Date   

Re: Elad S3 versus Perseus and FDM Duo

Simon Brown
 

Conrad,

FWIW I'm playing with the WinRadio Excelsior Ultra - now this is some
receiver!

https://www.winradio.com/home/g69ddce.htm

This is quiet!

Simon Brown, G4ELI
https://www.sdr-radio.com

-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of
Conrad, PA5Y
Sent: 30 March 2022 15:28
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

Hello Brian

Yes sub 1dB noise figures definitely cost dynamic range.
That is true and unnecessary, perhaps I misunderstand but you seem to be
indicating that I am advocating sub 1dB noise figures on 144MHz. I am not
and Chris Bartram was absolutely right.

I said, earlier in the thread.

....... dynamic range is certainly not optional. I put systems together
based upon total system analysis which includes both noise figure and
dynamic range. On 2m with a 1dB NF which is a little better than needed for
terrestrial operation in my semi-rural location. I use the free AppCAD
program for system noise figure and dynamic range analysis, although a
spreadsheet also works fine.

I think that a system noise figure of 1dB on 2m is better than needed. I
agree that 2dB is good enough for terrestrial use and even then only for the
very fortunate. 1dB is slightly better than 2dB. For most people who are not
on EME, these days 3-4dB is adequate for terrestrial use on 144 MHz due to
manmade noise. Also in EU contests (including the UKAC) you are better off
prioritising dynamic range much of the time.

Which is why I use a step attenuator after the first LNA stage, I can adjust
it extremely quickly depending on conditions. Try it, you will find that is
optimal for the EU VHF DXer who suffers from high station density.

By the way sub 1dB noise figures on 432MHz and above are very worthwhile and
certainly not that difficult to achieve these days.

73

Conrad PA5Y



-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Brian
Morrison via groups.io
Sent: 30 March 2022 14:52
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

On Wed, 30 Mar 2022 11:22:30 +0000
"Conrad, PA5Y" <g0ruz@...> wrote:

Yes sub 1dB noise figures definitely cost dynamic range.
Back in the day (i.e. about 1979/80) Chris Bartam G4DGU of muTek determined
that 144MHz system noise figures of less than 2dB for terrestrial signals
were unnecessary due to the total noise at the antenna from sky and ground
sources. The well-known muTek preamps were designed to have a NF of ~0.9dB
(using a BF981 or 3SK88 FET with noiseless feedback) and then to allow a
further 1dB contribution from the rest of the receiver to minimise any
reduction in dynamic range. If you had the complete replacement muTek
front-end which had a high-level diode-ring mixer, class A LO amplifier
chain and post-mixer high IP3 IF amp then this DR reduction was much less
but many of us had far less money then :(.

I would not expect these external limitations to have changed in this regard
over the intervening 40+ years, although the radios have become more
expensive their performance has improved quite a bit in other respects.

--

Brian G8SEZ














--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Default audio volume?

Max
 

I just had a quick look at the XML Favourites file export and see Simon says at top of file:

"The contents of this file must not be changed if the program is to operate correctly. To avoid problems, please do NOT edit this file."

If you are not 100% comfortable with what you are doing then I suggest you stick to my first suggestion: Recall > Update > Re-Save each Favourite in turn that you wish to amend. Or use Simon's method of excluding the stored level when recalling from a Favourite. 

Untick "Apply Level":



Max


Re: Default audio volume?

Max
 

On Thu, Mar 31, 2022 at 06:22 AM, D M wrote:
Can somebody tell me where can I set the default audio volume instead of the original default value of 50.
Volume setting and also audio output source are both parameters stored with each Favourite. Or, as Simon says, you can exclude that parameter from recall if you wish.
 
See here:
https://www.sdr-radio.com/Favourites
 
To amend the stored value, easy route:
Recall Favourite, change volume setting, then "Update" Favourite.
 
To do all at once, using Favourites Organiser, export Favourites as XML. SAVE A SAFETY COPY.
 
Editing file in text editor (like Notepad), search for the volume parameter (sorry, I have not got time to search for what it is, but it will be pretty obvious) then "Find and Replace" for all or required entries. Then re-Import the amended Favourites file.
 
Hope it helps.
 
