[Boatanchors] [nationalradio] FS: Nice NC-98 with Rare SW Broadcast Bandspread Dial

[Jack Antonio]

On 3/6/2019 3:11 PM, Richard Knoppow wrote:

>     Hum probably means it needs new power supply filter caps but all the 
> receivers you mention will need recapping and maybe some resistors 
> replaced due to age drift.

Not normally my cup of tea, but a clean, cheap NC-98 followed me home
from a hamfest.

Typical issues were solved, such as high value resistors, dried out
filter cap, bandspread cord needed restringing, but I was left with
an annoying hum, that varied with the volume control.

Finally found that the problem was that the wire to the arm of
the volume pot was unshielded, and picking up hum from the AC
wiring to the switch. Replaced it with shielded wire, and hum gone.

It looked all factory, so didn't immediately suspect that was the
cause of the problem. I can't imagine that National would let a
receiver go out with that much hum, so don't know why this
particular receiver had the issue.

Jack Antonio
WA7DIA