Boyd Allen
Active member
Finally, a sensible, authoritative answer. Thanks. I will be very interested in what you come up with.
Vern juenke machine
- Thread starter Lou Murdica
- Start date
JerrySharrett
Senile Member
BINGO, an LC Circuit. That goes a long ways back in my ancient Heathkit/ARRL days. Thanks Normastzen.
Now, with todays digital components can you build something that is more FINITE? This thing is barely a comparator
let alone having the ability to give finite outputs?
http://en.wikipedia.org/wiki/LC_circuit
Kind-of, sort-of (graphically, at least) http://www.azom.com/article.aspx?ArticleID=8016
Or generally:
http://images.search.yahoo.com/sear...M4NV8x?_adv_prop=image&fr=ie8&va=eddy+current
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Normmatzen
New member
Analog vs Digital
Jerry,
No, I'm playing in the analog domain!
All those fancy machines you found are still based on a simple inductor sensor and an oscillator, all analog functions. What they use the digital for is the calculations and metering as it is far too easy these days to buy a 50 cent digital signal processor and program it to do all these functions.
I am using quality operational amplifiers to do all the oscillator control, rectification and active filtering that Mr. Juenke did with very simple and old circuits (probably from an old ARRL handbook!). The very high and controlled gain of the modern op-amps should give me enough stability to do a first order calibration of film thickness.
Alas! I do take the analog output and pipe it to a digital panel meter as they are now WAY cheaper than the oldies with pointers Mr. Juenke used!
Norm
Jerry,
No, I'm playing in the analog domain!
All those fancy machines you found are still based on a simple inductor sensor and an oscillator, all analog functions. What they use the digital for is the calculations and metering as it is far too easy these days to buy a 50 cent digital signal processor and program it to do all these functions.
I am using quality operational amplifiers to do all the oscillator control, rectification and active filtering that Mr. Juenke did with very simple and old circuits (probably from an old ARRL handbook!). The very high and controlled gain of the modern op-amps should give me enough stability to do a first order calibration of film thickness.
Alas! I do take the analog output and pipe it to a digital panel meter as they are now WAY cheaper than the oldies with pointers Mr. Juenke used!
Norm
Any way you look at it Vern Juenke goes on my hero list......... It's really easy to do Stairway To Heaven "better than Zep did" but the way I see it, Plant and Page are the dudes....the originators, the innovators, the AUTHORS of a fine work.......... VERN JUENKE WROTE THE SONG!!!
Bravo
al
Bravo
al
JerrySharrett
Senile Member
Vern used Simpson meters....."'spensive!
Nissan_Ranger
New member
This has been a fascinating thread to read. I bought my Juenke comparator somewhere around nine or ten years ago. I would suspect it might have been close to the last of the production. I use it to separate anomalous bullets from the crowd AND group bullets by where they register baseline on the scale. Bullets that swing the needle from edge to edge are rejects. Loading them results in flyers. Not really BAD flyers, but not grouping with the rest of them. I have noted the following:
1. Some bullets are so consistent there seems to be little reason to spin them except for the odd one that might be damaged. Bergers measure 5 or less DUs 99.5 percent of the time. Lapua match bullets are even better.
A box of Bergers that was inadvertently dropped on a concrete floor had several that measured close to 10 DUs. A hummer that was thrown on the floor went up to 10 DUs.
2. Measuring Hornady Amax bullets results usually in three groups that require three distinctly different settings of the 'fine' adjustment knob. Means three distinct groups of bullets. Setting up for a max means doing 25 to 50 bullets to establish a baseline for the groups which I then label as 'left', 'center', or 'right'. A couple of 'hummers' are kept for checking calibration. The bullets are kept separated and used in their groups in turn to maintain consistency within each group.
3. Hornady SST hunting bullets have about 5 to 10 bullets per box that are 5 or less DUs. About 10 to 20 are 5 to 14 DUs The rest are 15 and over with a few that are scale to scale. The hummers give me one hole groups at a hundred. The 15 and over give me slightly larger groups with maybe one just about touching but outside the main hole. I shoot groups of five.
4. 22 size bullets under 55 grain are a bugger to measure. Once the point of measure is set, I must NOT move the adjustable piece that the bullet turns against. It is very difficult to find the same spot again even with help of the baseline bullet.
Regards
1. Some bullets are so consistent there seems to be little reason to spin them except for the odd one that might be damaged. Bergers measure 5 or less DUs 99.5 percent of the time. Lapua match bullets are even better.
A box of Bergers that was inadvertently dropped on a concrete floor had several that measured close to 10 DUs. A hummer that was thrown on the floor went up to 10 DUs.