Max


Keyboard shortcuts

Pierre FK8IH <jb.gallauziaux@...>
 

New to SDR-Console and having used before Quisk, is there a shortcut like the "space bar" to trigger the PTT? Is there also a way to change the frequency digit by digit but I recognize typing a figure then typing the frequency in the opened window is convenient?
73 - Pierre - FK8IH


Re: Default audio volume?

Simon Brown
 

You can’t but look at:

 

  • Ribbon Bar, Favourites, Selection, Same Playback Device, Apply Level

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of D M via groups.io
Sent: 31 March 2022 06:22
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Default audio volume?

 

Can somebody tell me where can I set the default audio volume instead of the original default value of 50. When i jump around the the  favorites frequencies it gets reset to 50 regardless to what I changed to earlier. Is it one of the xml files i need to tweak ? 

Thanks
deep


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Default audio volume?

D M
 

Can somebody tell me where can I set the default audio volume instead of the original default value of 50. When i jump around the the  favorites frequencies it gets reset to 50 regardless to what I changed to earlier. Is it one of the xml files i need to tweak ? 

Thanks
deep


Re: Elad S3 versus Perseus and FDM Duo

jdow
 

144 MHz and 445 MHz dynamic range around here is simply unreal. LNAs have a wide bandwidth on their input, typically. That means you are receiving some VERY weak signals. Unfortunately pagers still exist. And around here pager transmitters are in the kW region. Having one relatively nearby can periodically desensitize a receiver in addition to creating IMD products. With rtlsdr dongles this is easy to see here with little whips depending on where I am tuned. AirSpy R2 dongles can show it on frequencies too close to the pager frequency.

{^_^}

On 20220330 07:45:07, Brian Morrison wrote:

On Wed, 30 Mar 2022 14:28:27 +0000
"Conrad, PA5Y" <g0ruz@...> wrote:

That is true and unnecessary, perhaps I misunderstand but you seem
to be indicating that I am advocating sub 1dB noise figures on 144MHz.
I am not and Chris Bartram was absolutely right.
I'm not Conrad, you're definitely correct in your earlier statements.
Others seemed to be advocating lower noise figures in general, as you
say there is a breakpoint somewhere above 200MHz where the sky and
reflected ground noise falls off and at 70cm a 0.5dB NF is nice to have
if you put the LNA at the correct place right next to your antenna.

It's interesting that you say the DR needed on VHF is harder to achieve,
but I suppose it must be due to the RMDRs due to the LO being worse at
higher frequency. Stepped attenuators have their place, you just have
to understand their effect which is not particularly difficult as it's
just a normal cascaded NF/gain diagram and calculation.



Re: Elad S3 versus Perseus and FDM Duo

jdow
 

Of course, when you are up at 2 meters and above (perhaps even 6 meters to a lesser degree) putting the LNA at the antenna feed point gives you a "free" dB of noise figure reduction. There is also a potential TX gain for putting the PA up there, too.

{^_-}

On 20220330 07:28:27, Conrad, PA5Y wrote:

Hello Brian 

Yes sub 1dB noise figures definitely cost dynamic range. 
That is true and unnecessary, perhaps I misunderstand but you seem to be indicating that I am advocating sub 1dB noise figures on 144MHz. I am not and Chris Bartram was absolutely right.

I said, earlier in the thread.

....... dynamic range is certainly not optional. I put systems together based upon total system analysis which includes both noise figure and dynamic range. On 2m with a 1dB NF which is a little better than needed for terrestrial operation in my semi-rural location. I use the free AppCAD program for system noise figure and dynamic range analysis, although a spreadsheet also works fine.

I think that a system noise figure of 1dB on 2m is better than needed. I agree that 2dB is good enough for terrestrial use and even then only for the very fortunate. 1dB is slightly better than 2dB. For most people who are not on EME,  these days 3-4dB is adequate for terrestrial use on 144 MHz due to manmade noise. Also in EU contests (including the UKAC) you are better off prioritising dynamic range much of the time. 

Which is why I use a step attenuator after the first LNA stage, I can adjust it extremely quickly depending on conditions. Try it, you will find that is optimal for the EU VHF DXer who suffers from high station density. 

By the way sub 1dB noise figures on 432MHz and above are very worthwhile and certainly not that difficult to achieve these days. 

