[R-390] R-388 caps (OT)

[John Flood]

This interests me as well as I am doing a "quick" cleanup and checkout of a R388A for someone local who was "Given" one and had no clue what it was.  He couldn't understand why I was drooling over the dust covered black thing and he couldn't get my attention to the complete shiny Hallicrafters station with matching speaker that was given to him at the same time.  Then he said take it home and check it out and play if you want.  Thought about saying no but not for long...  where was I....  oh ya those dogbone caps.  He doesn't want me to do a complete restore of it  but I'd like to advise him about these and I have not run into these caps much before.   This unit is running well at this point with little work, just a cleaning, a new tube and lamps.  I know you'll all say check the caps but what I was mainly looking for here are these dogbones in the same class as the BBOD's and must be removed at all cost while the children are hidden to
 protect innocence or are they of higher quality breeding like single malt medicinal compound?
 
John Flood
KB1FQG   
----- Original Message ----
From: wli <wli98122 at yahoo.com>
To: R-390 at mailman.qth.net
Sent: Thursday, July 24, 2008 10:52:31 PM
Subject: [R-390] re: R-388 caps (OT)

How durable the *dogbone* ceramic capacitors in the R-388/URR? They are widely employed as bypass caps... like .01µF everywhere it seems. How were they made?

Do they deteriorate like the paper caps of that era? My impression is no. But I do not really have any experience with this type of capacitor.

In contrast, I have seen many leaky *Black Beauties* in other receivers I have restored, and have replaced them with Orange Drops or other modern caps.

Thanks

W. Li




_____________________________________________________________
R-390 mailing list
Home: http://mailman.qth.net/mailman/listinfo/r-390
Help: http://mailman.qth.net/faq.htm
Post: mailto:R-390 at mailman.qth.net
Unsubscribe: http://mailman.qth.net/mailman/options/r-390