very handy working with Xenon strobe supplies. I don't think they have a very high frequency response - but again I'm not looking at the manual and have forgotten some of the specs that do not impact how I use the probes. I certainly suggest holding on to it. If you need it nothing else is going to do the job! I do believe it is intended for scope applications only and I have no idea if it is usable as a DVM HV probe. However, with nice 40 KV meter probes available for around USD 50.00 I wouldn't use my scope probe for that anyway. I hope this helps. Warm regards, Ken ----- Original Message -----
From: Bruce Lane<mailto:kyrrin@...> To: tekscopes@...<mailto:tekscopes@...> Sent: Saturday, September 13, 2008 10:59 AM Subject: [TekScopes] P6015A HV Probe: Applications? Fellow tekkies, I was cleaning up today, and came across an item I picked up from Boeing Surplus some years ago: A P6015A high-voltage probe in just about mint condition. I have vague memories of buying it because it was in such good condition, and because I had nothing that could do HV probing at the time. However, not having used it as yet, I'm curious as to what applications this probe was used for 'in the lab,' as it were. The immediate apps that come to my gray matter are checking the HV line of a CRT for ripple or noise, as well as safely monitoring the plate terminal in high-power RF amps (I'm thinking HF bands, kilowatt-class) for parasitics or other undesirables. However, not having that much experience in dealing with HV, I'm curious as to what other apps such a probe might serve. Thanks. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- <> kyrrin (at) bluefeathertech do/t c=o=m "Quid Malmborg in Plano..." |
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Re: P6015A HV Probe: Applications?
Actually I have several P-6015A HV probes. The older ones came with a can of some Fluorocarbon solution which could be put into the probe allowing for measurement of even higher voltages. I don't exactly remember how or why because I haven't used that feature in a long while.The ones with the freon fill are P6015s, and the newer ones with the silicone gel fill are P6015As. Without freon, the P6015s are rated to 13kV. Otherwise, the rating is 20kVDC/40kV peak. I don't think they have a very high frequency response - but again I'm not looking at the manual and have forgotten some of the specs that do not impact how I use the probes.It's 75MHz, which is pretty impressive. P.S. For all kinds of test equipment specs see my website: |
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Re: P6015A HV Probe: Applications?
Hi, Chuck,
* REPLY SEPARATOR * On 13-Sep-08 at 13:09 Chuck Harris wrote: Hi Bruce,<snippage> something like that. Download the manual, you will find that the voltageThank you. I thought about that after pressing 'send.' ;-) You're right. Other than possibly developing a Tesla coil, as Dave suggested, I can't imagine what I might use it for otherwise. That being the case... I will wait to see what other responses might come up, and re-evaluate keeping it around. If I can't think of any valid reason to do so, now or future, I will probably offer it up for sale. Thanks again. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- kyrrin (at) bluefeathertech do/t c=o=m "Quid Malmborg in Plano..." |
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Re: P6015A HV Probe: Applications?
Craig Sawyers
However, not having that much experience in dealingI used one back in the late '70s while developing a small pulsed carbon dioxide laser. Bit of a chewing gum and string affair. This used a high charging voltage (10kV or so IIRC) from an HV power supply via a chain of resistors in a length of plastic hose to a ceramic hockey puck array of capacitors. The laser was then pulsed by applying several hundred volts in a spike to pre-ionising wires in the discharge volume, and hence discharging the capacitor array into the gas. I used the P6015A to diagnose the discharge dynamics and optimise the performance of the laser. Craig |
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P6015A HV Probe: Applications?
Fellow tekkies,
I was cleaning up today, and came across an item I picked up from Boeing Surplus some years ago: A P6015A high-voltage probe in just about mint condition. I have vague memories of buying it because it was in such good condition, and because I had nothing that could do HV probing at the time. However, not having used it as yet, I'm curious as to what applications this probe was used for 'in the lab,' as it were. The immediate apps that come to my gray matter are checking the HV line of a CRT for ripple or noise, as well as safely monitoring the plate terminal in high-power RF amps (I'm thinking HF bands, kilowatt-class) for parasitics or other undesirables. However, not having that much experience in dealing with HV, I'm curious as to what other apps such a probe might serve. Thanks. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- kyrrin (at) bluefeathertech do/t c=o=m "Quid Malmborg in Plano..." |
Bruce Lane
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