Re: Status: IC-7000 Audio Levels for V/UHF and HF modes #draws #hfmodes #ic7000


Jack Spitznagel
 

Basil, John

I setup Beta 6 today. The install was painless, it may be my growing comfort
with the setup, but it ran smoothly. Testing was where thing fell apart.
Unfortunately I still struggling to get the both the direwolf and fldigi
drives level adjusted with the IC-7000.

It appears that the poster who suggested a 100k ohm (variable) resistor in
the audio line from the DRAWS to the transceiver may be correct.

I will upload a text file of my observations while running the "Ackerman"
no-test-equipment deviation method" style adjustments and using the
"measure_deviate.sh" script if desired... but this should cover almost
everything:

In short:
1. Audio drive was too high for the IC-7000 as it was defaulted by
AX25/direwolf setup.
2. Used the "setalsa-udrc-alinco.sh" script to set the audio levels to a
level that "worked"
NOTE: I tried all of the scripts you included. The Alinco" levels produced a
signal my HT and APRS gateway could decode - it sounded hot though.
3. While "measure_deviate.sh" was activated, reduced PCM all the way, then
increased it until I heard no increase in volume of the received signal.
That point occurred at about -6.00 dB - but ALC on the rig was still very
high. LO Driver Gain level was already at -6.00 dB.
4. Re-enabled the AX.25/direwolf stuff and observed that these levels still
resulted in decodable APRS [packets).
5. Killed AX.25, went to fldigi and SSB to see how the audio output was
driving the 7000. ALC was still very high.
6. Increasing PCM increases distortion sound and visual splatter on Spectrum
Lab.
7. Backing PCM to -21.00dB saw the ALC start to drop - but would not drop
below 50% point.
8. Once PCM drops below about -25.00dB, the ALC starts to pump and the
signal gets dirty sounding with a feedback-like harmonic beginning to be
heard with loud hiss and crackling noises.

These "best outcome" alsamixer levels are still not optimal by any
descriptions I have read. I don't challenge that.
PCM L:[-21.00dB], R:[-21.00dB]
ADC Level L:[-5.00dB], R:[-5.00dB]
LO Driver Gain L:[-6.00dB], R:[-6.00dB]
IN1 L:[10kOhm], R:[10kOhm]
IN1 L:[Off], R:[Off]

Conclusion - AFAICT, clean audio IS being produced at higher PCM and LO
Driver Gain levels - but the signal is at too high a level for the IC-7000.

NOTE: I seem to remember I had to use the dropping resistor setting in the
SignaLink with this radio. So that leads me to the conclusion that a
variable resistor/ resistance network will be needed to get clean audio at a
level that the IC-7000 (and apparently some other radios) seems to like.

Next time I have the unit apart, I will try to find a good test point to
measure the actual amplitude of the signal with a handheld digital
oscilloscope I have.

Thanks for your patience with my ramble.

KD4IZ
Jack Spitznagel
FM19oo





--
J Spitznagel
Science River LLC
KD4IZ

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