Thank you very much for replying to be, I've always been fascinated in these kind of things. I am looking forward towards the video you will be posting.
On a side note, do you have those units tested and calibrated yearly? A unit in bad working condition is a big liability for a firefighter (imagine a bad air tank or hose coupling!) Also, those are higher range units (mine is x1, 10, and 100). Open the beta shield and hold the open window against the check source on x10. You should read between 2 and 2.5 mR/hr.
+antiprotons west coast CA roughly ~ 1200ft and not a while lot of rocks nearby but I'm near the mountains. OH and the seller is giving me a free Radium-226 source in addition with the counter.
I know the video is 6 years old but... I hope you still remenber how these device works. There is a lot of cdv700 on ebay that are not calibrated but here is my question: can I just get one that "works" and calibrate it myself? If the check source is depleted, I just need to buy a calibrated source (cs137) and calibrate the cdv700 by turning the screw inside right?
Well... they are both right. Different models had different check sources. My Victoreen 6A has a DU source. I confirmed this with gamma spectroscopy. The beta emissions are not very penetrating and the gamma from my unit is less than 0.5 uSv/hr, a very small amount of radiation. Personally, I would not very worried given that your average smoke alarm is much hotter (even gamma).
Tom, How would a DX-2 (US geiger counter. claims to be as sensitive in beta gamma as $1000 geiger counters) glass tube exposed on the side for 3-4 inches with scale from 0-1000 uSv/h and 0-100 mR/h powered by a 9V battery. $190 a little more expensive than the wires and double SBM-19 counter ($175) that I wanted to build custom, but according to reviews for prospecting in mines and in nature worth the price. Also claims to beat the Gamma Scout. The DX-2 also has a screw on the back for manual calibration.
A standard 6993 tube will work. My Victoreen unit has a Lionel brand tube in it so it must have been replaced at one time. If you want to use a different tube, make sure it is rated to 900V. Many are not. SE International makes a pancake probe called the CDV-700RP TFG Radiological sells them for $330 so not cheap. If you're looking at Soviet surplus again make sure the tube is rated for 900V or you'll have to build a circuit.
You can self calibrate using the check source on the side. It's not really 100%, but it works. Ludlum might do it (ludlums com). If not, they would know who.
+antiprotons did that sound like I'm getting two sources? If so usually in the room when they give the radiation pill they'll have a geiger counter and I'll have them measure the thorium to get a baseline if I have to calibrate the counter.
Hi Antiprotons thanks for your reviews only came across your channel a short time ago and I have learned a lot thank you . How do you rate the Russian Soeks eacotester Geiger counter as I was thinking of getting one and it seems ok at 200 euro about 240 to 250 us dollars . Kind regards from Ireland
Superb overview of this unit. Maybe best video on youtube in terms of differing samples + readings and explanations--fantastic!!!!. I've collected these units on a very small scale since high school but I've certainly never seen one with that cute external speaker. It looks like a stereo speaker, I wonder why it has 2 speakers... the old school "microphone"/screw on connector is beige/white almost looks like a retrofitted part. Of course it's only mono, no possibility of stereo whatsoever here. that little 2 speaker thingy mounted on the side reminds me of early 'cassette tape styled stereo speakers' meant to plug into your tape player walkman and was a speaker that played audio. It had the benefit of being of able to be stored inside your crappy cassette walkman.
Enjoy! Make sure to open the beta shield and place the wand shield open against the check source on x10 mode. Look for a reading of 2.5 to 30 mR/hr, to know the unit is correctly calibrated.
antiprotons mine comes with a Thorium calibration test source, what should that conservatively read out between? want it as accurate as can be. getting a dose of Iodine I-131 in about 8 weeks and want to see how much radiation i put out.
DEOXYS987 The only source which will work with the 2.5-3 mR/hr at x10 is the original builtin check source. Any other source would require a calibrated reading. Basically, someone places the unit in a given configuration and makes a reading of the source. They know (via another unit or lots of math) what the reading should read. They calibrate the unit to that. It should always much up or be known to be off calibration.
We have 12 of these units on our fire dept. They are the ear phone style. The other night we boiled water in the microwave and held the wand inside the oven and over the cup. We did NOT have the shield open, had the setting on X-1000, we had a reading of "50". The unit clicked once every 15 seconds, what EXACTLY where we reading??
Good point about the lead 210 and the bismuth 210. Bi210 will remain in secular equilibrium due to it's super short halfife. I calculated that your units (probaly 53 years old +/-) are now about %19 of what they once were: 100e^-((ln(2)/22.2years)*53years) So, perhaps you could try to divide your reading by 0.19 and see if it's correct... If you get 0.475 mR/hr then 0.475 / 0.19 = 2.5 mR/hr = calibrated? Short of buying a new source, that might do.
