Re: An odd bipolar transistor effect......
On Fri, Nov 22, 2024 at 10:20 AM, wn4isx wrote:
I have 1N34's older then I!
Then chances are (in fact it is almost guaranteed) they are Germanium.
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But if you bought a 1N34 today, it might not be.
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Andy
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... to see if glass diodes emit any detectable light . . .
You won't need a scope or night vision, just turn out the lights and peel off packing tape hard and fast . . .
Most likely works with other tape as well.
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Re: An odd bipolar transistor effect......
On Thu, Nov 21, 2024 at 11:30 PM, wn4isx wrote:
1N34 are pretty bad but they are germanium ...
Just an FYI -
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I am told that "most" Germanium diodes sold today are not the Germanium diodes they originally were.? Instead, they are Schottky diodes, Silicon-based, packaged with Ge diode part numbers.? I guess the manufacturers figure that as long as they meet the datasheet specs, all is well and good and 'nobody' can tell the difference.? Apparently that is done not just by the counterfeit part makers, but by the legit ones too.
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It's a bit disappointing.
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Andy
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Re: An odd bipolar transistor effect......
On Thu, Nov 21, 2024 at 09:15 PM, wn4isx wrote:
Photons are emitted when the electrons and holes recombine in the collector/base. And the photons could excite voltage production via PV effect in the base emitter junction.
Below is written by the guy who created LTspice (Mike Engelhardt), which he wrote in the LTspice user's group about 15 years ago:
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Bipolar BE breakdown is technically a failure mode also,
because it modifies the transistor doping and the gain
decreases.? BTW, if ground the emitter of an NPN transistor,
leave the collector unconnected, and reverse bias the base
to breakdown, the collector tends to go negative because
the breakdown creates photons which are converted back to
current in the BC junction.? Does anybody know the net quantum
efficiency of that process?? I did a quick check on a 2N3904,
and found it less than 1ppm, which was the limit of my
multimeter.
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So I guess the photo emission and voltaic effect works either way: BC to BE in one case, or BE to BC in the other.
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Andy
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Re: An odd bipolar transistor effect......
Also the reason why transistor junctions are lower leakage than glass diodes. Sam Reaves
ARS W3OHM
Owner / Moderator of: LeCroy Owners Group on Groups.io
Sencore Owners Group on Groups.io Sprint Layout Group on Groups.io?? Pulsonix EDA Group on Groups.io
LPKF Owners Group on Groups.io
Electronics and Mechanical Hardware Design Engineering Manager
Staff Scientist Andritz Rolls Global Research Center (RETIRED)
A lifetime ago, May 1974, a visiting professor to the EE program explained an odd 'side effect' in some transistors.
Photons are emitted when the electrons and holes recombine in the collector/base. And the photons could excite voltage production via PV effect in the base emitter junction.
He demonstrated the effect.
Normally this is a laboratory curiosity and we were told we'd never see any indication in the real world.
I wrote it down in my class notes, underlined and promised to look into the effect...and promptly almost forgot about it. Life was too filled with class work, then marriage, jobs, and hobbies...
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Today a friend sent me a link...
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The video is interesting and appears to demonstrate the effect.
Note: My 1980s 2N2222 barely worked, modern 2N2222 and modern 2N3904 worked extremely well. I intend to check every family of transistors I have.
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I can't think of any practical application, but the effect is interesting.
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Now to borrow a nightvision (starlight) scope and see if glass Ge and Si diodes emit any detectable light when forward biased.....
And somewhere I have some phototransistors, it will be interesting to see if they emit any detectable light when forward biased.
And will photovoltaic cells emit any detectable light when forward biased.
So many experiments, so little time....
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Re: Lock washer and nut for BNC bulkhead connector ??
Apologies! I need to re-read?the original question. My thread info was for the chassis mounted BNC to soldered wire. Will have to find a BULKHEAD?BNC- BNC and measure I'm sure the bulkhead will require larger than a 3/8 inch hole. note to self: READ READ READ carefully, then understand what I just read!! Just found?a bulkhead?BNC female-female, and Starrett says it is 1/2-27. Sorry for the misinformation. Norm W6NIM
Barb Stewart, KE7HIE ?3/28/1938 -9/26/2024
OK funny story about BNC female bulkhead connectors.?
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Some hams and shortwave listeners use BNC female bulkhead connectors to fabricate a ground window, AKA ground bulkhead. This allows you to ground the shield of all your coaxial cables at one point. you mount the bulkhead connectors in a sheet of metal and ground the sheet. Easy peasy compliance with one part of the US National Electrical Code.
