Sciencemadness Discussion Board - Interests in Radioactivity & Nuclear History

Interests in Radioactivity & Nuclear History

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hyfalcon - 7-2-2014 at 13:27

I'm wondering if the original claimant and myself might be distant relatives since we carry the same spelling of last names.

IrC - 7-2-2014 at 16:48

Quote: Originally posted by bfesser

Yes, I think you are reading that right—I noted the date on the picture, as well.

OK, makes sense as copper was rising in price even back then. In 75 the road was hell for 11 miles on down to the mine. Tore my muffler off getting in there. Seemed like it had been in disrepair for years but I don't know how many. I bet they really improved it by 1989 when that pic was taken. Yeah, hard to find anywhere with open mineral rights anymore. Even back then big companies were claiming entire quarter sections in blocks at a time. No idea what is involved now though, since Clinton repealed the 1873 mining act laws back in the 90's. Probably companies lease the land from the government today, but I have never looked into it since the late 80's.

IrC - 11-2-2014 at 16:13

Trying to design a circuit for a tube I just bought. Problem is I cannot read the data sheet. Tried to OCR but my program does not appear to handle Cyrillic. I had thought I could enter the OCR'ed text into a translate site if I could figure out how to turn it into text. Anyone here able to translate?

dontasker - 11-2-2014 at 17:58

Tried a couple things and ended up with this:

Quote:

The counter type MST-17gas discharge counter ?????i????????, socket design with???????? windowed, designed to work ????????????- ???????????-??????????.1. The main technical bathrooms1. The voltage accounts . not 1600 in2. The length plateau ???????i .characteristics??????? not less than 150 inW. ?????? plateau Cour des comptes specifications . 0.05 per cent, and 1 in4. ???????? von (highest) . . . . 25 ???i???.5. The Workshop exposure (??????????1 .10006 -b. The diameter (??????????1 _ 41) ml7. length (the largest( 100 pits8. The diameter input window. . . . 20 mm9. Surface densitynot more than 5 meter south/xu'11. ????????-????????? ???????????????? dataI. load resistance 0 My2. ?????????? ??????????? containerhae more 1on the uf111. Instructions for ????????????for long x ????????? counter ??????-????: 1.Do not allow to enter the counter all kinds of insect infestation,??????? impair his ???????????? properties.2. Protect from counter and ???????????? damage.pent?dDO

Not really sure what "The main technical bathrooms" is supposed to mean.

bfesser - 11-2-2014 at 18:27

IrC, my OCR & translation were similarly garbled, but here's my own interpretation…

<table bgcolor="#EEEEEE"><tr><td colspan="2" align="center"><strong>MCT-17</strong></td></tr><tr><td colspan="2" align="center"><u>Main technical data:</u></td></tr><tr><td>Min. working potential:</td><td>1600 V</td></tr><tr><td>Plateau length:</td><td>≥ 150 V</td></tr><tr><td>Plateau slope:</td><td>≤ 0.05 %</td></tr><tr><td>Inherent background:</td><td>≤ 25 CPM</td></tr><tr><td>Maximum rate:</td><td>10000 CPM</td></tr><tr><td>Diameter (max.):</td><td>40 mm</td></tr><tr><td>Length (max.):</td><td>100 mm</td></tr><tr><td>Mica window dia.:</td><td>20 mm</td></tr><tr><td>Mica window density:</td><td>5 mg/cm<sup>2</sup></td></tr><tr><td align="center" colspan="2"><u>Max. permissible operating data:</u></td></tr><tr><td>Anode load resist.:</td><td>10 MΩ</td></tr><tr><td>Inter-electrode cap.:</td><td>< 10 pF</td></tr></table>
If you care to see it, I came up with this Russian Cyrillic OCR:

Quote:

Счетчик типа МСТ-1 7 Газоразрядный счетчик бета-излучения. торцевой конструкции со слюдяным окошком. предназначенный для работы в устройствах специа ния. ’ ' 1. Основные технические Данные !. Напряжение начала счета . . не более 1600 в 2. Протяженность плато счетной характе- ристики . . . . . . . . не менее 150 в 3. Наклон плато счетной характеристики . 0.092; на 1 в 4. Темновой фон (наибольшим . . . .5пчч нив . Рабочее облучение (наибольшее: Диаметр (наибольшпйд . Длина (наибольшая) 1 г: о. 8. Диаметр входного ониа . . . . около 20 мм 9. Поверхностная плотность счетчика не более 5 мг/см’ ||. Предельно-допустимые эксплуатационные данные 1, Сопротивление нагрузки . . . . . . 10 Мом до Наибольшая шунтирующая емкость не более 10 пф Ш. Указания по эксплуатации Для продолжительной и устойчивой работы счетчика необхо- дИМ01 1. Не допускать попадания на счетчик всякого рода загрязне- ннй, могущих ухудшить его изоляционные свойства. 2. оберегать счетчик от ударов и механических повреждений.

Which Google translates to:

Quote:

Counter type MCT- July 1 gas-discharge counter beta radiation. end design with a mica window . designed for use in devices of specialists . ' ' 1 . Main technical data ! . Starting voltage account. . not more than 1600 2 . The length of the plateau of the counting characteristics . . . . . . . . not less than 150 3 . The slope of the plateau of the counting characteristics . 0.092 ; on 1 in 4 . Dark background ( most .... 5pchch cornfields . Operating exposure ( highest Diameter ( naibolshpyd . Length (maximum ) 1 g : Fr. 8. Input onia diameter of about 20 mm .... 9. Counter surface density of not more than 5 mg / cm '| |. Maximum permissible operating data 1 load resistance ...... 10 megohms to Most shunt capacitance of less than 10 pF Sh operating instructions for continuous and stable operation of the necessary counter - dIM01 1. avoid contact to counter any kind of pollution IDD that may impair its insulating properties. 2 . counter protect against shock and mechanical damage.

dontasker, I think the algorithm misread 'the main technical specifications.'

