Hi guys. Havn't posted in a long time but i need some guidance. Im lucky enough to own a 200mhz dual time base dual trace Philips PM3370 scope in mint condition apart from a completely shot DC to DC ferrite convertor. (24v pulse @40khz primary gives 4kv approx, (+13kv after trebler) and a lower tap at 2kv for the - cathode supply). I have full service info and manual, the part no's in the service data match those on the broken ferrite. I have drawn a blank with the part no's after over a year of looking on and off. Im pretty sure a replacement equivalent is the answer. I have a limited knowledge of high frequency supplies and cant attempt a rewind as its 3000+ turns finer than human hair! I have spoken over phone with a few specialist transformer companys in the UK and all agree that a direct or equivalent replacement is the way to go but couldnt help any more than that. Its such a shame as i was given the scope by a friend an old tech. He gave me some contacts but most had retired 20 years ago bless him.! Im open to any help, ideas and vast experience.
Thanks Tom
Thanks Tom
Tom,
It appears that your unit belongs to a family of scopes which might have the same EHT board:-
PHILIPS PM3370 / PM3380 / PM3390 / PM3384 / PM3394
I'm sure the EHT transformer will be based upon a standard core, but you need to know the core material (for example 3E3 which is used for HF Pulse transformers) or some such - I suspect it will be a lower frequency material.
If the transformer only supply's the EHT to the tube, maybe a small encapsulated HV supply? However, normally the transformer will have other HV taps...
I tried to search for the scope with little luck... Shame it seems like a decent unit.
It appears that your unit belongs to a family of scopes which might have the same EHT board:-
PHILIPS PM3370 / PM3380 / PM3390 / PM3384 / PM3394
I'm sure the EHT transformer will be based upon a standard core, but you need to know the core material (for example 3E3 which is used for HF Pulse transformers) or some such - I suspect it will be a lower frequency material.
If the transformer only supply's the EHT to the tube, maybe a small encapsulated HV supply? However, normally the transformer will have other HV taps...
I tried to search for the scope with little luck... Shame it seems like a decent unit.
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I didn`t know of these other related scopes apart from the PM3370 but they couldn`t have been very common as we only ever saw the 3370 in for repair and for a while we did all the Philips service on this scope in the UK. I don`t recall an EHT fault as such - some unblanking problems but mostly faulty / badly fitted BY127s on the lowvoltage supplies.
I`ve just been looking at pictures and I`m not sure these other scopes are related. The PM3370 was traditional format (vertical) scope with a plug-in vertical amplifier that could be exchanged for other units, rather like the Tek 545 / 6 / 7. It was current in the seventies and still being offically serviced well into the eighties.
The 3380 / 90 / 84 / 94 seem to be much later, flat format and no plug-in.
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I'm not sure as they are so rare - but I found this:-
Fluke PM3370A Autoranging Combiscope 60MHz 100MS S | eBay
But its only 60MHz and not 200MHz as per the OP post.
Fluke Combiscopes seems to be the best search term if its indeed this Generation of scope.
http://www.ebay.com/sch/i.html?_nkw=FLUKE+COMBISCOPE
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If it is a combiscope then this looks like it might make an EHT donar unit 🙂
Fluke PM 3370B 60MHz Combiscope | eBay
its pretty upsetting to see such damage to decent equipment.... 🙁 this scope would have been decently usable for a EE student etc....
Fluke PM 3370B 60MHz Combiscope | eBay
its pretty upsetting to see such damage to decent equipment.... 🙁 this scope would have been decently usable for a EE student etc....
Strange - they seem to have re-used the PM3370 designation for an entirely different scope - perhaps ignorance of their history after the Fluke takeover.
https://www.google.co.uk/search?q=P...p%2Fcharge-controller%2Fmessage%2F878;477;605
https://www.google.co.uk/search?q=P...p%2Fcharge-controller%2Fmessage%2F878;477;605
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Off topic, political and personal postings removed. The original question asked is quite clear and yet this has all rapidly degenerated into a 'mine is better than yours' self promoting discussion.
Stick to the topic.
Mooly,
I'm rather upset at your bulk edit as I spent a couple of hours gathering and writing up the information about the Tek 7K series for other DiyAudio members who might not be aware of these cheap and readily available scopes and you've just gone and removed it all - well that's a loss to the forum community IMO.
You missed the point of my DETAILED listing with links for the more useful Tek7K series plugins avaible if you understand the post as 'mine is better than yours' self promoting discussion. How was I self promoting? I've NOTHING to promote, I'm not selling anything nor offering any services - rather I was offering advice based upon my experience of the 7K series for those who cannot afford more expense equipment.
I was trying to make the point in the face of absurd claims that while the 7K scopes might be 30 years old, they are still hard (impossible) to replace and certainly not at anywhere near "affordable prices" - this is relevant to the DiyAudio community as the Tek7K can be purchased from Ebay for next to nothing.
