Re: T41 Hilbert Filter Design
But isn't the Hilbert transform a quite sharp bandpass filter?? Also you have a transmit equalizer, which can low-pass filter?
I'm surprised more filtering is necessary.? Noise injection from a mystery source?
?
A swept tone into the microphone input while observing on a spectrum analyzer will show you what you are getting.
T41EEE uses 12ksps Hilbert phase shifters and this makes equalizer lowpass above about 3kHz essentially useless.
?
--
73 Greg KF5N
|
Re: T41 Hilbert Filter Design
I've added a lowpass IIR filter to the transmit audio chain. You can see the code modifications here:
I've attached a recording of my transmitted audio (into a dummy load with a monitor attached). It sounds nicer that it did before. I used an SDR to demodulate the RF.
The filter I added has only a single stage and can be improved to get sharper cutoff. That'll be a project for the rewrite I'm currently doing, unless someone out there wants to take this on in the mean time.
On Sunday, May 25th, 2025 at 9:54 AM, Oliver KI3P via groups.io <oliver@...> wrote:
OK, I've pushed these changes to github. I tested my radio with both settings and can't say that I can hear a difference, but the changes are more correct.
John W2TX pointed out in an email that the bandwidth of the transmitted signal is too broad. I'm going to investigate that next -- trying to interleave my rewrite of the whole code base with these tweaks to the older version of the code.
On Sunday, May 25th, 2025 at 7:36 AM, Terrance Robertson, KN6ZDE via groups.io <tmrob4@...> wrote:
Yes, I've used 279 for the size of FIR_dec3_EX_I_state?and FIR_dec3_EX_Q_state.? Also, I set the size of FIR_int3_EX_I_state and FIR_int3_EX_Q_state to 151 in lines 1132 and 1133.
|
T41 with Polar Modulation
After learning that Hans Summers was at Dayton Hamvention promoting his QMX which can now operate SSB using Polar Modulation, this got me thinking.
Has anyone considered a T41 using Polar Modulation?
How difficult would the software be to implement? I am sure I can sort the hardware side of things.
?
John, G0SDF
|
Re: T41 Hilbert Filter Design
OK, I've pushed these changes to github. I tested my radio with both settings and can't say that I can hear a difference, but the changes are more correct.
John W2TX pointed out in an email that the bandwidth of the transmitted signal is too broad. I'm going to investigate that next -- trying to interleave my rewrite of the whole code base with these tweaks to the older version of the code.
On Sunday, May 25th, 2025 at 7:36 AM, Terrance Robertson, KN6ZDE via groups.io <tmrob4@...> wrote:
Yes, I've used 279 for the size of FIR_dec3_EX_I_state?and FIR_dec3_EX_Q_state.? Also, I set the size of FIR_int3_EX_I_state and FIR_int3_EX_Q_state to 151 in lines 1132 and 1133.
|
Re: T41 Hilbert Filter Design
Yes, I've used 279 for the size of FIR_dec3_EX_I_state?and FIR_dec3_EX_Q_state.? Also, I set the size of FIR_int3_EX_I_state and FIR_int3_EX_Q_state to 151 in lines 1132 and 1133.
|
Re: T41 Hilbert Filter Design
The size of the FIR filter's state vector should be numtaps+blocksize-1. For the decimation filter in question, this is 24+256-1 = 279.
?
To be explicit, can you confirm that changing the sizes of the arrays FIR_dec3_EX_I_state and FIR_dec3_EX_Q_state to be 279 items long in lines 1104 and 1105 of the .ino fixes the problem?
?
If this is correct, I'll push this to GitHub.
?
?
|
Re: T41 Hilbert Filter Design
On Fri, May 23, 2025 at 06:20 AM, Albert Peter wrote:
I will have to have a look. I did revise some of the fitlter designs in the last version.
I tracked down a problem I was having in SSB transmit to the size of the decimate state vectors, FIR_dec3_EX_I_state, FIR_dec3_EX_Q_state.? If these are allocated to DMAMEM, the RF out on the RF board at times exhibits a raised skirt in both side bands.??I'm a novice in filter design and use, but it appears the FIR_dec3_EX_I_state and FIR_dec3_EX_Q_state are too small. ?Properly sized this doesn't happen.? The FIR_int3_EX_I_state and FIR_int3_EX_Q_state vectors appear to be too big, but this isn't a problem, except more memory is used.?