[edit] I wonder if Ukrainian would be a better fit, as I think many tubes were manufactured there.

[Edited on 12.2.14 by bfesser]

IrC - 11-2-2014 at 20:58

Thanks to both of you for putting in effort on this, it gives me enough information I think. I had guessed the voltage was 1,600 and load 10 megohm because it seemed to be logical but feel much better having verification. This tube is great and hard to find. Did not want to damage it. What OCR did you use? All I have is the built in scan to OCR in my Lexmark printer/scanner and it can only handle A-Z, 0-9. Last question, it has an end cover (Cu?) disk with tiny hole. I assumed it was a de-scaler by limiting input aperture (window size). Does anything in the text indicate the amount of reduction and to what type radiation? Looking at "Наклон плато счетной характеристики . 0.092", I was wondering if 0.092 represented the factor reduced from 100 percent with cover in place.

I should add: what about KOI8-R? The seller is in Bulgaria, so it would make sense he was selling surplus from the Ukraine.

http://en.wikipedia.org/wiki/KOI8-R

Also is there useful information on these two pages? I would do this myself using google translate but all I have are images not text to work with.

bfesser - 12-2-2014 at 05:05

I run Linux, so this may not be as helpful as you'd hoped:

To generate the OCR, I first cropped, converted to grey-scale, and adjusted the brightness/contrast of the image in <a href="http://www.gimp.org/" target="_blank">GIMP</a> <img src="../scipics/_ext.png" />, then exported to PNG. I <del>converted the PNG to PDF using <a href="http://www.imagemagick.org/script/index.php" target="_blank">ImageMagick</a> <img src="../scipics/_ext.png" /> and</del> imported the <del>PDF</del> [PNG] into <a href="http://symmetrica.net/cuneiform-linux/yagf-en.html" target="_blank">YAGF</a> <img src="../scipics/_ext.png" />, a GUI for <a href="https://code.google.com/p/tesseract-ocr/" target="_blank">tesseract-ocr</a>. I generated the OCR after adjusting the text-box area and installing/selecting the Russian OCR library (tesseract-ocr-rus with aspell-ru). From there, I just copy-pasted the Russian Cyrillic OCR into <a href="http://translate.google.com/" target="_blank">Google Translate</a> <img src="../scipics/_ext.png" /> and selected Russian to English.

Unfortunately, there are no details in the text for dose-rate coefficients or the shield. The "0.092" was a mis-recognition of "0.05" from "The slope of the plateau of the counting characteristics . 0,05 % per 1 V." I verified the numbers in my table with those from the original image and what little Russian I've learned to read, ignoring the OCR entirely.

[edit] Manually entered one character at a time:

Quote:

1.5. Содержание драгоценных металлов:
Платина 22,13 г на 1000 шт. (теоретическая норма).
2. Указания по эксплуатации
Для обеспечения продолжительной и устойчивой работы счетчика следует:
а) не допускать попадания на счетчик всякого рода загрязнений могущих ухудшить изоляционные свойства стекла;
б) оберегать счетчик, в особенности его торцовую часть, от ударов и механических повреждений.

Технические условия 3. 394. 047 ТУ.

16 Окт 1980 ОТН-7

<table align="center" class="quote" cellspacing="0" cellpadding="0"><tr><td class="quote">Translation:</td></tr><tr><td class="quotemessage">1.5. Contents of precious metal:
Platinum 22.13 g per 1000 pieces. (theoretical norm).
2. Notes on operation
To ensure continued and stable operation of the meter one should:
a) avoid contact of the counter to any kind of pollution which may degrade the insulating properties of the glass;
b) protect the counter, in particular its front end portion, from shock and mechanical damage.

Technical conditions 3. 394. 047 TU.

October 16, 1980 OTH-7</td></tr></table>Did you receive hard copies of the data sheet with the tube?

[note] Thank you to Theoretic for suggesting several revisions to my somewhat awkward translations.

[Edited on 13.2.14 by bfesser]

IrC - 12-2-2014 at 07:21

Just one sheet, the image I posted above, MST-17 and the back side MST-17 MICA WINDOW8. Resolution poor as I had to reduce the size for posting. I can mail it to you if you PM your mailing address (you already have mine from a PM a while back). I don't need it as I have the full res scans I made and tend to keep all important data in my computer anyway (and on stored DVD's as backup). Actually easier to read it on screen than on the paper itself anyway. The other images are from the auction page:

http://www.ebay.com/itm/151092929730?ssPageName=STRK:MEWNX:I...

You can see the other images on the page I bought it from. He has I think 3 left and the price was great. Took 2 or 3 weeks to arrive but came in perfect condition, well packed in mail you have to sign for which to me is even better security of arrival than regular mail.

Thanks for your work on this. He has three other similar tubes but I opted for buying two of the $30 beta tubes rather than the higher priced Alpha tubes:

http://www.ebay.com/itm/GEIGER-MULLER-COUNTERS-SBT-7-MICA-WI...

http://www.ebay.com/itm/GEIGER-MULLER-COUNTER-SAT-7-REGISTER...

http://www.ebay.com/itm/GEIGER-MULLER-COUNTER-SI9A-REGISTER-...

If I was rich I would grab them all as from long searching I know they are difficult to find, especially at reasonable cost.

[Edited on 2-12-2014 by IrC]

bfesser - 12-2-2014 at 07:22

No problem. I'd love to see the original, and I would enjoy the chance to fully translate it. I have the opposite tendency, having difficulty reading anything on a computer screen, and finding hard copy much easier. I'll be mailing an envelope of unidentified electronic components to you, soon.

I had been browsing eBay for similar mica-window tubes over the last few weeks. Unfortunately, I don't have the funds to purchase any just yet. In the meantime I've been occupied with trying to source JFETs for home-brew ion chamber detectors, and scrounging miscellaneous parts from my local surplus shop (<a href="http://ax-man.com/whereweare/ax1map.html" target="_blank">Ax-Man</a> <img src="../scipics/_ext.png" />

.

