On Nov 25, 6:28*pm, NT wrote:
On Nov 16, 4:23*pm, Michael Black wrote:









On Wed, 16 Nov 2011, dave wrote:
On Wed, 16 Nov 2011 08:01:11 -0600, D. Peter Maus wrote:

On 11/15/11 19:05 , flipper wrote:
On Fri, 11 Nov 2011 10:45:09 -0600, "D. Peter Maus"
*wrote:

On 11/11/11 08:42 , Lord Valve wrote:
If the **** hits the fan, most hi-mu triodes will work well enough to
build a regen set. Where to get the B+ is the problem.

That simple, since there's only a few tubes.

9v "transistor" batteries in series. *It doesn't take that many to get
reasonable B+ and since tubes are low current, it's reasonable.

Of course, towards the end of the life of tubes, one could get some that
ran off 12v, intended for use in car radios. *Not so useful now since they
were produced in a limited time span as transistors were taking over, so
quantity is relatively limited.

The R392 ran off 24 or 28 volts, using those low plate voltage tubes. *Of
course, it had a lot of tubes so the filament drain was large.

Of course, some people experimented with low voltage on regular tubes. *A
loss of gain, but sometimes that was a good thing.

* * Michael

In the 19-teens it was common to run triodes with no negative bias,
and very low V_anode, like 20-30v. It worked, and cuts HT battery
cost, but of course distorts the grid signal.

NT

Sounded like ****, IOW.

Common tubes usually start working okay at 45 to 90 volts. The R-392
used selected tubes at 24-28 volts, and works okay, but not as well as
if they had had more. Collins S/Line used 150 volt B+ for what that is
worth.