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A Geiger Counter for the Ham Shack

K0FF (K0FF) on May 26, 2010
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KØFF Homebrew Tips

 
Geiger Counters in the Ham Shack
 
 
Many hams are also interested in nuclear radiation detection for a number of reasons. A few of those reasons might be:
A) Collecting radioactive radio tubes
B) Testing high power equipment for X-Ray emissions
C) Testing and cleaning up surplus radio gear (radium paint abounds!)
D) ARRL has approved GAMMA RADIATION as a ham band for contests!!
 
For many years I never saw any decent radiation detection gear at hamfests. Since the late 1990's the US Gov't has been surplussing out those Civil Defense units that were stored in basements and attics all over our country, many of which now wind up for sale cheap.
 
There are several versions of these yellow, CD placarded hand held detectors. Ones marked CD V-715, CD V 710, CD V-720 and a few others WITHOUT external sensors or cords are high range ion-chamber detectors and have little use except near an atomic detonation.

One model is a true Geiger Counter, the CD V-700. This one has a silver handheld probe attached to the unit by a cord. Sensitivity of this Geiger Counter is very good and has many everyday uses around any home or ham shack.
 
Unfortunately the electronics in these 50 year old units is deteriorating, causing intermittents and down right failures.
 
Even though all the true Geiger Counters bear the ID CDV-700, there were several different manufacturers, each with their own circuit preferences. Between makers, even the battery count ( all use D Cells) varies from 2 to 5 cells!
Also there were different versions within the same maker, such as model 6, 6A and 6B. All versions use an earphone (no speaker) and have a meter with 3 ranges.
 
 
Many regard the Lionel units to have the best circuit design, however the mechanical details are lacking.
Units made by Anton and some others are pretty much collected as display items due to wretched unreliability. One manufacturer, Electro Neutronics Inc, abbreviated ENi has some really good components and mechanical design, but their circuit is the worst and most unreliable of all.
 
In my opinion the physical layout of the ENi is better than that of the Lionel, so the merger of the Lionel circuit concept into the ENi mechanical layout really does give the best of both worlds.
What follows is a drastic modification to an ENi, updating it with some modern components, while changing the circuit to better follow that used by the Lionel. This melding of the two technologies I dubbed the LENi.
Below each picture is the link to the high resolution version, should you care to download it for details.
 
Once the basic LENi conversion is finished, additional improvements may be added to further upgrade the usefulness of the device. The Speak2Me speaker module has been the most popular add on. From there it is easy to add, volume control, Sonalert, power LED, Fast/Slow Response switch, reset zero button, pulse LED, variable high voltage, digital readout, internal sensors, etc.




Fig. 1 ORIGINAL SCHEMATIC OF ENi CD V 700:
 



Fig. 2 FINAL SCHEMATIC OF LENi:
 
 Scan it and stick it in the case bottom over the old schematic.
 
 
 
Fig.3 New cover for instruction manual too:
 
 
Except  for this schematic, and ENi board layout, all the other pages in the manual are from the ENi CD V 700 6B.
 
Look at the schematics of both the ENi and the Lionel to
observe the "before" and "after" circuits.

By performing the simple and inexpensive K0FF LENi mod, you can
create an Lionel clone from an ENi.

The LENi modification procedure:
 
 
Fig. 4 - Parts marked in red will be removed for replacement. Cut one trace on the PCB between the red X's:
 
 


1) On the component side of the board, replace Selenium HV diode CR-5 with a new silicon diode, 7 kV @ 100 mA. Two 1N4007's in series will work fine.

2) Remove R13 and replace it with an 820 Ohm resistor.

3) Add a .0022 uF 50 V capacitor between Base (B) and Collector C) of transistor V4. This can be tacked on the solder side of the board.

