Date   

Re: DUOr interference from headphone outputs #eladduo #fdm-duor #duor

Ad Dieleman
 
Edited

I don't think that the interference comes from spurious switching signals from a class D amplifier: the 2.4 MHz signal disappears completely when loading the output with a low enough resistance, i.e. no high-frequency filtering at all. The filter I applied also doesn't really filter out HF signals, it just loads the output with 4.7 ohm for frequencies over roughly 50 kHz, this being the 3 dB cutoff point. So I still think that the output stage is oscillating under certain circumstances, be it a class D amplifier or something else.


Re: DUOr interference from headphone outputs #eladduo #fdm-duor #duor

Klaus Brosche, DK3QN
 

Hi Andy,

That's exactly was I was wondering about :-))

The average designs around this class-D chip family go w/o any LPF at the output.
I do not know how this is implemented in the DUO(r).

In case the outputs (stereo) are not LPF-limited, the PAM-xxxx devices turn
into 'transmitters', as is true for any class-D amp, especially if speaker/headphone
cables are longer than a few inches/centimeters!

Thus, a proper designed LPF at the amp output is a real 'must' with such kind
of amps.

The 'PAMs' are typically used in low power one-box FM receivers with internal
speakers and a very short cable connection between PAM-xxxx out and the
(internal) speaker chassis.

Klaus, DK3QN


Am 24.09.2020 um 22:01 schrieb Andy G4JNT:

This sort of device



On Thu, 24 Sep 2020 at 20:58, Klaus Brosche <klaus.brosche@...> wrote:
Possibly one of these low power class-D PAM-xxxx chips?

Klaus, DK3QN

Am 24.09.2020 um 20:52 schrieb Andy G4JNT:
I saw something like that.  I guess the Duo might use a Class-D switch-mode audio amplifier chip for speaker and headphones
There's no real reason NOT to use one in that position, they're very efficient.



On Thu, 24 Sep 2020 at 19:35, Ad Dieleman <addieleman@...> wrote:
This afternoon I was doing some measurements on audio signals on the DUOr's headphone outputs. Suddenly I saw a 2.4 MHz signal on my oscilloscope with an amplitude between 0.5 and 1 Vpp. The occurrence of that signal depends on the length of wire connected to the headphone output and crucially occurs most often when no load is present apart from the high-impedance oscilloscope input. Once the output is loaded with 10 ohms or so the 2.4 MHz disappears. I already use a ferrite core through which the headphone cord is wired but that doesn't suppress it. Ultimately I made a Boucherot filter-like setup, connecting a resistor of 4,7 ohm and a capacitor of 612 nF in series across the output. See the picture. No more interfering signals this way. I'd suspect the audio amplifier starts to oscillate under certain load conditions.



The filter box. Decided to resist the temptation to open the radio, so built a separate box to be inserted between loudspeaker/headphone and the radio output.




Re: DUOr interference from headphone outputs #eladduo #fdm-duor #duor

Andy G4JNT
 

This sort of device



On Thu, 24 Sep 2020 at 20:58, Klaus Brosche <klaus.brosche@...> wrote:
Possibly one of these low power class-D PAM-xxxx chips?

Klaus, DK3QN

Am 24.09.2020 um 20:52 schrieb Andy G4JNT:
I saw something like that.  I guess the Duo might use a Class-D switch-mode audio amplifier chip for speaker and headphones
There's no real reason NOT to use one in that position, they're very efficient.



On Thu, 24 Sep 2020 at 19:35, Ad Dieleman <addieleman@...> wrote:
This afternoon I was doing some measurements on audio signals on the DUOr's headphone outputs. Suddenly I saw a 2.4 MHz signal on my oscilloscope with an amplitude between 0.5 and 1 Vpp. The occurrence of that signal depends on the length of wire connected to the headphone output and crucially occurs most often when no load is present apart from the high-impedance oscilloscope input. Once the output is loaded with 10 ohms or so the 2.4 MHz disappears. I already use a ferrite core through which the headphone cord is wired but that doesn't suppress it. Ultimately I made a Boucherot filter-like setup, connecting a resistor of 4,7 ohm and a capacitor of 612 nF in series across the output. See the picture. No more interfering signals this way. I'd suspect the audio amplifier starts to oscillate under certain load conditions.



