Hello John,
Friday, October 16, 2015
Ah, right, OK John, thanks for that. I may try a galvanically isolated
matching transformer. I realised late last night that my wife's
complaining of the workshop alarm having gone off seemingly randomly a
couple of times, was associated with me transmitting when it went off
again. The RCD in the main fuse box tripping a little earlier has now
got her wound up about this new facet to my hobby and extremist views
such as "you'll burn the house down", and "you'll pay for the freezer
contents if it goes off whilst we are away"... are being uttered :)
> Hello Chris,
> I use the term “isolation” to emphasise the fact that it does
> provide galvanic isolation, which an auto-transformer does not.
> The transformer here is a ferrite ring type N90AB from Maplin, with
> a 5 turn primary winding and a 10 turn secondary. The transmitter is
> a 30 W class E design based on the spreadsheet by G3NYK. In this
> configuration, with the antenna system presenting 50 ohms, the
> amplifier sees the desired load of about 12 ohms.
> 73 John F5VLF
--
Best regards,
Chris mailto:[email protected]
|
