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2016-03-22 by Cecil Bayona
I use Ferric Chloride, and Ammonium Per-sulfate, my favorite is the Per-sulfate, it s not so stinky, somewhat clear, and won t corrode everything around like
2016-03-22 by Harvey Altstadter
I used it for a short time. I loved that I could see the etch process through the solution. I think I stopped because I couldn t get it any more. On
2016-03-22 by Harvey Altstadter
We used hydrofluoric in my Failure Analysis Laboratory. We buffered it with ammonium fluoride, as I remember it. It was used to remove the glass over layer
2016-03-22 by Harvey Altstadter
Our system was pre CompuServe. It was a mainframe located at another aerospace contractor located several miles away. I remember that the system monitor used
2016-03-22 by Andrew Volk
I used ammonium persulfate back in the early 70’s for my master’s work in college making communication devices for handicapped. We etched boards that were
2016-03-21 by Harvey White
... I wanted to, and I ve found it hard to come by. I d rather use it, since I have an etchant tank developed specifically for it. HCL and peroxide are very
2016-03-21 by keith printy
Anyone here besides me ever use ammonium persulfate? When I worked in an electronics plan that was what we used to etch our boards. We would put it in a
2016-03-21 by keith printy
Hydrofluoric is very dangerous. If you wish to use it ,you can get it at heating=cooling supply houses. I work in that trade and will not use it,just too
2016-03-21 by keith printy
I remember that back in high school. I believe it was through compuserve , which is now owned by AOL From: Homebrew_PCBs@yahoogroups.com
2016-03-21 by Brad Thompson
On 3/21/2016 1:45 PM, Harvey Altstadter hrconsult@cox.net ... Hello-- Gruesome, indeed. One advisory message on our primitive 1970s-era time-sharing system
2016-03-21 by Harvey Altstadter
Aargh! You reminded me of my first encounter with the time sharing service that our company contracted with in the 70 s. Dial up, 300 baud, acoustic coupler.
2016-03-21 by casy_ch@tbwil.ch
Oh yes! Mine had to be fixed with a velcro tape to the telephone earphone, 75 and 300 Baud. Jean-Claude, HB3YDH Am 21.03.2016 um 04:48 schrieb Jean-Paul Louis
2016-03-21 by Brad
That is really neat. My CT1024 looks more like the ones you see in google images. The keyboard has black keys. That note from Don Lancaster is fantastic!
2016-03-21 by Jean-Paul Louis
This reminds me of my first modem (circa 1985). It was not fast but it worked at the time to connect to the university network.
2016-03-21 by Harvey White
... I did that with my first color TV. Needless to say, it had a hot chassis so I borrowed an isolation transformer. ... I wanted (and this dates me a lot) a
2016-03-21 by Homebrew_PCBs@yahoogroups.com
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Homebrew_PCBs group. File : /TV
2016-03-21 by Homebrew_PCBs@yahoogroups.com
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Homebrew_PCBs group. File : /TV
2016-03-21 by Homebrew_PCBs@yahoogroups.com
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Homebrew_PCBs group. File : /TV
2016-03-21 by Homebrew_PCBs@yahoogroups.com
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Homebrew_PCBs group. File : /TV
2016-03-21 by Homebrew_PCBs@yahoogroups.com
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Homebrew_PCBs group. File : /TV
2016-03-21 by Homebrew_PCBs@yahoogroups.com
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Homebrew_PCBs group. File : /TV
2016-03-21 by Homebrew_PCBs@yahoogroups.com
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Homebrew_PCBs group. File : /TV
2016-03-21 by Harvey Altstadter
Tom, Your description of the modified TV for use as a monitor triggered my memory. Although I didn t build the TVT, I used the handbook to modify a small
2016-03-21 by rolohar@...