The filter box. Decided to resist the temptation to open the radio, so built a separate box to be inserted between loudspeaker/headphone and the radio output.



Re: DUOr interference from headphone outputs #eladduo #fdm-duor #duor

Klaus Brosche, DK3QN
 

Possibly one of these low power class-D PAM-xxxx chips?

Klaus, DK3QN

Am 24.09.2020 um 20:52 schrieb Andy G4JNT:

I saw something like that.  I guess the Duo might use a Class-D switch-mode audio amplifier chip for speaker and headphones
There's no real reason NOT to use one in that position, they're very efficient.



On Thu, 24 Sep 2020 at 19:35, Ad Dieleman <addieleman@...> wrote:
This afternoon I was doing some measurements on audio signals on the DUOr's headphone outputs. Suddenly I saw a 2.4 MHz signal on my oscilloscope with an amplitude between 0.5 and 1 Vpp. The occurrence of that signal depends on the length of wire connected to the headphone output and crucially occurs most often when no load is present apart from the high-impedance oscilloscope input. Once the output is loaded with 10 ohms or so the 2.4 MHz disappears. I already use a ferrite core through which the headphone cord is wired but that doesn't suppress it. Ultimately I made a Boucherot filter-like setup, connecting a resistor of 4,7 ohm and a capacitor of 612 nF in series across the output. See the picture. No more interfering signals this way. I'd suspect the audio amplifier starts to oscillate under certain load conditions.



The filter box. Decided to resist the temptation to open the radio, so built a separate box to be inserted between loudspeaker/headphone and the radio output.



Re: DUOr interference from headphone outputs #eladduo #fdm-duor #duor

Andy G4JNT
 

I saw something like that.  I guess the Duo might use a Class-D switch-mode audio amplifier chip for speaker and headphones
There's no real reason NOT to use one in that position, they're very efficient.



On Thu, 24 Sep 2020 at 19:35, Ad Dieleman <addieleman@...> wrote:
This afternoon I was doing some measurements on audio signals on the DUOr's headphone outputs. Suddenly I saw a 2.4 MHz signal on my oscilloscope with an amplitude between 0.5 and 1 Vpp. The occurrence of that signal depends on the length of wire connected to the headphone output and crucially occurs most often when no load is present apart from the high-impedance oscilloscope input. Once the output is loaded with 10 ohms or so the 2.4 MHz disappears. I already use a ferrite core through which the headphone cord is wired but that doesn't suppress it. Ultimately I made a Boucherot filter-like setup, connecting a resistor of 4,7 ohm and a capacitor of 612 nF in series across the output. See the picture. No more interfering signals this way. I'd suspect the audio amplifier starts to oscillate under certain load conditions.



The filter box. Decided to resist the temptation to open the radio, so built a separate box to be inserted between loudspeaker/headphone and the radio output.


DUOr interference from headphone outputs #eladduo #fdm-duor #duor

Ad Dieleman
 

This afternoon I was doing some measurements on audio signals on the DUOr's headphone outputs. Suddenly I saw a 2.4 MHz signal on my oscilloscope with an amplitude between 0.5 and 1 Vpp. The occurrence of that signal depends on the length of wire connected to the headphone output and crucially occurs most often when no load is present apart from the high-impedance oscilloscope input. Once the output is loaded with 10 ohms or so the 2.4 MHz disappears. I already use a ferrite core through which the headphone cord is wired but that doesn't suppress it. Ultimately I made a Boucherot filter-like setup, connecting a resistor of 4,7 ohm and a capacitor of 612 nF in series across the output. See the picture. No more interfering signals this way. I'd suspect the audio amplifier starts to oscillate under certain load conditions.



The filter box. Decided to resist the temptation to open the radio, so built a separate box to be inserted between loudspeaker/headphone and the radio output.


