Re: R: Re: LF: TXing 2200m WSPR

[Chris Wilson <dead.fets@gmail.com>]

Hello N1BUG,


What  does the scope show if you look at each side of the choke in the
PA?  I  did  some  tests ages ago using the stacked chip caps on the PA
side  of  the  choke  compared  to  conventional  leaded  caps and the
difference  was  marked. I would certainly try a proper dust iron core
for  the  choke, ferrite can't be right... I don't use a LPF after the
U3S but my amp is "Class D" and is happy with being driven with square
waves.

Friday, December 29, 2017, 11:13:03 AM, you wrote:

> One final thing.

> Thought maybe something in the antenna was breaking down (arcing or 
> corona), so made another check:

> I now have the capability to run the PA on 13V or 19V. At 19V I can 
> make more power into the antenna before the signal goes dirty, 
> compared to 13V. RF power is RF power. If it was something failing 
> in the antenna system I think it should happen at the same RF power, 
> no matter what DC supply voltage I use on the PA...

> Paul





-- 
Best regards,
 Chris                            mailto:dead.fets@gmail.com