PA output transformer winding confusion and best configuration to match 50ohms

[gbugh]

I'm getting really confused by how other amateur radio operators are drawing their schematics and need some feedback to make sure I'm understanding them correctly.

Example, see the PA schematic here: http://www.alg.myzen.co.uk/radio/136/qrptx.htm

This drawing has dots on pins 1, 3 and 5. Dots are supposed to represent same phase signals, right?
Same phase signals occur at opposite ends of 2 or more parallel windings, not the same ends, right? But further down on the same webpage, pins 1, 3 and 5 are drawn all on the same ends of the 3 windings.

So does this mean in amateur radio, operators have adopted a new standard that dots denote the same end of multiple windings instead of same phase signals? Or are some of them really using the dots to denote same phase signals while others are using dots to represent same ends of the windings? What is the most common convention?

I also see some amateur radio operators have a center tap connection to the transistor or MOSFET output like the above link and like this:
**broken link removed**

and some do it like this:

http://kitsandparts.com/rfamp.php
and this
**broken link removed**

Which way is better?

Thanks,

73 de AF5IE George

 

[chuckey]

I believe that the dots represent the "start" of each winding , which are presumed to be wound in the same direction. So in your example I would wind it as a trifilar, work out how much wire you need for your 12 turns, cut three bits and loosely twist them together then wind the 12 turns with your thick bit of wire, sort out the various wires with a buzzer.
Frank

 

[gbugh]

OK, thanks. I guess the dots do represent the same phase signals for the time periods after the transistor switches OFF because the field would then collapse on all the windings the same.

 

[godfreyl]

Example, see the PA schematic here: **broken link removed**

This drawing has dots on pins 1, 3 and 5. Dots are supposed to represent same phase signals, right?

Yes

Same phase signals occur at opposite ends of 2 or more parallel windings, not the same ends, right?

Wrong

But further down on the same webpage, pins 1, 3 and 5 are drawn all on the same ends of the 3 windings.

Yes, so they have the same phase.

btw, Those three windings are connected in series, not parallel.