So @Aleph(0) and her avatar could be Poles apart.

"Her"?
Avatars mean nothing about their owners. I'll even bet that sinus23 is not a cat!

 

The OP's profile states the owner is a 32 year old female.
Authentic? Who can tell.
My avatar suggests I might live or travel in Italy.
One can day dream.

 

I'm probably the only person on this site that displays a photo of my real face, but that was 40 years ago, so I think my present disguise will suffice for the purposes of privacy.

 

My oldest copy of Towers, oops!#! Ball (9th) lists a dual emitter transistor designation as shown.
However I can't see one listed in the main body of the text.

Thanks for that!

Do you have any additional information in regards to the linked publication? Is it a catalog?

Although a cursory search shows 'hits' for 'Ball Electronics' in Anaheim, CA and Gadsen, AL -- said concern{s} don't appear sufficiently 'venerable' to be the publisher of the reference?

Again, many thanks!

Best regards
HP

 

The OP's profile states the owner is a 32 year old female.
Authentic? Who can tell.
My avatar suggests I might live or travel in Italy.
One can day dream.

So @Aleph(0) and her avatar could be Poles apart.

Ya gotta know, as per number theory, all bets are off in the realm of the transfinite! Golly! Golly!!!

Whimsically
HP

PS
Ummm... that's 'transfinite'
So, Aleph(0), no defamation suits today...K?

 

I'm probably the only person on this site that displays a photo of my real face, but that was 40 years ago, so I think my present disguise will suffice for the purposes of privacy.

Time, time, time never ask what's become of us... (Attribution: Simon? Wilson? -- I dunno...)

On a serious note -- You may be surprised at the efficacy of facial recognition algorithms... (not to be confused with Google's 'useful', albeit limited, 'search by image' tool...)
I wish more people took privacy seriously... Seems I'm one of those 'old-fashion' folks who believes in the 'ounce of prevention' paradigm -- as opposed to the current trend of 'live recklessly and [attempt to] repair'... (can we say LifeLock?)

Best regards
HP

 

Radio Valve and Transistor Data
A M Ball

9th edition 1970
First published 1949

Iliffe Books
London

"Tables of data of Valves, Cathode ray Tubes, Transistors, Diodes Rectifiers and Integraded circuits"

By the 11th edition, which I believe to be the last, Iliffe had been taken over by Newnes and the book had become

Semiconductor Data Book.

Edit FYI Towers was a much later series of data books.

 

I’m not angry --- Though I’m bound to say I’ve scant patience with parsimony! -- especially where more is to be lost than saved! Although my offer of assistance yet stands, be advised that your misplaced priorities (to wit: trivial 'economy' over quality) has a veritable withering effect upon my alacrity in this regard…


3-Meter (88.1 MHz through 107.9 MHz) broadcast stations are ubiquitous! My advice, however, is that you appeal directly to the appropriate member of the technical staff (inasmuch as management tend to be ‘media types’ and media types… Um... well... enough said!)


That is precisely what one would expect (with the qualification that, instead of attaining the positive rail, the output approaches same within Ca. 2 volts)

Point being: single (i.e. unbalanced) supply applications involving low input levels require a device exhibiting a common-mode input range extending to the negative rail…
Be advised, however, that (unless explicitly stated otherwise) the output swing will not likely include the rails…


Succinctly: the emitters implement a logic "AND" function in that forward bias of the device requires forward bias of all base-emitter junctions… Whereas the collectors are merely mirrors (pun intended!) --- FWIW I was unaware that such devices are available as discrete units?!


Since you asked I’m bound to express my (strongly held) opinion that public deposition of personal ‘info’ (including images of oneself) is folly!!!

Best regards
HP

PS
OBTW your vacillating syntactic 'style' just gets scarier and scarier!!!

