Digest for sci.electronics.repair@googlegroups.com - 8 updates in 4 topics

Foxs Mercantile <jdangus@att.net>: Feb 04 08:56AM -0600


> However, this is a working radio. I ask myself if I really want to
> replace all the other (small) caps. [Then I say to myself.... if it
> works, dont fix it].
 
To quote a good friend of mine, "There are only two kinds of paper
dielectric capacitors. Those that are bad, and those that are going
to be bad."
 
> Where I do NOT feel comfortable changing them, are in all RF and IF
> stages.
 
The paper caps in the RF and IF stages are bypassing and coupling
capacitors. They need to be changed as well.
 
> well, don't screw up a good thing.... Then too, if the caps in those
> circuits are .05 or .003, I WANT a .05, not a .047. (And it seems
> that .05 is no longer made).
 
"Working" is a subjective thing. Known failure prone parts are just
a time bomb waiting to convert working to not working. And possibly
causing collateral damage when they fail.
 
Back then, they liked "round numbers." Then the industry standardized
on incremental changes.
As a matter of course, .02 now is .022, .03 is .033 and .05 is .047.
Unless you're playing with tuned audio filters, the difference is
statistically zero.
 
 
 
 
 
 
 
--
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com
Tom Biasi <tombiasi@optonline.net>: Feb 04 10:15AM -0500

On 2/3/2017 8:47 PM, Carter wrote:
 
>> It's a very complex issue. Your feelings are just that, yours.
 
> Sorry, personal, individual "feelings" has NOTHING to do with moving the
> Doomsday Clock ahead. The whole world might take exception, do ya think?
 
No
jurb6006@gmail.com: Feb 04 07:22AM -0800

>"I found a company that made an electrochemical equivalent. It was
housed in a glass cylinder, similar to a common 3AG glass fuse. Inside
was some chemical solution. When a few volts of DC was applied,
electrolytic action caused one end to slowly turn dark, thus
indicating the amount of time that the DC was applied. Sorry, but I
couldn't find the vendor or an equivalent online. When the required
maintenance was performed, the indicator would be replaced as it could
not be reset. "
 
They used something similar in time lapse video recorders. When those links or whatever went, you are required to replace the video head.
Phil Allison <pallison49@gmail.com>: Feb 04 05:01AM -0800

Look165 is a absolute fucking IDIOT wrote:
 
> Only a stupid idiot would connect primary and secondary in parallel.
 
** So must be one of your type.
 
 
> What I was meaning is to disjoint the two half-windings and put them in
> parallel ON EACH SIDE.
 
** Precisely what I was thinking you meant.
 
 
> The insulation in that case is 240/2=120V
> (170V peak to peak).
 
** But when wire is *SERIES* places 480V between adjacent enamelled wires.
 
 
 
> I have designed hundreds of transformers in my life (certified UL EN
> etc..) and also planar transformers !
 
** Then you need to be taken out an FUCKING SHOT DEAD !!
 
You fucking tenth wit wog top poster.
 
Go fuck yourself - you damn LIAR
 
 
 
 
.... Phil
legg <legg@nospam.magma.ca>: Feb 04 09:21AM -0500

>Electrically, this makes sense, but I am not 100% sure, so I thought I'd
>ask.
 
>Also, this Transformer is rated at 750 va.
 
The 750VA rating applies to the part at it's label voltages. If there
is a dual primary - two windings which, connected in series, will
support 480V and which, connected in parallel will support 240V, then
a primary current of 1.5A is expected in each winding under rated
operation.
 
Reducing the voltage does not change the current capability of these
windings. If you halve the applied voltage, you halve the throughput
power rating, in this case, to 375VA.
 
A less efficient winding method, with a single tapped winding, will
use different gauge wire for the 240V section of the winding.
 
The same considerations apply to the secondaries.
 
Wired as 240in to 240out will produce a 1:1 isolation transformer.
 
RL
legg <legg@nospam.magma.ca>: Feb 04 09:25AM -0500

On Fri, 3 Feb 2017 22:44:16 -0800 (PST), Phil Allison
 
>But only if the parallel pairs of windings have the *exact* same number of turns.
 
>If not, you get major overheating.
 
>.... Phil
 
Windings with the same label voltage will have the same turns. This is
checked automatically/electronically during fab. Unbalanced turn coils
are discarded/scrapped.
 
RL
Andrew Rossmann <andysnewsreply@no_junk.comcast.net>: Feb 04 07:42AM -0600

In article <f9b441b1-b4a4-4512-8e32-d4d6bae5391a@googlegroups.com>,
petereasthope@gmail.com says...
> user from adjusting the clock when it can't keep time with power off?
> A failure in the BIOS?
 
> Thanks, ... Peter E.
 
As others mentioned, you probably need to replace the battery first. It
may be blocked due to that. The most common battery is a CR2032,
although you can possibly use a CR2025 or CR2016 in a pinch if you
happen to have one. The only difference is the thickness. 3.2mm, 2.5mm,
1.6mm.
 
--
If there is a no_junk in my address, please REMOVE it before replying!
All junk mail senders will be prosecuted to the fullest extent of the
law!!
http://home.comcast.net/~andyross
"pfjw@aol.com" <pfjw@aol.com>: Feb 04 05:10AM -0800

On Saturday, February 4, 2017 at 12:49:32 AM UTC-5, Phil Allison wrote:
 
> > Not only that, but as he did not actually purchase the offending
> > item directly, he has no idea which bin it came from - NOS or New Stock.
 
> ** There are no "old stock" ones from CE that look exactly like that ones in the advertising - you LYING PILE Of SHIT !!!
 
There are old-stock caps from Mallory and others that CE sells as OLD STOCK CAPS, complete with new shiny label. They sell them mostly to instrument-amp people who have no idea what a cap is supposed to do for the most part, and build legends around "Black Cat" and "Bumble-Bee" and other names, and actually will remove good caps to install old caps.
 
Likely exactly what happened with your Fender.
 
Again, reasoning from the specific to the general makes you the idiot. No matter how much invective you throw at the problem, you are still an idiot.
 
Peter Wieck
Melrose Park, PA
You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page.
To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.

1 Response to Digest for sci.electronics.repair@googlegroups.com - 8 updates in 4 topics

February 10, 2017 at 9:41 AM

Did you know that you can shorten your long urls with Shortest and receive money for every visit to your short links.

Post a Comment