Retevis RT9000D DSP audio/noise blanker?

[express315]

I did my best to steer clear of chinese radios due to ridiculous menu structures, poor reliability and multitude of glitches.
Lately I became interested in 222 mhz ham band but could not afford spending money on latest Alinco.
I bought RT9000D 220-260 mhz from Retevis HK website. I have also looked at TYT TH9000D, which seems to be exactly the same thing.
In the end Retevis won because I could download manual, driver and software from the sellers website.

RT9000D tested well during couple of 222 mhz FM nets, both via simplex and via repeater.
However I had noticed right away that radio sounded very differently from my many other analog FM radios.
First of all there was no noise even with the squelch down. Second - the audio was very flat and featureless, as if coming out of a digital radio.
The latter is exactly why I refuse to do digital and prefer analog voice for all my ham activities.
Other than radio display going blank regularly and needing a power down to reset (at least some glitch was naturally anticipated!) the radio works fine.
After programming the RT9000D front buttons the same way I do for my Vertex radios (using Retevis cable and software) the radio has become usable.
Whatever functions were assigned there from factory no sane person can ever navigate without getting completely lost.
Finally today I got time for bench testing and hooked up the radio to a service monitor. I can confirm it does 15, 30 and 60 watts output.
RX sensitivity is normal and the squelch behaves the usual- opens at slightly higher signal level compare to when it closes.
However again there is a noise blanker that still attenuates the audio till about 10dbm more signal strength after squelch opened.
When tested Tx, Rx with another radio the audio coming out of RT9000D sounds very "digital" and there is a pronounced echo (delay),
just like when playing with two digital radios one next to another. I am very much convinced that there is a DSP audio processor/noise blanker installed
in the audio path of RT9000D. I very much would like to get rid of it if I am able to figure out how to.

My question for any of you who have had experience with TH9000D or RT9000D if you have had similar processed audio or a normal analog audio?

 

[knockoffham]

I did my best to steer clear of chinese radios due to ridiculous menu structures, poor reliability and multitude of glitches.
Lately I became interested in 222 mhz ham band but could not afford spending money on latest Alinco.
I bought RT9000D 220-260 mhz from Retevis HK website. I have also looked at TYT TH9000D, which seems to be exactly the same thing.
In the end Retevis won because I could download manual, driver and software from the sellers website.

RT9000D tested well during couple of 222 mhz FM nets, both via simplex and via repeater.
However I had noticed right away that radio sounded very differently from my many other analog FM radios.
First of all there was no noise even with the squelch down. Second - the audio was very flat and featureless, as if coming out of a digital radio.
The latter is exactly why I refuse to do digital and prefer analog voice for all my ham activities.
Other than radio display going blank regularly and needing a power down to reset (at least some glitch was naturally anticipated!) the radio works fine.
After programming the RT9000D front buttons the same way I do for my Vertex radios (using Retevis cable and software) the radio has become usable.
Whatever functions were assigned there from factory no sane person can ever navigate without getting completely lost.
Finally today I got time for bench testing and hooked up the radio to a service monitor. I can confirm it does 15, 30 and 60 watts output.
RX sensitivity is normal and the squelch behaves the usual- opens at slightly higher signal level compare to when it closes.
However again there is a noise blanker that still attenuates the audio till about 10dbm more signal strength after squelch opened.
When tested Tx, Rx with another radio the audio coming out of RT9000D sounds very "digital" and there is a pronounced echo (delay),
just like when playing with two digital radios one next to another. I am very much convinced that there is a DSP audio processor/noise blanker installed
in the audio path of RT9000D. I very much would like to get rid of it if I am able to figure out how to.

My question for any of you who have had experience with TH9000D or RT9000D if you have had similar processed audio or a normal analog audio?

I am just guessing, but in the last few years I have owned a multitude of horribly documented cheap Chinese radios. If it has a proprietary CPS, there is probably an improperly named setting somewhere in a menu that disables the audio processor. A lot of the proprietary Chinese radios have all their menu functions also able to be changed via programming software. Another probably lame suggestion is maybe there is something in the user manual?

 

[express315]

Thank you for the response. I have certainly looked through the manual settings menu and found nothing of the like.
I will look again in the stock cps software for the switch, in case I missed it.
On the other note I have made a mistake I think by getting the latest PLUS version.
I suspect the previous "standard" version may not have had this audio processor/ noise blanker.
Manufacturer's website mentions nothing of it but some retailers call it "AI noise cancelling".
I call it garbage. Last night I took part in a chat over repeater and I was disgusted how much distortion and extra noises it creates.
When incoming signal audio level is low and the processor threshold is not triggered and I can hear clear undistorted and unprocessed audio though attenuated by this noise blanker. It acts as if there is a second squelch just in the audio path. Once audio signal level threshold is crossed a loud crack is heard and now the audio comes through without attenuation but now all digitally garbled. Very similar if not identical of how digital radios sound at insufficient RF signal levels.
I looked inside and compared what I saw with pictures posted on internet. I did not find any hardware differences except for those related to a different RF band. These radios are not chip - about $150 usd on average and there are lots of them in use. There must be people around with access to schematics and better overall knowledge of this radio. I have not found yet any group, chat or forum dedicated to this radio model.