[edit] I thought the description sounded familiar. I had that listing in my watch list.

On a related note, I've been thinking about purchasing some vacuum tube anode caps for reliable, safe, and non-permanent connections with tubes. I measured the ends of an SI-3BG and an SBM-20 with callipers, and think these <a href="http://www.ebay.com/itm/321011263672" target="_blank">¼" anode caps</a> <img src="../scipics/_ext.png" /> will work for them. I'm sure there are caps to fit your new tube, as well.

[Edited on 12.2.14 by bfesser]

IrC - 12-2-2014 at 07:45

Quote: Originally posted by bfesser

I've been occupied with trying to source JFETs for home-brew ion chamber detectors

http://www.ebay.com/itm/130888052558?ssPageName=STRK:MEWNX:I...

Trust me you can try every jfet on the planet but if they are not specifically electrometer jfets, performance sucks. It is all about Idss. From 2 ma to 20 ma typical for most numbers, only around 0.05 ma for the 2N4117A. You can spend endless time blowing money on circuits which without being based on a very low Idss jfet, will never be what you hoped for. By the way if building a photodiode detector is your goal, this parameter is even more important. No jfet I have ever found comes close by orders of magnitude to the 2n4117A.

Attachment: 2N4117.PDF (28kB)
This file has been downloaded 654 times

Completed Translation

bfesser - 13-2-2014 at 13:07

<strong>IrC</strong>, thanks for the advice. I already had that eBay listing in my watch list, along with a couple others. The 2N7117A is also available new from Mouser, but the PN4117A has been discontinued, though I have seen it on eBay. I also plan to pick up some 2N5484 JFETs for less demanding applications.

Quote: Originally posted by IrC

Trying to design a circuit for a tube I just bought. Problem is I cannot read the data sheet. Anyone here able to translate?

