Andy,Rik, after thinking a while over the transformer of Andy's PA and referring to http://www.g4jnt.com/pamatch.gif I'm sorry to say that I'm still quite (say 99,9%) sure that it is a conventional 1
I don't use a Bird wattmeter. Don't trust any directional type of meter for proper power measurements. I have a 1GHz specified 30dB rated 1kW Bird attenuator (calibrated) plus HP 432 power meter
BINGO - Tnx Rik, thats it, convincing. Sorted So my thing IS 1:4 turns ratio, (1:16 Z ratio) just as the calculations said it needed to be, and is indeed, effectively, an auto transformer. Oth
Uncertainty of a bird wattmeter with a 1kW slug would be around +/-50W, with a 2,5kW element +/-125W. Power master is a bit better with +/- 30W. 73 Clemens DL4RAJ -- Original Message -- From: andy.g
Andy, have a look here : http://www.polyfet.com/HFE0503_Leong.pdf http://www.semelab.com/rf/documents/Push-Pull%20Circuits%20and%20Wideband%20Transformers.pdf 73, Rik ON7YD - OR7T Van: owner-rsgb_lf_
I've no practical experience with Mosfet PAs. Nonetheless according to your diagram this is definitely a 1:3 transformer. Ther's no way how an autotransformer mode could come into play somehow. scree
Oh yes,be careful about this precious piece of measuring equipment. But then,with < +/- 0,2dB you come out at an uncertainty within of around +/- 42W at 900W. 73 Clemens DL4RAJ -- Original Message --
A follow up to this sage After much puzzling over the design, and comment here about how it must be 3:1 teh only solution was to measure it. So I connected up and measured voltages. Indeed, it d
