[TenTec] Tentec Audio fidelity doubt

Carlos PECO BERROCAL carlos.peco at gmail.com
Wed Jul 22 02:48:24 EDT 2020

I found the same issue when I bought my Argonaut VI, I posted about it here
in the Ten-Tec list back then.

In my case, it was (and still is, as I haven't fixed it) the audio
amplifier. It might be the amplifier itself, or the large electrolytic
capacitors within.

In the meantime, buy/make a cable to get the audio from the auxiliary
connector and take it to a powered speaker. HOWEVER, please note that the
level on that connector is a blast for most powered speakers, so in my case
I had to add an attenuator.

Additionally (and only if you are young and with very sensitive hearing)
you might notice some weak digital audio artifacts there, only noticeable
in quiet bands and only on certain frequencies, or when you move the dial
up and down. If you analyze the schematics you'll notice that the DSP board
has two audio outputs: one goes to the auxiliary connector and the other
one goes to the audio amplifier. Well, in my case I found that the one
going to the audio amplifier was noisier than the one going to the
auxiliary connection, perhaps it has to do with PCB track routing. I just
cut a track and patched the audio amplifier to the "quiet one".

Your mileage might vary as we might have different revisions of the PCB,
and/or different firmware.

BTW, were you the one asking about the 9 MHz output? I have an SMA
connector in there. It works, but the frequency response is not flat and on
top of that you'll see the leakage from the second IF mixer (the one that
downconverts to the DSP-IF. Happy to take some screenshots with my spectrum
analyzer. However, the "click and tune" feature works (SDR Console V3 with
RFSpace SDR-IQ receiver).

In summary: get a powered speaker and hook it to the auxiliary output,
after attenuating it a bit. It is a very nice radio, very quiet (what you
hear in the speaker is mostly band noise, and not noise generated by the
radio itself) and I don't get tired of it. I understand that you compare it
with your 7300, but they are different things.

Carlos VK1EA

On Wed, Jul 22, 2020 at 3:23 PM Chang Song <tru64ufs at gmail.com> wrote:

> Hello, folks.
> I have heard so much about Tentec's legendary audio fidelity, I decided to
> purchase a Tentec Argonaut VI.    I mostly use SSB.
> I also have an IC7300.
> From the moment I started using it, I realized that the voice came out from
> the speaker
> and the headphone jack on the Argonat VI is very very mushy.
> Adding to the fact that it does not have spectrum scope.
> I can hardly understand voice with moderate signal level while on IC7300,
> even weaker signal, I can clearly understand voices.
> Is this normal for TenTec?   Or the audio fidelity applied only to CW..
> although
> I don't think it is better than IC7300 either.
> --
> Chang Song
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec

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