I compiled everything from the two scans:<table align="center" class="quote" cellspacing="0" cellpadding="0"><tr><td class="quote">Russian (Cyrillic) Transcription:</td></tr><tr><td class="quotemessage" style="font-family: monospace;"><table><tr><td colspan="3" align="center"><img src="http://www.scimad.org/users/bfesser/m_circle.png" alt="Ⓜ MELZ logo" width="50" /></td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-size: 12pt; font-weight: bold;" colspan="3">Счетчик типа МСТ-17</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: justify; text-indent: 15pt;" colspan="3">Газоразрядный счетчик бета-излучения, торцевой конструкции со слюдяным окошком предназначенный для работы в устройствах специального назначения.</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-weight: bold;" colspan="3">I. Основные технические данные</td></tr><tr style="height: 5px;"></tr><tr><td style="text-indent: 15pt;">1.</td><td style="text-align: justify;">Напряжение начала счета … не более</td><td style="white-space: nowrap;">1600 в</td></tr><tr><td style="text-indent: 15pt;" valign="top">2.</td><td style="text-align: justify;">Протяженность плато счетной характеристики … не менее</td><td style="white-space: nowrap;" valign="bottom">150 в</td></tr><tr><td style="text-indent: 15pt;">3.</td><td style="text-align: justify;">Наклон плато счетной характеристики</td><td style="white-space: nowrap;">0,05 % на 1 в</td></tr><tr><td style="text-indent: 15pt;">4.</td><td style="text-align: justify;">Темновой фон (наибольший)</td><td style="white-space: nowrap;">25 имп/мин.</td></tr><tr><td style="text-indent: 15pt;">5.</td><td style="text-align: justify;">Рабочее облучение (наибольшее)</td><td style="white-space: nowrap;">10000 имп/мин.</td></tr><tr><td style="text-indent: 15pt;">6.</td><td style="text-align: justify;">Диаметр (наибольший)</td><td style="white-space: nowrap;">40 мм</td></tr><tr><td style="text-indent: 15pt;">7.</td><td style="text-align: justify;">Длина (наибольшая)</td><td style="white-space: nowrap;">100 мм</td></tr><tr><td style="text-indent: 15pt;">8.</td><td style="text-align: justify;">Диаметр входного окна … около</td><td style="white-space: nowrap;">20 мм</td></tr><tr><td style="text-indent: 15pt;" valign="top">9.</td><td style="text-align: justify;">Поверхностная плотность счетчика … не более</td><td style="white-space: nowrap;">5 мг/см²</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-weight: bold;" colspan="3">II. Предельно-допустимые эксплуатационные данные</td></tr><tr style="height: 5px;"></tr><tr><td style="text-indent: 15pt;">1.</td><td style="text-align: justify;">Сопротивление нагрузки</td><td style="white-space: nowrap;">10 Мом</td></tr><tr><td style="text-indent: 15pt;" valign="top">2.</td><td style="text-align: justify;">Наибольшая шунтирующая емкость … не более</td><td style="white-space: nowrap;" valign="bottom">10 пф</td></tr><tr><td colspan="3"></td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-weight: bold;" colspan="3">III. Указания по эксплуатации</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: justify; text-indent: 15pt;" colspan="3">Для продолжительной и устойчивой работы счетчика необходимо:</td></tr><tr><td style="text-indent: 15pt; text-align: justify;" colspan="3">1. Не допускать попадания на счетчик всякого рода загрязнений, могущих ухудшить его изоляционные свойства.</td></tr><tr><td style="text-indent: 15pt; text-align: justify;" colspan="3">2. Оберегать счетчик от ударов и механических повреждений.</td></tr><tr><td colspan="3"></td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-weight: bold;" colspan="3">IV. Схема соединения электродов счетчика</td></tr><tr style="height: 5px;"></tr><tr><td colspan="3"></td></tr><tr><td align="center" colspan="3"><table align="center"><tr><td align="center"><img src="http://www.scimad.org/users/bfesser/MCT-17_diag.png" width="80" /></td><td valign="top" style="padding: 10px;"><table cellspacing="0" style="border: 1px solid black; border-collapse:collapse;"><tr><td style="border: 1px solid black; padding: 5px;">Обозначение</td><td style="border: 1px solid black; padding: 5px;">Наименование электродов</td></tr><tr><td style="text-align: center; padding: 5px;">А<br />К</td><td style="padding: 5px;">Анод<br />Катод</td></tr></table></td></tr></table></td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center;" colspan="3">ДЛЯ СВЕДЕНИЯ:</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: justify; text-indent: 15pt;" colspan="3">У приборов, предназначенных для работы в странах с тропическим климатом, наружные металлические детали покрыты вазелином, с целью предохранения их от коррозии, а потому, при вводе их в эксплуатацию, следует предварительно снять слой вазелина.</td></tr></table></td></tr></table><table align="center" class="quote" cellspacing="0" cellpadding="0"><tr><td class="quote">English Translation:</td></tr><tr><td class="quotemessage" style="font-family: monospace;"><table><tr><td colspan="3" align="center"><img src="http://www.scimad.org/users/bfesser/m_circle.png" alt="Ⓜ MELZ logo" width="50" /></td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-size: 12pt; font-weight: bold;" colspan="3">Counter type MST-17</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: justify; text-indent: 15pt;" colspan="3">Gas-discharge counter of beta radiation, with mica end window design intended for operation in special purpose devices.</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-weight: bold;" colspan="3">I. Basic technical data</td></tr><tr style="height: 5px;"></tr><tr><td style="text-indent: 15pt;">1.</td><td style="text-align: justify;">Starting counting voltage … not more than</td><td style="white-space: nowrap;">1600 V</td></tr><tr><td style="text-indent: 15pt;" valign="top">2.</td><td style="text-align: justify;">Extent of counting plateau characteristics … not less than</td><td style="white-space: nowrap;" valign="bottom">150 V</td></tr><tr><td style="text-indent: 15pt;">3.</td><td style="text-align: justify;">Slope of counting plateau characteristics</td><td style="white-space: nowrap;">0.05 % per 1 V</td></tr><tr><td style="text-indent: 15pt;">4.</td><td style="text-align: justify;">Dark background (maximum)</td><td style="white-space: nowrap;">25 pulses/min.</td></tr><tr><td style="text-indent: 15pt;">5.</td><td style="text-align: justify;">Operating radiation (at most)</td><td style="white-space: nowrap;">10000 pulses/min.</td></tr><tr><td style="text-indent: 15pt;">6.</td><td style="text-align: justify;">Diameter (maximum)</td><td style="white-space: nowrap;">40 mm</td></tr><tr><td style="text-indent: 15pt;">7.</td><td style="text-align: justify;">Length (maximum)</td><td style="white-space: nowrap;">100 mm</td></tr><tr><td style="text-indent: 15pt;">8.</td><td style="text-align: justify;">Diameter of the entrance window … about</td><td style="white-space: nowrap;">20 mm</td></tr><tr><td style="text-indent: 15pt;" valign="top">9.</td><td style="text-align: justify;">Surface density of the counter … not more than</td><td style="white-space: nowrap;">5 mg/cm²</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-weight: bold;" colspan="3">II. Maximum permissible operation data</td></tr><tr style="height: 5px;"></tr><tr><td style="text-indent: 15pt;">1.</td><td style="text-align: justify;">Load impedance</td><td style="white-space: nowrap;">10 MΩ</td></tr><tr><td style="text-indent: 15pt;" valign="top">2.</td><td style="text-align: justify;">Maximum bypass capacitance … not more than</td><td style="white-space: nowrap;" valign="bottom">10 pF</td></tr><tr><td colspan="3"></td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-weight: bold;" colspan="3">III. Notes on operation</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: justify; text-indent: 15pt;" colspan="3">For continuous and stable operation of the counter it is necessary to:</td></tr><tr><td style="text-indent: 15pt; text-align: justify;" colspan="3">1. Keep the counter from contact with any kind of contamination which might impair its insulating properties.</td></tr><tr><td style="text-indent: 15pt; text-align: justify;" colspan="3">2. Protect from counter from blows and mechanical damage.</td></tr><tr><td colspan="3"></td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center; font-weight: bold;" colspan="3">IV. Counter electrode connection diagram</td></tr><tr style="height: 5px;"></tr><tr><td colspan="3"></td></tr><tr><td align="center" colspan="3"><table align="center"><tr><td align="center"><img src="http://www.scimad.org/users/bfesser/MST-17_diag.png" width="80" /></td><td valign="top" style="padding: 10px;"><table cellspacing="0" style="border: 1px solid black; border-collapse:collapse;"><tr><td style="border: 1px solid black; padding: 5px;">Notation</td><td style="border: 1px solid black; padding: 5px;">Electrode designation</td></tr><tr><td style="text-align: center; padding: 5px;">A<br />C</td><td style="padding: 5px;">Anode<br />Cathode</td></tr></table></td></tr></table></td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: center;" colspan="3">NOTICE:</td></tr><tr style="height: 5px;"></tr><tr><td style="text-align: justify; text-indent: 15pt;" colspan="3">With instrument versions designated for use in countries with tropical climates, exterior metal parts are covered with Vaseline, for protection against corrosion, but because of this, in their commissioning, you must first remove the layer of petroleum jelly.</td></tr></table></td></tr></table>By the way, I looked up the manufacturer's logo out of curiosity, it was <a href="http://rutubes.com/category/melz-tube-moscow-russia/" target="_blank">Moscow Electric Plant, "MELZ"</a> <img src="../scipics/_ext.png" />. Curiously, they're still around, but they're now known as Moscow <a href="http://www.melz-evp.ru/" target="_blanK">Electro-Lamp Plant, MELZ-EVP</a> <img src="../scipics/_ext.png" />. I don't think they've made radiation detection tubes in a few decades, though.

Attachment: 2n5484.pdf (355kB)
This file has been downloaded 547 times

IrC - 13-2-2014 at 14:20

Thanks for the tedious hard work. That 2N5484 jfet will be as bad if not worse than a cheaper MPF102 for electrometer or gamma photodiode detection front ends although it may have a better top end frequency wise. Good for a second stage amplifier, would even work OK for a static field monitor*. You must get the 2N4117. In a metal case preferably. You must get down to the 0.05 ma Idss range or better for serious top quality work.

