And those Corotron (proper name) voltage regulator tubes go bad and allow the voltage to go high, which can destroy the pulse transformer (T1) which is not to be found anymore. That Corotron VR tube should be replaced with a zener stack voltage regulator ASAP. I suspect that's why so many are no longer working. eBay sellers have pre-built zener stacks available. It's an easy direct replacement. Help a friend, pass the word.

my friend took his geiger counter to the camping store and the thorium lamp mantles all hanging on the shelf together gave a really strong signal. made the store employees freak out.

@@IMSAIGuy There is a guy I met in an antique shop who has been restoring the camping style lanterns for years. He collects them of course. I showed him the geiger counter response on some of the ash in the bottom of one of his. I always try not to alarm people but educate them on safer handling. I explained that it's nothing to freak out over but be careful to wash hands after handling/work and avoid inhaling the ash dust. Same thing with the old radium clocks/watches. If you're looking for a nice test source, it's easily found in vintage orange pottery because it's mostly a low energy beta emitter with quite nice high CPM. Very little gamma.

Always check watches and clocks as well for Radium, very interesting to find

Their REAL oscilloscope gets terrible reviews. But that little component tester is a gem.

Where in Jersey? I was licensed there in '57 and had a Gonset Communicator. In Hunterdon County. I wonder if my Elmer, W2AZZ checked in. I was WV2ECZ.

@@barrybogart5436 Bergen County

This is very useful information, you are the fist person I have come across online to flag that, thank you.

@@Anthony_Matabaro_3D_360 You are welcome. I've been shopping for counter myself and was wondering what the difference is and why the difference in price. I'm planning to get a low end scintillator counter.

Christmas prezzie to yourself ? !

@@andymouse Yes, good idea. I mean that's what I thought all along. :)

I also thought of adding a piezo. Perhaps try 2.5 khz resonant freq ones rated 30v p-p. They were the best sounding for CDV700 anyway. Radio Shack part number 2730073 can still be found online/ebay etc.

@@nefariumxxx Maybe a distant relative of mine ?...Merry Squeakmass !🐭

@@nefariumxxx I've used them before, (I had one as a doorbell. LOL). But it's too big to fit inside the case. I am waiting to see if anybody else tries it first. I'm not risking mine. Ha ha.

Yep, the black plastic PRI versions are known to leak a bit of contamination. Don't know about the Detectron version. It looked ok.

did it work?

@@irondan357 Never ordered the unit :) Mr. Imsai Guy should do a follow-up :)

The CD V-700 also came with a "check source", a bit of a radioactive isotope under a sticker on the side of the unit. The isotope varied with the maker; depleted or natural uranium was common, though the Instruction and Maintenance Manual for the Lionel Model 6B indicates that a "Radium D+E beta source" with an approximate half-life of 22 years is present under the nameplate. This produced, at the time of installation on the machine, about 1-2 mR/hr adjacent to the source, a value which was clearly visible on the analog meter as well as audible via the headphones that accompanied the units. Measured with the probe's beta window uncovered and the probe directly in contact with the operational check source, this is about 100 times normal sea-level background levels of radiation, and similar to the near-field from a uranium oxide-glazed red Fiestaware saucer. The level drops back to background levels a few feet from the source. Since the half-life of the different operational check source materials used varied and since all CD V-700's were manufactured prior to 1964 and are now approaching a half-century old, the amount of radiation emitted from the source may be much lower than when the unit was originally issued. Therefore, accurate calibration via the source cannot be assured.[2]

Not Sr-90 on American stuff. That was used on foreign counters though. American Civil Defense stuff mostly used depleted U and also Radium 226. Some of the more fizzled out test source stickers even used "Radium D+E" (From ORAU) "Radium D and radium E are the historical names that Ernest Rutherford used for lead-210 (Ra D) which has a 22-year half-life, and bismuth-210 (Ra E) which has a five-day half-life". Now good luck remembering all that. :)

@@nefariumxxx Victoreen used depleted uranium.

@@loupgarou1261 yeah, they list the various flavors on the ORAU page if you google it. I don't see my ENI brand mentioned right now but remember it also being depleted U.

Me too

theyre on aliexpress for 45 right now

link in the description to an english speaker

Ha ha, what about machinist's surface gauges?

Many of these units are missing the check source

@@marcreynolds7948 There are replacements available.

