Date   

Re: How do you like your pre-selector? #fdm-duo #pre-selector

Paul White
 

On Thu, Mar 19, 2020 at 01:02 PM, Clint Chron wrote:
I suspect that there would not be enough demand for the special filters to warrant Elad’s financial investment in the project.
I'm sure you're right, Clint, but the individual filter boards are relatively cheap and I don't suppose Elad is making a loss on these?

But your eBay link is interesting, and that could be a cost-effective, general-purpose alternative. Thanks!


Re: How do you like your pre-selector? #fdm-duo #pre-selector

Paul White
 
Edited

Paul Jones, You are a star!


Re: Fancy S-meter #eladduo #eladsw2 #smeter

Paul White
 

On Wed, Mar 18, 2020 at 10:51 PM, Neil Coley wrote:
I’d do away with the S meter on sw2. Its obviously just decoration.
Shite.


Re: Fancy S-meter #eladduo #eladsw2 #smeter

Paul White
 

On Wed, Mar 18, 2020 at 11:30 PM, Neil Smith G4DBN wrote:
Signal to noise ratio or relative signal levels are much more useful.
So the SNR figure adjacent to S-Meter would be wonderful...


Re: SW2 S-Meter #fdm-sw2 #fdm-s2 #smeter

Paul White
 

Thank you for your suggestions, Neil. I'll take these in reverse order.
 
I'm not technical enough to write custom code or interpret FFT data, and anyway shouldn't need to for something as basic as reading off a standard metric from the main display.
 
There are dozens of graphics configuration settings for spectrum and waterfall, including refresh rate and averaging (though not anything cleverer than on/off). The S-Meter is the poor relation, with only a limited rise and fall time range of control (that I interpret as) to/from the peak reading: fine for peak estimation and useless for the average.

Spectrum (not waterfall) averaging seems to me to be a purely graphical process that hardly (or maybe not at all) affects the S-Meter reading. Thankfully. Refresh rate *does* reduce the S-Meter sampling frequency, but that's it - no averaging, it simply hides more data.
 
The IF spectrum window marker values are scaled differently from those in the main window, and I've no idea how to compensate for that.
 
A few additional points:
 
* Using markers is all very well for an in-depth investigation of one or a few signals, but has too much operational overhead for routine listening, measurement and reporting. Part of that arises from having to switch cursor/click behaviour between two functional modes.
 
* There *may* be work-arounds that could come close to what I am asking for, but (by the looks of things) would involve extra work and probably some mental arithmetic or worse. In principle an averaging S-Meter should be easy to implement and give the desired result in the right place, in the right format, and with no operational overhead.
 
* I quite understand that my request may not resonate with radio amateurs (who are possibly the majority user base) as their needs seem to be quite different from the SWL community, and the even smaller number who want to get "down and dirty" with fancy measurements.
 
* All I can do is state my point of view on a modification that would be a great help in my tiny world, without any expectation of sympathy or satisfaction.
 


Re: How do you like your pre-selector? #fdm-duo #pre-selector

Klaus Brosche, DK3QN <dk3qn@...>
 

If you are 'ok' with a manually-tuned low-cost preselector, it might be worthwhile to have a look
at the BCC (Bavarian Contest Club) preselector (design dated from ca. 1998).

There is a brief description including schematics and component data available in English:

http://www.bavarian-contest-club.de/projects/presel/list.htm

On that webpage there is a further link to the full description (PDF) in German.

The design could be simplified to one's specific needs by adapting/eliminating
some of the rotary switches


For the Input and Output transformers (9:1), Mini-Circuits T9-1-X65 parts can be
used, if one doesn't want to wind trifilar on FT-50-43 ferrites.

There had been a discussion back in 2012 at qrpforum.de about the circuitry,
including screenshots of Graphs.
The text there is all in German, however you may just copy-and-paste that into
Google translator. Especially the Posts written by DL4ZAO are quite detailed.
You may also read the Posts by DF5SF, DJ1ZB, DL5CN:

https://www.qrpforum.de/forum/index.php?thread/7840-drehko-alternative-bcc-preselektor/&pageNo=1

73, Klaus, DK3QN


Re: How do you like your pre-selector? #fdm-duo #pre-selector

Clint Chron
 

Hi Paul,

 

This is a test to see if JPG pictures come through in an email on the groups.io site.

