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schottky diode now another question!

DK
 

Hans,

Thank you for your prompt and very informative reply! 

I have another question, this time Peters DL6DSA’s LCD Contrast improvement modification. Peter writes:

"I have found a simple solution for improving the adjustability of the R47 contrast potentiometer in the QCX: By adding additional resistance between the grinder of the R47 and GND, 

The grinder? I don’t think we use this term ( as applied to a potentiometer; a sandwich but not a potentiometer )! 

Is the grinder the “wiper” often the center pin of the potentiometer? I really enjoy learning the differing terms we use for a common hobby. 

I have the 30  M kit which I will build as soon as I return stateside.

Thanks!

D.K. KD6TK 

On Dec 1, 2017, at 19:52, Hans Summers <hans.summers@...> wrote:

Hi Al

That is true, about the main reverse polarity protection diode. However he's not asking about that one, he's asking about the diode in this modification: http://qrp-labs.com/qcx/qcxmods.html#pwrup

73 Hans G0UPL

On Fri, Dec 1, 2017 at 3:48 PM, Al Holt <grovekid2@...> wrote:
It's the lower voltage drop. If a 'regular' silicon diode is used the drop across it is about .6V. The drop across the Schottky is more like .4V. This puts a slightly higher voltage on the PA FETs and a little more power out.


Hans Summers
 

Hi DK

I quoted Peter DL6DSA's comment directly. I have no idea but I assumed "grinder" is a direct translation from German. I found it more convenient to not try to alter any text, just quote it as given. We all know what he means!

73 Hans G0UPL


On Fri, Dec 1, 2017 at 4:09 PM, DK <donaldphilbin@...> wrote:
Hans,

Thank you for your prompt and very informative reply! 

I have another question, this time Peters DL6DSA’s LCD Contrast improvement modification. Peter writes:

"I have found a simple solution for improving the adjustability of the R47 contrast potentiometer in the QCX: By adding additional resistance between the grinder of the R47 and GND, 

The grinder? I don’t think we use this term ( as applied to a potentiometer; a sandwich but not a potentiometer )! 

Is the grinder the “wiper” often the center pin of the potentiometer? I really enjoy learning the differing terms we use for a common hobby. 

I have the 30  M kit which I will build as soon as I return stateside.

Thanks!

D.K. KD6TK 

On Dec 1, 2017, at 19:52, Hans Summers <hans.summers@...> wrote:

Hi Al

That is true, about the main reverse polarity protection diode. However he's not asking about that one, he's asking about the diode in this modification: http://qrp-labs.com/qcx/qcxmods.html#pwrup

73 Hans G0UPL

On Fri, Dec 1, 2017 at 3:48 PM, Al Holt <grovekid2@...> wrote:
It's the lower voltage drop. If a 'regular' silicon diode is used the drop across it is about .6V. The drop across the Schottky is more like .4V. This puts a slightly higher voltage on the PA FETs and a little more power out.



Willi, OE1WKL
 

Grinder is the result of an unfortunate translation from German. In German the term "Schleifer" is sometimes used for the center pin of a potentiometer, which should be translated as "slider" in this context, because this element "slides" along the resistors surface. But "schleifen" can also mean "to grind" ("eine Axt schleifen = to grind an axe), and as a result the "Schleifer" became a grinder.... ;-)
Vy 73
WIlli, OE1WKL