My avatar use random pic from web, its appearance to self is like they say /close enough for government work/ Happy you understand about privacy and no offense about Polish joke! not so thin skinned as that even if I was Polish! I say average Polish better avatar than robot yes? and no silly! I have no source for multiple electrode bipolar transistor, I read it on op amp datasheet trying to figure out troubles with circuit and I’m not so parsimonious as destitute toward the acquiring of yu181 tube now you like that I give you those advanced words? I want to drive ultrasonic transducer I salvaged from humidifier pls tell me how to discover frequency of resonance? And best way to drive?

 

Radio Valve and Transistor Data
A M Ball

9th edition 1970
First published 1949

Iliffe Books
London

"Tables of data of Valves, Cathode ray Tubes, Transistors, Diodes Rectifiers and Integraded circuits"

I still have my 8th Edition version.
Max.

 

Time, time, time never ask what's become of us... (Attribution: Simon? Wilson? -- I dunno...)

Wilson (Heart) from the song "Soul of the Sea". The actual line is

"Time, time, time, time
Never ask what's become of us"

The opening line from "A Hazy Shade of Winter" written by Paul Simon is

"Time, time, time, see what's become of me."

 

My avatar use random pic from web, its appearance to self is like they say /close enough for government work/ Happy you understand about privacy and no offense about Polish joke! not so thin skinned as that even if I was Polish! I say average Polish better avatar than robot yes? and no silly! I have no source for multiple electrode bipolar transistor, I read it on op amp datasheet trying to figure out troubles with circuit and I’m not so parsimonious as destitute toward the acquiring of yu181 tube now you like that I give you those advanced words? I want to drive ultrasonic transducer I salvaged from humidifier pls tell me how to discover frequency of resonance? And best way to drive?

Okay! Aleph(0) you’ve had your fun --- Now please, who are you?
Prior to a display of affected indignation, pray consider the following points:

1) Your original post was directed toward myself and under a user name which ‘dovetails’ with my long expressed interest in Set Theory and, in particular, Transfinite Algebra…
-Ratiocination: Mistakes happen and so does coincidence

2) You inquired about the AL-1200, and, more ‘interestingly’, about a difficulty which I have long held out as the quintessential example of good engineering talent in collision with poor marketing strategy (Sincere disclaimer: I have no association with Ameritron nor with the design or marketing of the AL-1200)
Rationalization: As with most ‘low-end’ equipment, there're a lot of ‘em out there and a common problem is a common problem…

3) You use a ludicrously (and, IMO, deliberately) transparent ESL ‘vernacular’...
Rationalization: Everyone has, and is entitled to, their own ‘style’…

4) With the exception of a brief exchange of posts on the ‘general’ forum you correspond soley with me and on this thread…
Rationalization --- Newcomers are often ‘bashful’…

BUT THEN:

You selected an avatar which so strikingly resembles my daughter that I had the phone in my hand before closer examination of the image proved otherwise… ‘Tho I confess I should have known better! My kids have better things to do!

AND NOW:

You’ve made an inquiry in regards to DIY high power ultrasonics! --- I assert that, with the exception of myself, nobody! but nobody!! ‘Plays about’ with transducers scavenged from US. humidifiers!!!
Notice that I’ve exhausted my ‘benefit of the doubt’ rationalizations subsequent to point #4

Conclusion, I suspect that you are a (past or present) 'real world' acquaintance having a bit of 'sport' at my expense?

Seriously, I’m not angry and I sincerely hope you will continue as a member of these fora --- Still, I daresay I’d rest a wee bit easier were you to ‘lay your cards on the table’ as it were… (if you insist you may respond [to this point only] via PM) (in general I discourage private messaging for it's conflict with the essential principal of public fora...)

But to respond to your question: (like the inveterate good Samaritan I seem to be)

As with most low frequency and/or high power (and, hence, physically ‘thick’) piezo devices, the transducers exhibit a rather low level of activity… Thus you may wish to merely implement a multivibrator (with, for instance, a broad-band Op Amp) featuring the transducer in the feed-back loop --- Fundamental resonance should occur somewhere between 500kHz and 2MHz) Please be advised that, owing to significant risk of (over EMF) damage to test equipment, I do not recommend ‘sweeping’ the device… --- As far as driving it, merely implement a power oscillator --- for 'VXO', overtone or non-resonant operation, a VCO excited 'H" bridge is unbeatable!

