|
Lionel VR tube info
6
Hello, I have a Lionel CD V-700 Model 6b currently in good working order. I am looking for information on replacing the HV regulator tube for future reference. The documentation only states it is a Lionel part# 416. Is the tube a GV3A-900 equivalent or something else? Is it possible to drop a zener stack directly in place of the tube? Thanks, Clint
|
|
Experiment packages ready to send- select postage due: Geo
We're trying a new shipping method through eBay for Group Buys and Experiment Packages. The ads are arranged according to country and weight. There may be bugs in the process, but so far, it's worked smoothly for both US and overseas. Cheaper that buying postage at the US Post office, plus it's tracked via eBay notification and so on. For USA ONLY there are several ads listed according to weight. Under 1 lb. can go by cheap first-class mail. Above that it's usually Priority, and there may be other carriers available to you too, that's something we'll learn together. PAY $1 for one shipping label to cover the fee, then eBay will charge you the discounted postage. Nice, clean, fast. NOTE: Above 10 lb. is usually required a "large package". Under 10 lb. can be a large, or small package depending upon the size of the contents. MIKE L. your box including the AC millivoltmeter and audio generator (a.k.a. Group Pulser Project) fits 20-25 lb. IF we leave out the above instruments, it will qualify for the 9-10 lb. category: Peter S. your package is in the under 1 lb. limit: Alan J. 12 lb. (so there's room for more): If you're package doesn't fit a category or is not listed above, please contact me. The current Group Buy is for E&L CADET breadboards. Pictures soon. These are the ones with the function generator and other essential instrumentation and accessories built in. PRIORITY MAIL- 20-25 lb.= https://www.ebay.com/itm/295167977663 15-20 lb.= https://www.ebay.com/itm/295167976503 10-15 lb.= https://www.ebay.com/itm/295167965402 9-10 lb.= https://www.ebay.com/itm/295167959912 4-5 lb.= https://www.ebay.com/itm/295168093153 FIRST Class USPS Mail <1 lb. https://www.ebay.com/itm/295167943931 Geo
|
|
Off Topic -- My Friend Needs Help
Re: Off Topic -- My Friend Needs Help Dear Enthusiasts, Please forgive me for going Off Topic, but my friend Dom needs some help. Please see the link below: Please help our Brother get back on track https://www.gofundme.com/f/please-help-our-brother-get-back-on-track Thank you. Sincerely, Cliff P.S.: I've never done this before...
|
|
My original research of 20 years. (c) 2022 George Dowell, Viscom Inc., GEOelectronics@... Have fun Geo
|
|
Sequencing round led display for behind Victoreen cdv-700
7
I have a vic with the cut down battery box. I am considering adding a 2.3 inch circular led sequencer board behind the plexiglass meter. I have done this with a Cajoe geiger kit and a converted linear led chaser kit. You have to convert the 555 chip from astable multivibrator to monostable and adjust the input resistance. The other chip is a 4017. You could see the relative radiation from across the room by how fast the circle spins. Looks similar to an atomic test countdown counter. I was wondering if anyone has tried something similar? Thanks
|
|
HV Transistor ENi-1 V1 Some waveforms and Voltages seen and measured on a working CDV-700 / LENi mod, in preparation to try a Russian PNP Ge. transistor in that circuit. First tests are made with the original, hand selected by ENi HV transistor marked ENi-1. The only difference I have found between ENi-1/ENi-2/ENi-3 transistor is the gain factor. They all appear to be a 2N404 as available in 1962, all are PNP, and are all the same physically, but segregated in their own gain into rough groups, with frequent overlap in those groups as tested today. Gain variants were quite common in the early 60's when the manufacturers would make huge runs of a "type", then measure each one to see what they had actually turned out to be. There were hundreds of part numbers back then, populated by individually selected transistors from a single production run. We still deal with that same issue today in certain semiconductors, but instead of different numbers, they are rated to different tolerances. Needless to say, devices with the exact same part