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A local ham with a Ph.D. in EE decided to build a ground window. He ordered a bunch of bulkhead connectors, bought a ~1 foot x 3 feet, 1/8 inch copper sheet. Drilled holes in it (which must have been a lot of fun), mounted his bulkhead connectors, grounded it properly, connected his coaxial cables.
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And was confused when a nearby lightning strike fried most of his gear.
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He used insulated BNC female bulkhead connectors.
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Which defeated the entire concept.
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Note: You can use SO-259, "F", TNC, RCA bulkhead connectors on your ground window.
[There are 3.5mm mono and stereo and 1/4" mono and stereo bulkhead connectors, I was on the phone with a friend who assured me "Yes Terry they exist." So I did a net search and sure enough they do exist. Which might be nice for an audio studio.]
I'd tried to explain the error of his logic but was dismissed, after all, what could a mere BS EE know?
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-- Barbara Stewart 3/28/1938 - 9/26/2024 Sent from my antique Win7 desktop
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Re: Lock washer and nut for BNC bulkhead connector ??
Thanks all. Some funny stories there.
Dave
On 21/11/2024 18:43, Norm Stewart via
groups.io wrote:
toggle quoted message
Show quoted text
Finally found
my Starrett?thread gauge. Two types of BNC bulkhead mounts:
the 3/8 inch is definitely 3/8-32; the 1/2 inch, which
insulates the BNC shell from the panel, is 1/2 27, as near as
these 90 year old eyes could tell, but 1/2- 28 was a very near
fit. Just for info: the UHF bulkhead mount is 5/8-24.
Norm, W6NIM
On Tue, Nov 19, 2024 at
4:58?PM C. Michael Stone via <enots123= [email protected]>
wrote:
On Tuesday, November 19, 2024 at 02:50:46 PM
PST, Leon Robinson < leon-robinson@...>
wrote:
If my memory is correct, I'm
pushing 84, it is 3/8" 24 thread.
Leon
Robinson ?? K5JLR
Political Correctness is a Political
Disease.
Politicians and Diapers should be
changed
often and for the same reasons.
On Tuesday, November 19, 2024 at
10:23:00 AM CST, Roy J. Tellason, Sr. via
<roy= [email protected]>
wrote:
On Tuesday 19 November 2024 09:10:30 am
David Slipper via
wrote:
> I picked up a LARGE handful of 50ohm
BNC bulkhead connectors but some of
> them lack nuts and washers :-(
>
> What size are they ??
>
> The thread is not M10 so I assume its
"imperial".
Probably.
> M10 crinkle washers are too big.
Perhaps you'll find something useful in
one of the references on this page:
--
Member of the toughest, meanest,
deadliest, most unrelenting -- and
ablest -- form of life in this section of
space, ?a critter that can
be killed but can't be tamed. ?--Robert A.
Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon
to a society ruled by lies. --James
M Dakin
--
Barbara Stewart
3/28/1938 - 9/26/2024
Sent from my antique Win7 desktop
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Re: Lock washer and nut for BNC bulkhead connector ??
Finally found my Starrett?thread gauge. Two types of BNC bulkhead mounts: the 3/8 inch is definitely 3/8-32; the 1/2 inch, which insulates the BNC shell from the panel, is 1/2 27, as near as these 90 year old eyes could tell, but 1/2- 28 was a very near fit. Just for info: the UHF bulkhead mount is 5/8-24. Norm, W6NIM
On Tue, Nov 19, 2024 at 4:58?PM C. Michael Stone via <enots123= [email protected]> wrote:
On Tuesday, November 19, 2024 at 02:50:46 PM PST, Leon Robinson < leon-robinson@...> wrote:
If my memory is correct, I'm pushing 84, it is 3/8" 24 thread.
Leon Robinson ?? K5JLR
Political Correctness is a Political Disease.
Politicians and Diapers should be changed
often and for the same reasons.
On Tuesday, November 19, 2024 at 10:23:00 AM CST, Roy J. Tellason, Sr. via <roy= [email protected]> wrote:
On Tuesday 19 November 2024 09:10:30 am David Slipper via wrote:
> I picked up a LARGE handful of 50ohm BNC bulkhead connectors but some of
> them lack nuts and washers :-(
>
> What size are they ??
>
> The thread is not M10 so I assume its "imperial".
Probably.
> M10 crinkle washers are too big.
Perhaps you'll find something useful in one of the references on this page:
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
-- Barbara Stewart 3/28/1938 - 9/26/2024 Sent from my antique Win7 desktop
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On Wednesday 20 November 2024 04:18:08 pm David Slipper via groups.io wrote: I have a small pair of medical forceps - they lock onto the wire end and
stop it flying into orbit Hemostats, yeah. I have two of those, one straight and one with an angled tip. They're very handy... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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I had a similar "accident" while working on a cuckoo clock. One set of chains dropped onto a plug not fully pushed into the socket. Needless to say I had to replace the set of chains.