 

Here is a spectrum display of the AM broadcast band at my QTH in Phoenix, AZ.

 

 

I get ADC overload on my Duo radio, even though there are no signals that are stronger than -10 dbm.

 

Here is the same spectrum using an AM band stop band (reject) notch filter:

 

ADC overload is gone.  Using this band stop filter, I can listen to beacon signals in the 200 – 500 Khz band.

 

If the pictures do not come through, then please send me your email address and I can send them to you.

 

73

Clint

W7KEC

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Paul Jones
Sent: Thursday, March 19, 2020 3:15 AM
To: EladSDR@groups.io
Subject: Re: [EladSDR] How do you like your pre-selector? #fdm-duo #pre-selector

 

Paul

 

I have requested a few months ago new filters to also cover the main broadcast bands that swl users can make use of. 

 

Also a dedicated am 520-1800 notch filter

 

Paul EladUSA 



On Mar 19, 2020, at 06:07, Paul White <paul@...> wrote:

Hi, Clint
Isn't it a little disappointing that the available filters are designed for the amateur bands only?
I wouldn't have the skills to build on the unpopulated boards.


Re: How do you like your pre-selector? #fdm-duo #pre-selector

Clint Chron
 

Hi Paul White,

 

I suspect that there would not be enough demand for the special filters to warrant Elad’s financial investment in the project.   The current Elad ham band filters, while effective, do not use a standard design.  Please keep in mind that the available Elad filters are wider than a ham band, so they are usable for some SWL bands.  I am hoping that Elad will provide schematics for the SWL/Ham bands using their FPCB-B3 and FPCB-H5 bare circuit boards. 

 

Here is what I measured on the Elad filters for the low/high -3 db filter points:

 

80M       3.2 – 4.5 MHz

40M       6.4 – 8.6 MHz                     standard 3 pole filter designed with Elsie would have a band pass of 6.6 – 8.3 MHz

20M       12.4 – 15.3 MHz

 

The current Elad circuit boards are very small and can probably only accommodate a filter with a small number of poles (max of 3 toroid coils).  A bare board could be redesigned to use filters that could be modeled with a program such as Elsie.  The board could be designed to use through-hole parts (no SMT parts) so that it would be easy to assemble.   If you only need a filter for a specific SWL band, then one could easily be built and installed in a small enclosure.  I have a AM broadcast band reject notch filter that covers 500 to 1600 Khz.  I use this filter to get rid of the ADC overload on my Duo (there are strong AM broadcast stations near my QTH).  With this filter, I can listen to the 200 to 500 Khz band.  With the typical AM band high pass filter, any frequency below 1600 Khz would be filtered out.

 

Here is a link to a HF band pass filter board that has continuous coverage of all bands (ham and SW) from about 1.7 to 64 MHz in 10 separate bands:

https://www.ebay.com/itm/BPF-band-pass-filter-for-SDR-HERMES-ANAN-10-HF-transceiver/152111322734?hash=item236a8a966e:g:0RcAAOSwgHJZyjz7

 

The board uses BCD control for changing bands.  I have designed a small BCD controller circuit board that interfaces to the DB9 connector on the S2 and Duo radios.  You could also use the Elad SFE Experimenter board to do the same thing.

 

Good luck.

 

73

Clint

W7KEC

 

 

 

From: EladSDR@groups.io [mailto:EladSDR@groups.io] On Behalf Of Paul White
Sent: Thursday, March 19, 2020 3:08 AM
To: EladSDR@groups.io
Subject: Re: [EladSDR] How do you like your pre-selector? #fdm-duo #pre-selector

 

Hi, Clint
Isn't it a little disappointing that the available filters are designed for the amateur bands only?
I wouldn't have the skills to build on the unpopulated boards.


Re: How do you like your pre-selector? #fdm-duo #pre-selector

Neil Smith G4DBN
 

Sounds like an opportunity for someone to design and make filter boards for other specific uses.  I'd like a narrow one for 136kHz for example.