number and no tolerance specified, as available to hobbyists today (eBay etc.) are all over the place in terms of performance, but usually nowhere near the stated value. To me this indicates what's being sold are off-falls from the grading process, even if they are in tape-and-reels. I tried to document the base and collector DCV, ACV P-P (peak-to-peak), the frequency in Hz at each, and a waveform at each, to compare to any differences when simply substituting V1 with a Russian transistor. The emitter in grounded in the LENi V-1. The Russian transistors are the same germanium type, polarity and pinout, but a few differences in construction are obvious (the base lead is also the metal case). In separate and not shown here gain measurements, the Russian transistors have a more consistent gain factor, and in al cases, it was as high or higher than the best category in the ENi-1/ENi-2/ENi-3 hand selected lots. Pictures and data will be in the next posts. Note: in the Scope/Analyzer I use, the waveform is scaled automatically by the smart probe, and the Voltages are measured by a 3rd. wire in the scope probe so don't need to be scaled (what they read is direct). It is rated to 2000V so beware, on some measurements, they may cause damage your scope if duplicated. Geo
|
|
Hello, I purchased a non working CD V-720, and found the meter "nuts" were not present which caused the meter to not show any movement...obviously. After connecting the meter, it seemed to be ok enough to zero, but..... most ranges were maxed out which I take as high leakage current from something dirty. The insides looked pretty clean compared to others with battery leakage damage. I removed the chamber and the leakage currents were reduced to a ~0.5R/hr reading on the 1x scale. I cleaned the glass insulators on the chamber with 99% IPA and a Qtip and the chamber leakage went down to about 12 R/Hr on the 10x range. Looking at the schematics, I see mine is different from what was published in 1961. I have a 8.2k resistor across the meter, and the 470k resistor near the potentiometer is 100K ohms. I am wondering if they made changes in 1971 when a faint stamp shows CD calibrated the meter. It looks like my meter was made in 1962 with "62" on the meter and a 62 date code on the vacuum tube. I scraped off the flux residue on the solder side of the PCB (kept dry), and that sorda helped, bringing the 1x leakage currents to show ~0.25 R/hr on the 1x scale. I am thinking the glass insulators are still dirty which is causing the upscale readings, and there is a leakage path on the PCB or switch somewhere. Questions: What was the 470K -> 100K resistor mod supposed to do? What is the resistor across the meter for? Does this meter require a desiccant in the can to help reduce the upscale readings? Thanks for any help, I attached the check results with and without the chamber, name plate and one of the component side. I left them full resolution such that one can zoom in if need be. -- Stephen Nelson KD6VEX
|
|
FOCUS: Gaseous Ionization Detector ¨C Gas-Filled Detector
Gaseous Ionization Detector ¨C Gas-Filled Detector Detector of Ionizing Radiation ¨C Geiger Tube Gaseous ionization detectors are radiation detection instruments used in radiation protection applications to measure ionizing radiation and particle physics to detect the presence of ionizing particles. These detectors are designed to measure the ionization produced when an incident particle traverses some medium and are based on radiation¡¯s ionizing effect. For ionizing radiation to occur, the kinetic energy of particles (photons, electrons, etc.) of ionizing radiation is sufficient. The particle can ionize (to form ions by losing electrons) target atoms to form ions. Simply ionizing radiation can knock electrons from an atom. The basic gaseous ionization detector consists of a chamber filled with a suitable medium (air or a special fill gas) that can be easily ionized. The most widely used types of these detectors are based on the effects produced when a charged particle passes through a gas. The operating medium: should be chemically stable (or inert) so that the moving ionization electrons are not easily captured by the molecules of that medium should have a low ionization potential (I) value to maximize