Re: ELAD FDM-S3 USA Shipping Date

Larry Dodd
 

Thanks Paul. Appreciate that news. Looking forward to receiving the S3. Thanks to all at Elad for producing this top of the line SDR. 

Larry, K4LED 


Re: Looking for duo art #duo-art

 

Hi Kevin
can you give me your email?
Mine is ik2xrw@...

Thanks.


Tmate2: adjusting AUX Output Audio

Otso Ylönen
 

Hi,
 
I cjust reated the following feature request to Elad Support:
 
It is possible to adjust the primnary audio output of each VRX using the Tmate2 now. However, ability to adjust the secondary volume would be more useful. In order to access more than one audio channel via an audio (recording) application simultaneously, one has to use VAC or similar, and that means that only the secondary audio channels of each VRX are in use.

Proposal: add a configuration option for Tmate2 settings to allow selection between the primary/Main and secondary/AUX outputs.
 
BR, Otso


Re: ELAD FDM-S3 USA Shipping Date

Paul Jones
 

Larry, 

First batch has gone out, Hoping next shipment from italy within a few weeks, I just checked and believe it or not you are next on the list, ;) so you’ll be first once they arrive...

Paul EladUSA 


On Sep 23, 2020, at 21:52, Larry Dodd <101science@...> wrote:


Any estimates for S3 shipping dates in the USA? 
Thanks,
Larry, K4LED 

On Sep 23, 2020, at 3:09 AM, Fenu <fenu@...> wrote:

Hello,
I have write two emails to Elad Europe in Italy to try preorder the S3.
I just keep no answer from there. What's wrong with this company?
Is the S3 only sold in the US or what? Even if the website is not ready, an email can definitely be answered.

73
Fernando


Re: ELAD FDM-S3 USA Shipping Date

Larry Dodd
 

Any estimates for S3 shipping dates in the USA? 
Thanks,
Larry, K4LED 

On Sep 23, 2020, at 3:09 AM, Fenu <fenu@...> wrote:

Hello,
I have write two emails to Elad Europe in Italy to try preorder the S3.
I just keep no answer from there. What's wrong with this company?
Is the S3 only sold in the US or what? Even if the website is not ready, an email can definitely be answered.

73
Fernando


Re: WOOHOOOO! THE S3 IS ON THE WAY!!

Paul Jones
 

Jeffrey,

We are still waiting on the specs of the radio from Italy, they are busy, but we will get the Info soon. 

As far as filters go, each filter in the USA is $24 we currently only have filters for ham bands plus 500khz and 1700khz 

I have asked Franco to design us some broadcast band filters also like 31m etc. 

We are trying to get the new radios out as soon as we can, I’ve already sold my first batch, and they’re on the way to customers. 

All I can tell you as far as specs, if you already own one of our products ie S1/S2 Duo/DuoR the s3 is probably the best RX we have ever built. Franco is working on the info do we can post it. 


On Sep 23, 2020, at 12:12, Jeffrey Pawlan via groups.io <jpawlan@...> wrote:


I have been waiting for a complete specification sheet with details about measured dynamic range and spur levels.  I wrote more than a week ago and was told that I would receive it in a day.

I also see that the filter slots are mostly empty and I and this group needs to know the cost for getting the full set of band filters that will prevent the A/D converter from overload from out of band signals.



Re: WOOHOOOO! THE S3 IS ON THE WAY!!

Jeffrey Pawlan
 

I have been waiting for a complete specification sheet with details about measured dynamic range and spur levels.  I wrote more than a week ago and was told that I would receive it in a day.

I also see that the filter slots are mostly empty and I and this group needs to know the cost for getting the full set of band filters that will prevent the A/D converter from overload from out of band signals.



Re: ELAD FDM-S3 Preorder for Europe

Fenu
 

Hi Vianney,

Ok, I understand the situation.
Then I expect an answer from you soon via email.

73
Fernando


Re: Looking for duo art #duo-art

Kevin Larcombe
 

Paul,

Are you still looking for a DUO ART?