Neil G4DBN

#notvolunteering


On 19/03/2020 10:07, Paul White wrote:
Hi, Clint
Isn't it a little disappointing that the available filters are designed for the amateur bands only?
I wouldn't have the skills to build on the unpopulated boards.
-- 
Neil
http://g4dbn.uk


Re: How do you like your pre-selector? #fdm-duo #pre-selector

Paul Jones
 

Paul

I have requested a few months ago new filters to also cover the main broadcast bands that swl users can make use of. 

Also a dedicated am 520-1800 notch filter

Paul EladUSA 


On Mar 19, 2020, at 06:07, Paul White <paul@...> wrote:

Hi, Clint
Isn't it a little disappointing that the available filters are designed for the amateur bands only?
I wouldn't have the skills to build on the unpopulated boards.


Re: SW2 S-Meter #fdm-sw2 #fdm-s2 #smeter

Neil Smith G4DBN
 

I find the markers in the IF window more useful than those in the main window. If you set the averaging in the IF window to 60 or 100, then the numbers are smooth enough to use for sun noise measurements on microwave bands.  You can reduce the jumpiness of the on-screen measurements by changing the averaging on the main waterfall to 20 or so, and smooth out the S meter readings by changing the update interval from the default 60 ms, but I don't know if that does an averaging process, or just discards the intervening measurements!

For anything really clever, it is probably easier to work on the waterfall data which is streamed out of the extio port, and do the analysis using some custom code.

Neil G4DBN

On 19/03/2020 10:01, Paul White wrote:
Ivo's post prompts me to air my own comment on the SW2 S-meter.
 
I'm not an expert user. There are two radio/software combinations available to me whose S-meter by reputation provides a well-defined, accurate and reliable total (not peak) power measurement: RSP1A+SDRuno and S2+SW2.
 
My use of S-meter readings includes:
(a) meaningful logging of received signal strength, for signals of any type
(b) comparative assessment of changes to system components (e.g. antenna mods)
 
I have no specialised signal measurement equipment, hence the reliance in (b).
 
In those activities (for my comfort) there are two enhancements to SW2 that could help considerably:
(1) showing Marker 1-type data in the "desert" next to the S-meter
(2) calculating/displaying an average S-meter reading as well as SNR
 
The argument for (1) is that bringing up marker data is time-consuming. For (2) it is that even relatively stable signals show fluctuations that cannot accurately be averaged by eye.
 
Refinements could be:
(3) user control over averaging period
(4) calculating/displaying the S-meter variance (standard deviation)
 
I would find (3) especially useful for slow fading, and (4) as a measure of fading severity.
-- 
Neil
http://g4dbn.uk


Re: How do you like your pre-selector? #fdm-duo #pre-selector

Paul White
 

Hi, Clint
Isn't it a little disappointing that the available filters are designed for the amateur bands only?
I wouldn't have the skills to build on the unpopulated boards.


SW2 S-Meter #fdm-sw2 #fdm-s2 #smeter

Paul White
 

Ivo's post prompts me to air my own comment on the SW2 S-meter.
 
I'm not an expert user. There are two radio/software combinations available to me whose S-meter by reputation provides a well-defined, accurate and reliable total (not peak) power measurement: RSP1A+SDRuno and S2+SW2.
 
My use of S-meter readings includes:
(a) meaningful logging of received signal strength, for signals of any type
(b) comparative assessment of changes to system components (e.g. antenna mods)
 
I have no specialised signal measurement equipment, hence the reliance in (b).
 
In those activities (for my comfort) there are two enhancements to SW2 that could help considerably:
(1) showing Marker 1-type data in the "desert" next to the S-meter
(2) calculating/displaying an average S-meter reading as well as SNR
 
The argument for (1) is that bringing up marker data is time-consuming. For (2) it is that even relatively stable signals show fluctuations that cannot accurately be averaged by eye.
 
Refinements could be:
(3) user control over averaging period
(4) calculating/displaying the S-meter variance (standard deviation)
 
I would find (3) especially useful for slow fading, and (4) as a measure of fading severity.


