Re: 5watt amp/u3s

m0bmn
 

Thanks Alan,

Will get the iron hot, look out C5!

73/4 Paul M0BMN

 

 

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From: Alan de G1FXB via Groups.Io
Sent: 20 July 2019 15:10
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] 5watt amp/u3s

 

Hi Paul,
Yep, Still pull C5
In doing so you create a breakout point for the PA.

Hans recommends using one of the conveniently positioned vacant Q3 BS170 pads where you can find RF and GND connection both close by and send it to the PA input.

PA output gets patched back onto the U3S
Hans suggests RFI and the adjacent GND pads where amplified RF now gets routed into the inbuilt LPF position
and 10 way backbone connector for the expansion LPF positions if fitted, as normal.

As you noted, over time AN004 layouts have not kept up with the PCB revisions.
Not a show stopper the pads are still there, just not exactly in the same place.

Alan

On 20/07/2019 00:13, m0bmn via Groups.Io wrote:

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Think I have just realised how this is done, a zoom in on the newer PCb shows? on the 10 way (5 x2) socket

GND/RFI and GND/RFO which are the connections I need I guess. Do I still chop c5 as before.

73 Paul

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