[R-390] Re: Staggertuned IF Question

[David Wise]

Silver mica's were a later development which superseded the molded ones.
Production overlapped for quite a while, moreso for some values
than others, with a lot of variation between manufacturers.
Cost was undoubtedly a factor too.  I wouldn't be surprised
to see a mix.  For our purposes today, SM's are superior in
all respects.

Dave Wise

> -----Original Message-----
> From: r-390-bounces at mailman.qth.net
> [mailto:r-390-bounces at mailman.qth.net]On Behalf Of n4buq at knology.net
> Sent: Thursday, September 14, 2006 11:09 AM
> To: R-390 at mailman.qth.net
> Subject: [R-390] Re: Staggertuned IF Question
> 
> 
> I notice the values for the caps and resistors in the cans 
> aren't specified 
> except to say they are part of the transformer.  I wonder if these 
> components could be the culprits here?  They sure look like a pain to 
> replace, but could do that if necessary.
> 
> I peeked at them during my lunch break and if I could see 
> them well enough, 
> I noticed that some of the caps are the rectangular molded 
> variety while 
> the others appear to be dipped silver micas.  I wonder if the 
> differences 
> were due to their capacitance values or if SMs were better on 
> the input or 
> output and the others were better in their respective 
> posions.  If I did 
> replace these, I assume I'd use SMs in both positions but was curious.
> 
> Thanks,
> 
> Barry - N4BUQ