Found this PDF of an update mod to the ancient [but useful] CDV 700 Geiger counters.

Florida had a ton of the CDV 700's apparently and got Ludlum to make available a kit to upgrade certain CDV 700's to become similar to the Ludlum Model 3 counter.

The PDF is slow to load and has a lot of interesting pixs of the mod.

Years ago we did work for FDLE and found them great to work with and very innovative. Looks like another part of Fl.gov is too.

Enjoy...

http://luckan.altervista.org/DOCs/RSP09CDV-700Upgrade.pdf

or...

http://luckan.altervista.org/DOCs/RSP09CDV-700Upgrade.pdf

[when it works...]


Here's a link to COMPLETED ebay auctions so you can see what the CDV-700 and related items are selling for and how popular they still are.

http://www.ebay.com/sch/i.html?_sacat=0&_from=R40&LH_Complete=1&_nkw=CDV-700&_pgn=2&_skc=50&rt=nc

Bad link to update.

The address isn't bad.
It just doesn't work if you click on it.
If you copy and paste it into the address of a new page it works fine.
I have no idea why.

EXPY37:
Thanks for the pdf.

Used Model 3's in good condition aren't terribly expensive...

Guys, when considering the CDV 700, make sure you take a look at this post by member X-Nuke from 2008 (I also recommend all of his other posts from 2008 on the subject, very informative.)  Basically in a high energy gamma field the CDV 700 can register zero, allowing you to walk into it and be fried.  The intent of the CDV-700 was to scan people coming into shelters with the "hot dog" to see how hot they were and what the extent of decon would need to be.  Not sure if these upgrades you guys are considering fix that or not.
I have decided based on his info to try and find an Eberline E520, which was widely used in the nuclear power industry, and overlap with the higher range meters (CDV 715, 717.)
 

The CDV-700 was designed for three thing 1) training (you can safely use the CDV-700 with sources that cause a full meter reading and demonstrate the effectiveness of shielding and distance and learn to locate the source. 2) Decontamination (not just to identify contamiantion, but to verify decontamiantion and 3) first responder use on nuclear accidents (weapons, shipping, reactors, waste, etc.)  It does a good job of all three.  But the saturation is mosly an effect of it's primitive electronics.  New meters used a processor to overcome most of the saturation problem.

While there are ways electronically to reduce the effects of saturation on a Geiger tube, it's very principle of operation dooms it to minimal usefulness in high radiation fields.

Modern Geiger tubes can be made less sensitive, smaller cross section, different gas fill incl a quench gas, etc, to increase their tolerance of high field radiation without saturation. Tremendous work has been done in this area since the 1930's and is still ongoing. Amazing to study the history.

An example is the old timey LND 726 tube.

LND 726

Electronically, the high voltage can be pulsed to the tube and other means, but it still boils down to if being used as a high field radiac meter, something else has been used ---historically.

That's why the CD kits included additional radiation meters such as the CDV-715 and others. Also dosimeters.

These early CD detectors used 'ion chambers' [still a very useful device with many applications] usually filled with air at atmospheric pressure and a special sensitive tube that can detect and amplify the minute current that flows from the wall of the ion chamber [the big central can in the CD meters] to a probe near its center. High levels of radiation ionize the air within the camber and the electronics indicate the current flow on a meter.

Dosimeters work similarly, with a quartz fiber that is charged to about 100 volts or so [that's with the small charging box you often see sold with them] inside a small ion chamber. As radiation passes thru the dosimeter's wall, the charge on the quartz fiber is lost and it moves relative to its support.

A magnifying lens with a scale reads the position of the quartz fiber ---that appears as a black line on the scale.

The dosimeters come in various radiation sensitivities per hour, and the more sensitive ones can actually be dishcharged with a couple Fiesta plates or radioactive ore.

Lots of VERY hot uranium ore samples on ebay at low cost.

Great fun and these are cheap enough now to take apart and study their internals.

I gotta ask: Has anyone at Ludlum's ever heard of solder mask?

Those printed circuit boards look like they were etched, plated and drilled in someone's garage...

