[Hammarlund] SP-600/Black Beauties/Transitional Piece?

[James A. (Andy) Moorer]

Various sub-assemblies, like the cans and the terminal strips, were 
assembled separately and stocked separately (assuming Hammarlund used 
the common production techniques of the time). Some of the manuals, like 
the Air Force ones, show these assemblies before they are installed in 
the radio. All the dangling leads stick straight out, ready for 
connection. There would have been a number of hybrids that used up the 
remaining stock of the various sub-assemblies - I would guess maybe as 
many as a hundred or so would have mixtures of ceramics and BBODs.

-A

-- 
James A. (Andy) Moorer
www.jamminpower.com



On 3/8/2012 9:18 AM, Joe Connor wrote:
> I'm currently working on an SP-600 JX-17 serial number 17,2XX. Under the chassis, it has all ceramic-disk caps that appear to be factory-installed. I breathed a sigh of relief because that will save me a lot of work. According to the literature, Hammarlund converted to ceramic disks at around serial number 17,5xx. I figured I had lucked out.
>   
> As I went into the IF cans to make sure the resistors were within spec, I was surprised to find that both 455khz IF cans had black beauties. They were, of course, leaking badly. The 3,955khz IF can had ceramic disks. I opened the T-9 can and looked into the RF deck with a flashlight and saw all ceramic disks. It was strange that only these two IF can had black beauties. Maybe Hammarlund was simply using parts that it had on hand?
>   
> The morale of the story seems to be this: even if you have a set that appears to have all original ceramic disks, it's a good idea to peak into the hidden areas to make sure that a black beauty or two aren't lurking about.
>   
>   
>                                     Joe Connor
> _