+++++++++++++++++ From: "Bob - AG5Q" To: , Subject: Re: [Elecraft] KSB2 Toroid Winding Sense? Date: Mon, 19 May 2003 14:17:29 -0500 Hi Dave, Winding the toriod as shown has the effect of reversing the phase between the input and output. In this particular case that doesn't matter and since T1 and T2 are wound the same, the phase reversal cancels out anyway. There are some transformers in the K2 that do have to be connected with the exact phase for proper operation, for example, T3 on the RF board. These are usually shown on the schematic with little dots at one end of each winding. 73/ Bob - AG5Q ----- Original Message ----- From: "Dave Jewell" To: Sent: Monday, May 19, 2003 1:41 PM Subject: [Elecraft] KSB2 Toroid Winding Sense? > KSB2 Toroid winding sense? > On page 11 of the KSB2 manual, it shows the winding diagram for T1. I've > had no problems winding toroids in the K1, K2 and assorted other places(!) > but if you look carefully at this diagram you'll see that the primary and > secondary are wound in the opposite "sense". Is this correct? > > In other words, lead 4 enters at the top and winds clockwise around the > core. Lead 2, on the other hand, enters at the top and proceeds > ANTICLOCKWISE around the core. > > I mention this because the instructions clearly state that "Some turns of > the 1-2 winding MAY (emphasis mine) cross over those of the 3-4 winding." > >From a topological point of view, it is impossible for them not to cross > if 1-2 and 3-4 are indeed wound in an opposite sense. Some clarification > would be appreciated. > > By way of contrast, look at (e.g.) Figure 6-25 (page 64) of the main K2 > manual. Here, both windings of T1 are clearly wound in the same sense > because lead 1 and lead 3 both enter the core at the top and proceed > clockwise around the core. > > Have I sniffed too much flux or what? :-) > 73, Dave GW0LUA ++++++++++++++++