With jaded regards...
HP

 

Do you guys remember a long while back there was a member with multiple logins who would argue with himself across multiple threads? I cannot recall his names.

But, this thread seems strikingly similar.

I think HP a.k.a. Aleph is spoofing us. Just IMHO.

 

Wilson (Heart) from the song "Soul of the Sea". The actual line is

"Time, time, time, time
Never ask what's become of us"

The opening line from "A Hazy Shade of Winter" written by Paul Simon is

"Time, time, time, see what's become of me."

Many thanks! I prefer to give proper attribution now I can! --- I daresay you'd be a formidable opponent in a match of 'Trivial Pursuit'

Best regards
HP

 

Do you guys remember a long while back there was a member with multiple logins who would argue with himself across multiple threads? I cannot recall his names.

But, this thread seems strikingly similar.

I think HP a.k.a. Aleph is spoofing us. Just IMHO.

I can't say I blame you for your suspicions considering she's just given me a silly amount of feedback points -- However, I assure you I am not the OP! --- I promise you this (i.e. 'Hypatia's Protege') is my only user on these fora Serriously I hope any such suspicions are robustly investigated, sock-puppets are kid's stuff -- not my style

Thank you for your candor
HP

 

Time, time, time never ask what's become of us... (Attribution: Simon? Wilson? -- I dunno...)

On a serious note -- You may be surprised at the efficacy of facial recognition algorithms... (not to be confused with Google's 'useful', albeit limited, 'search by image' tool...)
I wish more people took privacy seriously... Seems I'm one of those 'old-fashion' folks who believes in the 'ounce of prevention' paradigm -- as opposed to the current trend of 'live recklessly and [attempt to] repair'... (can we say LifeLock?)

Best regards
HP

"Time, time, time, see what's become of me. "A Hazy Shade of Winter", performed by Paul Simon and Art Garfunkle.
http://www.lyrics.com/a-hazy-shade-of-winter-lyrics-simon-garfunkel.html
and I see that KJ6 has already done most of the work on this.
But, no, this is not enough for Trivial pursuit. That game has lots of questions about Hollywood Movies, and that makes me fail against the kind of people that don't know copper oxide is black.
Perhaps because knowledge of the real world is not trivial?

Try Googling, "#12". The results are absurd.
This is the only place I have ever posted my face. If the person looking for me has face recognition software, he's probably a police person and can find me, anyway.

 

But, no, this is not enough for Trivial pursuit. That game has lots of questions about Hollywood Movies, and that makes me fail against the kind of people that don't know copper oxide is black.
Perhaps because knowledge of the real world is not trivial?

I do believe you're on to something there...

Try Googling, "#12". The results are absurd. This is the only place I have ever posted my face. If the person looking for me has face recognition software, he's probably a police person and can find me, anyway.

You've got me there! -- I guess, in my case, it's a matter of 'once bitten'

Best regards
HP

 

Do you guys remember a long while back there was a member with multiple logins who would argue with himself across multiple threads? I cannot recall his names.

But, this thread seems strikingly similar.

I think HP a.k.a. Aleph is spoofing us. Just IMHO.

I do remember such a thing. He started out as jgatsby then morphed into split infinity. I have the same reaction as you; appears he's back.

 

I'm not sure Aleph is one of our old trolls because the errors in spelling, typing, and grammar are different.

The Mod Squad has much better tools than I and I shall allow them to do their job without interference.

 

A poster using a pretty girl's face as an avatar appears to be the new sport to post inconsequential, off the wall comments.

see here

http://www.scienceforums.net/topic/88424-help-i-dont-get-it/page-2

 

We've officially run out of interesting things to talk about. Toilet use, people talking to theirselves ..... Conversation dried up. Time to go in search of intelligent life.