On 11/26/2010 9:48 AM, Plotus wrote:
snip However, yesterday I lost my
OD3 tube. While working, I noticed that it put off a what appeared to
be... ultraviolet or bluish colored light, and about mid-day the radio
quit working. Wondering what might have went out, I let the radio return
to room temp and later turned it back on with the top lid opened a
couple inches to view the bulbs in operation. From what I could see,
they all lit except the OD3 tube which I initally noticed because of the
color, so I asume that is the cause of inoperability. snip

Hi,
An 0D3 tube normally glows blue or pink when operating.
It is a gas-filled voltage regulator,
and operates like a 150V Zener diode.
The fact that the 0D3 is now dark and your radio has stopped working
indicates that you have lost the dc supply in your HQ-120.
I'd look carefully at the electrolytics in your power supply,
one may have developed a short.

73,
Ed Knobloch