Hello, I am just curious because I don't have much knowledge on anything radiation wise because I've only done chem 20 ( first year of Chem in highschool ) which only went over Isotopes for a little bit which I already knew but I was wondering what the Bq in 'Cesium 137 - 3737 Bq" means?
+antiprotons Here is what the seller said about the testing element and just wanted to get your opinion on it. "If you put the dial on 10x and hold it closely to the thorium source, it should go between the 1 and 2 on the guage. Give it a minute. That's reading between 10 and 20 counts per minute with is where the unit should be. If you go over to the 1x it should peg at the right end." does that sound about right?
Odd... on 10x, the readings are 0 to 30,000 CPM... so I think they mean 10,000 to 20,000 CPM. Is it calibrated? Did they provide a calibration statement or certificate?
Really good video! Is it safe to keep in the house with the check-source that it has built in? I have a very basic knowledge of physics. Thinking back to high school physics I'm assuming the sticker will block Alpha and Beta rays coming out of it? I'm assuming the gamma amount is too low to even travel out of it? I was intending to store it in a cupboard under the stairs. Thanks!
Well, you have a geiger counter attached to the source so try to measure if there is any diference in radiation from background at 1 foot from the source.
NOTES: Please watch in FULL HD (lower right of screen, "gear" button) The following sources were tested: Cesium 137 - 3737 Bq Cesium 137 - 37000 Bq Old barely detectable Radium Compass Strontium 90 - 3700 Bq Polonium 210 - 666 Bq (as of 7/22/12) Pitchblende Uranium (United Nuclear) Stay tuned for two more videos (CRM-100 and Inspector EXP)
Odd. Are your units calibrated yearly and in good order? Could you have a bad unit? You really shouldn't pick up 50k CPM (or any above background) in a microwave.
What kind of distance can the cdv700 with standard probe be expected to pickup trace radiation, for "radiation hunting" items around the house,etc.... I have a GQ GMC-300, and it seems anything below a few thousand CPM, it won't start picking up unless it's 3-4" from it.
The method to determine this is called the distance inverse square law. For example, if your unit detected 1% of gammas it detected (1% efficiency) and you had a radioactive object emitting 37000 photons per second... how many CPM would you get above background at x distance? Well, First you determine the area of your tube which directly faces the source. If half of the probe faces the source and the probe is 8cm around and 12 cm long, than half would be 48 cm^2 of area exposed to the source. At 100 cm, you would detect: 0.01(37000 photons / 4*pi*(100cm)^2) = 0.2944 (not even 1) additional CPM. At 10 cm distance, you get: 2.9444 CPM above background... See? I'd suspect you would need to be within a foot of most objects. Let me know if you need more info and I can make a short video showing.
Bq is short for Becquerel. 1 Bq means 1 decay per second. Decay is random, but there is always a statistical average. If an atom decays, on average, 100 times per second, it is said to have an activity of 100 Bq. Now, decays are alpha or beta only. Gamma rays come after a decay, so 100 Bq does not always mean 100 gamma rays. In the case of Cs137, for 100 decays you get a gamma about 85.1% of the time. I'm posting a video about each form of decay, in detail, very soon.
First off I love the video very helpful, I just bought a Lionel CD v-700 6b and I would like to get a speaker for it and I'm wondering Where did you get the speaker and what is it called.
If the microwave was on, you probably damaged the probe. Electromagnetic induction occurs when something like a microwave induces a current in the center wire of the Geiger tube, causing a nearly steady current. It simulates what would occur in a mega powerful radiation field. The unit jammed and the needle feel to zero. Never do that as it kills the unit. They do not detect anything related to microwaves.
My friend, can you please elaborate more on the check source that is attached to the device, I found very conflicting information, some say its Ra 226 some say DU, I'm just a biginer with these things and I picked out a unit same as yours, but I'm a bit worried to handle it. Thanks!
Yes and no... Assuming that the unit is in good condition or refurbished, the CDV700's probe can detect uranium glass and natural uranium, but the sensitivity is low. If the glass is nice and hot or the uranium is close to the surface and hot, then yes. A $250 replacement pancake style probe can up the sensitivity. I'd recommend an Inspector USB, instead.
