Digest for sci.electronics.repair@googlegroups.com - 12 updates in 3 topics

etpm@whidbey.com: Nov 15 09:41AM -0800

On Mon, 14 Nov 2016 17:21:30 -0800, John Robertson <spam@flippers.com>
wrote:
 
 
>JustRadio sells good caps, but they aren't photoflash rated - pretty
>safe bet on that!
 
>John :-#)#
I can't use 100 caps. I did find photoflash caps but the leads are
kinda thin. I'm still waiting to see if Just Radio thinks their caps
will do.
Eric
etpm@whidbey.com: Nov 15 09:42AM -0800

On Mon, 14 Nov 2016 17:45:28 -0800 (PST), whit3rd <whit3rd@gmail.com>
wrote:
 
 
>ESR gets to be important with low voltage high current, where a fraction of
>a volt of ripple is a malfunction. Fraction of a volt difference on a 450V capacitor
>charge is negligible.
So photoflash rating is probably not necessary?
Thanks,
Eric
etpm@whidbey.com: Nov 15 11:38AM -0800


>There was considerable discussion on exactly when you should terminate
>the pulse, but mine was constrained to somewhere near zero current by
>the triac.
Greetings Mike,
The machine I am working with is a Unitek model 1-048-03. Is this the
same as yours? If not do you know if it is close enough to use for
trouble shooting and operating the machine I am trying to get working?
If it would be useful is there some way you could get a copy to me?
Maybe scan and email? I don't mind paying you for your trouble. I
wouldn't even ask but so far I have not been able to find a manual of
any type for the model my son has.
Thanks,
Eric
mike <ham789@netzero.net>: Nov 15 01:04PM -0800

> any type for the model my son has.
> Thanks,
> Eric
 
It's a unitek 125.
All I have is a very poor schematic and three pages of
part of the cal procedure.
 
http://i.imgur.com/vSg8agC.png
http://i.imgur.com/mrQIq1f.png
http://i.imgur.com/lE2DroY.png
http://i.imgur.com/8Nv2KpU.png
http://i.imgur.com/TZyfuLp.png
 
If you have a way to archive them permanently, please do so.
They won't stay on my page for long.
 
This is my DIY battery tab welding fixture made out of an arbor press.
 
http://i.imgur.com/er1BqSb.jpg
http://i.imgur.com/OeQZdWH.jpg
 
I emailed Unitek years ago. At that time, they were very helpful.
Geo <nhhu-o3hu@dea.spamcon.org>: Nov 16 09:25AM

On Mon, 14 Nov 2016 10:38:12 -0800, etpm@whidbey.com wrote:
 
<snip>
>in one pin and then out the other to the next OA2WA tube and so on. It
>looks like there is no output from the last tube in the series. So
>maybe this is why the caps won't charge.
<snip>
 
I cannot see properly from the photos - but is there a connection to
the last (bottom) regulator cathode?
I would guess it might be to chassis so "no output" is correct.
 
If all three glow then the voltage across each should be fine.
"pfjw@aol.com" <pfjw@aol.com>: Nov 16 05:35AM -0800

OK!! EVERYBODY!!
 
Step back a minute and have a look at what is being discussed here:
 
a) This is a TUBE-based spot welder designed probably more than 60 years ago.
b) The bean counters (a scourge even then) would NEVER have specified photo-flash capacitors when just a bit more of conventional capacitance would address 'slow chemistry' at a fraction of the cost.
c) A healthy gap on the transformer would eliminate sateuration issues in this application - 'at no additional cost' and without complications, and entirely permanently.
d) This is a piece of industrial equipment designed to be used by production worker who very likely have neither the time nor the inclination to do anything other than follow directions, set the various knobs and switches then GO for hours at a time.
e) And, as with any decent tool from any decent manufacturer, it is designed to be serviced in a simple and straightforward manner by techs who need do no more than follow directions from a standard troubleshooting schedule.
f) And, finally on this list, replacement parts, especially generics (capacitors, tubes) will be entirely conventional - no silliness about "matched pairs" for instance, or boutique caps. If one has a small machine shop in Bucksnort, Tennessee ( https://en.wikipedia.org/wiki/Bucksnort,_Tennessee ) one does not have the time to search down something exotic. One is going to get on the phone to Graybar and order whatever it says on the can, and Graybar will have it in stock. http://www.graybar.com/ And, back in the day Graybar stocked industrial tubes as well.
 
Meaning that there is NOTHING esoteric about this device, and it will not require ANY special 'stuff' to make it go. The caps in this device are toast. If even one of them "rattles" then all of them, being of similar age, living in similar environments and doing similar work, are also done. Not replacing all of them is just plain stupid. Full Stop.
 
Purchase physically rugged caps that either are, or add up to, 200uF & 450 VDC per each, at least. Make sure that the soldering points and connections can handle anticipated voltages and currents. Replace all the tubes, even if they are not necessarily done, as now you will be starting fresh, nor is the investment all that much. If I have 2D21s, I would send the whole shebang to Oregon/Washington State for US$30 including shipping and think I was making too much. Otherwise, AES will do the same for perhaps half-again as much.
 
Sheesh, guys and gals - it is almost as if this were rocket science. It ain't nohow.
 
Peter Wieck
Melrose Park, PA
w9gb <gregory.beat@gmail.com>: Nov 15 04:03PM -0800

Robert -
IF you desire Hospital Grade -- then you will pay more for that designation/certification.
You do realize that surplus Hospital and military outlets (NOS) are where to look for bargains??
$10 to $20 each is COMMON for that designation.
 
