Apache Labs Community Forum

This problem appeared few month ago in my radio.
I started having reports that my voice sounds raspy or check your modulation.
I was running Protocol1 and decided to upgrade to Protocol2.
This helped some however the problem persists because some station still reported distortion of my voice.
This looks to me like ADC or FPGA failure.
Any advice on that would be appreciated.

Adam AC8CE

Adam,

There's not nearly enough information here to figure out the problem.

I assume by "TAPR Hermes" you mean you are running a homebrew rig built around an early Hermes card. Is that correct?

The other thing is that we should be looking for "horses not zebras". Meaning that it's very unlikely there is a problem with the FPGA or ADC. It's far more likely the problem is a much simpler one.

I would recommend you go back to Protocol 1. It is much more reliable and smoother running on Hermes. Once the problem is fixed then you can try going back to Protocol 2.

A more detailed description of your setup would be helpful. What mic? Attached how? Are you running Thetis or PowerSDR? What version? How is the unit packaged? What does the RF chain look like?

Have you tried any basic experiments? For instance, is the output of TUN OK? Is the two-tone output OK? If they are it would go a long way to eliminating the FPGA and ADC as problems.

Scott,

My Hermes board is one of the first fully assembled board available that time at TAPR.
I made two changes to the board to get it ready for Protocol2.
I provided 5VDC from external PWS and soldered wire over one of the PCB traces per Keil LA2NI recommendation. I was very sorry to hear that he became SK.
When that problem appeared I was running Thetis -v2.9.0.2 and 16-bit Hermes Protocol1 ver. Hermes_v3.3.
I purchased new headset Heil Proset for testing because the old one started having loose microphone connection.
The new headset did not improve SSB signal quality so I decided upgrading Hermes firmware to Protocol2 'Metis_Hermes_Protocol_2_v10.9.1A'.
This help very little, some correspondents still reported my SSB signal distorted.
My Hermes CW signal is clean on all bands. I checked it with oscilloscope.
The receive filters 3.3kHz, 2.9kHz ect. work fine.
All NR, NB, SNB, ANF filters work fine as well.
Two weeks ago I switched to Thetis-v2.10.3.11.x64. This did not help.
I was not sure if the problem could be fixed so I bought the latest ANAN-10E.
I've been using it since two (2) days connected to the same 400W PA and guess what?
I'm receiving compliments on my SSB signal again. I hear 'great audio' reports again.
Anyway next week I will make two-tone test on Hermes, output of TUN was always fine.
I'm going to check output voltages of all PWS's on Hermes board as a first step of hardware debug.

Thank you for quick replay.

If anyone else experienced such a problem please reply to my post.

73 Adam AC8CE

Did you get the Proset with the dynamic or electret element?

Have you properly modified the microphone connector on the Proset? The supplied mono (tip/sleeve) connector will NOT work properly on any Hermes-based hardware, from the original Hermes all the way up to the latest G2.