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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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6th Jun 2023, 3:21 pm | #1 |
Nonode
Join Date: Aug 2007
Location: Walsall Wood, Aldridge, Walsall, UK.
Posts: 2,853
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Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
Can anyone suggest where I might obtain a nice instrument case with handles similar to the one pictured in this two–part article to build a 2 MHz Wideband Millivoltmeter please?
I've already purchased the dual P–Channel JFET and one of the two push–button switchbank assemblies and located suitable equivalent Western types to the Russian Operational Amplifiers used in this, as well as a suitable Transistor Array (the CA3086 which has two transistors with a common emitter pin intended for differential amplifier use ought to do!) so the design is eminently buildable, even today, and the PCBs (four!) like most ex–Soviet projects, simple single–sided layouts! Chris Williams
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It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed! Last edited by Chris55000; 6th Jun 2023 at 3:28 pm. |
6th Jun 2023, 10:05 pm | #2 |
Banned
Join Date: Mar 2021
Location: Morpeth, Northumberland, UK.
Posts: 936
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
Thank you. I now know there are far crazier Luddites than myself at large
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6th Jun 2023, 11:51 pm | #3 |
Nonode
Join Date: Aug 2007
Location: Walsall Wood, Aldridge, Walsall, UK.
Posts: 2,853
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
When it comes to electronic circuits, having an affinity for the circuits and designs of the past is far more enjoyable than trying to design PCBs around strange things a quarter of the size of a finger–nail that are obsoleted by their maker before the ink has dried on the datasheet!
That is, after all, the whole purpose and ethos of this entire Forum, and what's more to the point, a piece of equipment built to this design would outlive me by many years! Chris Williams
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It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed! |
7th Jun 2023, 12:12 am | #4 | |
Banned
Join Date: Mar 2021
Location: Morpeth, Northumberland, UK.
Posts: 936
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
Quote:
Just designed and built for my own use a variable regulated HT and filament bench PSU combining IC's and discrete transistors and mosfets for the lower voltage parts and an ECC81 and 6550 for the high voltage end.... all done old skool on ally chassis, point to point wired and with an Elstone mains TX. We're reading from the same hymn sheet bro! до побачення for now |
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7th Jun 2023, 12:48 am | #5 | |
Pentode
Join Date: May 2023
Location: Clovis, California, USA.
Posts: 194
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
I would look at a VTVM most can use a up to 250Mhz probes.
I just built one using a op amp . Dave https://www.vintage-radio.net/forum/...d.php?t=201174 Quote:
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7th Jun 2023, 5:55 am | #6 | |
Pentode
Join Date: Sep 2019
Location: Perth, Western Australia, Australia.
Posts: 199
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
Quote:
Before I really dug into it, I assumed the boards would be double-sided. |
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7th Jun 2023, 6:09 am | #7 |
Nonode
Join Date: Jun 2010
Location: Spalding, Peterborough, Cambridgeshire, UK.
Posts: 2,850
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
That case looks similar to some Farnell instruments made from late 70s onwards, DSG1 that I have here comes to mind. I wonder if anyone has any scrap Farnell items that might suit?
I imagine it will be just your actual meter size that dictates what you need, so can you give some idea of what size case is needed? Rob
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Apprehension creeping like a tube train up your spine - Cymbaline. Film More soundtrack - Pink Floyd |
7th Jun 2023, 9:15 am | #8 |
Heptode
Join Date: Sep 2010
Location: Hythe, Hampshire, UK.
Posts: 626
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
Metcase are a good source for this sort of thing https://www.metcase.co.uk/en/Enclosu...ith-Handle.htm
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7th Jun 2023, 9:23 pm | #9 |
Nonode
Join Date: May 2016
Location: Cornwall, UK.
Posts: 2,314
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
Hammond also do various steel/aluminium ones that could have their accessory D handles bolted onto the front panel.
Your example reminds me of the Ferrograph RTS2. I haven't found one with integrated front handles in the same way as your picture, but I think you can get quite close. |
8th Jun 2023, 1:22 pm | #10 |
Banned
Join Date: Jan 2023
Location: Neath, Port Talbot, Wales, UK.
Posts: 286
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
Where did you a find a dual P channel jfet? They seem to be rather like hen's teeth.
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8th Jun 2023, 3:22 pm | #11 |
Nonode
Join Date: Aug 2007
Location: Walsall Wood, Aldridge, Walsall, UK.
Posts: 2,853
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
They're available on eBay!
Look for К504НТ2Б on eBay! However, if you reverse the transistor polarities (you can use 2N3904 and 2N3906 on the input board plus using the upper rail as +15 V and the lower rail as –15 V you can use a dual N–channel JFET salvaged from old oscilloscope preamplifiers, etc! The two KC170A zener diodes can be replaced by BZX61C7V5s! PCBs will be commenced when the Push–Button Switch Bank arrives from AliExpress, and a separate thread will be posted for the final circuits, PCB layouts and construction data! Chris Williams
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It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed! Last edited by Chris55000; 8th Jun 2023 at 3:31 pm. |
13th Jun 2023, 3:43 am | #12 | |
Pentode
Join Date: May 2023
Location: Clovis, California, USA.
Posts: 194
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Re: Ukrainian Wideband Millivoltmeter Project – Case Suggestions?
I used a case from Amazon.
Used plexiglass front with photo print in the sandwich. https://www.amazon.com/dp/B08BS243RC...EDMYX21364C82X Dave Quote:
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