?
How to reproduce:
- FIR_dec3_EX_I_state and FIR_dec3_EX_Q_state in DMAMEM, compile v66-9 with "Faster with LTO", PTT sometimes gives raise sideband skirt in signal out from RF board.
- Also, compile v66-9 with "Smallest Code", PTT causes a crash.
|
Re: M5Stack Dial - ESP32-S3 Smart Rotary Knob
Lynn, KU7Q, is using this in his CTR2-Dial Product. It's intended for use with remote operating apps that supports MIDI commands. It works great with Marcus Roskosch's Apple products apps.
|
Re: Problem running Arduino on Linux under Kubuntu / Ubuntu
Ken ? The suggestions from Jerry are good but they're not a permanent fix. The files in /tmp are exactly that: temporary. They will be recreated as and when needed the next time you boot the system. ? The problem probably lies in a configuration file buried deep in the darkest depths of /etc, where whatever creates these files gets its config from. ? You're probably better of searching for similar problems on the Ubuntu forums rather than here (and my apologies if anyone here does have an answer). ? Some people consider this DANGEROUS but I would try running the command as root to see if it makes any difference. But you do so at your own risk. ? And a hint for those not used to using the Linux terminal and command line: Use "tab" completion to make entering commands, file names etc easier. So instead of typing the whole of the ? "sudo ls -l /tmpo/.mount_arduinIn8mwB/chrome-sandbox" command just do ? ?sudo ls -l /tmp/.mo<tab key> If it does nothing then either: ? it's got more than 1 possible completion so give it 2 <tabs> and it will ? ? show you the possibilities OR ? there's no ".mo" to comple ? ? It looks to me like the last six characters in .mount_arduinIn8mwB are randomly generated each time you run the command, so the above hint should make life easier. Regards Keith G0GNL
|
Re: T41 Hilbert Filter Design
What are the audio reports like barefoot?
Jack, W8TEE
On Friday, May 23, 2025 at 05:26:33 PM EDT, jerry-KF6VB <jerry@...> wrote:
On 2025-05-23 14:05, jjpurdum via groups.io wrote: > Are you running barefoot or through your amp? *** Through the amp.? I also use my FTDX10 through the amp, and people report crystal clear audio. ? ? ? ? ? ? ? ? ? - Jerry, KF6VB > > Jack, W8TEE > >? On Friday, May 23, 2025 at 04:13:31 PM EDT, jerry-KF6VB > < jerry@...> wrote: > > I just downloaded the latest V066.9 from Oliver's github.? Trying it > out > now. > > People are complaining that my transmit audio is muddy.? And with the > transmit equalizer enabled, it's beyond horrible.? I can actually hear > that in a monitor receiver. > > I tried using the equalizer to brighten up the top end for better > intelligibility, but no joy.? People are telling me that varying its > settings > does nothing at all. > > On the plus side, power down does work now. > >? ? ? ? ? ? ? ? ? - Jerry > > -- > Jack, W8TEE > > > Links: > ------ > [1] /g/SoftwareControlledHamRadio/message/34003> [2] /mt/113214259/243852> [3] /g/SoftwareControlledHamRadio/post> [4] /g/SoftwareControlledHamRadio/editsub/243852> [5] > /g/SoftwareControlledHamRadio/leave/10484476/243852/1943518115/xyzzy
-- Jack, W8TEE
|
M5Stack Dial - ESP32-S3 Smart Rotary Knob
By way of I was just looking at this
?
With my limited programming skills it would be a coin toss if it ended up on the shelf of shame or in something useful but in the right hands this could be interesting, assuming it isn't too noisy.
?
|
I should clarify that the "muddy audio" problem is not new with this version.
The last version I was using had it also.
- Jerry, KF6VB
|
Re: T41 Hilbert Filter Design
On 2025-05-23 14:05, jjpurdum via groups.io wrote: Are you running barefoot or through your amp? *** Through the amp. I also use my FTDX10 through the amp, and people report crystal clear audio. - Jerry, KF6VB Jack, W8TEE
On Friday, May 23, 2025 at 04:13:31 PM EDT, jerry-KF6VB
<jerry@...> wrote:
I just downloaded the latest V066.9 from Oliver's github. Trying it
out
now.