Dan Kahn
On Wednesday, November 20, 2024 at 03:01:47 PM EST, Roy J. Tellason, Sr. via groups.io <roy@...> wrote:
On Wednesday 20 November 2024 10:59:40 am wn4isx via groups.io wrote:
> A friend called this morning, he was changing the strings on his electric guitar and the high E cut off bit flew and landed between a 120V male plug and the socket.
>
> Needless to say there was a bright flash then darkness as the breaker opened.
>
> I really shouldn't have giggled so hard, I think I hurt his feelings.
Heh.
(...)
> Aside from the danger of unexpected electrical fun, those cut off bits of wire then to go flying at fairly high speed and can injure your eye(s), so wear safety glasses! Or the piece can get caught in carpet and thence into your foot when you step on it barefooted. This isn't theory, I've managed to do that.
Or grab the end bit that you're trimming off with a pair of pliers...
If you look at some datasheets for transistors,? they specify a maximum "G" force for the part.? That's what gets applied to the wires if you cut them,? typically,? and it can be quite high.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
|
I just got my "discover electricity" flashback thanks! I had already learned how to use a butter knife as a prying device and to connect antenna to tv. A butter knife is NOT a good tool to pry the plug out of the socket lol.BOOM.?
As I mentioned in a previous post, I've noticed an inordinate number of electronic enthusiasts also play guitar, or, God Have Mercy, banjos.
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A friend called this morning, he was changing the strings on his electric guitar and the high E cut off bit flew and landed between a 120V male plug and the socket.
?
Needless to say there was a bright flash then darkness as the breaker opened.
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I really shouldn't have giggled so hard, I think I hurt his feelings.
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I've asked for photos of the fried outlet and plug but remembered Rod Elliot warned of this in an article on his web page.
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Remember, the rest of the world uses some damn odd AC power connectors.
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Now if that bit of string had landed inside his vacuum tube guitar amplifier, which was on, major fun [damage] might have happened.
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Aside from the danger of unexpected electrical fun, those cut off bits of wire then to go flying at fairly high speed and can injure your eye(s), so wear safety glasses! Or the piece can get caught in carpet and thence into your foot when you step on it barefooted. This isn't theory, I've managed to do that. Not quite as much unfun as stepping on a 2N3055 pins up barefooted, I have that 2N3055 mounted on a nice stained oak board, with the blood still on the transistor case.
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But it still hurt.
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[Do you know what perfect pitch for a banjo is? Hitting the dumpster on the first toss. The @#$% things typically won't stay in tune! Much worse then violins....]
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I have a small pair of medical forceps - they lock onto the wire end and stop it flying into orbit
Dave
toggle quoted message
Show quoted text
On 20/11/2024 20:04, Roy J. Tellason, Sr. via groups.io wrote: On Wednesday 20 November 2024 10:59:40 am wn4isx via groups.io wrote:
A friend called this morning, he was changing the strings on his electric guitar and the high E cut off bit flew and landed between a 120V male plug and the socket.
Needless to say there was a bright flash then darkness as the breaker opened.
I really shouldn't have giggled so hard, I think I hurt his feelings. Heh.
(...)
Aside from the danger of unexpected electrical fun, those cut off bits of wire then to go flying at fairly high speed and can injure your eye(s), so wear safety glasses! Or the piece can get caught in carpet and thence into your foot when you step on it barefooted. This isn't theory, I've managed to do that. Or grab the end bit that you're trimming off with a pair of pliers...
If you look at some datasheets for transistors, they specify a maximum "G" force for the part. That's what gets applied to the wires if you cut them, typically, and it can be quite high.
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On Wednesday 20 November 2024 10:59:40 am wn4isx via groups.io wrote: A friend called this morning, he was changing the strings on his electric guitar and the high E cut off bit flew and landed between a 120V male plug and the socket.
Needless to say there was a bright flash then darkness as the breaker opened.
I really shouldn't have giggled so hard, I think I hurt his feelings. Heh. (...) Aside from the danger of unexpected electrical fun, those cut off bits of wire then to go flying at fairly high speed and can injure your eye(s), so wear safety glasses! Or the piece can get caught in carpet and thence into your foot when you step on it barefooted. This isn't theory, I've managed to do that. Or grab the end bit that you're trimming off with a pair of pliers... If you look at some datasheets for transistors, they specify a maximum "G" force for the part. That's what gets applied to the wires if you cut them, typically, and it can be quite high. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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On Tuesday 19 November 2024 09:49:05 pm wn4isx via groups.io wrote: I almost made a not so small fortune by cloning the MXR Phase 90.
It was easy to clone and nightmare to match the JFETs.
