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Sep 23rd, 2021, 9:13am
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1  Original Projects and Builds / Other Builds and Projects / Re: Rowe/AMI R-4359 beautification project
 on: Sep 18th, 2021, 12:55pm 
Started by Administrator | Post by Administrator
So work is proceeding only very occasionally on this project.
 
While attempting to assemble the entire case (including the rack mount "ears") I ran into difficulty with the wooden sides.
 
I ended up cutting the sides from the original "lid" or cover, and using them as separate pieces.  The also required some additional cutting of the new top aluminum plate, but I now have the basic chassis assembled as it will be.
 
Next step is to get serious about drilling the top plate.  I have a little more finalizing of the top plate "drill plan", and then it will go under the drill press.
 
I would still much rather anodize than paint the top plate, but that is not a project that I feel like tackling myself, and I don't know of anyone locally that will do it, so it will probably either go to the local powder coater, or just get spray painted.
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2  Mobile Linux Devices / General News / Re: FNIRSI-1014D 100MHz Digital Storage Scope
 on: Sep 5th, 2021, 1:59pm 
Started by Administrator | Post by Administrator
A little more information about repair of  FNIRSI-1014D 100MHz Digital Oscilloscopes exhibiting issues with AC/DC input coupling:
 
If the components mentioned in the above posts are missing all together, or are damaged in the repair process, here is the information about these components:
 
They are KAQY214 Series Optically Isolated Solid State Relays.  The specific part/package used in the FNIRSI-1014D is KAQY214S.  The Data Sheet is Here.
 

 
 
If you need a replacement, there are numerous vendors on AliExpress and eBay selling them.  A pack of 10 costs about $5 to $10 on eBay, shipped from China (Shipping may add a few dollars to that price.)
 
 
 
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3  Mobile Linux Devices / General News / Re: FNIRSI-1014D 100MHz Digital Storage Scope
 on: Sep 4th, 2021, 1:14pm 
Started by Administrator | Post by Administrator
So what do I think of the FNIRSI-1014D 100MHz Digital Oscilloscope now that mine is working "properly"?
 
 

Photo Linuxslate.com.  Test setup with  FNIRSI-1014D and Kooltech Signal generator.
 
Well, If you want the short version of this review, note that I put the word "properly" in quotes.
 
I cannot recommend the purchase of the FNIRSI-1014D given the gross and apparently on-going quality control failures, firmware issues, and problems that I and others have reported.
 
I purchased mine locally, so I could have returned it to the store where I bought it from.  Others would have to deal with sending it back to China, and possibly issues with language and different attitudes in different cultures about returns and or refunds.  Even in my case, asking for a refund from a local small business run by people I consider friends would have been at least a bit awkward.  As mentioned I am thankful that I am able to make a repair like this, and for the help from Nercy Eletrônica.  I realize that repairing brand-new merchandise is not something everyone can or would want to take on, and nobody should have to.
 
The concept of trust when it comes to test equipment should also not be overlooked.  Trust is the reason Fluke, Tektronics, Hewlett-Packard, and other companies charge premium prices for their products.  Engineers, technicians and lab managers continue to gladly pay those prices because they know they are getting a product that not only works, but also produces results they can bank their careers on.
 
I would strongly suggest that even budget or casual hobbyist users spend the extra $40 to $70 for a similar unit such as the Hantek DSO2D10.
 
If you want to accept the risk of hardware failure and/or inaccuracy, purchasing (and possibly repairing) a vintage or surplus CRT oscilloscope is another, and IMHO opinion better, option for those wanting an oscilloscope without spending thousands of dollars on brand-new lab equipment*.
 
That said, I am now happy with mine, and I intend to keep it.  I may even go as far as to say that having to fix it boosted my sense of ownership.  It contains (a little) of my own work.  It is unique.
 
i also have to give it credit for a bright and crisp screen.  At least until you encounter one of the firmware bugs, the user interface looks very nice, and is intuitive to navigate.
 
The FNIRSI-1014D is also small and easily portable.  Since it includes a fold-down handle, and is powered by USB, all that is needed is a portable phone charger (battery pack) -- and perhaps a bit of double sided tape -- to make it a truly portable oscilloscope that retains a full-size screen.  Current draw is about an amp, so it would run for several hours from a 5000mah phone charger.
 