4) Remove R12
 
5) Prepare a 900V Zener diode regulator sub board as follows:
 
Nine 100 Volt Zener never yield 900 Volts, but a bit below, usually 20 Volts or so. You can make up this shortfall by adding a 10th Zener, I use a 51 V unit for a total of 10 Zeners in series, and 915 Volts:
 
Fig. 5- Prepare Zener Regulator Sub Board:
 
 
Fig. 6 - Wiring the Zener Regulator Sub Board:
Resistors R-17 and R-12 ( on the LENi Schematic) are attached to the Regulator sub-board as flying components. The finished assembly board:
 
Fig. 7 - Placement Detail of Zener Regulator Sub Board:
 
 
6)  Replace the input capacitor, C5 (a .01) with a .0025 @ 3kV. The reduced coupling helps prevent overload and destruction of the input transistor.
 
7) Cut a portion of the circuit trace between the hole where CR-7 anode was (lead opposite the bar end) and the ground (+) buss. This connection is now severed for ever. CR-7 is removed and replaced with a jumper wire, which also proceeds to bridge the gap from the former anode hole to the switch contact pad immediately adjacent (this is the trace that goes to transformer Pin 6. Doing so effectively ungrounds the emitters of V2 and V3 and reroutes them to the negative battery terminal, via the on-off switch as shown in schematic to correspond exactly to the Lionel circuit.
 
Fig. 8 - Detail of step (7):
 
 
Fig. 9 - Replace CR-7 with jumper ( zero Ohm resistor)
 
 
 
8) Next step will be to change the metering circuit, to improve
operation, hang time, and eliminate premature failures.
Add the resistors R-14, R-15 and R-16 to the solder side of the board, across the gap created in the foil in step (7), to points labeled A, B, C in the detail. I make"Y" out of the 3 resistors and tack solder them on the foil side of the board.
 
Fig. 10 - Detail "add resistors":
 
 
Optional: Add a BNC connector to the panel in the place where the cable originally entered. Adding a mating connector to the probe cord allows for interchanging additional probes for special applications.
 
7) Resolder all the pads for the Large Scale IC Module, the part where the CAL pot is located. These are often loose or bad from vibration, and this is a good time to ddress this problem. Look closely at all the other pads, especially the transformer connections, and touch up the solder as needed. LENi's use a single point ground, a screw located near the transformer. This *MUST* be tight and have the star washer in place for a good ground. A loose screw here is the number one cause of intermittent operation, and even component failure.

That's all the basic electronic changes. Of course I always encourage a BNC be added for probe changing. Please turn off the unit when changing probes.
 
 
 
Fig. 11 - Probe with BNC added:
< DIV> 
 
 
 


Lastly, the unit will now work fine from only 2 batteries instead of the original 4, so you can remove part of the battery box with a hacksaw, leaving about 1/2" of the cut battery chamber for housing the soundcard option. Save the cut of piece for housing future mods, like the AC power supply I always do away with the spring contacts that are supposed to make electrical connection to the board pads, and replace with hard-wired Teflon wires. The intermittents disappear like magic.
 
Fig. 12 - Battery wiring points (set is POSITIVE GROUND):
 

OTHER MODS:

Reset Switch = a pushbutton wired across the meter. Manually shorts out meter when driven way off scale by a high countrate.

X2 scale extension = a 10K pot in series with either meter lead, shorted out with a panel switch for X1. Adjust pot with a steady source for 1/2 reading.

Fast-Slow = Meter averaging capacitor, 100 uF for FAST, with a panel switch, add 330 for 430 total for SLOW.

Soundcard = (Speake2Me Module) http://www.qsl.net/k0ff/Speak2Me%20Module/

Volume Control = 1K pot in series with the 4 Ohm speaker. Usually placed in the vacated single button earphone jack hole. Alternative location is on battery case, rear apron, below snap catch.

PULSE LED = LED wired across speaker terminals on SOUNDCARD. No series resistor but you can use up to 820 Ohms for effect.

POWER LED = LED wired across 3V battery terminals, after on-off switch. Use 820 Ohm resistor.

Battery Condition = a DPDT momentary pushbutton that turns the meter into a voltmeter using a suitable series resistor(68k Ohm). Both sides of the meter need to be switched.

Headlights = White LED lamps or one White and one UV. Only used on LONi variant.

DRILLING PANEL for SWITCHES = all switch and pushbutton locations are spotted on the bottom of the panel by 1/4" circular mold marks. Center punch the desired location and drill from the bottom (to preserve paint on surface side).
 