the amount of ionization produced per energy deposited by any incident particle. should not be very sensitive to radiation damage so that its response to incident particles does not change markedly with use. Typical gases used in detectors are argon and helium, although boron-trifluoride (BF3) is utilized when the detector is to be used to measure neutrons. Gaseous ionization detectors are widely used in nuclear power plants, for the most part, to measure alpha and beta particles, neutrons, and gamma rays. The detectors operate in the ionization, proportional, and Geiger-Mueller regions, with an arrangement most sensitive to the measured radiation type. Neutron detectors utilize ionization chambers or proportional counters of appropriate design. Compensated ion chambers, BF3 counters, fission counters, and proton recoil counters are examples of neutron detectors.Basic Principle of Gaseous Ionization DetectorsDetectors of ionizing radiation consist of two parts that are usually connected. The first part consists of sensitive material, consisting of a compound that experiences changes when exposed to radiation. The other component is a device that converts these changes into measurable signals. The chamber has a cathode and an anode that are held at some large relative voltage, and the device is characterized by a capacitance determined by the geometry of the electrodes. As ionizing radiation enters the gas between the electrodes, a finite number of ion pairs are formed. The behavior of the resultant ion pairs is affected by the potential gradient of the gas¡¯s electric field and the fill gas¡¯s type and pressure. Under the influence of the electric field, the positive ions will move toward the negatively charged electrode (outer cylinder), and the negative ions (electrons) will migrate toward the positive electrode (central wire). The electric field in this region keeps the ions from recombining with the electrons. Collecting these ions will produce a charge on the electrodes and an electrical pulse across the detection circuit. The average energy needed to produce an ion in the air is about 34 eV. Therefore a 1 MeV radiation completely absorbed in the detector produces about 3 x 104 pairs of ions. However, it is a small signal that can be considerably amplified using standard electronics.Operating Regions of Ionizing Detectors ¨C Detector Voltage The relationship between the applied voltage and pulse height in a detector is very complex. Pulse height and the number of ion pairs collected are directly related. As was written, voltages can vary widely depending upon the detector geometry, gas type, and pressure. The figure schematically indicates the different voltage regions for alpha, beta, and gamma rays. There are six main practical operating regions, where three (ionization, proportional, and Geiger-Mueller region) are use
|
|
No.4- CD V-700 Shop Manual ENi ......... WHEW! FINALLY! The missing and most important shop manual for ENi CDV-700! Includes the retrofit version data.
3
Now in FILES under CDV-700 Shop Manuals folder. Many thanks to members Steve and Tanner in U.K. for dredging this up! Like always, it's a team effort! Geo
|
|
File /CDV-700 SHOP MANUALS/CPG4-1 CD V-700-6B Electro-Neutronics-merged (1).pdf uploaded
#file-notice
The following files and folders have been uploaded to the Files area of the [email protected] group. /CDV-700 SHOP MANUALS/CPG4-1 CD V-700-6B Electro-Neutronics-merged (1).pdf By: Geo Dowell <GEOelectronics@...> Description: No.4- CD V-700 Shop Manual ENi
|
|
eBay listings exaggerations
3
Geo, you sell a lot on eBay, maybe they would listen to you. I buy a lot of parts for repairs for tools from eBay and lately they seem to be slipping on basic listing enforcment. People are adding their phone numbers and saying "don't pay here" or "local pickup only." This isn't OfferUp, it's eBay. Plus as you all noted in other posts, battery capacities are just plain fake sometimes and there are EMF devices listed as "geiger counters". This is an example of that: https://www.ebay.com/itm/393967664561 I reported this listing and nothing was done: https://www.ebay.com/itm/384911755342 look in the notes at the bottom. Seller says don't pay here, call me a make a cash deal and lists a phone number. I could fill a page with listing numbers that shouldn't be there, but ebay doesn't make it easy to file a report. Someone should be paid to scan categories and clean things up. Here is a fake battery listing from Amazon, just to be fair to eBay. https://www.amazon.com/Flashlights-Capacity-Rechargeable-Emergency-Tokeyla/dp/B0B12GLR88/