2. Measuring Hornady Amax bullets results usually in three groups that require three distinctly different settings of the 'fine' adjustment knob. Means three distinct groups of bullets. Setting up for a max means doing 25 to 50 bullets to establish a baseline for the groups which I then label as 'left', 'center', or 'right'. A couple of 'hummers' are kept for checking calibration. The bullets are kept separated and used in their groups in turn to maintain consistency within each group.
3. Hornady SST hunting bullets have about 5 to 10 bullets per box that are 5 or less DUs. About 10 to 20 are 5 to 14 DUs The rest are 15 and over with a few that are scale to scale. The hummers give me one hole groups at a hundred. The 15 and over give me slightly larger groups with maybe one just about touching but outside the main hole. I shoot groups of five.
4. 22 size bullets under 55 grain are a bugger to measure. Once the point of measure is set, I must NOT move the adjustable piece that the bullet turns against. It is very difficult to find the same spot again even with help of the baseline bullet.
Regards
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Nissan_Ranger
New member
Maybe so. But it works for me and that is all I require.
B
Brian Adams
Guest
Lurking no longer.
Is this the same principal the Church of Scientology uses to "audit" members?
Wouldn't many bullet manufacturers be using this process for QA purposes, if it's as good as it's touted to be?
Vern and Arnold Juenke lived here in Reno, and were still running an ad in the local Yellow Pages as "Saturn Gun Works" in the 1970s. I wish now I had bothered to drop by their shop. They developed a line of wildcats called "ICL" for "Increased Case Load" but I'm probably boring the lot of you now.
James O’Hara, who holds four of the current 1000-Yard IBS agg records, uses a Juenke machine to cull and group and his bullets - but no longer weighs cases. Just sayin'.
Brian
Is this the same principal the Church of Scientology uses to "audit" members?
Wouldn't many bullet manufacturers be using this process for QA purposes, if it's as good as it's touted to be?
Vern and Arnold Juenke lived here in Reno, and were still running an ad in the local Yellow Pages as "Saturn Gun Works" in the 1970s. I wish now I had bothered to drop by their shop. They developed a line of wildcats called "ICL" for "Increased Case Load" but I'm probably boring the lot of you now.
James O’Hara, who holds four of the current 1000-Yard IBS agg records, uses a Juenke machine to cull and group and his bullets - but no longer weighs cases. Just sayin'.
Brian
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Nissan_Ranger
New member
Vern had a list of buyers on his long defunct website by way of advertising his success. it included a number of bullet manufactorers...
Lou Murdica
Member
We'll I'm going to the dark side this weekend. I'm shooting a quick 22 lr match 25 bulls at 50 yd
So I decided to sort my ammo on the juenke .
It reads something and I did sort them .
So what is it reading on rim fire .
I've already chose my ammo in testing so I'll have to wait after the weekend to shoot more in testing to see if I can cut down on flyers.
So I decided to sort my ammo on the juenke .
It reads something and I did sort them .
So what is it reading on rim fire .
I've already chose my ammo in testing so I'll have to wait after the weekend to shoot more in testing to see if I can cut down on flyers.
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JerrySharrett
Senile Member
Seriously Lou, loaded 22 rimfire could detonate if that is an eddy current. If it is ultrasonic it might be OK but be careful.
Remember, those rf guys use 10 flags at 50 yards.
????
please elaborate?
An EDDY CURRENT? Where's the energy coming from?
Incidentally I've popped quite a few 22lr and cf rounds outside the rifle. Takes some doing....
My Bro-in-law had one go off in his jeans (never carry a 9V battery in the same pocket w/22 ammo!) My cousin had to dig a 7X57 primer out of her leg because one a' the brothers set a box on the warming oven of the wood cookstove....
But my stuff was all testing, safely, as an adult.
Well except for the ones we threw in the campfire, and the ones in the burn pile every so often....
And the ones on the exhaust manifold at the wedding...
I like to think I was, "experimental"...
Some just say "mental"
al
Lou Murdica
Member
50 yd sorry
JerrySharrett
Senile Member
Do your own thing Al. I'm not outing a 22 rimfire on a Juenke!!
Dick Grosbier
Club Coordinator
I assume you have heard of the couple of brain trust guys who after having the headlights on their old pickup go out. Discovered that a 22 RF cartridge fitted almost perfectly, perfectly that is till the current got the case very hot.
OK.
I'm just asking.
Anyone else understand eddy currents? My sum total experience with them has to do with sliding AL around on magnetized surfaces! Hardly relevant
