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: old fashioned 535 - first start after 35 years
Stan and Patricia Griffiths
Hi Michael,
If the relay is opening again after closing, it is not getting coil voltage from its own contacts. If you burnish (clean) the relay contacts, it will probably hold in until the power switch is turned off. It is not usually necessary to check the +8650 volts on the CRT anode. If the -1350 is present, then the +8650 will be OK. All of the other power supplies must be working properly before you bother to measure the -1350. The other supplies are: -150, +100, +225, +350, and +500. Stan _____ From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Michael Petereit Sent: Monday, February 05, 2007 8:19 AM To: m38a1_1962 Cc: TekScopes@... Subject: Re: [TekScopes] Re: old fashioned 535 - first start after 35 years I tried again. Since the CRT is completely covered I cannot see any filament working. Shortly before the tube's diameter gets wider some connectors for deflection I guess. Even there some color avoid having a look onto any filament. Is it really colour or might it be dirt ? The tube is such long you can't have a look from the back unless you remove the backcover. But I would like to avoid as much disassembling as possible unless it worked once. Then any other cleaning will happen and I try to "renovate" the item. I'll try to get a high voltage adapter for my Gossen multimeter. Then I'll check the -1350V and the 8960V. br, Michael m38a1_1962 said the following on 05.02.2007 03:35: <mailto:TekScopes%40yahoogroups.com>, Artek Media <manuals@...> wrote: |
|
Re: old fashioned 535 - first start after 35 years
aobp11
Be careful, the CRT heater gets its supply directly from the big
mains power transformer, *not* from the HV transformer. When the isolation is bad then the HV won't start. See many earlier posts about CRT filament or heater problems. Albert --- In TekScopes@..., Michael Petereit <michael.petereit@...> wrote: any filament.you remove the backcover. But I would like to avoid as muchdisassembling as possible unless it worked once. Then any other cleaning willhappen and I try to "renovate" the item.Then I'll check the -1350V and the 8960V.---- If the voltages are all in tolerance, look at the theirhigh voltage rectifier tubes under the top HV cover to see if glowing.filaments are glowing. This will tell you if the HV oscillator is ----- No, according to 535-545 manual the CRT filament gets 6.3V from the mains transformer. Albert |
|
Re: Tek 492 SA experts, can you answer these questions?
Stan and Patricia Griffiths
Hi Chris,
I used to demo the 492 as a "receiver that looks like a scope". This made it much easier for the average person who was not familiar with spectrum analyzers to quickly grasp how it worked. I used the video output to drive a Radio Shack telephone amplifier by plugging the video out directly into the suction cup microphone input on the amp and I think the levels are just fine. The Radio Shack telephone amp is powered by a 9 volt battery so it is portable and cheap. Use zero span and slope detection for FM signals and peak detection for AM signals. At shows where I was exhibiting more than one spectrum analyzer, the 492 provided the audio for a TV signal and the 2710 provided the video. For those of you who may not know, you can actually get a TV picture to display on the screen of a 2710 spectrum analyzer. The biggest complaint about this was that it was not in "color". My response was that "green is a color". Stan _____ From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Chris Johnson Sent: Sunday, February 04, 2007 12:06 PM To: TekScopes@... Subject: [TekScopes] Tek 492 SA experts, can you answer these questions? I'm learning my way around the 492 and don't yet have manuals for it. (I'd rather get print manuals than a CD copy...got a set for sale?) I'd like to be able to use the 492 as a receiver for AM and FM transmissions, to be able to hear them. My 492 has options 1,2, and 3, so the only IF option I have to work with is the 10 MHz IF output. I need to know what are the output specs for the IF output, so I can determine how much gain I'm going to need. I plan to preamplify the IF output, feed it through a detector/demodulator, and then need to add more gain to bring it up to a level suitable for further processing, including audio band filtering and level adjustment. I would PRESUME that the correct mode to run in will be zero span, is this right? Not having actually used an analyzer in this application before, I'd appreciate it if anyone could give me a how-to guide on the setup and configuration of the analyzer and outboard equipment. If I'm wrong about how to do it, I'd rather know before I get started. CJ |
|
Re: old fashioned 535 -/ 541
I picked up a cheap 541 last week which worked, but not very well. The fan had broken free from it's mounts and was sitting on the chassis- I had to beg the guy I bought it from to please turn it off, I didn't really need further demo. It turned out that all the DC supplies were at least 20% low. I was surprised that it worked as well as it did! I adjusted the -150 back to where it is supposed to be (and the triggering vastly improved), but none of the other supplies changed at all. Is that normal? Even if the other supplies have their own problems, shouldn't they be traking the -150 to some degree? After about 5 power cycles the relay has stopped working, but the tube looks ok. I've had to manually engage the other relay (after warmup time). Everything in the back of the scope is really grungy with possible long term hi temp. It looks like had a long life, but the CRT is in great shape (light blue trace/phosphor). It was used for testing heads at Ampex.