I have 2 of these units that belonged to my grandfather. One of them is in pristine shape. I mean, it looks like new, like it has new paint. It also has a old speaker connected to it for sound. The other one is in very good shape, but looks to have been used some, with not speaker. I put batteries in them just long enough to test, and they both work. I do not want to sell them, but I am curious about what they would sell for? I never, ever see them for sale at auctions or any place. Oh, the one that is in very good shape is more of a greenish yellow. Does that identify it in any way as being different than the pristine, new looking one?
+Groundhog If they truly are in good shape, they could be sold for a fair value. Look on eBay for the current prices, but I paid almost 200 for mine. The recent mine cost so much was not just because it was in good shape, but because it also held that circuitry checked and refurbished. Of course, I would keep them just because I like Geiger counters =)
Uh, I meant to say my dad, not my grandfather. I have one marble out of several that is slightly radioactive. Also a old alarm clock that makes my geiger counters go crazy. Back in the 60s, I used to use that clock on my headboard for a while. I am a healthy 65 years old BTW. For now, I like playing around with those 2 geiger counters. Like I said, one of them looks like new! I live in NC BTW, not that that means anything.
Tom, I am beginning this hobby and I have two questions for you: 1. I found a CDV700 6A or 6B in working order (uncalibrated) for $80-90 the seller says each unit will be tested prior to shipping. Should I buy it and what are the calibration points for each type of unit (full designation: Victoreen Ocd CDV 700 6A or 6B). 2.What is the music featured in this video. I want to listen to it all the time.
ajsliter The unit will make no sound without headphones or a speaker. www.anythingradioactive.com/ sells external speakers and parts, as well as tested units. A CDV700 is not very sensitive and really more of a collectors item. Normally, I recommend an Inspector USB for a new user (they run around $550). The sensitivity difference is night and day (8 to 10 times greater). The price is good but for such a low price, you need to ensure you can work with old analogue parts. Calibration is not too hard, but you need a Co60 or Cs137 source handy to do it. You can calibrate with the check source, but it is not very accurate. On the x10 setting with the beta shield open and the probe over the check source, you should get 0.2 - 0.25 mR/hr. Units like that are always risky. I spent $150 on mine but got a money back guarantee and it was fully reconditioned.
antiprotons There is a reconditioned one with pancake probe for $150, but i thought I would want to search only for Beta and Gamma sources from rocks in the woods and maybe when I take a trip to Colorado in the summer find some sources in the mountains. Is there a more sensitive one for only beta and gamma that is around in the 100-200 range that you can point me to?
ajsliter I also Found a assembled Kit that uses an SBM 20 tube and appears to use 2 AA batteries mesures in uSv/h and CPM. Price is $75 what a bargain! Here is the link to see if you would recommend this to me. www.ebay.com/itm/NEW-NetIO-Geiger-Counter-Board-Kit-GC10-Full-Assembled-Kit-SBM-20-Arduino-/181420171331?pt=LH_DefaultDomain_0&hash=item2a3d7c2043
Those SMB20 Russian tubes are nice, but you will only get readings from the more powerful sources. Weaker sources will be hard to detect without long timed counts. Between the two, I'd pick a CDV700 reconditioned with a pancake... but you might also check for a Ludlum model 3. The model 3 is basically a modern CDV700-style unit typically shown with a pancake or pickle probe. Note, the probe does not always come with the Ludlum.
+antiprotons heres another message from the seller. Dont know if its coming With the thorium source and the depleted uranium source. Seller said: "The counter should measure 1-2 on the scale. It should be measured on the 10x which would be 10-20 counts per minute. The radioactive check source on this model is The Thorium which along with depleted uranium and radium 226 is used as a count source. When you get home from your procedure, measure the site. It will diminish over time." Ask the medical staff how many counts per minute you are getting.
Sounds like the original check source. They do not always get worse over time. It depends on the radio nuclides used. The doctors will not be able to tell you CPM as that is instrument specific. They will give you (if they even do) absorbed dose in Grays/hour, Equivalent Dose in Sieverts/hour, or acitivty in either Curies (ancient and depreciated) or Becquerels (decays per second).
antiprotons It looks like one of those suction cups on the side with what looks like a tablet in the middle, and on the rubber part of the tester it says TH-233. any ideas on how much it should read abouts? looks to be roughly the size of a small asprin.
DEOXYS987 Ekk. Talk about non standard. It will tell you the thing is working, but not much more. You are likely not concerned as much with dose rate as the dose you are exposed to cannot be helped (you can't get away from it). i'd stick with CPM as that is likely more accurate. Let's figure out your background... without being too specific, about where do you live? East coast, west coast, etc? What is your rough estimate of your altitude from sea level. Lots of rocks nearby?
