Dennis,
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Thanks much.? Right now I am not using Icom rigs but I remember that to a slight extent.? I tried pushing on the audio IC and no improvement as Paul suggested.? Going to set up an audio generator and a scope to try and trace the low audio down.
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Tnx again,
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Mike W9RE
On 12/18/2024 7:54 AM EST Dennis W1UE via groups.io <egan.dennis88@...> wrote:
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Mike
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The original unit used 2502-4 ICs to do the keying and PTT.? We replaced it with
a TLP442 or similar to improve keying with Icom rigs.
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I may have some in the shack- I'll look later today.
Dennis W1UE
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Hi Mike,
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There were some units that had bad solder connections on one of the surface mount chips - I think it was the audio amplifier.? I would open it up to check.
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Before you open the SO2R Box remove the speed pot knob and the nut that holds it to the case.? If you don't you will damage the pot.
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Once you have it open, connect it up and try it.? While you are listening to the audio press on the leads of the audio amplifier (the smaller surface mount chip) with an insulated tool - a toothpick would work.? If the audio level changes then you have a bad solder connection.
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??? Paul
I obtained? a spare (backup) SO2R Box+ and comparing it to my original unit I notice that the audio is say a good 6db lower when listening to radio 1 when plugged into either channel 1 or channel 2.? This is only with the radio plugged into either DIN,? 12Vdc and audio out plugged in and of course flipping the rx switch.
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Any things I should check or buy for replacing??
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Paul was there a chip that was universally replaced in the original buy?? I think the vintage of both units is the same.? Seems like I remember something about a green or white device that should be replaced (updated)?
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Tnx,
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Mike W9RE
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