Search found 1358 matches

by Lenp
Thu Jan 18, 2007 4:00 am
Forum: General Discussion
Topic: Building your own CPU from TTL chips
Replies: 42
Views: 19969

Stevech.

To help better date the 'adder' it used seleniun rectifiers.
Hands up, who knows what a bad selenium rectifier makes the room smell like!

Len
by Lenp
Mon Jan 15, 2007 9:05 pm
Forum: General Discussion
Topic: Building your own CPU from TTL chips
Replies: 42
Views: 19969

2 cents worth!

I just have to say that almost a lifetime ago I built an 'adding machine' with stepper relays and nixie tubes. Does that count for anything? (:-!)

Len
by Lenp
Wed Jan 10, 2007 4:58 pm
Forum: Up For Grabs
Topic: MC68HC11 Evaluation Kit! <<<GONE>>>
Replies: 2
Views: 2403

Yes, I still have the board. It is all from Motorola, and was available when the processor was first released. As for the bootstrap loader, I don't know. I never used this board, software or ever went more than a page flip through the manuals.
Len
by Lenp
Wed Jan 10, 2007 4:53 pm
Forum: Up For Grabs
Topic: Network Cards <<GONE>>
Replies: 7
Views: 3816

frhrwa

Yes, you are right. It seems that that Hoarding, Heavy, and Hauling are all family! I did have a local person who wanted them, was going to come get them, but hey, I still have them....that says it all!

Len
by Lenp
Tue Dec 26, 2006 5:54 am
Forum: General Discussion
Topic: Toner transfer pcb irony
Replies: 10
Views: 2768

Dean, I tried Oxyclean and it worked, but, seemingly not as well as oxalic acid. The oxalic acid comes as crystals and a solution is made as directed, or stronger! I sprayed (watch out for the mist) it on the stained fiberglass laundry tub and it was gone! Maybe Oxyclean is a product that contains s...
by Lenp
Tue Dec 26, 2006 4:24 am
Forum: General Discussion
Topic: Toner transfer pcb irony
Replies: 10
Views: 2768

What is the tinning product used in the PCB video? I could not catch the info from the flick! I have used Tin-It and don't care for it. I also use ammonium persulfate instead of ferric chloride, and, in a heated tank it's about as fast, much cleaner but more expensive. To clean up ferric chloride st...
by Lenp
Tue Dec 26, 2006 4:15 am
Forum: General Discussion
Topic: Toner transfer pcb irony
Replies: 10
Views: 2768

I just caught up with this interesting new post and am wondering if there are any advantages in this method over the TTS (blue) method for board making. We've used the blue film since it's introduction, making hundreds of prototype and small production runs and am curious if it would be worth switch...
by Lenp
Mon Dec 18, 2006 9:28 pm
Forum: General Discussion
Topic: Thermostat hack
Replies: 21
Views: 3721

If you are looking for an indicator for "Burner On' what about an exhaust stack temp sensor, bimetal or whatever. The milivolt system probably has too little output to do much more than it does, without amplification. The milivolt generator is likely just a thermocouple, or a group of seres junction...
by Lenp
Wed Dec 13, 2006 4:37 pm
Forum: General Discussion
Topic: Is SCA still active, and alive?
Replies: 4
Views: 1170

Is SCA still active, and alive?

Years ago SCA (Subsidiary Communications Authorization) was a big thing in FM broadcasting, residing typically 67Khz from the main carrier. Muzak, Physician's Radio Network, Talking Books for the blind and stock quotes were some of the broadcasts. Although they were for the most part pay services, k...
by Lenp
Wed Dec 13, 2006 6:06 am
Forum: General Discussion
Topic: Radio Shack fires person with experience in Electronics
Replies: 23
Views: 6681

At the height of the the Radio Shack success I remember buying huge boxes of returned 'defective' merchandise, for a few dollars a box. The manager said the warranty repairs cost HIM money and not corporate so he decided to dump them off at whatever he could get. Most of the 'defective' items were s...
by Lenp
Mon Dec 11, 2006 5:36 am
Forum: General Discussion
Topic: Electric water heater questions
Replies: 22
Views: 6518

Another thought.. In large buildings a domestic hot water recirculating loop is used. A small pump moves hot water from whatever heats it, circulates it around the building and returns it for reheating. The loop is tapped to provide hot water to the fixture using as short a path as possible. A time ...
by Lenp
Mon Dec 11, 2006 4:15 am
Forum: General Discussion
Topic: Radio Shack fires person with experience in Electronics
Replies: 23
Views: 6681

It's a little late but here's a slant on this topic... Recently one of our specialty distributor with a sales force that cut their teeth in the field was bought out by a larger group. The employees, who really had hands-on smarts that helped customer make product choices were told to dumb down. Say ...
by Lenp
Sun Dec 10, 2006 2:32 pm
Forum: General Discussion
Topic: Electric water heater questions
Replies: 22
Views: 6518

markp, you're right on target! By way of a little more info, the HWH draws the water from the top of the tank. It also uses a long pipe (dip tube) inside the heater to provide the cold water to the bottom of the tank. Because of stratification, the top water will be hotter than the bottom. So, when ...
by Lenp
Wed Dec 06, 2006 12:35 pm
Forum: General Discussion
Topic: BATTERY BOOM!
Replies: 43
Views: 11699

Hackelsup, welcome to the thread! Other opinions are always important. The exploding batteries I have associated with were in two different environments, so, at the risk of redundency, here's the information . Battery #1 The battery with no cell access, was installled on a garden tractor, operating ...
by Lenp
Tue Dec 05, 2006 9:49 pm
Forum: General Discussion
Topic: BATTERY BOOM!
Replies: 43
Views: 11699

rshayes...

Only one comment...

Q.E.D.


Len