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I have a partial spool of the original coaxial Belden wire. It was steel stranded and rated to withstand the probe voltage (at least 1kv DC). If you send me a self-addressed stamped small padded mailer I will send you 6 feet (enough to do 2 Vic) no charge.

David Nix

6861 NW 24th Place

Sunrise , FL 33313

Otherwise any coaxial wire that fits and is rated to 1KV will work

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that rubber like pad? I have a couple operating without it no problem.??

I have a Victoreen 6A with a damaged probe wire and I'm looking at repairing it. Does anyone know what material is used between the geiger tube and the tube socket inside the probe? ?Is it required for some reason?

Clint

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meaning they worked on cdv715. dont know about replacing corotron tube

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yes I believe so? ?I ordered a batch of those pentodes on ebay. . they worked.??

Lenox,

I have ordered the item from eBay.

I also have a CDV-715 n repair. Do you know if a 5886 electrometer pentode is a direct replacement for the hard to find Victoreen VX86?

Clint

Thank you,
Clint

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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

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
  ??

Thank you.

Sincerely,
Cliff

P.S.:? I've never done this before...??

I like your idea.? That could look pretty neat.? You should look in the group files if you haven't already:? Doug Moore's Archive's: A little pizzaz for the CDV-700.? Doug mounted a few flashing LEDs behind the meter with a custom built adapter. No modification required to the meter.? You might get some ideas.? If you use 3mm LEDs you might be able to fit 10 as a decade counter for use with the 4017.

If you only need a couple of chips you might consider point to point wiring on a blank board.? I do this often for small, one off projects.

Mike L.

Paul
?not the right formfactor and also its not a spinning light but just a level meter

It could be an alternate display to the analog meter.?

P

Russian Transistors used in all 3 positions on? ENi CDV-700 with LENi Mods. (LENiSKi)

Direct transistor swap, with particular performance testing done on the HV transistor. The LENi mod adds a Zener Diode regulator, so HV output remained the same as with original transistors. Everything went smooth and operation continued as normal, but the calibration changed with the new transistors, and was easily recalibrated with no issues.?

LENiSKi



V1-SKi-Base_189Hz



V1-SKi-Base-7.52_AC-VPP


V1-SKi-Base-0.415 DCV


With the in-line 3.3V regulator, the LENiSki draws 85mA **READ UPPER SCALES**(about normal for Batteries too) from?the DC Power Supply set to 11V (max input/output V differential for the 3.3)
This test was performed to see if the capabilities of the regulator were true to their specifications, but is 12V or more were contemplated, a 5V regulator would work if installed before the 3.3V regulator. REMEMBER CDV-700's are POSITIVE GROUND! Don't try to run them on a vehicle battery system, the case would be HOT. This issue can be addressed if the CDV700 and its probe is isolated from the case. A separate discussion.



HV output remains the same due to Zener Regulator in HV line.



Geo

Oscilloscope patterns of original V-1 HV transistor generator circuit:

Base-167 Hz:


Base 7.85 ACV-P-P


V1-Collector 334Hz


V1-Collector 2.61 DCV


V1-Collector 7.4 ACV



Geo

Note The LENi-SKi2 Russian transistor hack next.

On the test bench, CDV-700's etc. are fitted with a temporary quick disconnect (5.5 X 2.1, pin+) for their "Battery" power input.

The ENi CDV-700 normally operate from a two D-Cell Dry Battery, but on the test bench, we use a regulated DC Power supply, which in turn supplies an in-line 3.3V AMS1117 regulator module. Metering of Voltage and current are done by in-line instruments, as needed. The same 3.3V regulator is used for all CDV-700 tests to keep the measurements of different '700's etc.?constant and relevant over time.







Also, the boards are removed from their cases, for I/O, testing, and photographing in a simple jig


Geo

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