Impressive HB in Russian

Bruce Baxter, provided links via one of his notes on the "Homebrew_PCBs" list server that was very impressive, video narrative is Russian but, Homebrew is a universal language.

With permission, a copy of Baxter's original note/email text is provided here (normally, I would just link to the original note, but it contains many links that I want to capture here for future reference)

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> See this --à http://radiokot.ru/lab/hardwork/34/ Russian site, but with

> google translate is you will know everything.

Chris,

While Looking at your reference, I noticed the statement" "There is still everyone's favorite FGK-120".

I couldn't find any availability of the product in the US. However, from the photos of the Chinese marketers, I recognized it as a Tamerica LP-120 which is sold in the US for about $51. This is the laminator I use and it does a great job with toner transfer.

During my search for the FGK-120, I came across this URL,

http://easyelectronics.ru/izgotovlenie-pechatnyx-plat-videourok-nomer-dva.html

Although this is a bit off topic, The second video discusses a PCB tinning method using citric acid, boiling water and some metallic particles called alloy Rose. The process seems quite simple without any bad chemicals. A bit of searching identified alloy Rose as a low temperature solder (203-212 deg F) called Rose's metal or Rose's alloy composed of bismuth, tin and lead,

http://en.wikipedia.org/wiki/Rose%27s_metal

You can make your own,

http://www.angelfire.com/planet/skerjastrond/casting.html

or buy it,

http://www.mcmaster.com/#bismuth-alloys/=97u0jk

The McMaster-Carr product seems to have the lowest melting point (203 deg F) with

Bismuth = 52.5%

Tin = 15.5%

Lead = 32.0%

wikipedia-Solder has this to say about Bismuth alloys,

"Bismuth significantly lowers the melting point and improves wettability. In presence of sufficient lead and tin, bismuth forms crystals of Sn16Pb32Bi52 with melting point of only 95 °C, which diffuses along the grain boundaries and may cause a joint failure at relatively low temperatures. A high-power part pre-tinned with an alloy of lead can therefore desolder under load when soldered with a bismuth-containing solder. Such joints are also prone to cracking. Alloys with more than 47% Bi expand upon cooling, which may be used to offset thermal expansion mismatch stresses. Retards growth of tin whiskers. Relatively expensive, limited availability."

Based upon this, Rose's alloy may of limited utility for DIY PCB tinning. However, With the low melting temperature, it seems almost as useful as polymorph (friendly) plastic for prototyping parts .

Baxter

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UPDATE:

I have tried to obtain Bismuth from locations around Seattle, so far I have NOT located a source - Green (no-lead) Sinkers and Green Shotgun Shot has not sold well enough to stock it locally. Because of it's weight, an Internet purchase may be prohibitive for medium (e.g., 10lbs) quantities.

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UPDATE:


I now, have some Bismuth on order from Rotometals in San Francisco.

• http://www.rotometals.com/Bismuth-s/4.htm

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HomeBrew in Russian

I just added another Blog Link to the right side bar, "Easy Electronics" - it is written in Russian, but Hobby HomeBrew Electronic is a universal language - and Google Translates will help with the details.

After reading several of the posts, I think I will really enjoy this link.

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A Special Day

Today is a Special Day for many reasons, but three reasons are special to me.

• At one moment in time, today's time can be written as: 2010-10-10 10:10:10.1010, for a Geek this has to be a special point in time.

• This would have been my Father's Birthday (89) and in his honor each year I declare this day as Hero Day. My Father is my favorite Hero (see previous posts). I celebrated his Birthday today at 10:10:10.1010am local, he would have liked that, even without computers, he was very much a Geek of his time.

• Because I use Ubuntu for most of my computing needs, today is also special, because of the new revision of Ubuntu was released. Note: this new release was specially timed to coincide with this day of Oct 10th. Normally, release numbers reflect the year and the month, coincidently this year it ALSO reflect the month and the day! More than likely, this contrived coincidence will not happen again. Normally, releases come out about once each six months. The last release was Ubuntu 10.04, representing Apr 2010. But, maybe they will slip the scheduled release of 11.10 to November?  . . .  Nah.

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QRSS, WSPR on SDR

I could not sleep about 4AM,  so I got up to listen to my Softrock RX Ensemble SDR via MS XP, tuning to 10.1387MHz for both the LO and the Tune frequency provides the 1300 to 1600Hz audio signal for both the QRSS and WSPR decoders.

Normally, the audio would be decode by additional processes like ARGO (1300 to 1400Hz) for QRSS, and the WSPR program (1400 to 1600Hz) for WSPR. To re-route the audio to those two programs requires an additional sound card, or a "virtual audio cable" (VAC). SDR and the two decode programs can run concurrently, assuming WSPR is configured for receive only. The SDR audio bandpass filter makes it very easy to select the desired signals.

I do not have VAC and my second sound card was not working, so I slowed down the SDR audio water fall, and averaged two adjacent scans, and then was able to visually decode "KC7VHS" on QRSS. Several other QRSS signal were seen, but I was not able to decode them. Also, WSPR signals were seen, but obviously I could only observe.

My gaol is to reestablish my QRSS Grabber and report WSPR Spots with this receiver (at yet another location), but time for; an antenna installation, and a disk replacement tasks, are holding up progress. The computer system will be Ubuntu, as it provides multiple virtual X displays that the decode programs can run in. ARGO requires it's own unobstructed window as it uses "screen scrapes" to obtain images that are published by an Internet Grabber Server. Pop-ups makes using MS Windows to run ARGO some what difficult on a remote system, especially when the desire is to have more windows displayed than space on the screen.

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