I have a 120w with ATU that is a month old tomorrow, I'm seriously thinking about parting with it before it gets covered in dust, I'm keeping the FDM-DUO, and I have ordered another radio for remote use. (Perhaps the one I should have ordered to start with, lesson learned I guess)

The amplifier is very impressive as a product but sadly let down by poor integration. The issue for me is that the DUO-ART doesn't integrate with the SW2 software nor is there any other way of controlling it other than via EladRemote, There is no way I can fit the ART in the rack beside my desk and have control of it or monitor the status of it whilst operating in the shack. This can only be done with the EladRemote which  means reconfiguring the USB cables for local/remote use.

Note: I'm not knocking the software that Giovanni has written, but I gave up attempts to get EladRemote working due to the ART hardware limitations. 

I have ordered some boards to build an amplifier that I can put in the rack, and use a simple desktop GUI for status monitoring and control. (hopefully I can get an EXTIO-232) I think it would have been reasonable to expect Elad to provide this for the ART, or at least some simple examples to get me going. (Of course easier If there was a way of controlling it by USB rather than Ethernet)

If I haven't put you off let me know, I just wouldn't want you falling into the same trap!

Kevin GW0PUH


Re: ELAD FDM-S3 Preorder for Europe

Vianney Colombat
 


Hello Fernando,

we apologize for delay, we have tens of emails to answered to, some of them have to be answer by Franco which is full busy. ELAD Italy take preorders by email without down payment now, it's primarily to establish a request list, official preorders will be done after specifications published.

Regards,

Vianney


Il 23/09/2020 09:09, Fenu ha scritto:
Hello,
I have write two emails to Elad Europe in Italy to try preorder the S3.
I just keep no answer from there. What's wrong with this company?
Is the S3 only sold in the US or what? Even if the website is not ready, an email can definitely be answered.

73
Fernando
_._,_._,_



Le informazioni contenute in questo messaggio di posta elettronica sono riservate e confidenziali e ne è vietata la diffusione in qualunque modo eseguita (DL 196/2003). Qualora Lei non fosse la persona a cui il presente messaggio è destinato, La invitiamo ad eliminarlo e a non leggerlo, dandone gentilmente comunicazione al mittente.

The information contained in this e-mail and any attachments is confidential and may well also be legally privileged (DL 196/2003). If you are not among the named recipients, please notify the sender immediately by reply e-mail and then delete this message from your system, do not use the contents for any purpose whatsoever nor disclose them to anyone else.


ELAD FDM-S3 Preorder for Europe

Fenu
 

Hello,
I have write two emails to Elad Europe in Italy to try preorder the S3.
I just keep no answer from there. What's wrong with this company?
Is the S3 only sold in the US or what? Even if the website is not ready, an email can definitely be answered.

73
Fernando


WOOHOOOO! THE S3 IS ON THE WAY!!

Pete
 

THANKS PAUL!!


Re: Software

DAVID IW5BNL
 

Hi Vianney,

Thank you for your reply and clarification. 

Regards,

David
IW5BNL

Il giorno mar 22 set 2020 alle ore 15:47 Vianney Colombat <vianney@...> ha scritto:

Hi David,

in IQ mode the level is not limited to allow more possibilities building the desired modulation, while the internal modulator level must be limited due to compressor features and modulator operations to avoid splattering and broadening of the transmitted signal into the allowed tx channel.

Regards,

Vianney


Il 22/09/2020 15:25, DAVID IW5BNL ha scritto:
Hi Vianell,

I'm David, a very happy user of DUO. 
I'm running it under linux with GNURADIO and stand alone.
Can you please comment maximum driving level using internal modular and I/Q.
Apparently ,by some measurements carried out by some of us , the maximum driving level using an internal modulator (example using WSJT) ,is -7.7db lower the full scale of the internal sound card.
This limitation isn't present driving I/Q.after sending IQ command on CAT (Thanks to And G4JNT for measurements)
This will help people to use correctly the radio.

