[Hallicrafters] Fw: New Blue disc ceramic capacitors

[Jim Liles]

-----Original Message----- 
From: Jim Liles
Sent: Monday, May 06, 2013 12:33 PM
To: Paul Kraemer
Subject: Re: [Hallicrafters] New Blue disc ceramic capacitors

Hi Paul:
They are everywhere now.  I believe the C. H. Ina company is the source.

BTW, I am not suggesting that all of their products are quality deficient,
just be aware.  They make some of the most exquisite instruments available
and are within my cost rang and not available here.

Have not tested safety caps yet but due to the statistics, probably a good
idea.

My primary focus is VFO temperature compensation components, techniques, and
circuits that require linear components.

Thanks for the courteous response.

Kindest regards Jim K9AXN

-----Original Message----- 
From: Paul Kraemer
Sent: Monday, May 06, 2013 11:56 AM
To: Jim Liles
Subject: Re: [Hallicrafters] New Blue disc ceramic capacitors

Only blue disc ceramics I have seen are line safety type
Who made them?
Paul K0UYA
----- Original Message ----- 
From: "Jim Liles" <hallicrafterssr2000 at k9axn.com>
To: <hallicrafters at mailman.qth.net>; "'HallicraftersRadios'"
<HallicraftersRadios at yahoogroups.com>
Sent: Monday, May 06, 2013 11:48 AM
Subject: [Hallicrafters] New Blue disc ceramic capacitors


> Heads up regarding the new Blue disc ceramic capacitors.
>
> If you plan to use the NPO versions, be prepared to test them or accept 
> totally unpredictable results.  NPO traditionally indicates +/- 30 PPM. 
> Many of these caps test to be well beyond the traditional norm.  Many also 
> display a significant Hysteresis effect.  That’s to say the capacity will 
> very with temperature and not return to the same value at the original 
> temperature.  This is a class 3 ceramic behavior not class 1 which they 
> should be.
>
> Also, some of the Blue class 2 and class 3 caps used for bypass and low 
> level coupling i.e. Z5U, X7R etc have been measured to have some of the 
> most unbelievably bazar behavior measured to date.  Point --- a Blue .02uf 
> cap rated at 1000v, when exposed to as little as 600v measured to have 
> lost 90% of it’s capacity.
>
> The days of simply measuring a capacitor from stock and installing it into 
> a radio or instrument are history.  Check samples from the batch that you 
> purchase if they are newly manufactured.
>
> Kindest regards Jim K9AXN
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