Drill pattern as seen from TOP SIDE:
http://www.qsl.net/k0ff/LENi%20Geiger% 20Counter/Drill%20Template

Nomenclature: I use laser printed clear address type labels, sealed with "decal set".

On certain model ENi's the original panel lettering is painted on instead of raised like later versions. The paint is flush, so once the panel is drilled and nomenclature is added, a single sheet of adhesive backed clear laminating plastic can be overlaid for a really nice looking and permanent panel.

If the unit fails to calibrate, or some scales are off compared to others, always replace V2 and V3 first. Replace them both at once. In many instances, these parts will test OK but replacing them cures the problem.

Never replace the precision capacitors C-3 and C-4 unless broken or damaged, they are part of the calibration circuit and should be replaced with exact parts only.
 
Fully modified LENi with all add-ons:
 
Fig. 12A - LENi right side:
 
 
Fig. 14 - LENi left side:
 
 
 
Fig. 15 - LENi back side:
 
 
 
Fig. 16 - LENi bottom, shield open:
 
 
 
Fig. 16 - LENi bottom, shield closed:
 
 
Fig. 18 -  X-Ray view:
 
 
This webapge exists to encourage the hobby of nuclear rad detection:
 
 
 
If you have doubts that an amateur could find radioactive stuff in the ordinary environment, take a peek at some of the "finds" that I have done with my LENi:
http://www.qsl.net/k0ff/Road%20Rad%20Finds/


Happy Homebrewing, Geo>KØFF

Member Comments:
This article has expired. No more comments may be added.
 
A Geiger Counter for the Ham Shack  
by KC8ZEV on May 26, 2010 Mail this to a friend!
Great Post!!

Superb photos and schematics, a great weekend project.

I have seen many of these units around, I may have to give one a try.

Truly a "Hot" project!

73

KC8ZEV
 
A Geiger Counter for the Ham Shack  
by KC5MO on May 26, 2010 Mail this to a friend!
Great stuff! I have a Victoreen CD V-700, 715, 717, 720 and the 781. The 700 works but the meter movement sticks now and then. I will give the LENi a try.

Herb KC5MO
 
RE: A Geiger Counter for the Ham Shack  
by KA4KOE on May 26, 2010 Mail this to a friend!
I am sure this article will get many "glowing reviews".
 
RE: A Geiger Counter for the Ham Shack  
by KG4RUL on May 26, 2010 Mail this to a friend!
It could also be the source of many a scintillating conversation.
 
RE: A Geiger Counter for the Ham Shack  
by W8AAZ on May 26, 2010 Mail this to a friend!
I don't find my Anton to be "wretched", it works quite well but is in near mint condx. with strap and headphone. Works with radium watches, trinitite samples, etc. with the windows open on the sensor. Actually the only other use I can think of for it is to check stuff from China!
 
RE: A Geiger Counter for the Ham Shack  
by WY3X on May 26, 2010 Mail this to a friend!
I didn't see much in the way of an explanation as to what the "Speak To Me" module does. Is it just a loudspeaker for listening to the ticking, or does it actually warn you in a human voice to get the "H" outta Dodge because where you are is too "HOT" (when the ticking frequency increases to a high level)? Kinda like those annoying voices in cars several years ago- "your door is ajar". No, my door is a door! -WY3X
 
RE: A Geiger Counter for the Ham Shack  
by AI4WC on May 26, 2010 Mail this to a friend!
Is the BNC connector for attaching the new "Super Compact" yagi (soon to be available from MFJ)? I expect that it will be very helpful in allowing rad readings from long distances..
 
RE: A Geiger Counter for the Ham Shack  
by K0FF on May 26, 2010 Mail this to a friend!
KG4RUL said "It could also be the source of many a scintillating conversation. "

Groooooan! U been watching too much Uncle Miltie on TV.

But thanks for the comment!