I have never used that unit but the SBM-20-01 tube looks quite nice. Just guessing, I would imagine that the SBM-20-01 tube provides results similar to the 6993 tube (found in the CDV700). Under $300 USD for a Geiger counter is a great price! Are you sure you don't want to spend another $200 USD and get an Inspector? It would be massively more sensitive with it's large pancake tube. I posted an inspector video too... Been to Scotland, always wanted to see Ireland. =) Cheers!
Lucky you! You might find that the low grade stuff is fun. I found a deposit of uranium in my own town just recently! :) Unless you buy a Ludlum, the CDV700 is a must.
Great video as usual! Do you know of any way to calibrate a CD V-700 (for counts, not necessarily energy) without using the included checksource (the "radium D+E" on mine has likely decayed enough in fifty years to no longer be as active as the manual states)? It works for my element collecting related purposes, and I love the aesthetics of it, but I'd still like to get more accuracy if I can without buying another counter.
Yes, I wrote a Raspberry Pi program to count the rate of clicks from the unit's headphone jack. Once everything was set up, I put the probe near a suitable source and turned the unit's CAL potentiometer so that the counts per minute on the CDV-700 matched the rate that the program was reporting. The steps are: Buy a Raspberry Pi and set up Raspian. Learn Python programming and the Python library tools for measuring time and for reading the state of the GPIO pins. Write a program that measures the time needed to count 2000 pulses, and to report it in counts per minute. Connect the headphone jack to a potentiometer to drop the voltage from 14 volts to just under 5 volts, which is what the GPIO can handle. THEN connect the headphone pulses to a GPIO pin. Run the counting program, and turn the CAL potentiometer. This will give you a CDV-700 that correctly shows the counts per minute, and also the millirems per hour.
Counts per second is fine, but anything less than 60 counts per minute and you will likely read zero. If your background were 0.5 CPS and jumped to 0.9 CPS, you would still show nothing. In CPM, the same readings would be 30 CPM to 54 CPM, respectively. Any Geiger counter can detect uranium. Is your unit a Ludlum with a "pancake" style tube? (44-2 detector)
I got mine done by a private contact and I can otherwise do it myself, so I have not used any commercial sites for my CDV. I have heard good things about www.radmeters4u.com/calibrate.htm and they are accepting units again.
Search youtube for Jasonthepcmd cdv-700. I went to dollar tree and bought a $1 window intrusion alarm and wired the speaker to the CDV-700 with very good results. (My video above under my main channel talks about it) The two speaker units that anythingradioactive is selling are based two items that Dollar Tree sells for $1 (though they did put LEDs in them)
From what I've read around from other sources including a civil defense museum is that these should be run off two d cells with jumpers or four AAs because batteries now are way more powerful than the batteries these were designed for. You risk the chance of burning out the geiger. Myself i just got some AA cell adapters that fit in d cell slots and it works great
The music sounds sooooo out of place here. It belongs in a video game / anime cutscene, or a professional documentary, not here. The contrast is too jarring. Please never do this again.
Very interesting and well presented video, but what's with the music?
I found mine at a garage sale. I first picked it because I seen the telephone style head clip then I realized what it was. I bought for 1$.
Thank you very much for replying to be, I've always been fascinated in these kind of things.
I am looking forward towards the video you will be posting.
On a side note, do you have those units tested and calibrated yearly? A unit in bad working condition is a big liability for a firefighter (imagine a bad air tank or hose coupling!)
Also, those are higher range units (mine is x1, 10, and 100).
Open the beta shield and hold the open window against the check source on x10. You should read between 2 and 2.5 mR/hr.
What's with the underscore (music)? Very distracting! Otherwise, I really like your work.
Good information in this, but PLEASE remove the cheesy background music!
Didnt you see the butterflies and unicorns flying in the background?
+antiprotons west coast CA roughly ~ 1200ft and not a while lot of rocks nearby but I'm near the mountains. OH and the seller is giving me a free Radium-226 source in addition with the counter.
Thanks for a very thorough and comprehensive review of that victoreen model. Any idea who that was designed for?
I know the video is 6 years old but... I hope you still remenber how these device works. There is a lot of cdv700 on ebay that are not calibrated but here is my question: can I just get one that "works" and calibrate it myself? If the check source is depleted, I just need to buy a calibrated source (cs137) and calibrate the cdv700 by turning the screw inside right?
