Question: HR-10B Power Transformer

[wa1vwl]

That's 410 VAC end to end. However, this is a center tapped transformer
so the voltage being rectified is half or 205 volts. The 6X4 has some
losses through it so figure about 40 volts or so (it's not an exact
science). At C57, the filter capacitor, figure on about 230 VDC
appearing at that point. You are correct in assuming +/- 10% for the
voltage. That also depends on you line voltage which should be about 120
VAC +/- 10%. Some will quibble about that but it's in the ballpark. My
schematic shows a value of 210 VDC at C57 but I measure 230 VDC. Nothing
to worry about.

73/Gerry/W1ID

Mike Hardie wrote:
>
> Help!  I'm working on a dead HR-10B and have found the B+ to be well above
> specs. (Cofirmed with two different voltmeters.)  According to the
> schematic the transformer should be putting out 410 vac but its actually
> around 450, just at my "personal limit" of +/- 10%.  Downstream of the 6X4
> rectifier things get worse likely because of the RMS to d.c. multiplying of
> 1.4.  All the other B+ related voltages are also high.  The transformer
> doesn't seem to run hot but the 1500 ohm 10w resistor in the power supply
> sure does.  Anyone else had this problem?
>
> Mike at: hardiem at intergate.bc.ca
>
> --- --- --- --- --- --- --- --- --- --- --- --- --- --
> To subscribe: listserv at listserv.tempe.gov
> and in body: subscribe HEATH yourfirstname yourlastname
> To unsubscribe:  listserv at listserv.tempe.gov
> and in body: signoff HEATH
> Archives for HEATH: http://www.tempe.gov/archives
> --- --- --- --- --- --- --- --- --- --- --- --- --- --

--- --- --- --- --- --- --- --- --- --- --- --- --- --
To subscribe: listserv at listserv.tempe.gov
and in body: subscribe HEATH yourfirstname yourlastname
To unsubscribe:  listserv at listserv.tempe.gov
and in body: signoff HEATH
Archives for HEATH: http://www.tempe.gov/archives
--- --- --- --- --- --- --- --- --- --- --- --- --- --