[TenTec] replacement knobs for 238A tuner

[Peg Haese <haesem@uwplatt.edu>]

One knob on my new 238A failed immediately, the first time I turned it. 
Stan sent another one. The other one failed shortly after. I replaced them 
with Radio Shack ones that have a bright red face. That way there is no 
question they are not originals. The RS ones are larger and heavier made. 
Maybe TT needs to change their knob supplier as this is a long-standing 
problem with their rigs.
73 de Peg KB9LIE