toggle quoted message
Show quoted text
-Dave -------------- Original message --------------
From: Michael Petereit <michael.petereit@...> I tried again. Since the CRT is completely covered I cannot see any filament working. Shortly before the tube's diameter gets wider some connectors for deflection I guess. Even there some color avoid having a look onto any filament. Is it really colour or might it be dirt ? The tube is such long you can't have a look from the back unless you remove the backcover. But I would like to avoid as much disassembling as possible unless it worked once. Then any other cleaning will happen and I try to "renovate" the item. I'll try to get a high voltage adapter for my Gossen multimeter. Then I'll check the -1350V and the 8960V. br, Michael m38a1_1962 said the following on 05.02.2007 03:35:
|
|
Re: Tek 528 Waveform monitor, what is it?
This appears to be true with respect to all NTSC test equipment.
I have a ton of signal generators and various NTSC monitors and I wonder what they will be worth soon with digital TV coming? Kinda like my 8-track test tapes and now even my VCR test equipment is getting a lot less use (almost none). My whole shop will be worthless soon!! Boo-hoo..... |
|
Re: SC 501 sync
Jerry Massengale
Greg,
toggle quoted message
Show quoted text
Thanks for your good suggestion. The signal at the input of the trigger generator looked great and I assumed the balance circuits was okay. I checked the adjustment for trigger balance and found that the junction of r200/c200 was at -3V rather than +65mv. I adjusted for the +65mv and it syncs very good now. I should have checked the external sync too. Thanks for your good help. Jerry Greg_A <greg.a@...> wrote: Jerry hi, I looked for you schematics and I think you could concentrate on signal flow from Q184, Q190 up until U200 pin #15 - that should be trigger in for that chip. Greg At 07:13 AM 2/4/07 -0800, you wrote:
Greetings, I have an SC501 that has poor sync. The unit works better at Usec settings than Millisec settings. I can swap U200 with a unit that works good and see no improvement. I can set 2 units side by side on extenders and compare voltages and waveforms and not see anything suspicously different between the two. One is stable and locked, the other is very, very, close but not stable. When the sync on the bad unit is at it's most stable point, the blanking output slows dramatically and the screen flickers. The power supply voltages are good with no apparent ripple. The Msec timing cap, C230 measures the same on both units(0.987uf and 1.02uf). I am attaching the schematic for the U200 circuit. Suggestions are welcome. I would love to see a datasheet for U200. It is a Tektronix made IC, pn 0155-0055-00. Jerry |
|
Re: old fashioned 535 - first start after 35 years
Michael Petereit
I tried again. Since the CRT is completely covered I cannot see any
toggle quoted message
Show quoted text
filament working. Shortly before the tube's diameter gets wider some connectors for deflection I guess. Even there some color avoid having a look onto any filament. Is it really colour or might it be dirt ? The tube is such long you can't have a look from the back unless you remove the backcover. But I would like to avoid as much disassembling as possible unless it worked once. Then any other cleaning will happen and I try to "renovate" the item. I'll try to get a high voltage adapter for my Gossen multimeter. Then I'll check the -1350V and the 8960V. br, Michael m38a1_1962 said the following on 05.02.2007 03:35:
|
|
Re: old fashioned 535 - first start after 35 years
Richard Aston
The delay relay closes its contacts which energises the coil of a conventional relay which a: shunts the contacts of the delay relay, thus maintaining itself closed and b: disconnects the heater supply to the delay relay which allows it to cool so that it may be ready to provide another delay if the power is interrupted.