People are complaining that my transmit audio is muddy. And with the
transmit equalizer enabled, it's beyond horrible. I can actually hear
that in a monitor receiver.
I tried using the equalizer to brighten up the top end for better
intelligibility, but no joy. People are telling me that varying its
settings
does nothing at all.
On the plus side, power down does work now.
- Jerry
--
Jack, W8TEE
Links:
------
[1] /g/SoftwareControlledHamRadio/message/34003
[2] /mt/113214259/243852
[3] /g/SoftwareControlledHamRadio/post
[4] /g/SoftwareControlledHamRadio/editsub/243852
[5]
/g/SoftwareControlledHamRadio/leave/10484476/243852/1943518115/xyzzy
|
Re: T41 Hilbert Filter Design
Are you running barefoot or through your amp?
Jack, W8TEE
On Friday, May 23, 2025 at 04:13:31 PM EDT, jerry-KF6VB <jerry@...> wrote:
I just downloaded the latest V066.9 from Oliver's github.? Trying it out
now.
People are complaining that my transmit audio is muddy.? And with the
transmit equalizer enabled, it's beyond horrible.? I can actually hear
that in a monitor receiver.
I tried using the equalizer to brighten up the top end for better
intelligibility, but no joy.? People are telling me that varying its
settings
does nothing at all.
On the plus side, power down does work now.
? ? ? ? ? ? ? ? ? - Jerry
-- Jack, W8TEE
|
Re: T41 Hilbert Filter Design
Strange, both of my builds V10 and V12 have always received excellent audio reports. I have used several cheap (RS) elements in home made enclosures.
Did you use the dedicated Mic ground?
Tim W4YN
?
|
Re: T41 Hilbert Filter Design
I just downloaded the latest V066.9 from Oliver's github. Trying it out now.
People are complaining that my transmit audio is muddy. And with the transmit equalizer enabled, it's beyond horrible. I can actually hear
that in a monitor receiver.
I tried using the equalizer to brighten up the top end for better intelligibility, but no joy. People are telling me that varying its settings
does nothing at all.
On the plus side, power down does work now.
- Jerry
|
Re: Problem running Arduino on Linux under Kubuntu / Ubuntu
except that the file mentioned doesn't actually exist!
I solved the problem by downloading the zip file containing a conventional binary image.? Still have to set chown root and permissions though. ?? You can also just run the appimage with --no-sandbox.?? However that might be less secure!
|
On Fri, May 23, 2025 at 06:16 AM, Albert Peter wrote:
I will remove the CW messenger, but if you would send a screen shot of the T41 port, I will include that.
Screenshot of the code?? The code is available on my GitHub in the file .? It's over 500 lines so I'm not sure if a screenshot is useful.? Perhaps a scroll box?
?
Or do you mean a photo of the radio in that mode.? There's not much to that photo (see below) but if you can handle a video, I can send a short clip demonstrating the memory keyer and keyboard entry (just a CQ with my call sign).
?
|
Re: T41 Hilbert Filter Design
Thanks Terrance. I¡¯ll keep studying this. I have 66_9 and will use my PC with WSJT dave
toggle quoted message
Show quoted text
On May 23, 2025, at 5:50?AM, Terrance Robertson, KN6ZDE via groups.io <tmrob4@...> wrote:
? Hi Dave.? I assume you're interested in FT8 with WSJT on your PC. I know several folks have done data modes with their PC and T41 connected in various ways.? Some modes can be done without modifying the T41 software.? V66-9 does have a CAT control module but I am not familiar with it.? Others, including me, have added CAT control to their v11 software.
?
I've done a few things with FT8 specifically.? I've added an FT8 decoder to my T41.? It's not readily ported to the main code base as it requires some work to free up the needed memory.? With my current software, the Teensy only has 12k of heap left in FT8 mode, though saving memory hasn't been a focus of mine for some time and I've added a bunch of stuff that could still be optimized somewhat.? Full FT8 solely within the T41 might be possible but would require a lot more work?
?
I've also tried FT8 with WSJT with audio over USB from the T41 to PC.? I got it sort of working, but as discussed in this post, it really requires a patch to the Audio library to work correctly.? I haven't tried that yet, but I think others have. ?
?
|
Re: T41 Hilbert Filter Design
I will have to have a look. I did revise some of the fitlter designs in the last version.
Al
|
jjpurdum