Geo>K0FF
 
RE: A Geiger Counter for the Ham Shack  
by K0FF on May 26, 2010 Mail this to a friend!
KR4WM said:"I didn't see much in the way of an explanation as to what the "Speak To Me" module does. Is it just a loudspeaker for listening to the ticking, or does it actually warn you in a human voice to get the "H" outta Dodge"


Civil Defense units used earphones, but for most applications a speaker is preferred. There was a CDV-705 speaker unit made, but it is rare today, and is about half the size of the whole Geiger Counter. We chose to install a board inside the Geiger Counter and add a speaker and volume control, Naturally what you hear are the clicks. The "amplifier" is actually a monostable multivibrator, not a traditional audio amplifier. Using an audio amplifier will work, but it also amplifier the HV oscillator whine, making it unpleasant to use. No whine is present with the Speak2Me module, just the clicks. Only the clicks will trigger the circuit, not the whine.

You were probably kidding about the human voice announcements, but Larry Ludlum beat you to it. His Model Ludlum 2300 actually does have a voice, it was made back in the mid 1980's and to me the voice sounds like a Cylon Warrior:

http://www.qsl.net/k/k0ff//Ludlum%202300%20Voice/

Very few of these were ever made, but I have a working example in my collection.

73 Geo>K0FF

 
RE: A Geiger Counter for the Ham Shack  
by K7PEH on May 26, 2010 Mail this to a friend!
Things have changed a little bit since I built my geiger counter as a science fair project when I was in the 7th grade. Let me see, that was in the year 1959 I think, maybe 1960. One big difference is that I did not have a nice yellow container and a meter. The signaling part was a pair of headphones, no meter. The box was made from plywood with an opening for my geiger counter tube which was some kind of photomultiplier tube and I can't remember what it was. Although, I ordered it from Allied Radio I think. The whole project cost less then $20 I am sure, maybe less then $10 back in 1959/1960.

Yes, it worked. I had two sources, one was radium and the other was uranium from the science lab at the school.
 
RE: A Geiger Counter for the Ham Shack  
by KB2FCV on May 26, 2010 Mail this to a friend!
Cool article! I have a CDV-700 Geiger counter as well as the CDV-715 and CDV-720 (Fun to collect - neat stuff right out of the Cold War. Look great with my CD yellow Gooney box). I've used my 700 with Vaseline glass and a few other items. I don't think I necessarily want an intended use for the 715 or 720. They do pass the circuit test.

 
RE: A Geiger Counter for the Ham Shack  
by K0FF on May 26, 2010 Mail this to a friend!
KB2FCV said: " I have a CDV-700 Geiger counter Look great with my CD yellow Gooney box)."

Ubet! My 2M Gooney Box (CD Yellow of course.> has the FM modification on the Tx.'. Makes it actually usable even today.

73, Geo>K0FF
 
RE: A Geiger Counter for the Ham Shack  
by K0FF on May 26, 2010 Mail this to a friend!
KOPEK said: "Things have changed a little bit since I built my Geiger counter as a science fair project when I was in the 7th grade".

Boy have they ever! Back then a HV rectifier was a rare commodity indeed. Most of those home brew Geiger rigs had two nails fashioned into a spark gap for a rectifier. For a vibrator on the primary- a pushbutton provided the make-and-break manually.

Now we throw in a 1N4001 or two @ 4 cents max.

A funny true story: Back in those good-old-days (!?!), mobile radios in Police cars used selenium rectifiers. Some radios even used two bridge rectifiers in series, stacking the HV in Tx mode. Sometime in the mid 1960's a company in California ( Silicon Valley?) made the first really commercially practical silicon rectifier diode, in an epoxy casing. The nomenclature was 5A4. Wanting to swap out a goodly number of the old selenium stacks (nothing in the world smells worse than a burned selenium diode, uggh!), we submitted an order to our office for 5000 5A4 rectifiers.
A few weeks later here comes the delivery man who said: "We have your rectifiers, where can we unload them."

'Unload them'?? These should have been in a cigar box, but no, they were in a Semi Trailer. A *big* Semi Trailer!

What had happened was that our well meaning secretary had kindly corrected our "typo" and ordered 5000 pieces of the only rectifier she had ever ordered for us before, the 5U4.
As many of you know the 5U4 is a rather largish tube rectifier, and believe me, 5000 of them was quite a load!