* http://amasci.com/emotor/chargdet.html

Instead of an LED you can make a meter circuit say with a 50 ua movement, with short antenna on gate floating away from the device (touching nothing). It will slam the needle back and forth waving a comb (first run through your hair) from ten or more feet away. Even the MPF102 works great for this. I built one meter with both N and P jfets, two meters, which can measure field strength and polarity from far away. Storms approaching from miles away. However for work with ion chambers or low dark current devices Idss becomes very important.

Marvin - 13-2-2014 at 15:46

I could have done with reading that 2N4117 datasheet 2 years ago. I spent weeks off and on trying to figure out the difference between 2N4117A and PN4117A. The only datasheets I could find had much less data and described the PN part as a "switch" but it was 1/20th of the price. I bought a few for input clamping following end of life warnings. Had I known it was the same thing I'd have bought a bucketful.

IrC - 13-2-2014 at 18:49

Wish I had a large quantity, still waiting for 30 in mail which cost $45 with shipping, $1.25 each. Found this interesting circuit. They mention removing the glass window on diode and replacing with black Mylar to allow Alpha/Beta also. Had to squish pic so the resolution not as good but here is the link if you want the text and a better quality image:

http://www.next.gr/sens-detectors/rf-radiation/wideband-radi...

Main site has a lot of useful circuits (both RF and Radiation):

http://www.next.gr/sens-detectors/rf-radiation/

[Edited on 2-15-2014 by IrC]

Marvin - 14-2-2014 at 15:51

There are some good deals on the 2N part, but killed for me by the shipping cost.

Interesting schematic. Seems to be a mistake in it. Pin 14 goes to the 4.3v line and I think it should cross this and connect with the 9v line above it.

IrC - 14-2-2014 at 16:16

Quote: Originally posted by Marvin

There are some good deals on the 2N part, but killed for me by the shipping cost.

Interesting schematic. Seems to be a mistake in it. Pin 14 goes to the 4.3v line and I think it should cross this and connect with the 9v line above it.

Good thing you saw that, I just found the circuit online and did not carefully study it before I posted the image. Sucks when they draw schematics then fail to proof read them before dumping them online. I don't have a decent art program but I fixed it in a sort of sloppy way. I would have caught that if I tried to actually build it but I'm glad you saw it before others wasted time not understanding why their circuit failed to operate. I wonder how many globally have built that then ended up pulling hair out trying to get it functioning. At least thanks to your sharp eye and my sloppy artwork now they can get it here in a functioning version? Yeah your right, some sellers are insane on shipping. I found one seller that wanted ten bucks for ten, plus 9.99 to mail it. We all know under a buck is total cost to put ten tiny parts in an envelope with a stamp on it. Which often is how I do get things that small shipped after paying an inflated shipping cost.

Edit to add PDF for LM3900:

Attachment: lm3900-n.pdf (486kB)
This file has been downloaded 1053 times

[Edited on 2-15-2014 by IrC]

Marvin - 14-2-2014 at 16:24

What surprised me more was 9.0/10 from 88 votes, 800+ views and no comments. Reminded me of this.

IrC - 14-2-2014 at 16:28

Found a great circuit on that link you just gave.

Marvin - 14-2-2014 at 17:14

The detector circuit is quite similar to Maxim app note 2236, bfesser posted on page 3 of this thread. I knew it reminded me of something.

bfesser - 14-2-2014 at 20:06

Fixed, full-resolution:

<a href="http://www.scimad.org/users/bfesser/135-9425.png" target="_blank"><img src="http://www.scimad.org/users/bfesser/135-9425.png" width="250" border="1" /></a> <img src="../scipics/_ext.png" valign="top" />

Attachment: 135-9425.pdf (36kB)
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[Edited on 21.2.14 by bfesser]

IrC - 21-2-2014 at 15:01

My latest Russian Neutron Counter tube SNM-9 just arrived today and in my search for information to build a working circuit I found a useful table. At least useful for others, my number is not in it. Sucks but there it is, somewhat useful as it does give information on the tube type in general which I find helpful. When in doubt and lacking information it is often safe to design a circuit based upon similar components. Or at least the smoke appears less often? Below is the table. I translated and rebuilt it in English in the document file. So if anyone is building neutron counters using a tube in the list the doc file attached may be of use. Nothing was listed as to load resistance but every circuit I have found calls for a 10 meg resistor. Marvin called these 'Corona tubes' but honestly I have found little information on proper circuit design to run them. The most I have is 2,000 to 2,800 volts, happy around 2,400 volts with a ten meg-ohm load resistor.

СЧЕТЧИКИ НЕЙТРОНОВ
№
п.п. Тип прибора Технические условия Ном. рабочий диапазон напряжений,
В Напряжение начала счета (заж. корон. разряда

,
В Собственный фон,
с-1
не более Фоновый ток коронного разряда,
мкА
не более Габаритные размеры,
мм Масса,
г
1. СНМ 11 ОДО.339.070ТУ 1500-3000 600-700 0.017 27.5 Ø18.5*336 50.0
2. СНМ 12 ОДО.339.070ТУ 500-700 не менее 400 0.008 11.0 Ø8.5*215 16.2
3. СНМ 13 ОДО.339.070ТУ 450-600 не менее 450 8.10-5 5.5 Ø8.5*85 11.5
4. СНМ 14 ОДО.339.070ТУ 450-600 600-700 0.017 27.5 Ø18.5*153 24.0
5. СНМ 16 ОДО.339.071ТУ 2000-2800 не менее 2000 0.083 25.0 Ø18.5*158 30.0
6. СНМ 17 ОДО.339.071ТУ 2000-2800 не менее 2000 0.83 25.0 Ø18.5*251 40.0
7. СНМ 18-1 ОДО.339.546ТУ 1700-3000 1450-1650 0.83 25.0 Ø32.0*320 180.0
8. СНМ 32 ОДО.339.281ТУ 1500-3000 600-700 0.017 25.0 Ø18.5*323 42.0
9. СНМ 42 ОДО.339.281ТУ 1500-3000 600-700 0.017 25.0 Ø18.5*153 25.0
10. СИ 19Н ОДО.339.142ТУ 2000-2800 600-1750 0.1 15.0 Ø33.3*218 130.0
11. СНМ 18 ОДО.339.072ТУ 1275-1500 --- 0.05 --- Ø32.0*320 180.0