Just pulled the cover off a lovely Ludlum 2401-EW survey meter that uses an LND 712 Geiger tube. [alpha w/ end window]

http://www.ludlums.com/component/virtuemart/market-1/nuclear-power-plants-104/pocket-size-exposure-and-a-b-g-count-ratemeter-100-detail?keyword=2401-ew&Itemid=0

Dated early 2000's and no solder mask and a lot of SMD as well. Nicely made tho.

I wonder if they learned abt Phillips screws, everything is slotted.

My co got away from slotted screws in the 80's even while I was still wet behind the ears.

SkiB, there's a lot of Ludlum mod 3's but dang, the price... Ouch...

Yeh, they've gone up quite a bit since back when I was shopping.

I'm still jonesing for a Ludlum 25, but I still can't justify the scratch when I need so much other stuff.

I have a CDV-700 that's been refurbed and calibrated, and one of those (somewhat silly) "Nukalert" gizmos I got as part of a package deal.  

I have the CDV-700 at home with the thought of using it to detect contamination if anything really wild ever happened, and I keep the "Nukalert" in my pack at work.  If the "Nukalert" ever went off, I'd likely shite myself and draw down on the nearest folks.

Somebody needs to come up with a really good (fully functional) "Pipboy" design for Arfcommers.

I mostly agree since it starts chirping at 100 mR/hr.    Not a big amount by any means, but I'd still leave if it was an option.  If I were on duty, it might not be an option depending on whatever crazy scenario someone dreamed up.

I want something like a Ludlum 25 because it can measure from background all the way to lethal, acts as a dosimeter, and will fit in a pocket or on my gear.  It's pretty doubtful I'll ever need one, but my Agency is pretty good at sending me to stupid places sometimes.  I was thinking about writing up a purchase request, but they'd just buy them and then stash them away somewhere.  I'd rather own my own, and then it wouldn't disappear before I wanted it later.


Speaking of Nukalert, I now see that they have a new model called the Nukalert-ER.  http://www.nukalert.com/index_b.html It looks a lot better than the original one, but too expensive for my taste.  The Ludlum 25 is actually cheaper than what KI4U wants for the dang Nukalert!  I don't know how well they compare though.

Yep.

If cost isn't a major consideration, the 25 is just plain incredible.

How much are they? We all want to know...

Around 600 bucks.

Price list download here.

Yeah, the dang price went up recently.  They were closer to $500 earlier this year/last year.  I had thought about getting me one for Christmas the last three years running.  

I emailed and called around for quotes from some places that sell Ludlum, but couldn't find any deals anywhere.  I've never seen one go for sale on ebay either.


I really WANT one, but the odds of me ever actually NEEDING it are so low it's really hard for me to justify it at the preparedness level I'm at nowadays.


ETA:  Why don't one of you guys become a dealer and give us a group or Arf discount on them.

ETA #2:  Re: Ludlum price list-- I just noticed they have the CDV-700 retrofit parts on their price list.  They want $210 just for the board!

Wait for the DealExtreme copy - It'll be17 bucks (delivered), and also include an MP3 player!

That would be cool, cuz then I could fill the MP3 up with Fallout 3 tunes.....






(hopefully the embeds work, I can't see 'em on the damn ipad.)

why would you be walking around in a nuclear environment???



 

Damn.  We bought 2 Flukes (They bought Victoreen) at work for well over 2000 each.

BTW, one of the neatest places to play with these is the oil and gas industry where they have high levels of NORM (Naturally Ocouring Radioactive Material).  The levels can be will above what is seen in a lab or nuclear power plant.    I've been offshore and I guess they don't get NORM in GOMEX, but one company let me on a site out west they had some pretty high levels, and was a good chance to try the CDV-700 vs the FLuke vs the UltraRadac.  We've never had regulated sources at work- I've had access to Co60 trainign sources in the past but not any more.

What are your thoughts on using other detection equipment as contamination/rate/dose meters?  For instance, the RadEye G would work as a personal dose meter, and the iDentifinder has a count meter and a rate meter in addition to being an RIID.

Looked at the iDent and it has a zillion choices for detector options. It could prolly do everything you want with the right ones selected.

For nice hot sources, look on ebay for uranium ore specimens.

They can be very hot. Often the CPS are given for locations on the sample. I've seen close to a million CPS with a scintillation counter with some small samples.

Or go to an abandoned uranium mine and along the roads to it close by you likely can find all you want.