9 Oct 2016

300W Class D on 472kHz

G0MRF has produced a design and PCB for a 300W class D PA for the MF band. It needs a low level drive at twice frequency. For WSPR it needs the experimental software from K1JT that produces tones at twice frequency so they are right when driving this PA. Although kits of some parts are available, I do not think a complete kit is available. Using such a PA would increase my 630m ERP by several "S" points, even without antenna and ground changes.

See http://www.g0mrf.com/630m.htm


Steve McDonald said...

Roger...I gather that the new K1JT software is only useful if you can run your trcvr in 'open frequency mode' and it produces RF on 950kHz...not sure as I haven't seen any info on it??


Roger G3XBM said...

Steve, yes I think you are right. Maybe there is scope for a simple 950kHz 5-10mW crystal controlled TX for WSPR? I have not seen this software either. I guess the best approach is to divide down from a higher frequency crystal e.g. using a 4060.

Jay Wilson said...

This is very nice! I believe it to be twice the RF frequency and twice the inter-tone spacing for WSPR. Jay, W5OLF