The rest of the story is that she asked me if we couldn't go ahead and stock those 5U4's since we used them anyway, in our base station radios, and she would go ahead an order the right ones! ( Typical Government employee??).

Well, we didn't, but eventually those correct parts did show up and I remember spending many months methodically replacing all this old selenium's with those nifty little epoxy bullets..........

With so many selenium's in the junk bin, and me being the average inquisitive HAM, I had to find something to do with them. The answer came by removing the paint from the individual plates. Ever wonder why selenium plates are always painted? It is because they are light sensitive, that's why. Sure enough a handful would make a pretty decent photocell !!.

In the same vein, those old Police radios used vibrators. Many, many vibrators over the years (we had 500 cars and more). Inside each vibrator was a 270 Ohm, 1/2 Watt resistor. I meticulously took apart hundreds of the scrapped vibrators and clipped out those resistors. Looking around for a use for them, it struck me to solder 10 of them in parallel onto #6 brass washers at each end, in a sort of cylinder. This yielded 27 Ohms @ 5W. Two of those packages in series made a nice 54 Ohm Dummy Load. Pretty non inductive too, using that method. These were stacked end to end to make, 108 Ohms, and again in parallel with another double stack to yield 54 Ohms again. Dipped into a quart paint can full of "transformer oil" this monstrosity made a credible high power dummy load.....and since the resistors were of only 5% tolerance, a patient tech could hand select just the right values to wind up with 52 Ohms right on the button...........Your tax dollars at work.

73
Geo>K0FF
 
War Style Meters  
by KA4KOE on May 26, 2010 Mail this to a friend!
From Murphy's Surplus

http://www.murphyjunk.bizland.com/id45.html
 
RE: War Style Meters  
by KD6KWZ on May 26, 2010 Mail this to a friend!
I remember a "Popular Electronics" around 1973 had a schematic for a power supply for some Geiger Counters.

I do see new Geiger Counters for sale at this interesting site:

http://unitednuclear.com/index.php?main_page=product_info&cPath=2_76&products_id=485
 
A Geiger Counter for the Ham Shack  
by BODEPLOT on May 27, 2010 Mail this to a friend!
The photos remind me of many such encounters I have had since starting to monitor in 1965. Had to avoid several highway "hot spots."
 
RE: A Geiger Counter for the Ham Shack  
by KL0S on May 27, 2010 Mail this to a friend!
I always wanted one of these things and finally found a good deal on eBay (there are plenty of them there). Got my unit from Gary Davis who periodically sells units that he reconditions. Of all the sellers I found him to be the best. You can contact Gary at:

gddavis@axs4u.net

No monetary interest in all this on my part, just my experience with a good seller.

Dino KL0S
 
RE: A Geiger Counter for the Ham Shack  
by AE6RO on May 27, 2010 Mail this to a friend!
Just out of curiosity, since I know absolutely NOTHING about this, how do you check your Geiger counter to see if it really works? John

P.S. Really, I know NOTHING about it. So don't ask me.
 
RE: A Geiger Counter for the Ham Shack  
by K0FF on May 27, 2010 Mail this to a friend!
KL0S said:"I always wanted one of these things and finally found a good deal on eBay (there are plenty of them there). Got my unit from Gary Davis who periodically sells units that he reconditions. Of all the sellers I found him to be the best. You can contact Gary at:

gddavis@axs4u.net "

Likewise I have no connection but recommend Gary 100%. Tell him George sent you.

Geo>K0FF

 
RE: A Geiger Counter for the Ham Shack  
by K0FF on May 27, 2010 Mail this to a friend!
AE6RO said: "Just out of curiosity, since I know absolutely NOTHING about this, how do you check your Geiger counter to see if it really works? John "
|

John, did you ever have a radio receiver with a crystal calibrator? Or maybe use a signal generator to test a receiver?
Same concept, we use a test source, also called a check disc, test spot, operation test source, etc. to simulate radiation into the probe, thereby exercising the probe, cable and all electronics. Usually a small test source is attached to the side of the unit. Simply placing the probe right up against the source tests everything at once.

