Added resistance and Martin's worksheets

[Dave Jones]

There's a worksheet on Martin's site for an fe206e: http://www.quarter-wave.com/Project05/FE_206E_ML_TL.pdf

It contains the following formula, which appears to be intended for changing Qed (a.k.a. "Qes") based on added resistance.

Qed := 0.18*Re*(Re-Radd)^-1

(I attached the actual text below to show I didn't miscopy it.)

The Amazing Martin tosses partial differential equations around like tennis balls, but is that right? When Radd is 5 ohms, Qed works out to 0.737. I believe it should be 0.263.

[MJK]

Dave,

The Amazing Martin tosses partial differential equations around like tennis balls, but is that right? When Radd is 5 ohms, Qed works out to 0.737. I believe it should be 0.263.

Is it right that I toss partial differential eguations around like tennis balls, probably not since I struggle just like anybody else. You only see the end result and not the piles of discarded paper that got me to that point. For example, I have been wrestling with horn theory since March and probably have a few more months to go before I add a horn section to my site.

Back to the worksheet in question. I think that you need to look at the worksheet again, please don't focus on just one equation since it is really a series of steps. For the FE-206E the manufacturer's specs state the following values :

Re = 6.69 ohms
Qed = 0.18 (really Qes for the rest of the world)

In the worksheet, I define the following relationships.

Radd = 3 ohms

then

Re = 6.69 + Radd = 9.96 ohms

Qed = 0.18 x 9.69 / 6.69 = 0.26

I set things up this way so that I only have to change Radd and everything flows from there.

Hope that helps,

[Dave Jones]

Originally posted by MJK
Dave,



Is it right that I toss partial differential eguations around like tennis balls, probably not since I struggle just like anybody else. You only see the end result and not the piles of discarded paper that got me to that point. For example, I have been wrestling with horn theory since March and probably have a few more months to go before I add a horn section to my site.

Back to the worksheet in question. I think that you need to look at the worksheet again, please don't focus on just one equation since it is really a series of steps. For the FE-206E the manufacturer's specs state the following values :

Re = 6.69 ohms
Qed = 0.18 (really Qes for the rest of the world)

In the worksheet, I define the following relationships.

Radd = 3 ohms

then

Re = 6.69 + Radd = 9.96 ohms

Qed = 0.18 x 9.69 / 6.69 = 0.26

I set things up this way so that I only have to change Radd and everything flows from there.

Hope that helps,

Like I said, tennis balls.

Thanks for the help.