Well... they are both right. Different models had different check sources. My Victoreen 6A has a DU source. I confirmed this with gamma spectroscopy. The beta emissions are not very penetrating and the gamma from my unit is less than 0.5 uSv/hr, a very small amount of radiation. Personally, I would not very worried given that your average smoke alarm is much hotter (even gamma).
how lovely, just lovey, a magnificent video indeed sir
Tom,
How would a DX-2 (US geiger counter. claims to be as sensitive in beta gamma as $1000 geiger counters) glass tube exposed on the side for 3-4 inches with scale from 0-1000 uSv/h and 0-100 mR/h powered by a 9V battery. $190 a little more expensive than the wires and double SBM-19 counter ($175) that I wanted to build custom, but according to reviews for prospecting in mines and in nature worth the price. Also claims to beat the Gamma Scout. The DX-2 also has a screw on the back for manual calibration.
A standard 6993 tube will work. My Victoreen unit has a Lionel brand tube in it so it must have been replaced at one time. If you want to use a different tube, make sure it is rated to 900V. Many are not. SE International makes a pancake probe called the CDV-700RP TFG Radiological sells them for $330 so not cheap. If you're looking at Soviet surplus again make sure the tube is rated for 900V or you'll have to build a circuit.
You can self calibrate using the check source on the side. It's not really 100%, but it works. Ludlum might do it (ludlums com). If not, they would know who.
+antiprotons did that sound like I'm getting two sources? If so usually in the room when they give the radiation pill they'll have a geiger counter and I'll have them measure the thorium to get a baseline if I have to calibrate the counter.
hey, rkshirey again, just got my cdv-777 survey kit. love it.
It has that stereotypical yellow-green color that always reminds me of the radioactive industry.
I like the one with the round red front more :P
Thanks for the good advise, very helpful.
i have the cd 715 and it still works and is almost brand new
Hi Antiprotons thanks for your reviews only came across your channel a short time ago and I have learned a lot thank you . How do you rate the Russian Soeks eacotester Geiger counter as I was thinking of getting one and it seems ok at 200 euro about 240 to 250 us dollars .
Kind regards from Ireland
Superb overview of this unit. Maybe best video on youtube in terms of differing samples + readings and explanations--fantastic!!!!. I've collected these units on a very small scale since high school but I've certainly never seen one with that cute external speaker.
It looks like a stereo speaker, I wonder why it has 2 speakers... the old school "microphone"/screw on connector is beige/white almost looks like a retrofitted part. Of course it's only mono, no possibility of stereo whatsoever here.
that little 2 speaker thingy mounted on the side reminds me of early 'cassette tape styled stereo speakers' meant to plug into your tape player walkman and was a speaker that played audio.
It had the benefit of being of able to be stored inside your crappy cassette walkman.
Nice. Have you ever seen the polish DP models? I've got the DP-66M. Maybe i'll make a video with it.
The brand doesn't matter. Lionel, victoreen and others make that tube. It is also used in other 1960s-1980s geiger counters that do beta/gamma.
Thanks antiprotos. bought a CDV-700 last night
Enjoy! Make sure to open the beta shield and place the wand shield open against the check source on x10 mode. Look for a reading of 2.5 to 30 mR/hr, to know the unit is correctly calibrated.
antiprotons mine comes with a Thorium calibration test source, what should that conservatively read out between? want it as accurate as can be. getting a dose of Iodine I-131 in about 8 weeks and want to see how much radiation i put out.
DEOXYS987 Is it the original built-in check source or a hunk of thorium rock?
antiprotons Doesnt appear to be a hunk of rock.
DEOXYS987 The only source which will work with the 2.5-3 mR/hr at x10 is the original builtin check source.
Any other source would require a calibrated reading.
Basically, someone places the unit in a given configuration and makes a reading of the source. They know (via another unit or lots of math) what the reading should read. They calibrate the unit to that. It should always much up or be known to be off calibration.
We have 12 of these units on our fire dept. They are the ear phone style. The other night we boiled water in the microwave and held the wand inside the oven and over the cup. We did NOT have the shield open, had the setting on X-1000, we had a reading of "50". The unit clicked once every 15 seconds, what EXACTLY where we reading??
Very informative video--thank you!
Good point about the lead 210 and the bismuth 210.
Bi210 will remain in secular equilibrium due to it's super short halfife. I calculated that your units (probaly 53 years old +/-) are now about %19 of what they once were: 100e^-((ln(2)/22.2years)*53years)
So, perhaps you could try to divide your reading by 0.19 and see if it's correct...
If you get 0.475 mR/hr then 0.475 / 0.19 = 2.5 mR/hr = calibrated?
Short of buying a new source, that might do.
Would the LND 720 Muller tube replace the Victoreen 6993 Muller tube with any benefit? If not, where to purchase a 6993 Muller tube?
I'd stay with the 6993. The LND712 is nice, but too smaller for the probe housing and much lower gamma sensitivity.