73

Conrad PA5Y



-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Brian Morrison via groups.io
Sent: 30 March 2022 14:52
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

On Wed, 30 Mar 2022 11:22:30 +0000
"Conrad, PA5Y" <g0ruz@...> wrote:

Yes sub 1dB noise figures definitely cost dynamic range.
Back in the day (i.e. about 1979/80) Chris Bartam G4DGU of muTek determined that 144MHz system noise figures of less than 2dB for terrestrial signals were unnecessary due to the total noise at the antenna from sky and ground sources. The well-known muTek preamps were designed to have a NF of ~0.9dB (using a BF981 or 3SK88 FET with noiseless feedback) and then to allow a further 1dB contribution from the rest of the receiver to minimise any reduction in dynamic range. If you had the complete replacement muTek front-end which had a high-level diode-ring mixer, class A LO amplifier chain and post-mixer high IP3 IF amp then this DR reduction was much less but many of us had far less money then :(.

I would not expect these external limitations to have changed in this regard over the intervening 40+ years, although the radios have become more expensive their performance has improved quite a bit in other respects.



Re: Frequency Database - Display Only Entries For Current Time ??

Bill Walch
 

For my 2 cents worth, having a UTC based time filter would be a great feature. Rather than seeing all stations at a particular frequency, see only stations that "may" be transmitting at a particular time would be much more useful.

On 3/30/2022 9:14 AM, John Dusek wrote:

Yes, CSUB is exactly where I saw/used this concept the first time.

I remember back in the day using Ham Radio Deluxe (before it was sold), and it also did not have a filter on the frequency database function for current time - that's what originally had me research and find CSUB.

This "filter for current time" feature would be a great feature to add to the existing Filter feature on the SDRC Frequency Database.


Re: Elad S3 versus Perseus and FDM Duo

Brian Morrison
 

On Wed, 30 Mar 2022 14:28:27 +0000
"Conrad, PA5Y" <g0ruz@...> wrote:

That is true and unnecessary, perhaps I misunderstand but you seem
to be indicating that I am advocating sub 1dB noise figures on 144MHz.
I am not and Chris Bartram was absolutely right.
I'm not Conrad, you're definitely correct in your earlier statements.
Others seemed to be advocating lower noise figures in general, as you
say there is a breakpoint somewhere above 200MHz where the sky and
reflected ground noise falls off and at 70cm a 0.5dB NF is nice to have
if you put the LNA at the correct place right next to your antenna.

It's interesting that you say the DR needed on VHF is harder to achieve,
but I suppose it must be due to the RMDRs due to the LO being worse at
higher frequency. Stepped attenuators have their place, you just have
to understand their effect which is not particularly difficult as it's
just a normal cascaded NF/gain diagram and calculation.

--

Brian G8SEZ


Re: Elad S3 versus Perseus and FDM Duo

Conrad, PA5Y
 

Hello Brian

Yes sub 1dB noise figures definitely cost dynamic range.
That is true and unnecessary, perhaps I misunderstand but you seem to be indicating that I am advocating sub 1dB noise figures on 144MHz. I am not and Chris Bartram was absolutely right.

I said, earlier in the thread.

....... dynamic range is certainly not optional. I put systems together based upon total system analysis which includes both noise figure and dynamic range. On 2m with a 1dB NF which is a little better than needed for terrestrial operation in my semi-rural location. I use the free AppCAD program for system noise figure and dynamic range analysis, although a spreadsheet also works fine.

I think that a system noise figure of 1dB on 2m is better than needed. I agree that 2dB is good enough for terrestrial use and even then only for the very fortunate. 1dB is slightly better than 2dB. For most people who are not on EME, these days 3-4dB is adequate for terrestrial use on 144 MHz due to manmade noise. Also in EU contests (including the UKAC) you are better off prioritising dynamic range much of the time.

Which is why I use a step attenuator after the first LNA stage, I can adjust it extremely quickly depending on conditions. Try it, you will find that is optimal for the EU VHF DXer who suffers from high station density.

By the way sub 1dB noise figures on 432MHz and above are very worthwhile and certainly not that difficult to achieve these days.