Geo>K0FF

 
A Geiger Counter for the Ham Shack  
by KD6KWZ on May 27, 2010 Mail this to a friend!
"Just out of curiosity, since I know absolutely NOTHING about this, how do you check your Geiger counter to see if it really works?"

John: United Nuclear, and maybe other places, sell low level radioactive sources for the 3 main types of radiation.

As a side note, a story: There was a Physics Professor at a University in Kiev. He came in on a Saturday to do some work that used a Geiger Counter. He turned it on, and it was pegged instantly. At first, he thought the calibration of the Counter was off, but it checked out OK. He then got alarmed, due to the fact they had a small research nuclear reactor in their Department. He rushed to check on it, but it was OK.

It turned out that the Chernobyl accident happened early that morning.
 
RE: A Geiger Counter for the Ham Shack  
by K0FF on May 27, 2010 Mail this to a friend!
Might as well skip the middle man and go directly to the maker in Oak Ridge TN: Spectrum Techniques.

http://www.spectrumtechniques.com/


Half the price, same item. As a matter of fact, the so called dealers can't even stock or ship the test sources, they must be shipped from Spectrum Techniques to the end user. Tell them George sent you.

Anyone that is old enough to hold money can buy them but it takes a license to ship them NRC rules. Go figure.

Geo>K0FF
 
KOFF Made me do it!  
by KA4KOE on May 27, 2010 Mail this to a friend!
Went ahead and ordered a CDV-700b ENI from Gary Davis, reasonable, calibrated, and guaranteed.

We're gonna have fun with this one. Now need a FLIR camera to look for heat leaks in the house trim. THOSE ARE EXPENSIVE!

Philip
KA4KOE
 
RE: KOFF Made me do it!  
by W0FM on May 28, 2010 Mail this to a friend!
Geo,

Got my hands on one of those things back in the early 60's when a buddy and me were building a bomb shelter in his basement out of two cardboard refrigerator boxes covered with a shower curtain. We even scored two of the blue and yellow Civil Defense decals for the front flap.

We always thought the counter was "on to something" because it clicked quite regularly there in the "shelter".

Much later, I surmised it was probably the radium dial on my glow in the dark watch face, which, more often than not, was our source of light inside the box. Besides, radio acitve fallout would never have made it past that shower curtain.

73, Terry, WØFM
 
RE: KOFF Made me do it!  
by K0FF on May 28, 2010 Mail this to a friend!
id:" W0FM on May 28, 2010 Mail this to a friend!
Geo,

Got my hands on one of those things back in the early 60's when a buddy and me were building a bomb shelter in his basement out of two cardboard refrigerator boxes covered with a shower curtain. We even scored two of the blue and yellow Civil Defense decals for the front flap. "

Cool Terry! We had a the CD Gonsets and the the other Civil Defense stuff stored at the radio shop at the STL PD too where I worked back then.

Now the real trick was to get the girls to take a tour of the candle lit "bomb shelter".

Geo>K0FF

 
RE: KOFF Made me do it!  
by AE6RO on May 29, 2010 Mail this to a friend!
One thing is missing from this thread. Why in the world would anybody want or need a Geiger counter?!

If it is post-apocalypse, we will know what is hot (everything). If not, then what for? 73, John
 
Fire in the Human Spirit  
by K0FF on May 29, 2010 Mail this to a friend!
AE6RO said: Mail this to a friend!
"One thing is missing from this thread. Why in the world would anybody want or need a Geiger counter?!

If it is post-apocalypse, we will know what is hot (everything). If not, then what for? 73, John "

Geo says:

Let's see if I can tackle that question.

What we NEED;
God
Air
Food
Water
Love.

We also NEED to learn.

Do we need a Geiger Counter? No. But on the other hand do we actually NEED a Ham radio set? When in your pocket is a cell phone with unlimited long distance? Hardly. But we do need to learn./

When learning is fun it is a hobby. When learning is a hobby it is fun.

For me personally, I got interested in "science" back in the 1950's like so many folks my age did, thanks to Buck Rogers, Dr. Zarkov, Superman and all those 50's Sci-Fi movies, many of which featured ham radio and also Geiger Counters. Then came Sputnik and ATOMS FOR PEACE, and I was hooked.