Hello, I am just curious because I don't have much knowledge on anything radiation wise because I've only done chem 20 ( first year of Chem in highschool ) which only went over Isotopes for a little bit which I already knew but I was wondering what the Bq in 'Cesium 137 - 3737 Bq" means?
+antiprotons Here is what the seller said about the testing element and just wanted to get your opinion on it. "If you put the dial on 10x and hold it closely to the thorium source, it should go between the 1 and 2 on the guage. Give it a minute. That's reading between 10 and 20 counts per minute with is where the unit should be.
If you go over to the 1x it should peg at the right end." does that sound about right?
Odd... on 10x, the readings are 0 to 30,000 CPM... so I think they mean 10,000 to 20,000 CPM. Is it calibrated? Did they provide a calibration statement or certificate?
Really good video! Is it safe to keep in the house with the check-source that it has built
in? I have a very basic knowledge of physics. Thinking back to high school physics I'm assuming the sticker will
block Alpha and Beta rays coming out of it? I'm assuming the gamma amount is too low to even travel out of it? I was intending to store it in a cupboard under the stairs. Thanks!
It's a pretty small source. The inverse square law is your friend and is pretty safe to keep in your house. Just don't sleep with your check sources.
Well, you have a geiger counter attached to the source so try to measure if there is any diference in radiation from background at 1 foot from the source.
NOTES:
Please watch in FULL HD (lower right of screen, "gear" button)
The following sources were tested:
Cesium 137 - 3737 Bq
Cesium 137 - 37000 Bq
Old barely detectable Radium Compass
Strontium 90 - 3700 Bq
Polonium 210 - 666 Bq (as of 7/22/12)
Pitchblende Uranium (United Nuclear)
Stay tuned for two more videos (CRM-100 and Inspector EXP)
Odd. Are your units calibrated yearly and in good order? Could you have a bad unit?
You really shouldn't pick up 50k CPM (or any above background) in a microwave.
What kind of distance can the cdv700 with standard probe be expected to pickup trace radiation, for "radiation hunting" items around the house,etc.... I have a GQ GMC-300, and it seems anything below a few thousand CPM, it won't start picking up unless it's 3-4" from it.
The method to determine this is called the distance inverse square law. For example, if your unit detected 1% of gammas it detected (1% efficiency) and you had a radioactive object emitting 37000 photons per second... how many CPM would you get above background at x distance? Well, First you determine the area of your tube which directly faces the source. If half of the probe faces the source and the probe is 8cm around and 12 cm long, than half would be 48 cm^2 of area exposed to the source. At 100 cm, you would detect: 0.01(37000 photons / 4*pi*(100cm)^2) = 0.2944 (not even 1) additional CPM. At 10 cm distance, you get: 2.9444 CPM above background... See? I'd suspect you would need to be within a foot of most objects. Let me know if you need more info and I can make a short video showing.
How do you carry so much uranium/plutonium in your house? I thought all this radiation would decay the house building.
Where did you get that external speaker? I need one of those!
Bq is short for Becquerel. 1 Bq means 1 decay per second.
Decay is random, but there is always a statistical average. If an atom decays, on average, 100 times per second, it is said to have an activity of 100 Bq.
Now, decays are alpha or beta only. Gamma rays come after a decay, so 100 Bq does not always mean 100 gamma rays. In the case of Cs137, for 100 decays you get a gamma about 85.1% of the time.
I'm posting a video about each form of decay, in detail, very soon.
First off I love the video very helpful, I just bought a Lionel CD v-700 6b and I would like to get a speaker for it and I'm wondering Where did you get the speaker and what is it called.
If the microwave was on, you probably damaged the probe. Electromagnetic induction occurs when something like a microwave induces a current in the center wire of the Geiger tube, causing a nearly steady current. It simulates what would occur in a mega powerful radiation field. The unit jammed and the needle feel to zero.
Never do that as it kills the unit. They do not detect anything related to microwaves.
My friend, can you please elaborate more on the check source that is attached to the device, I found very conflicting information, some say its Ra 226 some say DU, I'm just a biginer with these things and I picked out a unit same as yours, but I'm a bit worried to handle it. Thanks!
+antiprotons No certificate to speak of from the pictures. Do not know how well calibrated that this unit is, he just says it works well. Any ideas?
These things really are rugged. Mine fell down the stairs and hit the hard wood floor and it still works.
Are these old units sensitive enough to check if U glass is real? Or to look for radioactive deposits in nature?