This was a table but the formatting does not come out right in this post. I have heard from some my old win 2k doc format (Word 6) will not open on newer machines so included is a text version. Also I just edited both files to include another table I found which lists a СНМ 9. Since C in Russian is the English S I am thinking it is the right number/specs for my newest tube. However now I wonder why the only circuit I found online shows it running at 2,200 volts. Very confusing. Here is one data sheet as well, in Russian. I can use google translate on text but not images.

Attachment: Neutron counter.doc (13kB)
This file has been downloaded 739 times

Attachment: Neutron counter.txt (3kB)
This file has been downloaded 795 times

[Edited on 2-21-2014 by IrC]

bfesser - 21-2-2014 at 15:20

Ooh, another translation project. I'll get to work right away. I must be a masochist, because I thoroughly enjoyed doing the last one. On a closely related note, I'm working on making a PDF of the previous translation, and will be uploading that soon as well. Thanks for sharing these, and please keep us updated on your new detectors.

IrC - 21-2-2014 at 16:08

Quote: Originally posted by bfesser

Ooh, another translation project. I'll get to work right away. I must be a masochist, because I thoroughly enjoyed doing the last one. On a closely related note, I'm working on making a PDF of the previous translation, and will be uploading that soon as well. Thanks for sharing these, and please keep us updated on your new detectors.

Actually, I decided to unpack it and found this sheet rolled up in the box, came with the tube. Far more valuable to me if you feel like translating something. I am wondering if the load is 10 meg-ohms, and operating voltage is 1,300 volts. Also load capacitance, other parameters, etc.. Had to squish the scan to post.

Confusing is the 700 listed on the sheet, in other tables as corona voltage. Yet 1,300 in that table was the operating voltage. When Marvin mentioned corona tubes that got me searching and thinking, yet not much is out there to use to understand using a corona tube. I am not actually sure myself. Which makes designing a circuit very difficult.

http://hardhack.org.au/neutron_monitor

From this link I find an idea for circuit design using these type tubes. You can see the tube is very lightly coupled, using a 10 picofarad capacitor. The tube used is a Boron Coated Cathode Corona Pulse Neutron Tube SI-19N.

Obviously for my tube the voltage will be 1,300 volts not 2,200 volts. Still have to search for something which explains the operation of these corona tubes in more detail. They give a starting voltage usually around 700 volts. Since when the counter is powered my tube will have a steady 1,300 volts, I am not sure what they mean by a 700 volt starting voltage. I spent some time looking around, even some fusor sites as Marvin mentioned. However it seems endless hours never finding a single source where a decent tutorial of corona tubes is discussed is always the result. If anyone has any decent links that would be nice. For now I am going to keep searching before building circuitry in hopes of not having to build several prototypes.

Somewhere in these threads I remember someone asking how would a CCD be used in detection. Found this patent by accident looking for corona tubes. The title seemed interesting enough to add the file in case anyone is interested.

Detector for thermal neutrons utilizing alternating boron slabs and CCD arrays - United States Patent 5399863

Attachment: US5399863.pdf (239kB)
This file has been downloaded 615 times

[Edited on 2-22-2014 by IrC]

bfesser - 22-2-2014 at 05:11

I can't quite make out many of the characters on the latest datasheet (8X-CHM9.jpg). Any chance you could email a full-resolution scan to me?

Attachment: SNM9-SNM14.pdf (1.7MB)
This file has been downloaded 941 times

[Edited on 22.2.14 by bfesser]

Marvin - 22-2-2014 at 10:41

From Doug Coulter's forum,
Pulses out of SNM 18-1 (at last)
First light on CHM-14 Russian B10 neutron tube
Neutron detector tubes

There is also some information on the fusor forums but I became sidetracked reading through trying to find the posts.

IrC - 22-2-2014 at 11:43

Quote: Originally posted by Marvin

From Doug Coulter's forum,
Pulses out of SNM 18-1 (at last)
First light on CHM-14 Russian B10 neutron tube
Neutron detector tubes

There is also some information on the fusor forums but I became sidetracked reading through trying to find the posts.

"but I became sidetracked reading through trying to find the posts"

Exactly why I keep burning hours getting little done.

On the first link: "Chris -- yes, the transistors are important to that circuit".

Do you know where a copy of 'that circuit' is? I'll keep looking around the forum. I did find on page 2 a preamp circuit but I am not sure if this is what they are talking about. Some of the text leads me to think this is an alternate or different circuit than the one the thread was discussing but I am not sure. They also had a useful data sheet which I'll include here.

Attachment: MMBT5087.pdf (100kB)
This file has been downloaded 722 times

Edit to add: I also notice they are coupling the tube with much more capacitance than the circuit I posted on page 5 which I found on a cosmic ray detection site. Also they discuss my tube and the OP seems to make no differentiation between that and his tube concerning the 2,200 volt anode voltage. Was this because he failed to study the datasheets? His tube is 2KV to 2,800 volt whereas the SNM-9 is 1,300 volts. Note English SN is Russian CH if you compare alphabets, at first a confusion for me until I realized various sites were talking about the same tube number. In effect SNM-9 is CHM-9. In any case they discuss 200 microsecond pulses and 250 pF coupling at much higher input impedance, whereas the Nasa Cosmic ray site was using 10 pF at 10 times less input impedance. Just seems to me 100 megohm load with 1 megohm input loaded at 250 pF is going to stretch a 200 uS pulse a hell of a lot more than 10 megohm load at 100K input impedance loaded by 10 pF. Or am I missing something here. I also see I am handicapped by equipment. They were saying a 100 MHZ DSO is sort of the bottom end for looking at these signals whereas my best DSO is a Tektronix 2220 which is a 60 MHZ DSO. Maybe I am SOL from the outset until I can afford better gear? Also note while they mention 250 pF, the circuit posted used 210 pF. I imagine they are still experimenting in an effort to get a better signal. What I do know is these neutron detector tubes are hell to work with. Leaves me wondering why the manufacturers do not have good information on their products to aid in design. Maybe I should set this aside for awhile, I was working on my mica window MCT-17 until this new tube finally arrived in the mail.