I'm rather upset at your bulk edit as I spent a couple of hours gathering and writing up the information about the Tek 7K series for other DiyAudio members who might not be aware of these cheap and readily available scopes and you've just gone and removed it all - well that's a loss to the forum community IMO.
You missed the point of my DETAILED listing with links for the more useful Tek7K series plugins avaible if you understand the post as 'mine is better than yours' self promoting discussion. How was I self promoting? I've NOTHING to promote, I'm not selling anything nor offering any services - rather I was offering advice based upon my experience of the 7K series for those who cannot afford more expense equipment.
I was trying to make the point in the face of absurd claims that while the 7K scopes might be 30 years old, they are still hard (impossible) to replace and certainly not at anywhere near "affordable prices" - this is relevant to the DiyAudio community as the Tek7K can be purchased from Ebay for next to nothing.
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John, I have sent you a copy of the post as a pm which you are free to re-submit without the OT comments and quotes.
The Tek 7S12, S6 + S52 TDR sampler system:-
7S12 - TekWiki
11.5GHz Bandwidth
20pS Per division Timebase (2pS with X10)
30pS Risetime
10pS Trigger jitter WITHOUT averaging
Here is the incident edge of the S6 + S52 system:-
https://dl.dropboxusercontent.com/u/86116171/7s12-s52-incident S6.jpg
Now that looks like a lessthen 30pS risetime edge – looking forward to your recommendation for modern budget solution.
Next we have the 7T11 / 7S11 which is much the same as 7S12 but without the TDR pulser head – but 2x channels of 14GHz (2xS6 or S4) and a 10pS (1pS x10 Timebase)
7T11 - TekWiki
7S11 - TekWiki
Or if we just want a simple way to look at clock jitter without the fear of damaging the sampling heads, then the Dual 1GHz 7S14 is your friend:-
7S14 - TekWiki
The 7S14 is a great way for Diyers to look at Clock jitter in digital systems.
Ok, so I'm rather bored with all this ultra high speed stuff and want a simple 4 Channel 350MHz with logic triggering:-
7A42 - TekWiki
The Tektronix 7A42 is a four-channel 350 MHz plug-in for 7000-series scopes.
It was specifically designed for logic signals (TTL, ECL, CMOS) and supports triggering based on Boolean conditions of the four inputs.
A fifth trace, "Trigger View", displays the trigger function output or external clock input.
Hey, how about a curve tracer – lets say today I need to measure the Gate threshold voltage of some pesky Jfets:-
7CT1N - TekWiki
The Tektronix 7CT1N is a curve tracer plug-in for 7000-series scopes.
How about a VERY accurate Frequency counter:-
7D14 - TekWiki
The Tektronix 7D14 is a 525 MHz frequency counter plug-in for 7000 series mainframes.
It uses the mainframe's readout system to display an eight-digit count on the CRT. Modes include frequency, frequency ratio and events count using manual or external gate.
When installed in a horizontal compartment, it can count the trigger pickoff from a vertical amplifier unit. This allows simultaneous viewing and counting of a signal in four-bay mainframes.
In a vertical compartment, the trigger signal (i.e. the "shaped" input) can be displayed as the module's Y output.
Or the 7D15:-
7D15 - TekWiki
The Tektronix 7D15 is a 225 MHz frequency counter plug-in for 7000-series scopes. It is optimized for timing measurements, having a 100 MHz oscillator and interval measurement averaging capability. It has two inputs and can measure frequency, period or time difference
OK, so how about just a “simple” scope:-
7104 - TekWiki
2x channels 1GHz, with CCD camera option that results in 100GSa/s storage feature.
The Tektronix 7104 is a 1 GHz, non-storage 7000-series oscilloscope mainframe that takes two 7000-series vertical plug-ins and two 7000-series horizontal plug-ins. It was introduced in 1978. There is also a rack-mount version, the R7103, albeit with only one horizontal bay.
The scope employs a micro-channel plate CRT design to get good screen intensity at high sweep speeds with moderate acceleration voltage.
The 7A29 1 GHz vertical amplifier and the 7B15/7B10 time base pair were introduced along with the 7104 to match the system bandwidth.
The options are endless for the 7K series – more here:-
TekWiki
7S12 - TekWiki
11.5GHz Bandwidth
20pS Per division Timebase (2pS with X10)
30pS Risetime
10pS Trigger jitter WITHOUT averaging
Here is the incident edge of the S6 + S52 system:-
https://dl.dropboxusercontent.com/u/86116171/7s12-s52-incident S6.jpg
Now that looks like a lessthen 30pS risetime edge – looking forward to your recommendation for modern budget solution.