Yes and no... Assuming that the unit is in good condition or refurbished, the CDV700's probe can detect uranium glass and natural uranium, but the sensitivity is low. If the glass is nice and hot or the uranium is close to the surface and hot, then yes.
A $250 replacement pancake style probe can up the sensitivity. I'd recommend an Inspector USB, instead.
Cool, tnx alot.
I have 2 of these units that belonged to my grandfather. One of them is in pristine shape. I mean, it looks like new, like it has new paint. It also has a old speaker connected to it for sound. The other one is in very good shape, but looks to have been used some, with not speaker. I put batteries in them just long enough to test, and they both work. I do not want to sell them, but I am curious about what they would sell for? I never, ever see them for sale at auctions or any place. Oh, the one that is in very good shape is more of a greenish yellow. Does that identify it in any way as being different than the pristine, new looking one?
+Groundhog If they truly are in good shape, they could be sold for a fair value. Look on eBay for the current prices, but I paid almost 200 for mine. The recent mine cost so much was not just because it was in good shape, but because it also held that circuitry checked and refurbished.
Of course, I would keep them just because I like Geiger counters =)
+antiprotons please can you watch my cdv 700 video
Uh, I meant to say my dad, not my grandfather. I have one marble out of several that is slightly radioactive. Also a old alarm clock that makes my geiger counters go crazy. Back in the 60s, I used to use that clock on my headboard for a while. I am a healthy 65 years old BTW. For now, I like playing around with those 2 geiger counters. Like I said, one of them looks like new! I live in NC BTW, not that that means anything.
Tom, I am beginning this hobby and I have two questions for you:
1. I found a CDV700 6A or 6B in working order (uncalibrated) for $80-90 the seller says each unit will be tested prior to shipping. Should I buy it and what are the calibration points for each type of unit (full designation: Victoreen Ocd CDV 700 6A or 6B).
2.What is the music featured in this video. I want to listen to it all the time.
Added information for #1: Unsure if headphones are included and readings on the 6A tested is .2Mr/h in X1.
ajsliter The unit will make no sound without headphones or a speaker. www.anythingradioactive.com/ sells external speakers and parts, as well as tested units. A CDV700 is not very sensitive and really more of a collectors item. Normally, I recommend an Inspector USB for a new user (they run around $550). The sensitivity difference is night and day (8 to 10 times greater).
The price is good but for such a low price, you need to ensure you can work with old analogue parts. Calibration is not too hard, but you need a Co60 or Cs137 source handy to do it. You can calibrate with the check source, but it is not very accurate. On the x10 setting with the beta shield open and the probe over the check source, you should get 0.2 - 0.25 mR/hr.
Units like that are always risky. I spent $150 on mine but got a money back guarantee and it was fully reconditioned.
antiprotons There is a reconditioned one with pancake probe for $150, but i thought I would want to search only for Beta and Gamma sources from rocks in the woods and maybe when I take a trip to Colorado in the summer find some sources in the mountains. Is there a more sensitive one for only beta and gamma that is around in the 100-200 range that you can point me to?
ajsliter
I also Found a assembled Kit that uses an SBM 20 tube and appears to use 2 AA batteries mesures in uSv/h and CPM. Price is $75 what a bargain! Here is the link to see if you would recommend this to me.
www.ebay.com/itm/NEW-NetIO-Geiger-Counter-Board-Kit-GC10-Full-Assembled-Kit-SBM-20-Arduino-/181420171331?pt=LH_DefaultDomain_0&hash=item2a3d7c2043
Those SMB20 Russian tubes are nice, but you will only get readings from the more powerful sources. Weaker sources will be hard to detect without long timed counts. Between the two, I'd pick a CDV700 reconditioned with a pancake... but you might also check for a Ludlum model 3. The model 3 is basically a modern CDV700-style unit typically shown with a pancake or pickle probe. Note, the probe does not always come with the Ludlum.
+antiprotons heres another message from the seller. Dont know if its coming With the thorium source and the depleted uranium source. Seller said: "The counter should measure 1-2 on the scale. It should be measured on the 10x which would be 10-20 counts per minute. The radioactive check source on this model is The Thorium which along with depleted uranium and radium
226 is used as a count source. When you get home from your procedure, measure the site. It will diminish over time."
Ask the medical staff how many counts per minute you are getting.
Sounds like the original check source. They do not always get worse over time. It depends on the radio nuclides used.
The doctors will not be able to tell you CPM as that is instrument specific. They will give you (if they even do) absorbed dose in Grays/hour, Equivalent Dose in Sieverts/hour, or acitivty in either Curies (ancient and depreciated) or Becquerels (decays per second).
antiprotons It looks like one of those suction cups on the side with what looks like a tablet in the middle, and on the rubber part of the tester it says TH-233. any ideas on how much it should read abouts? looks to be roughly the size of a small asprin.
