[Hallicrafters] AC Bypass Caps

[Carl]

That comment makes absolutely no sense.

Carl
KM1H


----- Original Message ----- 
From: "Asif Khan" <hallicraftersx28 at aol.com>
To: <Hallicrafters at mailman.qth.net>
Sent: Monday, December 13, 2010 1:14 AM
Subject: [Hallicrafters] AC Bypass Caps


>
> Everytime I restore  radios  I leave them out . They might been effective 
> back in the 1930's and 40's
>
> when the world was less 'noisy' !
> Nick
>
>
> -----Original Message-----
> From: Glen Zook <gzook at yahoo.com>
> To: Mark K3MSB <mark.k3msb at gmail.com>; List Hallicrafters 
> <hallicrafters at mailman.qth.net>; Mike Everette <radiocompass at yahoo.com>
> Sent: Sun, Dec 12, 2010 10:03 pm
> Subject: Re: [Hallicrafters] AC Bypass Caps in SX-111 MK 1.
>
>
> Actually, it really isn't leakage.  Capacitors are supposed to pass AC and 
> block
> C.  Therefore, any radio with those capacitors is going to have 1/2 of the
> ains voltage on the chassis.  Of course, with 3 wire cords that voltage is
> rounded out.  It is the same with 2 wire cords when the chassis is 
> grounded.
> hat is one of the reasons that the older equipment always had a ground 
> terminal
> except for AC/DC which often did not).
> Now when the capacitor does fail, then the full mains voltage and current 
> then
> an definitely be on the chassis.  Otherwise, the current is limited 
> through the
> apacitor because of the relatively high impedance inherent to the value.
> These days it is questionable as to whether or not to install line bypass
> apacitors, especially in receivers.  In my opinion, leaving them out isn't
> oing to hurt anything.
> Glen, K9STH
> Website:  http://k9sth.com
>
> -- On Sun, 12/12/10, Mike Everette <radiocompass at yahoo.com> wrote:
> I'm sure some folks will disagree with me... but I would recommend that 
> you not
> weat those line bypass caps.  In fact, LEAVE THEM THE HECK OUT.
>
> f they start to leak much at all, you are going to have AC voltage on the
> hassis.  I've seen radios with between 30 and 60 volts AC on them for this
> eason.  That's enough to give you one serious jolt.  And yes, this was due 
> to
> ine bypass capacitor leakage... not leakage in the power transformer.  In 
> all
> y experience,  which includes ham radio, commercial two-way, avionics, and
> roadcast engineering, I have seen only two power transformers develop
> rimary-to-frame leakage; but PLENTY of leaky line bypass caps.  I damn 
> near got
> illed once by a background-music system PA amplifier with a hot chassis 
> from a
> eaky cap, when the back of my head touched that chassi as I was reaching 
> my
> are and sweaty arm behind a HVAC duct to fish out a speaker lead.
> ha-ZAAAAAAM!  As a result, the very first thing I do when a "new" radio or 
> any
> ther device comes into my life is to make REAL sure to take the things out 
> of
> t!
>
> remain unconvinced regarding the benefits of having these capacitors in 
> the
> adio at all.... except to a funeral director.
>
>
> _____________________________________________________________
> allicrafters mailing list
> ome: http://mailman.qth.net/mailman/listinfo/hallicrafters
> elp: http://mailman.qth.net/mmfaq.htm
> ost: mailto:Hallicrafters at mailman.qth.net
> List Administrator: Duane Fischer, W8DBF
> * For Assistance: dfischer at usol.com **
>
> his list hosted by: http://www.qsl.net
> lease help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Hallicrafters mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hallicrafters
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Hallicrafters at mailman.qth.net
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html