I prefer Leviton, and have used Hubbell for other NEMA versions (straight and twist-lock).
You will notice that Home Depot and Lowes have switched to LeGrand and other cheaper brands.
---
McMaster-Carr and their "Will Call" window is 2 miles from my house (so I have ready access)
You can check prices on-line.
NEMA Electrical Pkugs and Receptacles
https://www.mcmaster.com/#electrical-plugs-and-receptacles/=1521gh9
===
NEMA is the North American standard AND we use 120 VAC, 60 Hz.
Majority of manufacturing for those NEMA plugs are Mexico or Central America (NAFTA).
--
I would not consider China sources via eBay, Alibaba, etc. for NEMA plugs.
clare@snyder.on.ca: Nov 15 08:19PM -0500

On Tue, 15 Nov 2016 13:32:25 +0000, Stormin' Norman
 
>Harbor freight has some decent male and female cord end connectors at a reasonable price, see:
 
>http://www.harborfreight.com/125-volt-15-amp-male-plug-93686.html
 
>If you absolutely must have hospital grade connectors, you can get the best deal buying them used on eBay.
You don't need hospital grade - which are overpriced - but you DO
need a quakity plug. Hubbell makes good ones (as well as cheap ones)
Leviton too.
PLUG PREMIUM GRADE WHITE 20A 250V
 
 
LEVITON
PLUG PREMIUM GRADE WHITE 20A 250V
Product #
LET5466C
 
Hubbell HBLHBL8215C

HUBBELL WIRING DEVICE-KELLEMS
PLUG STRBLADE ANGLE 15A 125V
Product #
HBLHBL5266CA
Just for starters.
Dean Hoffman <dh0496@windstream.net>: Nov 15 09:07PM -0600

On 11/14/16 6:40 PM, Robert Bannon wrote:
> this:
> http://www.parts-express.com/Data/Default/Images/Catalog/Original/110-403_HR_0.jpg
 
> Any suggestions?
 
Have you looked at Woodhead brand?
micky <NONONOmisc07@bigfoot.com>: Nov 15 10:17PM -0500

In sci.electronics.repair, on Tue, 15 Nov 2016 16:03:30 -0800 (PST),
>===
>NEMA is the North American standard AND we use 120 VAC, 60 Hz.
>Majority of manufacturing for those NEMA plugs are Mexico or Central America (NAFTA).
 
Central America is related to CAFTA. North America stops at the
Mexico-Guatemala border.
 
https://en.wikipedia.org/wiki/Dominican_Republic%E2%80%93Central_America_Free_Trade_Agreement
The agreement is a treaty under international law, but not under the
U.S. Constitution because in the United States laws require majority
approval in both houses, while treaties require two-thirds approval in
the Senate only. Under U.S. law, CAFTA-DR is a congressional-executive
agreement.
 
The U.S. Senate approved the CAFTA-DR on June 30, 2005, by a vote of
54-45,[2] and the U.S. House of Representatives approved the pact on
July 28, 2005, by a vote of 217-215, with two representatives not
voting.[3] Controversy arose over this vote because it was held open 1
hour and 45 minutes longer than the normal 15 minutes in order to get
some members to change their votes.[4] For procedural reasons, the
Senate took a second vote on CAFTA on July 28 and the pact garnered an
additional vote from Sen. Joe Lieberman —who had been absent on June 30—
in favor of the agreement.[5] The implementing legislation became Public
Law 109-053 when it was signed by President George W. Bush on August 2,
2005.
 
https://en.wikipedia.org/wiki/North_American_Free_Trade_Agreement
Following diplomatic negotiations dating back to 1990 among the three
nations, U.S. President George H. W. Bush, Canadian Prime Minister Brian
Mulroney and Mexican President Carlos Salinas, each responsible for
spearheading and promoting the agreement, ceremonially signed the
agreement in their respective capitals on December 17, 1992.[7] The
signed agreement then needed to be ratified by each nation's legislative
or parliamentary branch.
Jeff Liebermann <jeffl@cruzio.com>: Nov 15 09:09AM -0800

On Sun, 6 Nov 2016 16:40:35 -0800 (PST), captainvideo462009@gmail.com
wrote:
(...)
 
This is too easy.
WBZ has been running on reduced power for most of the last few weeks
thanks to an antenna problem:
<http://boston.cbslocal.com/2016/11/07/wbz-tv-wsbk-tv-operating-at-reduced-power/>
<http://boston.cbslocal.com/2016/10/22/transmission-issue-causes-outage-for-some-wbz-tv-viewers/>
No clue if it has been fixed, but judging by the lack of updates,
probably not.
 
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Pat <pat@nospam.us>: Nov 15 01:11PM -0500

On Tue, 15 Nov 2016 08:31:32 -0800 (PST), thekmanrocks@gmail.com
wrote:
 
>of medium markets and many major
>markets.
 
>Grasp that!
 
Don't forget the part where they have to modify their license at the
FCC after hiring engineers to show that the increased power doesn't
cause interference with any other licensed station in the area (or in
Canada). That process can takes a long time and is expensive even
before equipment is purchased. Most of the applications are on hold
right now waiting for the auctions to be complete. ATSC has lots of
issues, but creating a significant increase in greenhouse gases isn't
one of them.

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