[TenTec] Audio improvements on Argonaut VI

[Bob McGraw K4TAX]

Carlos et & al:

If you are finding the headphone audio cleaner than the speaker audio, 
the audio amp which drives the headphones and speaker is the same 
device.  This would seem to indicate the audio amplification is working 
correctly.

If you have an external speaker plugged into the headphone jack, the 
headphone jack is isolated via resistors and the AF amp will not drive 
an external speaker.    Try an amplified speaker such as computer desk 
top speakers.

The internal speaker itself may be defective thus the source of the 
distortion you are hearing.

As to the noise, without quantifying, it is hard to say if there is an 
issue.  Just because it can be heard is no reason to be of concern.  If 
it covers up weak signals then it is a concern.   A good test is to 
measure the audio output with a ACVM with no antenna attached, RX input 
terminated into 50 ohms, RF gain at maximum.  Then attach the antenna on 
a quiet band such as 10M. You should see a 3 dB to 6 dB increase in 
noise.  If so, there is no receiver issue.   If antenna noise is 3 dB to 
6 dB above receiver noise then you will hear any weak signals on the band.

Unless the radio is defective, any artifacts which you describe and 
under the conditions you apply are likely design related. Just because 
noise can be heard in the audio is no indication of any defects or 
design related issues.      I do not know of any Tentec approved 
modification to correct any of your concerns.

In the comparison with the two radios on my desk, a Tentec Eagle and an 
Elecraft K3S, with the RX input terminated and using headphones, RF gain 
at minimum and AF Gain at maximum, I hear a small amount of hiss from 
both radios.  With AF Gain at minimum, a very slight amount of digital 
noise is heard.  In both cases, the settings are far from normal 
operating conditions.

I do not have an Argonaut VI on the desk at present as mine is on loan 
to a friend.   In this regard,  have done a significant amount of the 
beta testing, being a member of the Tentec beta test team for firmware 
for the Omni VII, Eagle, and Argonaut VI radios.  In doing so, I find no 
operational conditions which are deemed a fault of design or 
manufacturer of the products when operated under normal conditions.

73

Bob, K4TAX