Given that the repair was quick (I literally had the back off for less than 15 minutes) and did not incur any significant additional cost, I still feel that I got a good deal.  I like it's features, appearance and portability.  
 
I will not however, blindly trust it, or ever rely on it for a critical measurement.  I will always look at that 7" LCD screen with suspicion.
 
*NOTE:  CRT Oscilloscopes employ lethal voltages, as well as other hazards including CRT implosion risk.  Repairs/adjustment should be attempted only buy those with the requisite skills.
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4  Mobile Linux Devices / General News / FNIRSI-1014D 100MHz Digital Storage Scope
 on: Sep 4th, 2021, 8:51am 
Started by Administrator | Post by Administrator
I recently purchased A FNIRSI-1014D LCD Digital Oscilloscope from MRAM Electronics - a local Surplus Electronics and Parts dealer.
 
He was selling them for $199, which is a very fair mark up from the typical cost on AliExpress, considering that I got "Instantaneous Shipping" (Cash and Carry).
 

Photo from AliEpress Venor Listing
 
 
However, after I got it home, I soon discovered it had a problem.
 
For a signal source, I connected it to my Koolertron 15MHz High Precision DDS Signal Generator Counter, which was also essentially new to me.  I purchased the Signal Generator from a vendor at the "World's Longest Yard Sale" back in August, and I had never tried it out.  I think I paid $10.00 for the Koolertron Signal Generator, and I have to say I'm very impressed with at least that half of the setup.  It's possibly my best purchase of the 3 states we visited during the "World's Longest Yard Sale".
 
So the problem with the FNIRSI-1014D Oscilloscope was that Channel 1 seemed to be stuck in AC coupling.  I could change the setting in the pop-up Ch 1 Menu, but no matter how it was set, the scope acted as if the input was AC coupled.  I checked test leads and the probes with my Fluke Scopemeter, thus verifying that FNIRSI-1014D was faulty.  I then realized that selecting AC/DC coupling for Channel 2 was not working correctly either.
 
Figuring it was a firmware issue, I started searching the web, but as of this writing, I do not see a firmware for the FNIRSI-1014D on the FNIRSI Support page.
 
A little more research got me to other people reporting the same problem, and eventually to this YouTube Video by Nercy Eletrônica (AKA NB Electronica -- Portuguese Language).  Without knowing Portuguese, and in fact without any sound at all, I could clearly see that he was describing the same problem, although his Channel 2 seemed to work correctly.
 
He also showed the fix -- Apparently, FNIRSI is having problems getting 2 of the components soldered in the right way.  The following screen shot from Nercy Eletrônica shows the board after he soldered the chips in correctly.  The chips in question and the proper orientation is shown by the arrows:
 

Photo is a screen shot from Nercy Electronica Video
 
Things to note:
1.  As mentioned, the screen shot shows the correct installation of the components in question. Note the extra solder on the component on the left showing that this picture was taken after his repair. (I'm not criticizing his work -- Mine now looks worse.)
3.  I believe that the markings on the PC board (under the components) are correct, and can be referenced to verify correct component installation.
4.  Note other component placement issues in the same picture.  (Are those piggy-backed components?)
5.  As mentioned, both of the marked components were installed upside-down on my unit, thus affecting both channels.
 
 
Steps to Repair:
1.  Disassemble the unit.  This consists of removing 3 small screws from the recessed holes at the top, and a total of 4 screws from near the folding feet.
2.  Disconnect the power wires from the PC board.
3.  Carefully heat and open the EMI shield from 1 or both input circuitry areas.
4.  Examine the installation orientation of the 2 four pin devices shown in the screen shot.
5.  Desolder one or both components if installed upside-down.
  a.  At first, I figured I could use my de-soldering equipment to remove the components.  I ended up doing it exactly as show in the video:
  b.  Add solder to form a bridge between the 2 pins on each side of the component.
  c.  Heat the now-bridged side to free both pins, and carefully lift that side of the component.
  d.  Repeat on the other side, thus freeing the component.
  e.  Remove excess solder from the pads and component with fine solder wick.
  f.  Clean the area with an alcohol wipe in preparation for re-installation.
  g. Orient the component correctly, and tack solder in place.
  h. Solder the component with a very small amount of additional solder if necessary.  Be sure to avoid solder bridges this time.
6.  Again use solder wick to clean up the shields and the hole in the PC board for the tab.
7.  Solder the EMI shield back, making sure it is fully down on the PC board.
8.  Reassemble the unit.  Don't forget to connect the power wires correctly.
 