 

[knockoffham]

Thank you for the response. I have certainly looked through the manual settings menu and found nothing of the like.
I will look again in the stock cps software for the switch, in case I missed it.
On the other note I have made a mistake I think by getting the latest PLUS version.
I suspect the previous "standard" version may not have had this audio processor/ noise blanker.
Manufacturer's website mentions nothing of it but some retailers call it "AI noise cancelling".
I call it garbage. Last night I took part in a chat over repeater and I was disgusted how much distortion and extra noises it creates.
When incoming signal audio level is low and the processor threshold is not triggered and I can hear clear undistorted and unprocessed audio though attenuated by this noise blanker. It acts as if there is a second squelch just in the audio path. Once audio signal level threshold is crossed a loud crack is heard and now the audio comes through without attenuation but now all digitally garbled. Very similar if not identical of how digital radios sound at insufficient RF signal levels.
I looked inside and compared what I saw with pictures posted on internet. I did not find any hardware differences except for those related to a different RF band. These radios are not chip - about $150 usd on average and there are lots of them in use. There must be people around with access to schematics and better overall knowledge of this radio. I have not found yet any group, chat or forum dedicated to this radio model.

Wow. That is strange. Well, hopefully it is a rebrand of another model and eventually you can find information out there. It sounds like the "plus" might have something to do with it. Maybe it would be worth checking AliBaba or AliExpress for similar models. Perhaps contact Retevis directly, I've had some of these companies be helpful in the past. Just for laughs here is a CPS screenshot of my newest cheap Chinese radio

 

[Ben3113VK5]

I have the UHF 9000D from TYT. There are 2 audio processors that I have found. The first is named 'RENC' under menu option 31 on my radio, this creates the issues you describe, I keep it off radio wide. The second is named 'COMP' under menu option 14.

 

[express315]

Thank you for your response! I will have a look and be back with results.

 

[W7SJ]

You guys ....

You fricken ROCK!

I've been pulling my hair out trying to figure this out for using the TYT HD-9000D for packet radio (using a Kantronics 1200 Plus TNC).

First off, I must say, poster "express325" described this issue SO well, that I am most impressed. So much so, that I had to sign up to this forum. But I am disappointed that he never followed up on this (Shame!, shame!, shame! LOL)...

But poster "Ben3113VK5", you sir, are DA BOMB.

There is so much "gak" (and HACKS) out there on YouTube sending people down rabbit holes over this issue that it's truly sickening.

And even I'm a bit embarrassed, - I myself didn't take the time to RTFM. It's right there !



So the receive audio on packet radio on the TYT HD-9000D is as loud, and as crisp/clean as can be!

...Heartfelt THANKS to all contributors in this thread. The info, and caliber of people in this forum are second to NONE!

Steve / W7SJ

 

[Ben3113VK5]

No worries, Happy to help.

Unfortunately since posting last year my TYT 9000D is no longer working. I was about to update the firmware so entered the 'firmware update mode' by holding down P1 and P2. I didn't actually update the firmware but now the radio doesn't boot properly, when powering on you can hear a slight hissing noise, the backlight is on but nothing on the display. I can re-enter the firmware update mode by holding down P1 and P2 but it won't accept any connection from my PC to actually update the firmware. Very odd, any tips would be appreciated.

 

[W7SJ]

No worries, Happy to help.

Unfortunately since posting last year my TYT 9000D is no longer working. I was about to update the firmware so entered the 'firmware update mode' by holding down P1 and P2. I didn't actually update the firmware but now the radio doesn't boot properly, when powering on you can hear a slight hissing noise, the backlight is on but nothing on the display. I can re-enter the firmware update mode by holding down P1 and P2 but it won't accept any connection from my PC to actually update the firmware. Very odd, any tips would be appreciated.

Wow, - that sucks. Do you still have the radio? Maybe you can send it to me (in Seattle) and I can play with it ? E-mail me, - you can get my e-mail address from the QRZ page for call sign: W7SJ.

Have you tried to contact TYT, or Retevis support about this? You might be toast, but there's got to be a way to force the internal boot loader to accept a firmware image. But if you interrupted a firmware update process, you might have corrupted the part of existing firmware that handles the USB communication (i.e. UART).

The good news is that Amazon is selling this exact radio for $127 under the TYT-9000D branding. So worse case, you ain't out a lot of money.

Q1: Where did you download the firmware image that you were intending to install "
Q2: Why did you not follow thru, and/or abort the firmware upgrade procedure ?

 

[Ben3113VK5]

I'm in contact with TYT, hopefully I hear back from them again early this week.

I downloaded the firmware from the TYT website (TH9000DPlus_UpdataFile2025_01_04GD_V127). I don't remember why I didn't proceed with the firmware upgrade (it was a couple of months ago) but I definitely didn't click upgrade, it's as though it hasn't exited the firmware upgrade state, even after a power cycle.

If TYT aren't any help I'm happy to gift it to someone who might be able to fix it or make use of it somehow. @W7SJ - I'll be in touch directly if TYT are no help.

If they are able to help I'll post the remedy on here.