73

Conrad PA5Y



-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Brian Morrison via groups.io
Sent: 30 March 2022 14:52
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

On Wed, 30 Mar 2022 11:22:30 +0000
"Conrad, PA5Y" <g0ruz@...> wrote:

Yes sub 1dB noise figures definitely cost dynamic range.
Back in the day (i.e. about 1979/80) Chris Bartam G4DGU of muTek determined that 144MHz system noise figures of less than 2dB for terrestrial signals were unnecessary due to the total noise at the antenna from sky and ground sources. The well-known muTek preamps were designed to have a NF of ~0.9dB (using a BF981 or 3SK88 FET with noiseless feedback) and then to allow a further 1dB contribution from the rest of the receiver to minimise any reduction in dynamic range. If you had the complete replacement muTek front-end which had a high-level diode-ring mixer, class A LO amplifier chain and post-mixer high IP3 IF amp then this DR reduction was much less but many of us had far less money then :(.

I would not expect these external limitations to have changed in this regard over the intervening 40+ years, although the radios have become more expensive their performance has improved quite a bit in other respects.

--

Brian G8SEZ


Re: Frequency Database - Display Only Entries For Current Time ??

John Dusek
 

Yes, CSUB is exactly where I saw/used this concept the first time.

I remember back in the day using Ham Radio Deluxe (before it was sold), and it also did not have a filter on the frequency database function for current time - that's what originally had me research and find CSUB.

This "filter for current time" feature would be a great feature to add to the existing Filter feature on the SDRC Frequency Database.


Re: Elad S3 versus Perseus and FDM Duo

Brian Morrison
 

On Wed, 30 Mar 2022 11:22:30 +0000
"Conrad, PA5Y" <g0ruz@...> wrote:

Yes sub 1dB noise figures definitely cost dynamic range.
Back in the day (i.e. about 1979/80) Chris Bartam G4DGU of muTek
determined that 144MHz system noise figures of less than 2dB for
terrestrial signals were unnecessary due to the total noise at the
antenna from sky and ground sources. The well-known muTek preamps were
designed to have a NF of ~0.9dB (using a BF981 or 3SK88 FET with
noiseless feedback) and then to allow a further 1dB contribution from
the rest of the receiver to minimise any reduction in dynamic range. If
you had the complete replacement muTek front-end which had a high-level
diode-ring mixer, class A LO amplifier chain and post-mixer high IP3 IF
amp then this DR reduction was much less but many of us had far less
money then :(.

I would not expect these external limitations to have changed in this
regard over the intervening 40+ years, although the radios have become
more expensive their performance has improved quite a bit in other
respects.

--

Brian G8SEZ


Re: Elad S3 versus Perseus and FDM Duo

Conrad, PA5Y
 

Hi Joanne.

 

Yes sub 1dB noise figures definitely cost dynamic range. They are only necessary for moon-nbounce above 144MHz. Using celestial sources I have a system noise figure of 0.4dB on 432 which is not quite state of the art but the laws of diminishing returns have hit so I have decided to settle for this. It is very good for a yagi array and my on air results suggest that it must be close to optimum.  

 

For the purposes of SDR usage and system design I have to settle for treating any SDR as a black box, there is nothing that I can do about this.  I have to trust that Elad have chosen a optimal pre ADC op amp for the S3.  As I have no test data from reputable 3rd parties I have to accept anecdotal evidence from users who I trust. I am mindful that the people responsible for the excellent Perseus are involved with the design of the S3. I will eventually do some tests myself.

 

I maintain that for VHF operating in Europe adding a step attenuator after a high dynamic LNA offers the most flexibility with the least consequences. As you say there is no free lunch but the system dynamic range loss is acceptable. It works in practice. I cannot change any of the subsequent stages on the fly, in fact I simply do not have the information nor time  to do so. I fully understand the implications of what I am doing.

 

I have absolutely no feel for HF as I have no experience but VHF I know.

 

Regards

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of jdow via groups.io
Sent: 30 March 2022 10:26
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

What about the stages that follow? They are also stages that can limit dynamic range. (The most effective trick for the noise figure increase and dynamic range decrease was calculated years ago for CATV systems. It's a gain of "e", the transcendental number. That is not the best from an economic standpoint, though. My spare time ham hacks through the 70s involved a lot of playing with noise figure, dynamic range, and receiver design to maximize this. It, too, falls victim to, "There Ain't No Such Thing As A Free Lunch." Every stage you add reduces dynamic range for frequencies that manage to pass through the stage. That was a pain in the panties for the S3A sonobuoy receiver given its architecture. Fortunately their dynamic range requirement as not at science fiction levels.