After re-assembly, both channels on my unit work correctly.  With the inputs set to DC, and a DC offset applied to the signal, the waveform moves up or down as it should.
 
Thanks to Nercy Electronica for his excellent skill in finding the problem, excellent repair skills, and a great video.
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5  Mobile Linux Devices / General News / Re: Electronica MK-52 Vintage Soviet Calculator
 on: Aug 26th, 2021, 7:34pm 
Started by Administrator | Post by Administrator
Updated Dice Roll Program for the MK-52.
 
In this version, the new seed is generated from the results of both pseudo random number generators, and not just the Middle Square routine.
 
Code:
00
01  6-  N(a)->X		4 Digit Seed must be stored in Register (a) -- Recall it.
02  22  X^2		Square -- Start of Middle Square Code
03  01  1
04  0C  EE
05  06  6
06  13  /		Divide by 1E6
07  35  {x}		Take the Fractional part (Removes the Left 2 Digits)
08  01  1
09  0C  EE
10  04  4
11  12  *		Multiply by 1E4
12  34  [x]		Take the Whole Part  (Removes the Right 2 Digits) -- End of Middle Square code
13  3L  RND		Random.  This is the actual Dice Roll
14  4L  X->N(b)		Store the result
15  01  1
16  0C  EE
17  04  4
18  12  *		Multiply by 1E4
19  34  [x]		Take the Whole Part.  This is the New Seed
20  4-  X->N(a)		Store the New Seed
21  6L  N(b)->X		Recall the Roll
22  06  6		 
23  12  *		Multiply by 6
24  34  [x]		Take the Whole part
25  01  1
26  10  +		Add 1
27  50  R/S		Stop so that result is displayed.
 

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6  Mobile Linux Devices / General News / Re: Electronica MK-52 Vintage Soviet Calculator
 on: Aug 21st, 2021, 8:08pm 
Started by Administrator | Post by Administrator
I recently pulled my MK-52 out of it's storage box, and reinserted the separately stored batteries.
 
Doing so made me realize that I had never shared my "Dice Roll" program -- so without further delay, here's the code, in what is hopefully a clear mnemonic/pseudo code form:
 
Columns:
1.  Memory Location
2.  Opcode/content
3.  Key Strokes
 
Code:
00  
01  6-  N->X(a)     4 Digit Seed must be stored in Register (a) -- Recall it.
02  22  X^2         Square -- Start of Middle Square Code
03  01  1
04  0C  EE
05  06  6
06  13  /           Divide by 1E6
07  35  {x}         Take the Fractional part
08  01  1
09  0C  EE
10  04  4
11  12  *           Multiply by 1E4
12  34  [x]         Take the Whole Part  -- End of Middle Square code
13  4-  X->N(a)     Store the New Seed
14  3L  RND         Random.  This is the actual Dice Roll
15  06  6             
16  12  *           Multiply by 6
17  34  [x]         Take the Whole part
18  01  1
19  10  +           Add 1
20  50  R/S         Stop
21  52  RTN         Goto 00 to run again. 


 
Code Design:
 
The MK-52, and it's close cousin, the MK-61 have very poor random number generators.  For any given seed, the pattern of pseudo random numbers will repeat after only a few iterations, especially for a low value integer, like a dice roll.
 
In the code above, I use a "Middle Square" routine to generate a new seed for every dice roll.  By using this combination of 2 random number generators, it seems to be a fairly unpredictable dice roll.  It does however remain only pseudo random.  If you are sitting down at the gambling table with a particularly tough group of comrades, I'd suggest leaving your MK-52/MK-61 in your back pocket.  In that position, it may save you from a bullet as your head for the door, if you pull it out and try to use it instead of the dice they offer, it may get you a bullet.
 
Note that the code above generates only a single 6-sided dice roll.
Note also that I use the MK-52 notation for hex values, for example memory location 14 contains the opcode for RND, which is Hex 3B, however, I write it as the MK-52 displays it: 3L.
 