|
|
As mentioned in another Bucket List post, " Not surprisingly, battery Voltage when using dry cells is not stable over time. I jokingly call dry cells a 1/4 cycle AC generator. Compared to a real sine wave plot, the start at the + peak and go down to the zero crossover level, one time. This changing Voltage was investigated, and sure enough, even a small change in applied DCV will alter the HV output and LV -15V output, causing changes in meter readings for a steady input pulse signal." Enter the AMS1117-3.3 regulator module: Alone this $1 USD module stabilizes the LENi and at least some other CDC-700, It goes in the line between battery or other DC power source and the battery negative (hot) wire. It works best from 3.7V up to over 15V. Changing the input V up and down leaves the CPM Meter, HV etc. stable. Perfect for 18650 conversions. Caveat: Running these AMS1117-xx way above their regulated Voltage ( say, more that a few V) will cause them to dissipate the excess energy as heat, limiting their current output. For 12V operation it might be wise to first use the similar 5V regulator module ahead of the 3.3V one. FYI, a converted ENi with SPeak2Me modules is running around 85mA current. More to follow Geo
|
|
Bucket List: a thoroughly modern ENi or....Industrial LENi? They say imitation is the sincerest form of flattery.. G-10 Glass Epoxy circuit board, tin plated brass through-holes. Silver plated solid copper wiring with Teflon sleeving Actually it's a rugged reusable test be for some radical upgrade experiments to the ENi/ LENi Geo
|
|
I picked up a $25 ENI cdv700 on Ebay, I plan to convert it to a LENI. What I learned from my last two ENI conversions - the LENI schematic shows 18k R18... pretty sure in place of a wire wound choke original on the ENI. The LENI instructions do not say to replace the choke. The only way I was able to get the last two LENIs working was to replace the choke with the resistor. I don't know why - I am not an electrical guy. When this ENI arrives April 7, I will give it a whirl again. The rest of the conversion is easy... just being careful with the soldering iron and the very delicate PCB and pads - they lift if you look at them funny. GEO ... I may order another one of your assembled Zener regulator boards - I built my last one, but it was a bit fiddly.
|
|
Who has the oldest and newest ENi CDV-700?
2
In my modest collection there are 3 yellow CDV700 6Bs all ENi's, original not modified. The oldest one is serial #15 and has the smooth top casting, the newest one is over 19,000 and has the raised lettertopp casting. Wonder how many ENi's were made in all, there's a list somewhere. Geo
|
|
This test has been on the Bucket List for quite a while. Bottom line, yes they do work, caveat: they don't work quite as well as an actual 2N404A but are easier to find, at least they were when I stocked up on them. Scope traces to follow and those will be good reference for any HV troubleshooting as well. The difference in performance is negligible but recalibration is necessary, and that probably goes for any transistor swap out, but especially in V1 position - the HV generator. Just a small change in the HV setting will also change the -15V low voltage supply to the metering section, and that Voltage is key to the meter readings obtained. As a matter of fact this test led me to investigate some other stability problems in the ENi/LENi/Lionel CDV-700-6B. Not surprisingly, battery Voltage when using dry cells is not stable over time. I jokingly call dry cells a 1/4 cycle AC generator. Compared to a real sine wave plot, the start at the + peak and go down to the zero crossover level, one time. This changing Voltage was investigated, and sure enough, even a small change in applied DCV will alter the HV output and LV -15V output, causing changes in meter readings for a steady input pulse signal. Geo PS note the Blue and Yellow theme of the LENisky II PCB. A tribute to Ukraine.