toggle quoted message
Show quoted text
The delay relay therefore drops out of circuit immediately it closes. It should not drop out with a 'big spark' thirty seconds later. Richard. casej451 wrote: As far as I know there is only one delay relay. It kicks in after |
|
Re: 7D02 Logic Analyzer
Kuba Ober
On Saturday 03 February 2007 00:37, you wrote:
I have a Tektronix 7603 mainframe, with a 7D02 logic analyzer plugin.I know nothing about it, but here's a hint: the 7D02 will surely have some software in the personality module -- probably the disassembler or dissassembly tables, etc. I don't know whether there is any software in the main unit or not. I'd assume there should be *some*. Anyway, this doesn't look too right. If you have the manual, I'd suggest to start troubleshooting it per the manual. The manual should also tell you what's the expected behaviour w/o the PM. If you need the manual, let me know off list. Cheers, Kuba |
|
Re: old fashioned 535 - first start after 35 years
As far as I know there is only one delay relay. It kicks in after
the tubes have had a chance to warm. The only time mine ever kicked out was when the thermal protection tripped, which it will do fairly quickly without the fan, with the cover off. Check the regulated voltages of the low voltage power supply. That is very important. Everything is referenced off the -150v supply. There are some .01 capacitors across the precision voltage dividers that probably leak badly. And speaking of capacitors, these scopes were originally full of Sprague "black beauty" paper capacitors. They will be black plastic things with a solder blob at one end. All of them should be replaced. The 535 uses a high voltage tripler made of 3 tubes. The capacitors which charge to make the high voltage were probably originally black beauties. If they are still there they are surely bad. John |
|
Re: old fashioned 535 - first start after 35 years
faustian.spirit
--- In TekScopes@..., "Petrosilius Zwackelmann"
<michael.petereit@...> wrote: so far but try what you suggested. start after around 1 minute a relais was working i the back, below the big fan. After another 30 sec the relais release with a big spark. I don't think it should release until you switch off the power. This must be the relay which switches on the anode voltages after the tubes are at working temperature. BTW does somebody know how many different thermal delay tubes there are? but do not relase the contact any more. I assume some capacitors might be charged to high and keep voltage. out . startIt may be as far back as two years ago but there was a lot ofdiscussion. be outtracing the circuits for bad electrolytic.. Many will suggest that --of business till you find a doaner scope |
|
Re: old fashioned 535 - first start after 35 years
Dave,
toggle quoted message
Show quoted text
I fond that thread but it didn't gave that conclusion. I used alcohol for slight mud, this scope was placed in a dirty an humid cellar for years without it's coverage. The aluminium is best cleaned by caustic potash but it will eat up tin too. Thus I tried with a industrial cleaner which worked pretty good. In the area of the high voltage transformator I didn't used anything else than alcohol. I was afraid of getting shorts by using chemical stuff. I try to build up ths voltage divider to measure the high voltage. BR, Michael -------- Original-Nachricht -------- Datum: Sun, 04 Feb 2007 14:27:26 -0600 Von: Artek Media <manuals@...> An: Michael Petereit <michael.petereit@...>, TekScopes@... CC: Betreff: Re: [Tekscopes] old fashioned 535 - first start after 35 years Michael --
"Feel free" - 10 GB Mailbox, 100 FreeSMS/Monat ... Jetzt GMX TopMail testen: |
|
Re: old fashioned 535 - first start after 35 years
Petrosilius Zwackelmann
Well, all tubes below the CRT are working. I didn't checked the CRT so far but try what you suggested.
