[Collins] New project KWS-1 Ser#1202

[Dr. Gerald N. Johnson]

I'd interpret black brown yellow as 10 plus 4 more zeroes, or 100,000 
pf, .1 mf, with another yellow with a gap indicating 400 volts. Another 
clue is physical size. .01 will have been about 3/8" diameter and 1-3/4" 
long while .1 will have been more like 7/8" diameter and 2-1/4" long as 
I recall. I can go dig up a vintage catalog to check on those sizes, but 
they are distinctly different in size.

The 7th edition book I've downloaded says both are .01. They feed vox 
and antivox audio to the vox detector diodes, 100K load resistor. My 
Shure reactance rule says .01 has a reactance of 100K at 160 Hz, so .1 
would have that reactance at 16 Hz. 160 is plenty low frequency for that 
circuit, I think. The schematic and parts list agree as does the 
simplified VOX/ANTIVOX circuitry in figure 4.2.

Now my 4th edition manual shows .1 in both locations, in schematic, 
section 4, and the parts list. So if these two books are correct, there 
was a change in value for those two parts between 1956 and 1958. I have 
no inside information on that.

Figure 6.8 in both books shows a bigger capacitor than a .01 with 5 
stripes, four for value and one for voltage, but capacitor color codes 
varied with vendor and sign of the moon. A check for physical size or 
with a capacitor value check may be the only way to be sure what came out.

My 32S-1 book schematic shows .1 for vox coupling and .01 for antivox 
coupling but the parts list shows both as .01 ceramic.

My late 32S-3A book schematic agrees with the S-1 schematic and the 
parts list agrees with the schematic.

I think .01 is big enough with that 160 Hz 3db roll off frequency in 
both locations.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.

On 5/15/2012 8:57 PM, Keith Sorensen wrote:
> Hello Dr.Johnson,
> I just picked up my second set of Gold Dust twins. I am re-capping the
> KWS-1 and noticed that the C113,C115 question has once again appeared,
> is it .1uf/400 or .01 uf.? I removed black beauties that were Brown
> Black yellow....my book says .1 / 400V. Please clarify...Thank you so
> much!!
>
> Keith-KE7GPO
> Sammamish Wa.
>> ______________________________________________________________
>>
>
>