I did end up looking at that, and then the page for flanger, which led me to the page for Eventide, which seems to be still around. I almost went to work for them once, and in the interview process the guy made it a point to tell me that they ordered just enough parts for production and that it'd be a real problem if I were to take any home for my own projects. I found that rather insulting, him assuming right off that if I went to work there I'd be stealing from them, and informed him that I had plenty of parts of my own, and wouldn't need to bother with any of theirs. I don't recall anything about having to match the jfets. Maybe I was seeing different stuff in those days? Maestro comes to mind. And I have a vague recollection of a phaser that used LDRs rather than jfets, though I'd have to do some digging to find out what one that was. All of that being in the pile called "schematics and service manuals that I'll probably never use again"... Now I'm wondering how complicated it would be to put together some sort of a digital effects box. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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ROFLMAO! ? Aside from the danger of unexpected electrical fun, those cut off bits of wire then to go flying at fairly high speed and can injure your eye(s), so wear safety glasses! Or the piece can get caught in carpet and thence into your foot when you step on it barefooted. This isn't theory, I've managed to do that. Not quite as much unfun as stepping on a 2N3055 pins up barefooted, I have that 2N3055 mounted on a nice stained oak board, with the blood still on the transistor case. -- Nuno T.
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On Tuesday 19 November 2024 09:49:05 pm wn4isx via groups.io wrote: In 1974 I built a plate reverb, 1/8 thick 48" wide by 60" long in a oak 4"X4" frame. It takes 4 strong people to move it (which I'm not these days). Sure beats a spring reverb (have one of them too).? Until digital effects matured, the plate reverb was it unless you had a large spare room to use as an echo chamber. I've only ever heard of those being used in recording studios. I never cared for the Leslie Speaker
They sound good on electronic organs but not so good on electric guitars. I like 'em, but then I like organs, too. Almost ended up with one a while back, but my car died around that time and I took the money the guy offered me instead. Last time I talked to him he was still looking for a Leslie cabinet. I did a mod on one of those once, the speed switching relay had some pretty burned contacts, so after getting a replacement I had the relay switching gate drive to a couple of triacs, and told the guy that he'd never have that problem again. I also have a Fender Rhodes electric piano but reeds have become almost impossible and insanely expensive to buy, It needs a lot of reeds/tines so it is destined for the recycler. Bummer. I like those, but didn't know that about them. Tines. Reeds are what you find in Worlitzer electric pianos. They break occasionally. Tuning those is done with a file on the little blob of solder on the end of the reed. You go too far, and you can always add some back. Lining those things up was a bit of a PITA. And then of course there's the voltage across that stuff, in the earlier ones it could give you quite a tingle... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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On Tuesday 19 November 2024 05:47:14 pm Leon Robinson wrote: The 2N3055 is a TO-3 Power Transistor, RCA Made the best one's. Motorola ones were used a lot too. I vaguely recall some particular model of Crown amplifier specifying that brand, and I saw them a lot in Baldwin organs. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Altium PCB files to Circuit studio
Circuit Studio can import Altium PCB files if they were saved in Altium version 5 format. Unfortunately, the PCB house did not do that so I cannot import the files. ? Any suggestions how to convert regular saved Altium files into saved as version 5? Is there any conversion software to do that? Bertho
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Those were also my go to semis when making test fixtures for production electronics. Those and ua741's
Dan Kahn
On Tuesday, November 19, 2024 at 06:27:08 PM EST, wn4isx via groups.io <wn4isx@...> wrote:
I made a small fortune, OK small fortune to a high school student, building quasi-complimentary guitar amps. By today's standards they were pretty awful but, for the 1966~1970, probably not so bad. This is close to the circuits I used, the exact semiconductors depended on what I could obtain, but the 2N3055 was standard. I built several with 2 per upper and lower and one (shudder, it had a nasty habit of oscillating about 30KHz, took me a month to tame) with 4 upper and lower. I've used 2N3055 for every thing from power amps to pass elements in linear supplies. I even built sliced the tops off 2N3055 that failed the Vce breakdown test and used them as "solar cells". They'd produce about 0.6V @ 10mA. [Yea how powerful.] I used "boatloads" of 2N3055, 2N22222, 2N2977 and even more 1N4004s.? ?
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Re: Lock washer and nut for BNC bulkhead connector ??
You won't find these at Lowes or Home Depot!
I had a heck of a time finding 1/2" 20 nuts and still looking for 1/2 - 20 Carriage Bolts (2" or maybe 1.5"
And my fancy nut checker only includes 1/2-13 and 1/2-20: ? So I doubt they have a 1/2-28 checker at Lowes or HD!
--
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Gooey
Sam Reaves
Bertho