And, yes, 6 meters is fairly noisy. By 60s and even 70s standards the noise figures we get by default were considered exotic and low. Pushing for tiny noise figures (<1dB) on 2 is sort of pushing reality a little bit, and can really cost you with dynamic range.

{^_^}

On 20220330 00:55:47, Conrad, PA5Y wrote:

I completely disagree.

 

If you have an LNA that will not overload and has sufficient headroom you can use a step attenuator after the LNA to ensure that the input levels to the subsequent stage are appropriate for the conditions. For EME you are concerned with sensitivity.  During a summer Es opening in Europe you will need to reduce sensitivity and accept a small noise figure hit. It is the best way to handle these enormous variation in signal levels. What I do not want is to take the hit in noise figure due to cable loss before the receiver.

 

This is not HF and the sensitivity is always the primary concern.

 

The dynamic range for VHF in EU means that dynamic range is certainly not optional. I put systems together based upon total system analysis which includes both noise figure and dynamic range. On 2m with a 1dB NF which is a little better than needed for terrestrial operation in my semi-rural location. The system dynamic range is 101dB on 2m when I use either my K3S or TS-890. I expect it will be 2-3dB worse with the Elad FDM-S3. However for 2m this is still very good.

 

On 6m the noise figure does not need to be that good even for EME due to sky temperature.

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of jdow via groups.io
Sent: 30 March 2022 09:18
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

A step attenuator plus LNA is not much of a solution for anything as it guarantees you a loss of dynamic range even for the no net change in noise figure case. It must be nice to live where dynamic range is optional.

{o.o}


On 20220329 06:43:54, Conrad, PA5Y wrote:

OK Simon.

 

I’m convinced.

 

My only comment would be that I do not use MDS as a metric as I always use an external preamp to set the system noise figure. Even on 6m where I sometimes do EME. While the NF requirements are quite low on 6m using an LNA allows the use of splitters for my transceiver and SDRs and also finding a sweet spot for any situation. It is easy to make a very high IIP3 LNA for VHF these days, just add enough gain to overcome cable/splitter losses and the receiver noise figure. During big Es openings I typically add 6-12dB attenuation, but this covers all eventualities. A step attenuator in the RX path is an essential accessory, does not matter if it is internal or external to the radio.

 

I must admit that I trust Elad and the photos of the innards of the FDM-S3 look very well implemented.

 

So I will buy one. 😊

 

I just remembered that I have a spare transverter for 2m so the downconverter may not be necessary, I will wait and see what Elad offer.

 

Regards

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 29 March 2022 15:27
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

Also,

 

I would just add that the S3 is a class product.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown
Sent: 29 March 2022 14:23
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

My 10 pence:

 

I assume that you cannot overlap the VHF and HF ranges, you select one or the other?
Correct

I see several VHF ranges in the manual, one of which is 108-147MHz under sampled at 98.304MHz, so for 2m I just need a good external band pass filter before the VHF input, correct? Of course I will need sufficient gain to make up for the relatively high noise figure, this is easy.
I think so but there’s a big downconverter coming – suffering from unobtainable parts atm.

On HF how does it compare to the Perseus, especially with respect to dynamic range. I have always found the Perseus to be almost good enough, another 3dB would be enough
It’s excellent. Can’t give you any figures, but FWIW I think the Airspy Discovery has better MDS than Perseus. Perseus is good but we do have better now.

How does the FDM-S3 compare to the FDM-DUO, I owned one and it was not as good as I expected based upon user feedback. However it would make a fine uwave transverter driver. I probably should have kept it.
NO comment really – I use the DUO on HF and to drive 4m / 2m / 70cms Q5 Signal transverters, BDR at least 110 dB. For microwave there’s always the Pluto with preamp etc.

If I like it I may buy a second one,  to cover 50MHz and MUF duties simultaneously, it all boils down to dynamic range

 

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 29 March 2022 12:58
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

I am seriously thinking of buying an Elad FSM S3. At first I was going to buy an ANAN-7000DLE but then I thought about it. The ANAN delays are variable and I don’t really need a transceiver. What I need are receivers.  I see the Elad being useful for tracking the MUF during the Es season and also creating multiple receivers connected to different instances of WSJT-X on 6m

 

A few questions to those who have them.

 

I assume that you cannot overlap the VHF and HF ranges, you select one or the other?