Not 100 percent sure but this may be the circuit they were talking about in the first link Marvin recently posted.

http://www.coultersmithing.com/forums/viewtopic.php?f=7&...

http://www.coultersmithing.com/forums/viewtopic.php?f=52&...

[Edited on 2-23-2014 by IrC]

neptunium - 19-4-2014 at 09:11

after reading on Irc`s story about hacks Canyon in northern Arizona, I rented a car in Flagstaff and went there to check it out for myself...
240 miles later i came to Fredonia, a sleepy desert town where gas stations closed at 5 pm.

about 12 miles west of town there is a dirt road that leads to Hacks Canyon.
21 miles south the entrance was closed by a gate that may be there to prevent cattle from roaming freely since dump trucks are still going in and out of the area once or twice a day.

I didnt want to pay for the repair on the rental or get stuck in the middle of inaccessible terrain so i walked arround looking for deformed cacti with my geiger counter

unfortunatly i was too far from the area of interest and dirt and sandstone is all i found there...
this is a beautiful area nonetheless and on the advises of Irc and upon reviewing the google earth map i know now where to go look .
I cannot wait to go back and camp there for 2 or 3 days but money and time off are in short supply .if anybody wants to join the expedition later this year it would be a welcome trip so we could once and for all see what is hidden beyond the western entrance of Hacks canyon!

Hacks canyon eastern entrance 3.jpg - 191kB

IrC - 19-4-2014 at 10:07

"see what is hidden beyond the western entrance of Hacks canyon!"

Western Diamondback Rattlesnakes. In numbers beyond imagination. A number of Black Rattlers and other nasty always painful things. To quote John Wayne from an old movie "everything wants to either stick you sting you stab you kill you". OK paraphrasing but I have not seen the movie in long years.

Edit to ask: can you blow up #2 image so I can read the sign at the gate. Never saw that before, plus near as I can tell from 40 year old memory that gate looks to be a long way from the location I described. How much land did they patent?

[Edited on 4-19-2014 by IrC]

neptunium - 19-4-2014 at 10:10

yeah spring is probably not the right time to avoid snakes...maybe winter when they asleep and hidden?

IrC - 19-4-2014 at 10:24

Quote: Originally posted by neptunium

yeah spring is probably not the right time to avoid snakes...maybe winter when they asleep and hidden?

In the first week of January the temps are coldest. Usually they wrap together in a giant very scarey very dangerous ball of hundreds of 6 foot average length Rattlers. Hiding in holes, caves crevices, whatever is as large and deep as they can find. Do not even go near one.

In the southern part of the state university teams picked these times to find and study pottery and artifacts from tribes such as Hohokam. I have heard many stories from them about running into these snake balls. Still, your right it is the safest time.

[Edited on 4-19-2014 by IrC]

neptunium - 19-4-2014 at 10:28

the picture size is too big to be accepted but the sign says..

rough road next 8 miles
4wd or high clearance
vehicles only recommended
beyond this point

judging from the google earth i think this is the western entrance but yeah about 5 or so miles away,,

IrC - 19-4-2014 at 10:35

"4wd or high clearance vehicles only recommended"

Have to laugh remembering retrieving my muffler and putting it in the trunk. Was a couple months before I put it back on the car. I have to wonder how many citations for fire hazard BLM rangers would have given me today. In 74 no one cared or even gave it thought. A Sheriff at the gas station in Fredonia did give me some menacing stares hearing me pull in to fuel up but even he seemed not very concerned about how loud the car was. I had by that time given up putting the muffler back on after a dozen times in the preceding months and just left in in the trunk. In any case the above quote is not joking.

neptunium - 19-4-2014 at 21:26

aside from the snakes and rough road, are the claims clearly indicated ? on google map there is a couple of large dark square that appears to be tarp... any idea what they are?

elementcollector1 - 19-4-2014 at 21:34

Any good prospecting sites (radioactive or otherwise) near western Washington?

IrC - 20-4-2014 at 00:27

Quote: Originally posted by neptunium

aside from the snakes and rough road, are the claims clearly indicated ? on google map there is a couple of large dark square that appears to be tarp... any idea what they are?

Only way to locate claims other than stumbling upon survey markers is to go to the county seat and look up descriptions. Around 94 Clinton did away with the 1873 mining act so there will be no new claims. You did not have to stop at that gate, only close it behind you every time you go through it. Only private property marked no trespassing is an obstacle and that picture is not indicative of that. You should have gone on through the gate when you were there. Maybe next time. I'll bet you missed out on going on into the canyon by stopping at that gate. All it means is cattle from different ranches graze on either side of the gate. Or only on one side and none on the other. Only the BLM could tell you that but in any case just for FYI on your next trip such signs do not mean you cannot go on down the road. If you fail to securely close the gate however I am sure if caught leaving it open expect big fines. I do not know about the 'tarps' you mention. Cannot answer that one.

neptunium - 22-4-2014 at 10:44

Quote: Originally posted by elementcollector1

Any good prospecting sites (radioactive or otherwise) near western Washington?

there is a spot in central Idaho but i am guessing it is underground and maybe too far ....unless you are planning a camping trip?

neptunium - 22-4-2014 at 10:55

late october or perhaps january . early morning can also b quite cold in the desert late september or somaybe even below freezing . that should keep the snake asleep for awhile.

