Richard, You know it is bad Kharma to talk about someting and not do "show and tell", complete with board shots and how what each piece
does.
If we are nice and buy you a beer can we send you some ICs and OpAmps
to check out and test for us DiYer who don't have access to such hi end
M&T gear. What did you get it for? From where did you dig it up.
Cheers from the pond's same side.
Here it is...... if you zoom in - you will see that the transistor is an oldie-but-goodie type 2N2219A. Just below 1nV/sqrtHz ! At 1mA.
I do not have the IC noise analyzer unit.... but I know where I might get one. Can only check transistors for now. And resistors with the other Quan-Tech model.
Just found it on Ebay and made an offer. It's a benefit of being retired and not have to spend money on house payments any more. So, I can use that money for other things. Paying some piece of property off for this freedom is a really big incentive for me.
THx-Richard
Last edited:
I believe it was Scott who said that the tech from Quan-Tech was in the ADI laboratories so often he had a cot there.
I have a 5173 and people are looking to buy it all the time.
yes, you read the nv/sqrHz directly from the meters.
I opened it up and the insides of my unit looks new--- no corrosion to parts or oxidation. i just cleaned the switch contacts and closed it up. But, I will replace certan electrolytics to be sure they have the full C value as marked on them.
Now I need to find the manual for it, somewhere.... just in case I have to fix/trouble-shoot it. The unit still has the pcb extender boards for repairing attached to the rear panel.
It is one of those specialized instruments for R&D and production, QA/QC. because after I test everything I have here and buy a few more transistors and test those also, I wont have a use for it any more and it will sit on the shelf. Later, I'll sell it to make room for something else. Meanwhile, I'll learn all I can from it. Good info for a LNA of any kind.
-RM
I opened it up and the insides of my unit looks new--- no corrosion to parts or oxidation. i just cleaned the switch contacts and closed it up. But, I will replace certan electrolytics to be sure they have the full C value as marked on them.
Now I need to find the manual for it, somewhere.... just in case I have to fix/trouble-shoot it. The unit still has the pcb extender boards for repairing attached to the rear panel.
It is one of those specialized instruments for R&D and production, QA/QC. because after I test everything I have here and buy a few more transistors and test those also, I wont have a use for it any more and it will sit on the shelf. Later, I'll sell it to make room for something else. Meanwhile, I'll learn all I can from it. Good info for a LNA of any kind.
-RM
Last edited:
Hello all,
Just a small message to say that i have ordered a new batch (small) of the ERMSDCv2 design of this thread, firstly to satisfy a demand.
I recall that i provide to all PCB buyers a very complete and extensive documentation and design files to build the project easily and without issue.
If you need any info to order one, please send me a PM.
Some pictures and documents about that below.
The new batch !
The project overall synoptic ;
The full schematics of ERMSDCV2.3 project (pdf file).
A fully wired circuit board;
The board enclosed, front panel view:
The board enclosed, rear panel view:
Many others informations can be found in previous pages of the thread,
in articular about measurements of performances and the full specifications of each functions.
Don't hesitate to read them if you think about build it !
Regards.
Frex
Just a small message to say that i have ordered a new batch (small) of the ERMSDCv2 design of this thread, firstly to satisfy a demand.
I recall that i provide to all PCB buyers a very complete and extensive documentation and design files to build the project easily and without issue.
If you need any info to order one, please send me a PM.
Some pictures and documents about that below.
The new batch !
The project overall synoptic ;
The full schematics of ERMSDCV2.3 project (pdf file).
A fully wired circuit board;
The board enclosed, front panel view:
The board enclosed, rear panel view:
Many others informations can be found in previous pages of the thread,
in articular about measurements of performances and the full specifications of each functions.
Don't hesitate to read them if you think about build it !
Regards.
Frex
Hello Frex,
I am finally getting around to populating my board. I have accumulated most parts over the last 12+ months since buying the pcb. I am getting the last components and finding some no longer manufactured.
The solid electrolytic caps are not something I'm familiar with, I've looked at the main headline specs and at this stage I'm thinking about using Nichicon VZ series capacitors in their place. Any reason this is a poor choice?
For the high pass filter caps (C22, C49) oscon I couldn't find anything that was an obvious equivalent on the element14 website. Ideally I would like to use Nichicon Muse ES (especially after reading this thread) in this position but would need to wait for an order from digikey/mouser that I won't be ready to place for a while. I do have a bunch of 330uF oscons on hand ... this moves the filter point to ~5Hz instead of 3.4Hz, I was thinking that I could use this initially, then replace later (few months time). Is there likely to be an issue with that of which I haven't thought?
Thanks,
Chris
I am finally getting around to populating my board. I have accumulated most parts over the last 12+ months since buying the pcb. I am getting the last components and finding some no longer manufactured.
The solid electrolytic caps are not something I'm familiar with, I've looked at the main headline specs and at this stage I'm thinking about using Nichicon VZ series capacitors in their place. Any reason this is a poor choice?
For the high pass filter caps (C22, C49) oscon I couldn't find anything that was an obvious equivalent on the element14 website. Ideally I would like to use Nichicon Muse ES (especially after reading this thread) in this position but would need to wait for an order from digikey/mouser that I won't be ready to place for a while. I do have a bunch of 330uF oscons on hand ... this moves the filter point to ~5Hz instead of 3.4Hz, I was thinking that I could use this initially, then replace later (few months time). Is there likely to be an issue with that of which I haven't thought?
Thanks,
Chris
Hello Chris,
For decoupling caps, you can replace solid electrolytic with Nichicon VZ without problem.