|
|
Looking for inexpensive Anton CD V-700
4
After looking at the schematics of the various models of CD V-700, I have become interested in the possibility of converting the Anton CD V-700 to operate on two D-cell batteries. So, I am looking for an Anton CD V-700 with the following qualities: 1. Operating ¨C I don¡¯t want to have to troubleshoot it before trying the conversion. 2. Has a good meter ¨Cworks and no cracks in the plastic. 3. Cheap ¨C the project might not work and I don¡¯t want to invest too much. 4. No or insignificant corrosion. 5. Exterior paint can have any amount of scratches, worn spots, etc. This is of no consequence. I can repaint it if the project works. Naturally I would make the necessary information available to this group and anyone else who needed it. It seems as if this might be a worthwhile project as the Antons are often less expensive than the others and this would turn an Anton into a decent instrument. Lenox
|
|
Bucket List- Step adjustable and continuously variable HV in ENi/LENi/Lionel CDV-700
Many Geiger Mueller probes are available that will work on the CDV-700 but they don't use the standard 900VDC that all 700's provide. We've developed several circuits to address this issue, both in the single fixed re-regulator, the step adjusted re-regulator, and the continuously adjustable regulator. Simple but effective single transistor, transformer based HV generators in CDV-700s are robust and purpose built. They are also power hogs. Most are capable of running 1600V safely, as a matter of fact, I cloned them into some pretty useful workbench HV supplies, one at 1600V fixed. Caveat: within the CDV-700 context, I recommend limiting max. HV to 1000V. Most Geiger Mueller tubes use far less, with 400 to 500 being quite common, 700V in US Military RADIACs. Any of these would work well on any CDV-700, save the wrong HV. We've also considered completely eliminating the "current hog" HV and LV generator, replacing the with more modern designs. The following posts will address these different solutions. Geo
|
|
Chapter 1) Hard to believe 20 years went by since the US Gov't started scrapping CDV-700s. A few passed through my shop. Most were ENi's (Electro Neutronics inc." the last versions, CDV-700 6B. built around 1964. They came in original Civil Defense individual boxes, within a larger shipping box or crate of 10, most even still had the original black and white stripped carbon D cells, made by Burgess. I can't remember how many of those long dead dry cells I stripped for their Zinc cans and carbon rod element. for projects (and much later for Zn and Mn element XRF calibration targets). Most of these were headed to scrap dumps, when some were gobbled up by early Junkers/sellers on eBay. One fellow in Alabama I think, had a warehouse full, and wanted to empty the warehouse for other storage. I was glad to oblige and helped the poor fellow out. We would get regular shipments or 5 or 10 crates, once in a while 20 crates, each crate with 10 gleaming as-new ENi CDV-700, individually boxed with all accessories and manuals (2 each box!). Back in those days, eBay did not allow pictures on their site, but you could post a link to pictures, which was rather a difficult prospect at the time, as anyone who would host them for you charged an arm and a leg. Remember 28k dial up modems? Anyone else remember when eBay was all text? Description's ran into the pages. I remember watching the originator being interviewed by the Business Channel host that I watched by satellite in 1998, and they ripped him up pretty good, basically saying it wouldn't work! In those days, my hobbies were Ham Radio, Electronics, Machine Shop, and Microscopes. In 1991 (correction- 2001) when the first plane hit I got out of the stock market before the second plane hit, and went full bore Geiger Counters. Thankfully Tom Harmon had the CDV700CLUB up and running, that was a great help getting started. With all these Geiger Counters lying around, it occurred to me that they could be modified into more interesting instruments. This did not sit well with some members of CDV700Club, saying they should be left pristine, warts and all. So around 1993 I started my own brand of GC group called GeigerCounterEnthusiasts@YahooGroups. At it's peak we had 2000+ members and it was the most popular Yahoo Group in the "Physics" category, and it was private not public.. By the time we ran out of Yahoo memory, there were 50,000 posts on the "first page" as it wound up being. The PAGE-2 version and others followed, with specialty groups for Gamma Spectrometry and later XRF.
|
|
Top row, left to right Battery current meter- 2 ranges 0-50mA and 0-500mA. Eni CDV-700 draws about 55mA, a single 100 or 200mA would be fine. Bare, transformerless, Eni CDV-700 PCB, updated with critical parts replaced/restored (more on range switch rebuilding later) Transistor leakage/Gain tester, built by moi about 55-60 years ago from a HealthKit. Today I would make it myself from scratch (circuit will be provided) Second row L-R Substitute original ENi CDV-700 transformer with 18" std. color coded PtFE wires Bk=1, Red=2 Org=3 Yel-4 Grn-5 Blu-6, sorry Violet stayed home (made this last night) Substitute CDV-700 meter with 18" color coded wires Universal bench I/O PCB test jig. Besides the soldering iron, this is my most used bench tool! Details of these and other test items to follow in later posts Geo
|
Image Name
Sat 8:39am
Sat 8:39am