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Re: U3S toroid - 2200m to 160m

 

Hello Chris,

Unfortunately I have no big amp of that type. I will be building a 25-50 watt HB9ASB LF/MF amp as described on the QRP Labs site. Apparently it benefits from somewhat more drive.

My RX status this year is uncertain but surely won't be as good as last year. More on that shortly.

73,
Paul N1BUG

On 10/11/2017 12:07 PM, Chris Wilson wrote:
Hello Paul N1BUG,
If you are just using your U3S on 2200m to drive a Class D amp you
don't need the toroid at all, just take drive direct from the Si chip
CLK0 pin. If you use the very latest firmware you can delete the
phase inverter IC and drive the FET driver IC directly from CLK1 and CLK2
Are you about to start RX on 2200m any time soon again? Good luck.
Monday, October 9, 2017

What is the consensus on single 25 turn vs. 10 turn bifilar if the
primary focus is low and medium frequencies? Is there any issue
installing the bifilar wound toroid laying flat in order to fit the
OCXO?
I am finally getting around to build my U3S with all the trimmings
(OCXO, GPS, etc.)
73,
Paul N1BUG
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