Whenever the question was: "What do you want to be when you grow up little boy?"

The answer was *always*:
"A scientist."
Period, no hesitation.


To me a true HAM is someone who wants to learn, tinker and is fascinated by the magic of any "dog that barks over here and bites over there".

Oh yeah and communicate, almost forgot that one. But to me it is the bottom of any list. Making the magic happen is at the top of the list, as is *trying* to understand how it works.

We know what radio does and how to use it. We don't know what makes it work. Not really. Nor do we know what makes magnetism or gravity "do it's thing". Think you do? Then explain it to me. And win a Nobel prize in the process.

Radio is electromagnetic radiation. So are IR, Light, UV, X-Rays, Gamma Rays. Many Hams like to tinker with electromagnetic radiation..... of all frequencies.

A Geiger Counter is merely a receiver for another set of frequencies. Yes Gamma Rays are a legitimate HAM BAND.

We choose to do this and the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too.............Oh sorry, that was another speech.



Geo>K0FF



 
A Geiger Counter for the Ham Shack  
by KL7AJ on May 30, 2010 Mail this to a friend!
I have a few old Geiger counters. A friend of mine has a few Hazmat suits, as well. We were thinking of donning hazmat suits and walking down the sidewalk of downtown Fairbanks, scanning the sidewalk with our Gieger counters, but not saying a word...just jotting notes down on a clipboard. This would be a great way to freak people out. :)

Eric
 
RE: A Geiger Counter for the Ham Shack  
by W8AAZ on May 31, 2010 Mail this to a friend!
OK Eric. I will watch the news online to see when you do that! Being curious, I decided to check a panel meter I bought at Dayton. Has a pointer that is coated with something but it does not glow anymore. Opened the aperture and put it down on the face of the meter and got a hit, like at least 1500 C/M which is center area of the X10 range. Makes alot of headphone racket too. Now I have a meter that seems useless because it is hot, and does not glow, anyway. Thinking of a safe way to remove the hot stuff from the pointer and just painting it orange. Or not.
 
A Geiger Counter for the Ham Shack  
by KD8MJR on May 31, 2010 Mail this to a friend!
Fantastic Article, man I thought I was tho only one who bought as surplus gieger counter, whew what a reklief to know that so many other Hams think like me :)

BTW for the people who ask why do we need one! I would point to a possible situation were our air and water may be localy contaminated after some kind of accident. What cost $50 now might cost a few thousand if everyone is rushing out to get one after a disaster.
 
RE: A Geiger Counter for the Ham Shack  
by KA4KOE on May 31, 2010 Mail this to a friend!
I have a few old Geiger counters. A friend of mine has a few Hazmat suits, as well. We were thinking of donning hazmat suits and walking down the sidewalk of downtown Fairbanks, scanning the sidewalk with our Gieger counters, but not saying a word...just jotting notes down on a clipboard. This would be a great way to freak people out. :)

Eric

That's insanely funny. Too bad in Post 911 you'd probably get arrested for all manner of things.

Us guys that like manpack radios have a similar problem....always carry your license!!

Philip
 
RE: A Geiger Counter for the Ham Shack  
by WA2JJH on May 31, 2010 Mail this to a friend!
I remember fooling around with one of the yellow PVC
detectors. I found it when a Cival Defense shelter got
decommissioned.

I was like 20 back then. We found all sortsa crap.
Water, survival wafers, and the crude med. kits.

The detector was only sensitive enough down to fractions of millirads. Only good if a nuke blew up in the past few weeks.
This is after I wasted money on the 22V batteries.

But heck you never know. You want find some PU-239 or U-235 at a flea market!
 
RE: A Geiger Counter for the Ham Shack  
by K0FF on May 31, 2010 Mail this to a friend!
4KOE sadi: guys that like manpack radios have a similar problem....always carry your license!!

Philip "

We see those fellows at Dayton walking around with their manpacks. It would be taken more seriously if they didn't wear those metal hardhats with tiny little Yagis mounted to them. My wife always jabs me in the ribs with an elbow and whispers "Don't even THINK about it!!).