Hi Tom Crawford: Wow! I kind of knew that if I put out some bait , some reader would dig out his old TV-Typewriter and tell us an interesting story. Thanks
2016-03-20 by Harvey Altstadter
The usual place would be a chemical supply house. Be aware that this is classed as a hazardous material, and there are extra HAZMAT fees associated with it s
2016-03-20 by Harvey Altstadter
The formula you show is for Copper (II) Nitrate Hydrate. That is bad stuff. See pdf attached. The benefit to sewer systems is not in the processing of sewage
2016-03-20 by Jeff Heiss
Where is nitric acid found? Is it practical compared to HCl/H202 or FeCl? From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] Sent:
2016-03-20 by AncelB
I do RF PCBs requiring micro strips etc. It must use double sided FR4 boards with consistent permittivity and very accurate trace thicknesses for impedance
2016-03-20 by Jean-Paul Louis
When I was doing my dual side PCBs at home (70’s and early 80’s), I always used two single side 0.031” copper clad FR4 that I etched while single sided.
2016-03-19 by Harvey White
... I should probably get some drill rod and make a fixture. ... Exactly what happens. I ended up monitoring the process and moving the boards around. Since
2016-03-19 by Harvey Altstadter
Ancel, Thanks for the link. He has some interesting approaches. I was with him all the way until the Nitric Acid. Bad stuff in any concentration. Luckily,
2016-03-19 by Tom Crawford
This TV Typewriter thread has triggered some interesting thoughts, that might be of interest. I recall building one of these, so took a look through my
2016-03-19 by Harvey White
... I agree, I have a professional staking tool that does that. Came upon it by complete coincidence. I d not be using the eyelets otherwise. ... Agreed, and
2016-03-19 by AncelB
You may find this useful: https://hackaday.io/project/7938-pcb-smt-maker-lab-home I do single pass toner transfer -double sided with good registration
2016-03-19 by Harvey Altstadter
Harvey, I purposely didn t mention eyelets. Aside from the tedium of placing large numbers of them, the process to keep the flare on one side, while getting a
2016-03-19 by rolohar@...
I have an appointment with my shrink first-thing Monday morning. RFH ... From: Stefan Trethan stefan_trethan@gmx.at [Homebrew_PCBs]
2016-03-19 by Harvey White
... Alignment between top and bottom is critical. The spacing between lines and the size of the lines themselves is often given by two numbers (in mills) 10/10
2016-03-19 by Stefan Trethan
... moment in itself! ;-) ST
2016-03-19 by Harvey White
... You can use eyelets, however, those are quite large in comparison, and you need a source for them, and a staking tool. ... I have tried both approaches,
2016-03-19 by rolohar@...
YES! It must be the original Don Lancaster. I apologize and deeply regret the error. This is the first time in about 30 years that I have actually been wrong
2016-03-19 by rolohar@...
NOTE: Both Lancaster obits may be wrong! I ll go back and double check. If people have been receiving information from Don Lancaster lately, then my
2016-03-19 by rolohar@...
Harvey Altstadter: Don Lancasters obituary is available on several websites, and I think it is on Wikipedia Here is one URL, if you are interested in reading
2016-03-19 by Harvey Altstadter
Brad, You are correct, this is quite a challenging project. Plated through holes: If you look at the board artwork in the article, you will find a view where
2016-03-19 by Brad Thompson
... Hello-- One process used in the 1970s involved drilling holes through a double-sided copperclad board, followed by an electroplating process that deposited
2016-03-19 by Brad Thompson
... Hello-- Based on some years as an E.E. and technical editor for trade magazines, I m a little suspicious. Here s a case in point: After a layoff in the
2016-03-19 by Brad
Separate discussion. I’m not planning to tackle this anytime soon, but I have been slowly acquiring parts and am hoping after I’ve gained lots of
2016-03-19 by Harvey Altstadter
Roland, Hmmm... the What s new section of his website was updated as recently as March 5 of this year. He has some comments on the new Sainsmart O scope. Says
2016-03-19 by Brad
True, but the device is still historically significant. At least, it was significant enough for a museum to want and display it. Seems odd they wouldn’t
2016-03-19 by Brad
Are you sure about that? I got an email from ‘Don’ in August of 2015 that said the following: “At the time I bought a whole pile of surplus keyboards,
2016-03-19 by rolohar@...
Brad: Don Lancaster passed away on October 24, 2013. He was 81 years old. I don t know who was (is) handling his correspondence (@Tanija). I think some of his