Any tips on improving SSB TX audio?

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n8jjo
 

Posts: 9
Joined: 12 Aug 2022, 02:24

Any tips on improving SSB TX audio?

Post by n8jjo »

I have a low band and a classic bands, both from Sunny. Have tweaked both for efficiency and harmonic suppression. I get consistent reports of distorted audio, ops says it sounds like I have RF on the signal. I have monitored myself using web based SDR's and the audio is.. not great. Muffled and distorted with no high frquencies. This is with both the internal and an external microphone.

I've tried making adjustments to noise gate and Rf drive to no avail.
Any tips out there on improving TX audio?

Thanks 73 John N8JJO
sy9dok
 

Posts: 4
Joined: 16 Sep 2022, 08:09

Re: Any tips on improving SSB TX audio?

Post by sy9dok »

Following, for any update. I have also the same problem , 73
n8jjo
 

Posts: 9
Joined: 12 Aug 2022, 02:24

Re: Any tips on improving SSB TX audio?

Post by n8jjo »

I haven't found any difference in transmit audio by switching filter settings.

I was planning on using the (tr)usdx in POTA activations, but the muffled audio increases the challenge.

Open to any and all suggestions. I am comfortable with swapping SMD components and have the appropriate hot air station.

Thanks and 73, John
dl6sez
 

Posts: 86
Joined: 30 Dec 2021, 22:54

Re: Any tips on improving SSB TX audio?

Post by dl6sez »

Hello Guys,
the only thing is to think about you are using an Atmega328 generating the Single Sideband signal with 8-Bit calculations at 20MHz. This can not sound like a KX3 or something like this rig... I never had a problem with uSDX (predecessor) and (tr)uSDX knowing this and yes your audio could be improved, but not with our hardware :)
The only things you can change and play to get the best tx audio is TX drive and maybe change the elecret microphone. Probably there are still shorts or to high performance changes in the elecret capsule due to shortages still be seen on the electronic parts. Nobody to blame or to bother about.

73 de Chris DL6SEZ
Chris DL6SEZ, JN48XL near Ulm, Southern Germany
n8jjo
 

Posts: 9
Joined: 12 Aug 2022, 02:24

Re: Any tips on improving SSB TX audio?

Post by n8jjo »

I completed some testing today on 60 meters NVIS, monitoring on a SDR about 100 miles from my location.

I tested the Pacific Antennas external mic. I have found that with the Noise Gate set at 8 and TX Drive set at 4 the audio is much, much better, very usable in fact.

I will test my hi bands unit if I can find a SDR within range and propagation.

73 John N8JJO
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