73 Geo>K0FF

 
RE: A Geiger Counter for the Ham Shack  
by KA4KOE on May 31, 2010 Mail this to a friend!
The guys I know don't do that, but the true HF manpacks almost always have a 9' whip extending from the radio....AT271 is standard issue.

Philip
 
RE: A Geiger Counter for the Ham Shack  
by K0FF on May 31, 2010 Mail this to a friend!
Phillip said : "Manpack, 9 foot whip"

Phillip, you know those 9" whips that break down and fold up, the one with a bungee cord type arrangement inside? Those make a great portable/ or maritime mobile base when used with a Hustler coil set. Cut the whip short, add a brass fitting on top to take a 3/8" threaded rod, attach the Hustler coil. I'll write that up in article form soon. I have been running one of those for years with various battery powered radios, mostly from ships.

Geo
K0FF/MM
region 1, region 2, region 3.
 
RE: A Geiger Counter for the Ham Shack  
by KA4KOE on June 1, 2010 Mail this to a friend!
I have a Hughes AS-1887A/PRC74 9' whip antenna that is essentially what you just described, but milspec, rare, and imminently very cool.

Philip
KA4KOE

 
RE: A Geiger Counter for the Ham Shack  
by KD8MJR on June 1, 2010 Mail this to a friend!
In every Hobby there is a point when you know a fellow hobbyist has gone off the Deep End :) Carrying a Manpack is a sure sign in this hobby :)
 
A Geiger Counter for the Ham Shack  
by KD7RDZI2 on June 1, 2010 Mail this to a friend!
oh as ARRL has approved GAMMA RADIATION as a ham band for contests, I wish to learn more about the effects of RF on human body... if ANY...
 
RE: A Geiger Counter for the Ham Shack  
by KA4KOE on June 2, 2010 Mail this to a friend!
Don't carry mine. It gets lugged to sites where we are camping. They are the ultimate outdoor radios for camping and boy scout events.

Its 20 lbs of solid aluminum and I'm a lot heavier than that, so packing a radio is out of the question for me!!!

HAM RADIO!!! Burns lots of calories twiddling those knobs and pushing dem buttons!

Philip
 
RE: A Geiger Counter for the Ham Shack  
by KA4KOE on June 2, 2010 Mail this to a friend!
Check it out....

http://www.neidlinger.us/greenies.pdf

Philip
 
RE: A Geiger Counter for the Ham Shack  
by KA4KOE on June 4, 2010 Mail this to a friend!
Got my ENI CDV-700 in yesterday. I've always wanted a counter and this article spurred me to do it.....

Thanks George!

Philip
 
A Geiger Counter for the Ham Shack  
by KC0LPV on June 7, 2010 Mail this to a friend!
There is a great freeware program for interfacing with a computer and taking long-term data using the CDV-700 or similar counters with audio output. It is called "CDV Counter" by David Honig.

Unfortunately the Geocities website where it was originally found is no longer (as all Geocities websites went away), and it is hard to track down. I just found the author's blog with a link to Sourceforge:

http://sourceforge.net/search/?type_of_search=soft&words=cdvcounter

Great for taking data over a longer period of time than your own patience and handwriting will allow.
 
RE: A Geiger Counter for the Ham Shack  
by K0FF on June 8, 2010 Mail this to a friend!
KC0LPV said: "There is a great freeware program for interfacing with a computer and taking long-term data using the CDV-700 or similar counters with audio output. It is called "CDV Counter" by David Honig.

Unfortunately the Geocities website where it was originally found is no longer "

Indeed, Revkatt has done a nice job on the interface. The program is available at my website

http://www.qsl.net/k/k0ff//CDVCOUNTERZIP/

and on GCE

http://tech.groups.yahoo.com/group/GeigerCounterEnthusiasts/

(look in the FILES section for CDVCOUNTER.zip

When wiring the Speak2Me Module's volume control with the CDVCOUNTER program in mind,
run the hot lead to the center pin or wiper on the volume control, and the speaker to one leg,
with the earphone jack on the other leg. While this is a little unconventional, it give smooth
volume control of the speaker in one direction and smooth level control to the computer in
the other direction, while at the same time muting the speaker.


Have fun

Geo>K0FF
 
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