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Re: Pseudo-Sine?

 

I use an old noise generator.? that is a very broadband signal
you can probably tailor it to the HF band
73 kd5yyk

On Monday, March 4, 2019, 11:46:12 AM CST, Jim Sheldon <w0eb@...> wrote:


Not enough coffee this morning Jerry,?
However, there is NO way to create a "pseudo sine wave" that will cover that frequency spread (1.8 to 30 MHz) with the current setup and Jerry's right, the only way is to use proper LPF filtering for all the bands. ?Unfortunately the 4 supplied are too broad to do the job properly and with only the supplied # of relays, it's not possible to switch extra ones in and out to achieve the desired results without some serious cut/paste modifications to even the V5 uBITX board.

Jim

------ Original Message ------
From: "Jerry Gaffke via Groups.Io" <jgaffke@...>
Sent: 3/4/2019 11:10:13 AM
Subject: Re: [BITX20] Pseudo-Sine?

You have that backwards.
CLK2 goes into the mixer at D1,D2, and is at the CW operating frequency.
CLK0 and CLK1 are dead in the water when transmitting CW.

Class C power amps are how most CW-only transmitters have worked over the last 100 years
Class C creates?a big honking square wave that then needs to be sorted out by effective low pass filters.
The solution for the uBitx is simple enough, make the transmit LPF's work properly.
Unfortunately, the relays are kind of tough for some of us to work on,
and few can be bothered to measure the results.

Jerry, KE7ER


On Mon, Mar 4, 2019 at 08:49 AM, Jim Sheldon wrote:
I don't believe that will work as CLK02 is not used for CW transmit. CLK01 produces "ON FREQUENCY OF TRANSMISSION RF (square waves) for CW
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