[R-390] Line Voltage Survey

[rbethman]

Perry,

The line voltage here in Northern Virginia is pretty consistent at 127 
VAC. The SP-600 is very happy with the 130 tap.

Since I went that route, I've had no problems.

The R-390A gets the buck/boost treatment. Therefore it is happy.

Bob - N0DGN

On 10/30/2011 12:20 AM, Perry Sandeen wrote:
> List,
>
> When checking the voltages on a SP 600 I discovered a problem primarily with my filament voltages.
>
> The basic problem is that in my semi-rural Tennessee area my line voltage consistently is 124 to 125 volts.  This was also true of my rural Colorado house.  Both also suffer from small surges and very short drop-outs.
>
> With the transformer tap set to 117 volts the filament voltage is:
>
> Line Voltage	B+ Volts	Filament Volts	Bias (S/B -51V)	Tap Setting
> 117 (Variac)	244	6.3	-52	117
> 124	252	6.7	-55.2	117
> 124	227	5.87	-48.3	130
>
> Tube manuals rate receiving tube voltages as plus or minus 5 percent.  So the acceptable value is 5.985 to 6.615.  So from a filament standpoint, the 130 volt setting is the lessor of two evils, while not considering the effects of the lower B+ and Bias voltages.
>
> This poses several questions:
> 1.  What do others have for their line voltage?  Please reply off list.  I’ll report the results to the list.
>
> 2.  Has anyone been able to test a SP 600 with a signal generator to see what, if any performance difference this might make.  (My signal generator is packed away for the moment.)
>
> The R390A largely avoids this filament problem as the power transformers I have are marked as 6.1 volts for the filaments.
>
> Thoughts?
>
> Regards,
>
> Perrier
>
>
>
>