toggle quoted message
Show quoted text
Btw: The startup behaviour of the scope is strange. On the first start after around 1 minute a relais was working i the back, below the big fan. After another 30 sec the relais release with a big spark. Now the startup is different. The relais is working after 30 seconds but do not relase the contact any more. I assume some capacitors might be charged to high and keep voltage. I'll try agai once I'm back home tonight. BR, Michael -------- Original-Nachricht -------- Datum: Mon, 05 Feb 2007 02:35:04 -0000 Von: "m38a1_1962" <m38a1_1962@...> An: TekScopes@... CC: Betreff: [TekScopes] Re: old fashioned 535 - first start after 35 years Before you go too far with the chassis cleaning and wholesale tube --
"Feel free" - 10 GB Mailbox, 100 FreeSMS/Monat ... Jetzt GMX TopMail testen: |
|
211 Scope Retirement
I was recently given a tek 211 portable scope in bad condition. It
will not be repaired, as i'm a tube type guy, but will be converted to a scope design of my own, for monitoring purposes. If anyone has any info on the CRT, it would be greatly appreciated, as i've been unable to glean the heater voltage from the manual. If someone with a working 211 could measure the voltages on all eleven CRT pins that would be even better, as it gives me a operating point to start from. thanks, Jake |
|
Re: old fashioned 535 - first start after 35 years
Before you go too far with the chassis cleaning and wholesale tube
testing, check and repair the low voltage power supplies first (be especially wary of the bypass capacitors across the precision voltage divider resistors). If the voltages are all in tolerance, look at the high voltage rectifier tubes under the top HV cover to see if their filaments are glowing. This will tell you if the HV oscillator is working. If they are glowing, the CRT filament should also be glowing. You won't be able to fix anything else until the power supplies are working. BAMA has a 535_545 manual listed for free download if you are in for some troubleshooting. Good luck. --- In TekScopes@..., Artek Media <manuals@...> wrote: discussion.
|
|
Re: Tek 492 SA experts, can you answer these questions?
arthurok
you might be able to just take the "video" output from the detector and run it into an audio amp
toggle quoted message
Show quoted text
for fm just demodulate it by slope detection "tune off peak and use a fairly narrow filter" ----- Original Message -----
From: Chris Johnson To: TekScopes@... Sent: Sunday, February 04, 2007 2:05 PM Subject: [TekScopes] Tek 492 SA experts, can you answer these questions? I'm learning my way around the 492 and don't yet have manuals for it. (I'd rather get print manuals than a CD copy...got a set for sale?) I'd like to be able to use the 492 as a receiver for AM and FM transmissions, to be able to hear them. My 492 has options 1,2, and 3, so the only IF option I have to work with is the 10 MHz IF output. I need to know what are the output specs for the IF output, so I can determine how much gain I'm going to need. I plan to preamplify the IF output, feed it through a detector/demodulator, and then need to add more gain to bring it up to a level suitable for further processing, including audio band filtering and level adjustment. I would PRESUME that the correct mode to run in will be zero span, is this right? Not having actually used an analyzer in this application before, I'd appreciate it if anyone could give me a how-to guide on the setup and configuration of the analyzer and outboard equipment. If I'm wrong about how to do it, I'd rather know before I get started. CJ |
|
Re: Tek 492 SA experts, can you answer these questions?
arthurok
deane kidd might have the paper manuals
toggle quoted message
Show quoted text
----- Original Message -----
From: John Miles To: TekScopes@... Sent: Sunday, February 04, 2007 2:29 PM Subject: RE: [TekScopes] Tek 492 SA experts, can you answer these questions? I haven't messed with the 10 MHz output, but try feeding it into a general-coverage receiver and see what the levels are like. Zero span will definitely be needed. For paper manuals, QService is great -- they are in Greece but they ship quickly, and the quality level is essentially OEM-grade. Go here: and enter 492 into the store search field. Make sure the serial # range matches yours (the major editions are either pre-B030000 or post-B030000). Can't say enough good things about the reprints I've ordered from them. -- john, KE5FX > -----Original Message----- > From: TekScopes@... [mailto:TekScopes@...]On > Behalf Of Chris Johnson > Sent: Sunday, February 04, 2007 12:06 PM > To: TekScopes@... > Subject: [TekScopes] Tek 492 SA experts, can you answer these questions? > > > I'm learning my way around the 492 and don't yet have manuals for it. > (I'd rather get print manuals than a CD copy...got a set for sale?) > > |
|
Re: Tek 528 Waveform monitor, what is it?
Chris Johnson
As it's strictly for monitoring NTSC standard video signals only, and
can't be used for high definition signals at all, it's of little use and will only become less useful as time goes on. Only those who have a need to test legacy NTSC video systems will find it useful. |
Marvin Moss
to navigate to use esc to dismiss