DEOXYS987 Ekk. Talk about non standard. It will tell you the thing is working, but not much more. You are likely not concerned as much with dose rate as the dose you are exposed to cannot be helped (you can't get away from it).
i'd stick with CPM as that is likely more accurate. Let's figure out your background...
without being too specific, about where do you live? East coast, west coast, etc? What is your rough estimate of your altitude from sea level. Lots of rocks nearby?
I have never used that unit but the SBM-20-01 tube looks quite nice. Just guessing, I would imagine that the SBM-20-01 tube provides results similar to the 6993 tube (found in the CDV700). Under $300 USD for a Geiger counter is a great price! Are you sure you don't want to spend another $200 USD and get an Inspector? It would be massively more sensitive with it's large pancake tube. I posted an inspector video too...
Been to Scotland, always wanted to see Ireland. =)
Cheers!
Lucky you!
You might find that the low grade stuff is fun. I found a deposit of uranium in my own town just recently! :)
Unless you buy a Ludlum, the CDV700 is a must.
Great video as usual!
Do you know of any way to calibrate a CD V-700 (for counts, not necessarily energy) without using the included checksource (the "radium D+E" on mine has likely decayed enough in fifty years to no longer be as active as the manual states)? It works for my element collecting related purposes, and I love the aesthetics of it, but I'd still like to get more accuracy if I can without buying another counter.
Yes, I wrote a Raspberry Pi program to count the rate of clicks from the unit's headphone jack. Once everything was set up, I put the probe near a suitable source and turned the unit's CAL potentiometer so that the counts per minute on the CDV-700 matched the rate that the program was reporting.
The steps are: Buy a Raspberry Pi and set up Raspian. Learn Python programming and the Python library tools for measuring time and for reading the state of the GPIO pins. Write a program that measures the time needed to count 2000 pulses, and to report it in counts per minute. Connect the headphone jack to a potentiometer to drop the voltage from 14 volts to just under 5 volts, which is what the GPIO can handle. THEN connect the headphone pulses to a GPIO pin. Run the counting program, and turn the CAL potentiometer. This will give you a CDV-700 that correctly shows the counts per minute, and also the millirems per hour.
Counts per second is fine, but anything less than 60 counts per minute and you will likely read zero. If your background were 0.5 CPS and jumped to 0.9 CPS, you would still show nothing. In CPM, the same readings would be 30 CPM to 54 CPM, respectively.
Any Geiger counter can detect uranium. Is your unit a Ludlum with a "pancake" style tube? (44-2 detector)
Who would you recommend for calibration, my cdv 700 6b is not reading right. Thanks
I got mine done by a private contact and I can otherwise do it myself, so I have not used any commercial sites for my CDV. I have heard good things about www.radmeters4u.com/calibrate.htm and they are accepting units again.
what is the music bruh are we reviewing geiger counters or teacups
Where Can I buy This set really cheap
It's so beautiful
What are the 3 windows on the tube? How is the tube connected to the machine?
there is a cord between the meter and tube, and the windows are for allowing beta particles throuh
Is it good for detecting radioactivity from granite?
It is okay for that. I would recommend a more sensitive unit, personally (unless you are uranium hunting... then a less sensitive unit is better)
antiprotons Well granite does contain TRACE amounts of uranium along with thorium and potassium-40.
Search youtube for Jasonthepcmd cdv-700. I went to dollar tree and bought a $1 window intrusion alarm and wired the speaker to the CDV-700 with very good results. (My video above under my main channel talks about it) The two speaker units that anythingradioactive is selling are based two items that Dollar Tree sells for $1 (though they did put LEDs in them)
turn on c-c
and enjoy
lol, nice vid anti
Great job! Just kill the damn music pls.
From what I've read around from other sources including a civil defense museum is that these should be run off two d cells with jumpers or four AAs because batteries now are way more powerful than the batteries these were designed for. You risk the chance of burning out the geiger.
Myself i just got some AA cell adapters that fit in d cell slots and it works great
I got the speaker from anythingradioactive com. :P
i want one but its 109 dollars
Turn off the music dude. Its so distracting and its too loud, so its competeing with your voice for listening resources.
No it was off
gosh this music is pretty annoying!
NOT METAL, its aluminum motard.
Asswipe, what do you think Aluminum is?
The music sounds sooooo out of place here. It belongs in a video game / anime cutscene, or a professional documentary, not here. The contrast is too jarring. Please never do this again.