The CPM values are probably a lot different and will depend if you have the beta shield open or close on the CDV700 probe. The FNIRSI has a decent response but it's not going to be super sensitive because it uses a glass walled tube and it's shielded inside the plastic case. Glass and plastic both block low energy beta counts. The stock CDV700 uses a thin metal wall tube but it's also not all that sensitive deliberately. The FNIRSI is a good value for the money. Just too bad the developers really dropped the ball on adding a "click per count" or source finding mode. It could be modified possibly by running a couple wires from the flashing LED to a piezo disc clicker. Try a 2.5 khz piezo perhaps.

and don't forget your nickel for milk at lunch

@@IMSAIGuy or a candy bar. Huckleberry pie, blackberry pie. Yay great times.

all nuclear decay is isotropic

@@IMSAIGuy Yes from the source, not the detector. Say you have a sample of radiation material in one corner of your room with normal Geiger counter you should go around the room to find it, but with directional Geiger counter the arrow leads you to it. In space such a directional Geiger counter, if you block the sun direction, could lead to detection of location of super Nova or other cosmic activity. We can also create directional gravitational wave detector with placing 3 gravitational wave detector on the 3 corners of a triangle in the space, say one on the earth another on the moon and a third one on say mars. By comparing the time of the event given the lag time, we can detect the direction on gravitational wave, the same way we detect source of earth quake using triangulation, so we can point our telescopes in that direction. We also can prove what is the speed of gravity, speed of light or infinity as quantum mechanical event.

@@aduedc if you can detect across the room with a geiger counter you are about to die. they only detect within a few inches. if you really want direction, just put it in a shielded box and poke a hole in it

@@IMSAIGuy you just need more sensitive detector. The mechanism of detection is when a particle or photon hits an gas atom, the gas molecules gets ionized and the ionized particles accelerated toward positive and negative terminals, and on their way they might hit other molecules which creates other ionized particles which amplifies the current. You can have the same thing with avalanche photo diode. Now the larger the area of Geiger tube or avalanche photo diode, the greater the probability of capturing the photon or particle, which means greater sensitivity. Therefore, to increase sensitivity you either have to design larger tubes and diodes or put several of them in parallel. When I drive from Los Angeles to San Diego On I5 I pass by San Onofre decommissioned nuclear reactor, I can detect the radiation by my cell phone's CCD on the high way in my car and I have not died yet! My phone's CCD is not very sensitive radiation detector. I just use android app that I bought for 5 box.

@@IMSAIGuy It's not like 'which way to run', more like 'which door or window to block off!'

Yup 4.468 billion years, U-238.

@@Phoenix88. Very good stuff, but can it be used in HOME PRODUCTS?

Not if it's destroyed by EMP pulse. The old CD units will still work, but will these new ones?

Not all radioactive minerals glow under UV light, All Geiger counters react to them. That's your answer.

no

yes, on my CD Geiger. there is a video on KZfaq now that shows adding one resistor to the FNISRI to make it click.

@@IMSAIGuy I have both, thanks!

what I want is a RadEye™ B20

Price I found on that is in the $600 range. It is a scintillator type counter though. More sensitive to low levels and more resistant to damage from higher levels.

@@BryanTorok the B20 is $2000

@@IMSAIGuy I was looking at the Radiacode 101 which is also a scintillator based counter with decent electronics for about $600. The B20 strikes me as way overpriced in that they market to industry, universities, and other institutions with deep pockets. I'm sure it is a great piece of equipment if you can afford it.

Those are cool but it doesn't detect Radon gas directly. You are mostly detecting background radiation coming up from the earth/bedrock granite as well as cosmic/space origin. Radon detectors use different technology. I use a device called Radon Eye because I live in a high radon zipcode. If you want to detect the secondary daughter particles from Radon, you can take a wipe off the whole car windshield right after a fresh rain following a period of dry weather. Radon progeny in the decay chain gets "scrubbed" out of the air by a fresh rain. The radon secondary particles (contamination) will adhere to the wipe which can then be detected by your Radiacode directly.

have a company send me one

kzfaq.info/get/bejne/ldSVibiezbDDqaM.html

didn't test it

too lazy maybe some day

thanks of all the comments. it help google recommend my channel.

The huge yellow one is a much better meter IMO.

@@loupgarou1261 maybe so . But the one I bought was the little hand held one. I was looking for instructions. You put up click bait that had nothing to do with the one I was looking for information for.