ESR is more important if you use bad power supply.
For signal filtering (C22 and C49), Sanyo SP type are obsolete but you can use
Panasonic OSCON type capacitors can be found at Mouser or Farnell.
Of course, you can change these caps by Nichicon Muse type caps. (you must check if they can be mounted "in place" eg: same size & footprint.
I using them, maybe MUSE UES unpolarized type would be a very good choice.
You can of course use 330uF OSCON, mostly if you already have some !
The very slight cutoff frequency move will not be a problem...
I hope that help you a little.
Regards.
FRex
For decoupling caps, you can replace solid electrolytic with Nichicon VZ without problem.
ESR is more important if you use bad power supply.
For signal filtering (C22 and C49), Sanyo SP type are obsolete but you can use
Panasonic OSCON type capacitors can be found at Mouser or Farnell.
Of course, you can change these caps by Nichicon Muse type caps. (you must check if they can be mounted "in place" eg: same size & footprint.
I using them, maybe MUSE UES unpolarized type would be a very good choice.
You can of course use 330uF OSCON, mostly if you already have some !
The very slight cutoff frequency move will not be a problem...
I hope that help you a little.
Regards.
FRex
Started to gather parts for this and 3 oscillators. Instead of MSR25 series I chose a mix of http://www.mouser.com/ds/2/418/NG_DS_1773265_A-732410.pdf and http://www.mouser.com/ds/2/418/NG_DS_1773230_G-721472.pdf depending on what was available in small numbers. Hmmm, I have to split theese builds over time as the note ended at about 130€... Capacitors in February 
BTW Frex - very nice boards!
Regards
BTW Frex - very nice boards!
Regards
Last edited:
Hi Frex, the 2n5486g seems to be obsolete. What fits here to conform to your specs or better? There might be other parts that are hard to find today - have you an alternative list for both the caps and dips?
Bss92 seems to be obsolete as well... Is this design obsolete? If not we need alternative parts and WHO is best fit to create a modern bom if not the designer? The styren caps are hard to find the exact ones but after hard searching I have found most of them.
Probably more to come. So as time goes the harder it will become to populate this board to the original specs. The oscillator is a bit simpler to find parts to.
Regards
Bss92 seems to be obsolete as well... Is this design obsolete? If not we need alternative parts and WHO is best fit to create a modern bom if not the designer? The styren caps are hard to find the exact ones but after hard searching I have found most of them.
Probably more to come. So as time goes the harder it will become to populate this board to the original specs. The oscillator is a bit simpler to find parts to.
Regards
Last edited:
Hello,
As jackinnj said , the 2N5486 can be find easily. So if necessary, this JFET can be replaced by any low leakage JFET that you could find at Mouser or others vendors.
For the BSS92, it is now hard to find, and pin-out is particular.
Anyway, you can replace it with ZVP3306A or any others low voltage PMOS, but you need to switch Gate and Drain (easy to do).
Don't worry, i really do not consider the design as obsolete, and only some active IC are not easily replaceable but they are all in full productions. All passive parts (and OPAMP) can be replaced if necessary.
So if you have a doubt about a replacement of particular part , i will always take a look and answering to with pleasure.
Frex
As jackinnj said , the 2N5486 can be find easily. So if necessary, this JFET can be replaced by any low leakage JFET that you could find at Mouser or others vendors.
For the BSS92, it is now hard to find, and pin-out is particular.
Anyway, you can replace it with ZVP3306A or any others low voltage PMOS, but you need to switch Gate and Drain (easy to do).
Don't worry, i really do not consider the design as obsolete, and only some active IC are not easily replaceable but they are all in full productions. All passive parts (and OPAMP) can be replaced if necessary.
So if you have a doubt about a replacement of particular part , i will always take a look and answering to with pleasure.
Frex
Hi,
this project is quite some days old, however since I've build the AN83 noise amplifier a few years ago myself in a 80dB version, together with some STM32 microcontroller and its internal 12bit adc to quantify noise, I also noticed to peaking in the transfer function.
Because I gave a 60dB version to a friend of mine and he is currently playing with it I'm again involved in this topic. I found, that tranfer function of the amplifier can be improved significant, when the 5k62 resistor at the LTC1562 is reduced to 5k2 by paralleling the resistor with 68k or 130k and 160k. The peaking in transfer function now vanished and gives a perfectly 3db corner frequency at 100kHz.
The results were verified by my friend and can be found here too:
Einfacher Messverstarker 10 Hz - 100 KHz - Mikrocontroller.net but also by a simulation in LTSpice, which perfectly matches real life measurements.
So maybe you guys want to add this modification to your amplifiers too.
-branadic-
this project is quite some days old, however since I've build the AN83 noise amplifier a few years ago myself in a 80dB version, together with some STM32 microcontroller and its internal 12bit adc to quantify noise, I also noticed to peaking in the transfer function.
Because I gave a 60dB version to a friend of mine and he is currently playing with it I'm again involved in this topic. I found, that tranfer function of the amplifier can be improved significant, when the 5k62 resistor at the LTC1562 is reduced to 5k2 by paralleling the resistor with 68k or 130k and 160k. The peaking in transfer function now vanished and gives a perfectly 3db corner frequency at 100kHz.
The results were verified by my friend and can be found here too:
Einfacher Messverstarker 10 Hz - 100 KHz - Mikrocontroller.net but also by a simulation in LTSpice, which perfectly matches real life measurements.
So maybe you guys want to add this modification to your amplifiers too.
-branadic-