[Coco] Fwd: Re: Died from old age?

[Chester Patterson]

I don't know about the rest of you but here Gene's contributions to the list
often get printed up and put in my "General Electronic Messing Around" three
ring binder. Below is a good one. My hat (and I DO wear hats, fancy cowboy
hats mostly. But not boots, too hot here for that) is off to you Mr.
Heskett. Live long and prosper.

Chester
TI2/KJ4HLT
Costa Rica

-----Original Message-----
From: Gene Heskett [mailto:gheskett at wdtv.com] 
Sent: Monday, December 22, 2014 11:42 AM
To: coco at maltedmedia.com
Subject: Re: [Coco] Fwd: Re: Died from old age?

On Monday 22 December 2014 11:35:56 Chad H did opine And Gene did reply:
> -------- Original Message --------
> From: Chad H <chadbh74 at hotmail.com>
> Sent: Monday, December 22, 2014 10:34 AM
> To: ooogalapasooo at aol.com
> Subject: Re: [Coco] Died from old age?
> 
> Well I have a ESR meter so I shouldn't have any problem pulling 
> capacitors and testing them.

Why should you have to pull them?  The only ESR meter I have any experience
with uses only 85 mv of AC voltage at 100 khz to make its measurement with.
This is so low that it does not turn on any parallel semiconductors it may
be attached to circuit wise, so the caps are checked while still in circuit.
Because of its time and part saving measurement ability when measuring
surface mounted caps in DVC-PRO broadcast VCR's, it saved me at least 2/3rds
of the time to repair and put back in service for many of the electronics
bits & pieces of a busy TV station for several years.

Its called a Capacitor Wizard, and sells for about 2 bills, made in Omaha
originally but I think the guy has moved to KC sometime it the last 20
years.  FWIW, caps suffering from ESR are often easily, but temporarily
fixed, by giving them a charge or discharge at a high enough rate to form a
micro-weld across the ESR causing aluminum oxide at the internal to external
terminal connection points.  Quite a few of the other so called ESR testers
do use enough voltage to "heal the cap", for a day or so.

IMNSHO, this particular device is the only one that measures them all, and
does it accurately and in circuit. ANYTHING else just wastes your time lying
to you.

Expensive enough at $200 or so that I do not personally own one, but I know
where one is that I can use anytime I need it.

> I just don't know about the DIP
> switches.  I also need to identify the thing underneath the crazy heat 
> sink.  I think its some sort of power transistor.  Here are pics of
> the board ... tinyurl.com/ko5dxy7.   Still looking for a service
> manual for this model.

That is a more or less std Si, NPN power transistor in a TO-3 case.  Never
had one fail, but a strong magnifying glass may disclose a micro-crack in
the solder around the pins on the bottom of the board.  Its cheap solder, so
suck it or solder-wick it off & replace it with decent, modern silver
bearing solder.  Use a temp controlled iron, needs 700F to remove that junk,
but only about 625F to 650F for modern silver bearing solders.  
Rosin core of course.

Lead free solders need more heat. 750F maybe. But I haven't used any of that
roll I bought with a new soldering iron 2 years ago, and now the iron has
failed & no help from the american dealer in Lincoln NE, its out of warranty
and I feel screwed $200 worth.  But guess what? I have a 54 year old weller
WTC that I pulled off the shelf, and it still works perfectly at whatever
temp is stamped on the button on the back end of the tip.  Old faithful.
Newer ones aren't so good, with fairly rapid heater failures when subjected
to on in the morning, off whenever the bench lights go off for the night
duties.  That one worked under such conditions at KOTA-TV for several years,
and is my emergency goto iron.


Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS