31-05-2017, 04:54 PM
I have a valve diode unit with a CV172 noise vacuum tube.
http://www.r-type.org/addtext/add072.htm
They adjust the filament voltage and have a meter measuring cathode current.
I figure it would be easy to have the HT 50Hz AC clamped by a voltage regulator (zenner)
so on one's CRO noise on, noise off at 50Hz. Since our SSB rigs have about 2KHz bandwidth
we could readily adjust SNR.
Came from Dural ARNSW T&T in an unmarked box. I was curious.
Alan VK2ZIW
http://www.r-type.org/addtext/add072.htm
They adjust the filament voltage and have a meter measuring cathode current.
I figure it would be easy to have the HT 50Hz AC clamped by a voltage regulator (zenner)
so on one's CRO noise on, noise off at 50Hz. Since our SSB rigs have about 2KHz bandwidth
we could readily adjust SNR.
Came from Dural ARNSW T&T in an unmarked box. I was curious.
Alan VK2ZIW