Regards,

David
IW5BNL

Il giorno mar 22 set 2020 alle ore 15:03 Vianney Colombat <vianney@...> ha scritto:

We shared the possibility to write own software for FDM-DUO platform. TX
modulator is seen from PC as an Audio device, sending I/Q it is possible
to build every kind of modulation (with the 4KHz BW limit), for RX we
provide I/Q streaming in windows (EXTIO dll) and Linux environment.
Example, for SDR Console we supported Simon Brown development.


Il 21/09/2020 19:01, Antony Watts via groups.io ha scritto:
> I would like to kick around a topic and get some opinions
>
> All of our radios today and software driven. The FDM-DUO for example
> has very few analog parts - just the PA! The rest  is software.
>
> And yet the radio cannot connect to the internet. There is no Over The
> Air updating. There afre no APIs that allow independent code development.
>
> Surely the FDM-DUO must be regarded as a hardware platform, with
> freedom for software developers to build their own apps. (for me
> notably Mac based SDR like the new Flex 6000 series.)



Le informazioni contenute in questo messaggio di posta elettronica sono riservate e confidenziali e ne è vietata la diffusione in qualunque modo eseguita (DL 196/2003). Qualora Lei non fosse la persona a cui il presente messaggio è destinato, La invitiamo ad eliminarlo e a non leggerlo, dandone gentilmente comunicazione al mittente.

The information contained in this e-mail and any attachments is confidential and may well also be legally privileged (DL 196/2003). If you are not among the named recipients, please notify the sender immediately by reply e-mail and then delete this message from your system, do not use the contents for any purpose whatsoever nor disclose them to anyone else.


Re: Software

Vianney Colombat
 


Hi David,

in IQ mode the level is not limited to allow more possibilities building the desired modulation, while the internal modulator level must be limited due to compressor features and modulator operations to avoid splattering and broadening of the transmitted signal into the allowed tx channel.

Regards,

Vianney


Il 22/09/2020 15:25, DAVID IW5BNL ha scritto:
Hi Vianell,

I'm David, a very happy user of DUO. 
I'm running it under linux with GNURADIO and stand alone.
Can you please comment maximum driving level using internal modular and I/Q.
Apparently ,by some measurements carried out by some of us , the maximum driving level using an internal modulator (example using WSJT) ,is -7.7db lower the full scale of the internal sound card.
This limitation isn't present driving I/Q.after sending IQ command on CAT (Thanks to And G4JNT for measurements)
This will help people to use correctly the radio.

Regards,

David
IW5BNL

Il giorno mar 22 set 2020 alle ore 15:03 Vianney Colombat <vianney@...> ha scritto:

We shared the possibility to write own software for FDM-DUO platform. TX
modulator is seen from PC as an Audio device, sending I/Q it is possible
to build every kind of modulation (with the 4KHz BW limit), for RX we
provide I/Q streaming in windows (EXTIO dll) and Linux environment.
Example, for SDR Console we supported Simon Brown development.


Il 21/09/2020 19:01, Antony Watts via groups.io ha scritto:
> I would like to kick around a topic and get some opinions
>
> All of our radios today and software driven. The FDM-DUO for example
> has very few analog parts - just the PA! The rest  is software.
>
> And yet the radio cannot connect to the internet. There is no Over The
> Air updating. There afre no APIs that allow independent code development.
>
> Surely the FDM-DUO must be regarded as a hardware platform, with
> freedom for software developers to build their own apps. (for me
> notably Mac based SDR like the new Flex 6000 series.)



Le informazioni contenute in questo messaggio di posta elettronica sono riservate e confidenziali e ne è vietata la diffusione in qualunque modo eseguita (DL 196/2003). Qualora Lei non fosse la persona a cui il presente messaggio è destinato, La invitiamo ad eliminarlo e a non leggerlo, dandone gentilmente comunicazione al mittente.

The information contained in this e-mail and any attachments is confidential and may well also be legally privileged (DL 196/2003). If you are not among the named recipients, please notify the sender immediately by reply e-mail and then delete this message from your system, do not use the contents for any purpose whatsoever nor disclose them to anyone else.

1521 - 1540 of 19585