Re: Fancy S-meter #eladduo #eladsw2 #smeter

Neil Smith G4DBN
 

If the noise blanker is enabled in SW2, or if the bandwidths in SW2 and on the DUO are not exactly the same, you will see differences.  Also the time constant on the DUO is long, but short on SW2, so getting a steady reading on noise is hard.  Much easier on a solid tone of course.  The calibration is within a dB or so of my HP signal generator all the way through the range on single tones.  Superhet S meters measure AGC voltage rather than the actual signal power, and things get very tricky with roofing filter IFs being in the AGC loop.

Can't say I ever use S meter readings though, they are pretty meaningless.  Signal to noise ratio or relative signal levels are much more useful.  The advanced marker measurement is very useful for that.

If Rob Sherwood says it is "close to perfect", that is pretty much case closed.

Check the bandwidths and frequecies are identical and that notches and noise reduction and noise blankers are off.  Check if the readings are different on a very strong pure tone and on band noise and a STANAG signal that is fairly constant level and see if there is anywhere the readings do match up.

Neil G4DBN

On 18/03/2020 23:15, Chris Moore wrote:
Here's what Rob Sherwood said:

S meter linearity and dBm meter linearity is as close to perfect as one could ask for.  Each S unit from S1 to S9 is 6 dB.  The dBm scale is within 1 dB from -120 dBm to -30 dBm, and is often perfect.  There is an occasional error of up to 2 dB when decreasing the signal in 5 dB steps vs. increasing the level in 5 dB steps. The S meter / dBm readings are not significantly affected by the 12 dB attenuator.  These readings are corrected in software to give the true signal level, which should be commended

I always assumed he was talking about the meter in SW2, but not sure.

On Wed, Mar 18, 2020 at 5:51 PM Neil Coley <coleyneil1@...> wrote:
In my experience, I’d say the duo is the most accurate. I’d do away with the S meter on sw2. Its obviously just decoration. 
I think real S meters are for superhets or Japanese hybrid sdrs - 7300/7610

The Elad S meters will get there eventually but for now......shite




On 18 Mar 2020, at 22:00, Ivo Frigo <ivo.frigo@...> wrote:


Good evening, everyone,
I noticed that the S-meters on the Duo and the SW2 indicate absolutely different values. For example, the same signal on the DUO is at S9, the software SW-2 indicates 9+20 (even just beyond) and Studio1 about 8.
What's going on? Who is right? Have I done something wrong? 
Thank you.
 
IN3EFR - Ivo
-- 
Neil
http://g4dbn.uk


Re: Fancy S-meter #eladduo #eladsw2 #smeter

Chris Moore
 

Here's what Rob Sherwood said:

S meter linearity and dBm meter linearity is as close to perfect as one could ask for.  Each S unit from S1 to S9 is 6 dB.  The dBm scale is within 1 dB from -120 dBm to -30 dBm, and is often perfect.  There is an occasional error of up to 2 dB when decreasing the signal in 5 dB steps vs. increasing the level in 5 dB steps. The S meter / dBm readings are not significantly affected by the 12 dB attenuator.  These readings are corrected in software to give the true signal level, which should be commended

I always assumed he was talking about the meter in SW2, but not sure.


On Wed, Mar 18, 2020 at 5:51 PM Neil Coley <coleyneil1@...> wrote:
In my experience, I’d say the duo is the most accurate. I’d do away with the S meter on sw2. Its obviously just decoration. 
I think real S meters are for superhets or Japanese hybrid sdrs - 7300/7610

The Elad S meters will get there eventually but for now......shite




On 18 Mar 2020, at 22:00, Ivo Frigo <ivo.frigo@...> wrote:


Good evening, everyone,
I noticed that the S-meters on the Duo and the SW2 indicate absolutely different values. For example, the same signal on the DUO is at S9, the software SW-2 indicates 9+20 (even just beyond) and Studio1 about 8.
What's going on? Who is right? Have I done something wrong? 
Thank you.
 
