Re: RFI from uBitx TX after AGC and other mods installed

Mark M

I have exactly the same situation with mine. I hear my voice loud & clear from the speaker, it's like a PA system.

It's Kees' kit installed like the photos...a three pin header, center to ground. The ground pin shows 0 ohm to ground with the board removed. I don't have the RF pot installed, just the jumper. When I remove the board and jumper the outer pins the radio works normally, no audio from the speaker on xmit. With the board in place, disconnecting the 5v stops the speaker audio.

I'm not sure the S meter driver is working either, I get less than 2 v even on a really strong BCB signal.

I'm afraid I might have reverse powered the board the first time I powered it up...the 5V marking was a little confusing, I think there was a thread about that here a while ago. It was not installed at that time, just hanging in mid air with the power & audio & s meter connections...I wanted to see if the S meter worked. I don't imagine that would have done it any good.

I have a borrowed scope so I can do some checking with that.

I also have a second kit that I haven't assembled yet. I might try it & see if it's any different (being careful with the power polarity).

Any advice will be appreciated.

Mark... AA7TA

On 6/24/18 1:18 PM, alans77 via Groups.Io wrote:
Don: I have a similar problem only I have not installed the RF gain control. On SSB phone transmit my voice comes out of the speaker loud and clear. I find it strange the audio amp / speaker are not muted when transmitting.
73 ,

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