Next we have the 7T11 / 7S11 which is much the same as 7S12 but without the TDR pulser head – but 2x channels of 14GHz (2xS6 or S4) and a 10pS (1pS x10 Timebase)
7T11 - TekWiki
7S11 - TekWiki
Or if we just want a simple way to look at clock jitter without the fear of damaging the sampling heads, then the Dual 1GHz 7S14 is your friend:-
7S14 - TekWiki
The 7S14 is a great way for Diyers to look at Clock jitter in digital systems.
Ok, so I'm rather bored with all this ultra high speed stuff and want a simple 4 Channel 350MHz with logic triggering:-
7A42 - TekWiki
The Tektronix 7A42 is a four-channel 350 MHz plug-in for 7000-series scopes.
It was specifically designed for logic signals (TTL, ECL, CMOS) and supports triggering based on Boolean conditions of the four inputs.
A fifth trace, "Trigger View", displays the trigger function output or external clock input.
Hey, how about a curve tracer – lets say today I need to measure the Gate threshold voltage of some pesky Jfets:-
7CT1N - TekWiki
The Tektronix 7CT1N is a curve tracer plug-in for 7000-series scopes.
How about a VERY accurate Frequency counter:-
7D14 - TekWiki
The Tektronix 7D14 is a 525 MHz frequency counter plug-in for 7000 series mainframes.
It uses the mainframe's readout system to display an eight-digit count on the CRT. Modes include frequency, frequency ratio and events count using manual or external gate.
When installed in a horizontal compartment, it can count the trigger pickoff from a vertical amplifier unit. This allows simultaneous viewing and counting of a signal in four-bay mainframes.
In a vertical compartment, the trigger signal (i.e. the "shaped" input) can be displayed as the module's Y output.
Or the 7D15:-
7D15 - TekWiki
The Tektronix 7D15 is a 225 MHz frequency counter plug-in for 7000-series scopes. It is optimized for timing measurements, having a 100 MHz oscillator and interval measurement averaging capability. It has two inputs and can measure frequency, period or time difference
OK, so how about just a “simple” scope:-
7104 - TekWiki
2x channels 1GHz, with CCD camera option that results in 100GSa/s storage feature.
The Tektronix 7104 is a 1 GHz, non-storage 7000-series oscilloscope mainframe that takes two 7000-series vertical plug-ins and two 7000-series horizontal plug-ins. It was introduced in 1978. There is also a rack-mount version, the R7103, albeit with only one horizontal bay.
The scope employs a micro-channel plate CRT design to get good screen intensity at high sweep speeds with moderate acceleration voltage.
The 7A29 1 GHz vertical amplifier and the 7B15/7B10 time base pair were introduced along with the 7104 to match the system bandwidth.
The options are endless for the 7K series – more here:-
TekWiki
Mooly,
Thank you, I've tried to reposted it here in edited form but all the embedded links are removed?
How can I copy the embedded links as there are too many to manually re-edit and it tock be an ordainment amount of time to compose - or can you edit and repost?
Done 🙂
Thank you, I've tried to reposted it here in edited form but all the embedded links are removed?
How can I copy the embedded links as there are too many to manually re-edit and it tock be an ordainment amount of time to compose - or can you edit and repost?
Done 🙂
Mooly,
Thank you - I've had the issue before while copying my posts from this forum that the embedded links are lost.
It could do with a little "introduction as its rather "misplaced" in its current context, but the information is present 🙂 Again, thank you.
For those looking for a cheap method to look at clock jitter in digital systems, the 7S14 is a great plugin - it works with any 7K series mainframe so you can use it with a smaller cheaper mainframe.
With the 7S14 you can only see the Edge jitter "width", if you use the delayed timebase mode you can look at an edge many cycles from the initial trigger point, so "summing" the jitter level over the delayed time period. Its educational, and a good introduction to observing Jitter on the cheap.
Back in 1990 I designed the Pink Triangle Dacapo DAC with the aid of the 7S14 - it was the start of my understanding of clock Jitter, before the days of internet and the easy access to information.
Thank you - I've had the issue before while copying my posts from this forum that the embedded links are lost.
It could do with a little "introduction as its rather "misplaced" in its current context, but the information is present 🙂 Again, thank you.
For those looking for a cheap method to look at clock jitter in digital systems, the 7S14 is a great plugin - it works with any 7K series mainframe so you can use it with a smaller cheaper mainframe.
With the 7S14 you can only see the Edge jitter "width", if you use the delayed timebase mode you can look at an edge many cycles from the initial trigger point, so "summing" the jitter level over the delayed time period. Its educational, and a good introduction to observing Jitter on the cheap.
Back in 1990 I designed the Pink Triangle Dacapo DAC with the aid of the 7S14 - it was the start of my understanding of clock Jitter, before the days of internet and the easy access to information.
Guys, thankyou so much for all your replys. Ive been away working and have only just read all of this. I need time to digest all of the above. Thankyou John W for your lengthy reply.
I will post some pics of the EHT unit and ferrite over next few days. In reply to the posting of the schematic, like i said i have full service data, thanks for help though.
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