[R-390] OD Demise Redux

[kc9ieq via R-390]

NOS carbon comps are getting to be pretty bad too when it comes to drifting up in value, at least from what I'm seeing here in my stash.  Unless the item I am restoring is rather rare or a near mint condition example qualifying as museum quality, I find myself almost exclusively using the Vishay PR02 line of 2 watt metal film resistors.   They have a 5%, tolerance, are rated for 500 volts, (look closely at carbon film and metal film resistor datasheets, many are rated to only a couple hundred volts), are almost exactly the same size as a 1/4W CC, and are even a reddish/brown color thst blends in halfway decently.  I'm at the (young, relatively speaking) age where I could very well have to go back and re-replace resistors in a rebuilt radio down the road, (20? 40? 50 years later?) if I used even brand new CC resistors as replacements.  They just are not sealed well enough to remain stable.  Plain and simple.  

I'm doing a 1958 Seeburg Stereo jukebox amp right now.  So far I've replaced 37 out of tolerance 1/4W CC resistors, and i'm only about 70% done with it.  I really wouldn't want to go back and have to do the WHOLE thing over again, down the road.  Lots of hours to do one of these things the right way.  

My .02

Chris 


Sent from my I are SMRTphone


-------- Original message --------
From: Cecil <chacuff at cableone.net> 
Date:10/22/2014  7:33 PM  (GMT-06:00) 
To: Perry Sandeen <sandeenpa at yahoo.com> 
Cc: R-390 List <r-390 at mailman.qth.net> 
Subject: Re: [R-390] OD Demise Redux 

I'm finding there are loads of carbon comp resistors available at hamfests...I've bought thousands in bulk and jumbled up...

Got to sort them or hunt through them to find what you want.

I think the same will be the case with orange drops...I've found many of those as well...not as many as resistors but there over out there..

Cecil

Sent from my iPad

> On Oct 22, 2014, at 6:48 PM, Perry Sandeen via R-390 <r-390 at mailman.qth.net> wrote:
> 
> List,
> 
> Wrote: The world is moving towards surface mount technology.
> Point to point wiring and thru the hole passive components is for us dinosaurs.
> Stock up now, if you can find ODs anywhere
> 
> Well now, I believe it isn’t quite all that bad. And Mouse
> still has a lot of OD’s left in stock. There just being slowly phased out.
> 
> OD’s are much higher priced that many good equivalents. Their
> price-performance ratio may not justify their use in volume manufactured
> equipment.
> 
> It’s true that some of the more exotic IC’s only come in SM
> technology. But some types are easier to get and adaptor and are easier to
> solder than others. But SM components aren’t applicable to our B/A units.
> 
> When looking for film capacitors at Mouser, the list over
> 300,000. Mostly name brands. 
> 
> They also stock a wide variety of resistors, mostly metal
> film or carbon film for the small wattage sizes.
> 
> What are getting almost impossible to find are the ancient
> carbon composition resistors that were OEM in our radio’s.
> 
> The market has decided that the metal film and carbon film
> resistors are far superior to CC’s and they are now priced significantly lower
> than CC’s. AB quit making them years ago so now only an obscure asian company
> has them listed with Mouser.
> 
> The good side of the issue is that there are many good SS
> parts for surge limiting, spike limiting and voltage regulation that weren’t
> economical/available years ago.
> 
> IMNSHO, one should shop for tube deals on ebay. The *super
> tubes* that can replace the 6DC6, 6BA6, and 6BE6 to name a few examples, can be
> found for quite reasonable prices if one waits. See the Osterwald R-390A
> article in ER magazine for an example. Or email me for a copy of my “almost
> ultimate R-390A schematics” which show the *super tubes* Ray used as well as
> annotations of commonly troublesome components as reported on this list from
> many sources. 
> 
> Regards,
> 
> Perrier
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
______________________________________________________________
R-390 mailing list
Home: http://mailman.qth.net/mailman/listinfo/r-390
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:R-390 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html