[Milsurplus] TCS-6 Rec. Selectivity

[Hue Miller]

>From TCS-6 manual:

"Units bearing the CKP prefix whose serial numbers
are under 300 and those bearing the CIH prefix 
whose serial numbers are under 3200 contain
i-f transformers having the following characteristics:
 6 Kc wide at 6 db down
11 Kc wide at 20 db down
19 Kc wide at 40 db down

Receivers bearing all other serial numbers contain i-f
transformers with the following characteristics:
11 Kc wide at 6 db down
18 Kc wide at 20 db down
30 Kc wide at 40 db down"

(end quote)  These are built by Air King and Hazeltine.
I assume these selectivity numbers apply only to TCS-6?
It appears FAIR's old ads that described TCS-12 as 
"extra desirable for cw" may have been in error; it kinda
looks like some numbers of the TCS-6 were the best, in
that regard. 
"Air King". I like that name. They should have supplied the
Texas Rangers after the war. -Hue Miller