IN3EFR - Ivo


Re: Fancy S-meter #eladduo #eladsw2 #smeter

Neil Coley <coleyneil1@...>
 

In my experience, I’d say the duo is the most accurate. I’d do away with the S meter on sw2. Its obviously just decoration. 
I think real S meters are for superhets or Japanese hybrid sdrs - 7300/7610

The Elad S meters will get there eventually but for now......shite




On 18 Mar 2020, at 22:00, Ivo Frigo <ivo.frigo@...> wrote:


Good evening, everyone,
I noticed that the S-meters on the Duo and the SW2 indicate absolutely different values. For example, the same signal on the DUO is at S9, the software SW-2 indicates 9+20 (even just beyond) and Studio1 about 8.
What's going on? Who is right? Have I done something wrong? 
Thank you.
 
IN3EFR - Ivo


Fancy S-meter #eladduo #eladsw2 #smeter

Ivo Frigo <ivo.frigo@...>
 

Good evening, everyone,
I noticed that the S-meters on the Duo and the SW2 indicate absolutely different values. For example, the same signal on the DUO is at S9, the software SW-2 indicates 9+20 (even just beyond) and Studio1 about 8.
What's going on? Who is right? Have I done something wrong? 
Thank you.
 
IN3EFR - Ivo


Re: Question about small dip on the center of the Elad screen

George Stein - NJ3H
 

Hello, Gerard, Tony, and Neil,

Thank you all for your replies.

I have checked  on the suggestions that you have made.  Everything seems as it should be based on your comments,  The issue did not go away.

However, I did discover that on the Setup/Advanced screen, the first item Device Configuration was set to the bottom choice, the one with 2 channels. When I changed it to any other configuration (like the one with 6144 in the choice), the problem went away.

So it appears the 2 channel option may be the culprit.

Curious what you might think about that with this finding.

Again thank all of you for your help.

Please stay safe and well.  Take care to avoid crowds.

Enjoy the rest of your day.;

Regards,
George, NJ3H
Redmond, Oregon USA
DMR ID:  3141315
AllStar Node:  49246
EchoLink Node NJ3H-L:  3135


On Wednesday, March 18, 2020, 6:57:39 AM PDT, Neil Smith G4DBN <neil@...> wrote:


Could this be something to do with ADC DC offset correction? Just guessing. Setting is on the Advanced tab of setup

Neil



Re: Question about small dip on the center of the Elad screen

Neil Smith G4DBN
 

Could this be something to do with ADC DC offset correction? Just guessing. Setting is on the Advanced tab of setup

Neil



A ELAD e a tutti

Bernard Malet
 

Buongiorno
Volevo dirti, prima di tutte le mie esigenze di hobby elettronico e
radiofonico, un grande saluto e molto coraggio a tutto il team ELAD Italia e
anche a quello degli Stati Uniti che ne hanno davvero bisogno per la salute e
il finanziamento, in
questo periodo inquinato da questo terribile virus e che
tutti i nostri amici italiani e quasi tutte le altre nazioni che attualmente
subiscono un rigoroso confino come noi da lunedì 18 marzo 2020 in Francia

A tutti EladSDR@groups.io DX molto buono e, soprattutto, grande cautela,
proteggiti bene

Cordialmente
Bernard

 

Bonjour

Je tenais à vous dire, avant tous mes besoins de hobby électronique et de radio, un très grand bonjour et beaucoup de courage à toute l’équipe ELAD Italie et aussi à celle des USA qui en ont réellement besoin de santé et de financement, dans cette période polluée par cet affreux virus et que tous nos amis Italiens et presque toutes les autres nations qui subissent actuellement un confinement rigoureux comme nous maintenant depuis lundi 18 mars 2020 en France

A tous du EladSDR@groups.io de très bon DX et surtout, grande prudence, protégez-vous bien

Bernard

 

Hello
I wanted to say to you, before all my electronic and radio hobby needs, a
very big hello and a lot of courage to the whole ELAD Italy team and also to
that of the USA who really need it for health and funding, in
this
period polluted by this awful virus and that all our Italian friends and almost
all the other nations which currently undergo a rigorous confinement like us
now since Monday March 18, 2020 in France

To all of EladSDR@groups.io very good DX and above all, great caution,
protect yourself well

Best regards

Bernard

 

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