Now i red somewhere that Hacks canyon had the highest concentration of radium and uraniium ore in the entire US. . . better yet at ground level!
i wonder how such a geological event is possible given that U is a heavy metal.?
Also there is another spot on the USGS map not far from Hacks either east or west with the same carracteristics...i can tell on their map if its east or west of Hacks but it would be worth digging if it hasnt been mined already...

Hacks is such a great place for many other reasons but Uranium ore is usually closely garded or underground or both.
so this makes it a fabulous place for mineral/element/thrill hunters!

I have a feeling though that this wont last much longer and we are in the last years of free digging arround in open areas.

dont want to drift off topic here but i fear the growing tighting of the government grip on (western) land and other physics/chemical related artefacts and places.
Paranoid ? maybe....but i have to show ID and register for certain items wherer i didnt have to not that long ago......

again, this would discourage curiosity and interest and contribute to a general sense of dumbing and over controlling of the masses.

hope this wont land me on some watch list

[Edited on 22-4-2014 by neptunium]

IrC - 22-4-2014 at 15:22

"i wonder how such a geological event is possible given that U is a heavy metal.?"

I would think it was brought up with magma flows. If you go from Hacks straight to the north rim of the GC you would be sliced to ribbons if you slid down a quarter mile to the river. Black glass and so dangerous it is frightening to stand at the top looking down the slope. One slip and all a cannibal would need is a box of hamburger helper and a fire. From appearance clearly a massive lava flow down the slope a billion or few years ago. Think about that giant reactor in Africa, discovered in 1972 at Oklo in Gabon.

http://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor

neptunium - 22-4-2014 at 17:14

but the rockys are about 70 or so million years old! granted a few volcanoes popped up here and there bringing the inside out and that would explained the mineral belt in NM

https://en.wikipedia.org/wiki/Uranium_mining_in_New_Mexico

but this part of Arizona is more sedimentary hence the Grand canyon!

or do i need to go back to my books of geology?
i understand the techtonic and the volcanoes popping up there i just didnt really see it in the landscape
maybe i need to explore some more

gladly! f..k the snakes! i totaly would!

[Edited on 23-4-2014 by neptunium]

IrC - 22-4-2014 at 17:52

I have no idea when never bothered to study it. I just said billion or so to provide a wide time frame meaning somewhere long ago. But it is clearly magma which flowed downwards a quarter to half mile, along the cliff over the river valley. If the Rockies are that young then this is confusing. I did not think a volcanic eruption that large had occurred in such a short time ago as 70 million years. Possible I guess. Too bad I never have time any more to study such things back when I was there it was very interesting. In 74 it was remote desolate wilderness as far as you can see. Looking right now I see they named it 'Lava Falls' and show an airstrip.

https://maps.google.com/maps?q=grand+canyon+north+rim&oe...

To be honest from long aged memory it did not look like a volcano ever existed there**. Looked more like a giant lake of lava that overflowed into the river valley up and down it's length for well over a mile. Will give you something to study anyway. I brought it up because you wondered what mechanism brought up heavy metals to the surface, and this was all I could think of. Even the roughest rocky areas around Hacks looks very volcanic in origin. The whole area is largely metamorphosed Pegmatites. Percentage wise I remember Obsidian, Olivine, Beryl, Tourmaline, others, as being in greater abundance all around for 50 miles. By this I mean I could have loaded trucks full of these glassy rocks it was so abundant. Not an expert geologist but I always linked such minerals to more or less volcanic terrain. No doubt all the sedimentary build up was in the millions of years since this obvious volcanic activity. Going 40 or more miles further N, E, and W it turned into mostly mountains of Dolomite. Go search around where Black Rock Road comes off I-15 past Littlefield you will see what I mean. Not for radioactive minerals, the area is as dead as it gets.

Edit ** Is it possible Ice Age Glaciers were this far south and in say the last 50,000 years or so ground down any volcanic peaks? Could there have been a string of volcanoes now so ground down the area looks lacking in volcanic peaks but overflowing with lava from long ago?

[Edited on 4-23-2014 by IrC]

Subcomputer - 23-4-2014 at 07:25

I happen to be near the Lemhi Pass deposit which depending on who you ask has a lot of Thorium or a LOT of Thorium. It happens that Lemhi and Custer counties had a bit of a Uranium rush in the '60s, there were never any productive mines opened but a lot of roads to nowhere. (The locals claim it's because the market fell out, the uranium really is there; but they say that about almost every mineral here.)

I'm really tempted to build/buy a geiger counter and scout some of the old roads to nowhere and try to identify the ore to see if it's the same lanthanide heavy stuff as the pass. It's different geological formations in some areas, so it should be an interesting summer project.

woelen - 23-4-2014 at 23:09

For some reason this thread was invisible in the thread list (software bug?). I bumped it to make it visible again.

IrC - 24-4-2014 at 08:53

Ghost in the machine?

neptunium - 12-6-2014 at 18:24

Quote: Originally posted by Subcomputer

I happen to be near the Lemhi Pass deposit which depending on who you ask has a lot of Thorium or a LOT of Thorium. It happens that Lemhi and Custer counties had a bit of a Uranium rush in the '60s, there were never any productive mines opened but a lot of roads to nowhere. (The locals claim it's because the market fell out, the uranium really is there; but they say that about almost every mineral here.)

I'm really tempted to build/buy a geiger counter and scout some of the old roads to nowhere and try to identify the ore to see if it's the same lanthanide heavy stuff as the pass. It's different geological formations in some areas, so it should be an interesting summer project.

i say go for it man! its a lot of fun and you might learn something in the process! alwys a good thing! maybe find yourself a cheap geiger counter or scintillation detector on ebay , get a portable GPS and a tent, supply, food etc...and pick up some interesting samples , if you can send me a small one i`ll do the gamma spectrum for you!

http://www.sciencemadness.org/talk/viewthread.php?tid=27963&...

[Edited on 13-6-2014 by neptunium]

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