I see several VHF ranges in the manual, one of which is 108-147MHz undersampled at 98.304MHz, so for 2m I just need a good external band pass filter before the VHF input, correct? Of course I will need sufficient gain to make up for the relatively high noise figure, this is easy.

On HF how does it compare to the Perseus, especially with respect to dynamic range. I have always found the Perseus to be almost good enough, another 3dB would be enough

How does the FDM-S3 compare to the FDM-DUO, I owned one and it was not as good as I expected based upon user feedback. However it would make a fine uwave transverter driver. I probably should have kept it.

If I like it I may buy a second one,  to cover 50MHz and MUF duties simultaneously, it all boils down to dynamic range

 

I assume that on 6m I can easily create what Flex call ‘slices’. For instance I use a 1536kHz sample rate and I can create multiple receivers, 2 attached to WSJT-X for FT8 and one for 50.110 for example.

 

73

 

Conrad PA5Y


--

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Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.

 

 


Re: Elad S3 versus Perseus and FDM Duo

John G4SWX
 

On Tue, Mar 29, 2022 at 12:57 PM, Conrad, PA5Y wrote:
I have an XPOL system on 2m and most of the time I do not see much rotation but 6m is a completely different matter.
The effect of Faraday rotation is proportional to the square of the wavelength!
Ionospheric propagation is further complicated by changes in the path length of the wave in the ionosphere. Ionospheric radio reflection is not specular at a single point in the ionosphere but refracted over a significant distance which changes rapidly due to small fluctuations in density. Hence, the polarisation is always changing and often quite rapidly.

John G4SWX


Re: Elad S3 versus Perseus and FDM Duo

John G4SWX
 

Conrad PA5Y writes:

  • I am thinking about building an XPOL RX for 6m for that very reason this summer. I have the antennas. Of course, I will run out of time!

 

Actually a fully X-pol 50Mhz array will give you a distinct advantage on all ionospheric propagation modes.

The suggestion of using a rotator on a Yagi, such as is sometimes used on 432MHz EME will not work on 50MHz due to the rapid changes in polarisation with time.

 

There has been a lot of recent research by Chris Deacon G4IFX and others. You can read a paper here:

https://www.researchgate.net/publication/335230569_Investigation_of_the_polarization_of_50_MHz_signals_via_Sporadic-E_reflection/link/5d69577792851c853880343d/download

 

Figure 1 shows quite clearly that Faraday rotation is changing in seconds rather than minutes as is the case on 144/432MHz EME

Or even watch a video of Chris early work presented at the 2016 RSGB convention, introduced by the RSGB VHF manager……………

 

https://www.youtube.com/watch?v=13Cs4nB1TjI

 

John G4SWX


Virus-free. www.avast.com


Re: Elad S3 versus Perseus and FDM Duo

jdow
 

At one point I considered two horizontal yagis spaced appropriately for stacking. Then let the stacking boom rotate from vertical to horizontal. That keeps the active antenna parts out of the way of support metal. Even rotating the boom can have the supports distort the pattern. With that configuration you can balance the array and the polarization rotator to give a more balanced load on the mast. Most configurations Ive seen in the past seem to forget this potential balance trick.

{^_^}

On 20220330 00:58:15, Conrad, PA5Y wrote:

That is something that I have considered but you really need a rear mounted yagi to avoid antenna degradation or mechanical issues. It is definitely worthy of serious consideration.

 

To see how it is done properly look at Frank Potts NC1I’s 432MHz EME array.

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of jdow via groups.io
Sent: 30 March 2022 09:55
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

Get a baby rotator to rotate it from H to V polarization. (Besides, REAL ops use SSB. Short of some recent digital audio work SSB gives best SNR for weak signals.)

{^_-}    (6 meter SSB since 1962 or so. 1 kW 6 meter SSB. But the aurora scatter was 6 watts SSB - Heathquit barefoot.)

On 20220329 12:37:31, Conrad, PA5Y wrote:

Bloomin ‘eck its very small 2.1m boom, that’s perfect! I might try the 11 ele even. Don’t most FM transmitters transmit vertical? I think Rob PE1ITR is into Band II DX, I will have a word with him.

 

Maybe I’ll get into it.