Enjoy.
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7  Linuxslate.com Reviews & Commentary / Review Discussions / Re: Polimaster 1208M Gamma Detector Watch
 on: Aug 20th, 2021, 7:20pm 
Started by Administrator | Post by Administrator
For completeness, and discussion, I will include the picture of the PM1208M main circuit board as shown in the review video, part 1:
 

 
A few notes:

  • This is the actual circuit board from my watch.
  • It is interesting to note that the Quartz Watch (Mechanical hands) is powered by a buck supply on the main board.  There is a battery compartment in the Quartz watch, but it is empty.  A spring (similar to the ones shown, but on the other side of the board) makes contact with the battery terminal at the bottom of the quartz watch battery compartment.  The small metal piece that would secure the quartz watch battery in place in the quartz watch is present, but it is secured out of the way.  Ground is provided by another contact.  This is different than on the PM1208, which requires 2 batteries.
  • The spring contacts shown on this side (3) are (staring from the lower right, and going counter clockwise):  Battery connection, Case ground, and Alarm (Piezo) drive.
  • In addition to the spring contact on the opposite side of the board that connects to the quartz watch, there are two springs that connect to the electroluminescent backlight.  There are also those rubberized contacts that connect the main board to the LCD display.  These can be easily broken, and often very finicky in other devices, but fortunately in this watch, I had no problem re-assembling them, and all display segments work correctly.
  • When I received my watch, the EL backlight did not work.  I realized that the two springs were missing.  I made some tiny coiled contacts from copper wire, and inserted them into the appropriate holes on the back of the LCD display.  While my EL backlight is very dim, it does work, and is adequate to see the display in total darkness. It is my suspicion that they were intentionally not there.  They were either not included at the request of the company (or government entity -- perhaps ROSATOM) that purchased PM1208M's, or they were removed later.  I suspect this was done to reduce battery replacement from employees operating the backlight too frequently.

 
I often think about the person my watch was originally issued to, where he worked, what readings it would have indicated, and his fate. Wherever you are -- whatever realm you find yourself in -- I will endeavor to take care of your watch.
 
Happy and Safe Rad Hunting!
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8  Linuxslate.com Reviews & Commentary / Review Discussions / Re: Polimaster 1208M Gamma Detector Watch
 on: Jul 29th, 2021, 8:41pm 
Started by Administrator | Post by Administrator
Part 2 of the Video Review has been uploaded.
 

 
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9  Linuxslate.com Reviews & Commentary / Review Discussions / Re: Polimaster 1208M Gamma Detector Watch
 on: Jul 26th, 2021, 9:36am 
Started by Administrator | Post by Administrator
"Have I Found Anything Radio Active?"
 
As mentioned in the Videos, the PM1208M is very slow to react to mildly radioactive items placed near it.  Attempting to us it for -- as an example -- shopping for radioactive antiques leads to frustration, and standing around antique stores looking like an idiot.
 
So as of this post -- No -- My PM1208 has not alerted me to any place or item that I didn't already know was radioactive.
 
However, it did verify that something was radioactive.
 
I was at MRAM Electronics -- a local Surplus Electronics and Appliance Parts store.  The person behind the counter said they had a piece of natural ore that they thought was radioactive -- Much like my "Piece of Hyperactive Nature".  He handed the rock to me, and after several minutes, My PM1208M verified that the stone was radioactive.
 
The guy seemed to feel at least a bit "validated" by my independent verification that the stone was delectably radioactive.
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10  Linuxslate.com Reviews & Commentary / Review Discussions / Polimaster 1208M Gamma Detector Watch
 on: Jul 26th, 2021, 9:14am 
Started by Administrator | Post by Administrator
I have uploaded Part 1 of the Video Review of this device to the CarCynic YouTube Channel:
 

 
This thread will be of discussion of the Polimaster watch dosimeters, including the PM1208, PM1208M, PM1603A,B, as well are the rare vintage/prototype models.
 
 
Check back here for:

  • Part 2 (Note: There will be a delay in the upload of Part 2, as I have determined that the video must be re-shot.)
  • "Have I Found Anything Radio Active?"  -- Reports of things or places that your Gamma Detector Watch has alerted you to.
  • Links to other forums (mostly in other languages) relevant to the Polimaster or other Geiger Counter Watches
  • Getting the Polimaster devices that use IRDA connected to a PC (especially using Linux)
  • General discussion of Gamma Detector/Geiger Counter Watches

To register and participate in this discussion, follow the instructions at the top of this page.
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