 

Conrad

 

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 29 March 2022 21:22
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

Conrad,

 

I use the Innov 8 element Yagi, highly recommended.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 29 March 2022 20:00
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

Hi Jim and others

 

So, if I want to track the MUF on Es how good an antenna do I need? I just want an early warning; for impending 2m openings. In the past I have used a dipole but that was years ago, things have moved on. I have space for a 5m long boom on an 8m mast. Can you point me to a few good broad band Band II antennas? Maybe an omni would be better for this purpose? I have very good antennas for 6m and 4m so I will have some warning.

 

I am going to buy an S3.

 

I am quite looking forward to it.

 

Conrad

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Jim Smith G0OFE via groups.io
Sent: 29 March 2022 20:21
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

Seconded.

Had mine since November the year before last, and it really is the dog's danglies, both on HF and on Band 2.

 

================================
Need help with SDR Console? If you have a problem:
Go to https://www.sdr-radio.com/support
Please follow instructions in that link.
===================================
Jim, Bournemouth, Dorset. IO90BR.
Elad FDM-S2, Airspy HF+, SDRPlay and Funcube Dongle SDR Recievers
8-element OP-DES for Band 2, 8-element LFA for 2m, 3-element LFA for 6m, 20m Windom for HF,. Wellbrook 1530 Loop for LF

On 29/03/2022 13:27, Simon Brown wrote:

Also,

 

I would just add that the S3 is a class product.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown
Sent: 29 March 2022 14:23
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

My 10 pence:

 

I assume that you cannot overlap the VHF and HF ranges, you select one or the other?
Correct

I see several VHF ranges in the manual, one of which is 108-147MHz under sampled at 98.304MHz, so for 2m I just need a good external band pass filter before the VHF input, correct? Of course I will need sufficient gain to make up for the relatively high noise figure, this is easy.
I think so but there’s a big downconverter coming – suffering from unobtainable parts atm.

On HF how does it compare to the Perseus, especially with respect to dynamic range. I have always found the Perseus to be almost good enough, another 3dB would be enough
It’s excellent. Can’t give you any figures, but FWIW I think the Airspy Discovery has better MDS than Perseus. Perseus is good but we do have better now.

How does the FDM-S3 compare to the FDM-DUO, I owned one and it was not as good as I expected based upon user feedback. However it would make a fine uwave transverter driver. I probably should have kept it.
NO comment really – I use the DUO on HF and to drive 4m / 2m / 70cms Q5 Signal transverters, BDR at least 110 dB. For microwave there’s always the Pluto with preamp etc.

If I like it I may buy a second one,  to cover 50MHz and MUF duties simultaneously, it all boils down to dynamic range

 

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 29 March 2022 12:58
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

I am seriously thinking of buying an Elad FSM S3. At first I was going to buy an ANAN-7000DLE but then I thought about it. The ANAN delays are variable and I don’t really need a transceiver. What I need are receivers.  I see the Elad being useful for tracking the MUF during the Es season and also creating multiple receivers connected to different instances of WSJT-X on 6m

 

A few questions to those who have them.

 

I assume that you cannot overlap the VHF and HF ranges, you select one or the other?

I see several VHF ranges in the manual, one of which is 108-147MHz undersampled at 98.304MHz, so for 2m I just need a good external band pass filter before the VHF input, correct? Of course I will need sufficient gain to make up for the relatively high noise figure, this is easy.

On HF how does it compare to the Perseus, especially with respect to dynamic range. I have always found the Perseus to be almost good enough, another 3dB would be enough

How does the FDM-S3 compare to the FDM-DUO, I owned one and it was not as good as I expected based upon user feedback. However it would make a fine uwave transverter driver. I probably should have kept it.

If I like it I may buy a second one,  to cover 50MHz and MUF duties simultaneously, it all boils down to dynamic range

 

I assume that on 6m I can easily create what Flex call ‘slices’. For instance I use a 1536kHz sample rate and I can create multiple receivers, 2 attached to WSJT-X for FT8 and one for 50.110 for example.

 

73

 

Conrad PA5Y


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Re: Elad S3 versus Perseus and FDM Duo

jdow
 

What about the stages that follow? They are also stages that can limit dynamic range. (The most effective trick for the noise figure increase and dynamic range decrease was calculated years ago for CATV systems. It's a gain of "e", the transcendental number. That is not the best from an economic standpoint, though. My spare time ham hacks through the 70s involved a lot of playing with noise figure, dynamic range, and receiver design to maximize this. It, too, falls victim to, "There Ain't No Such Thing As A Free Lunch." Every stage you add reduces dynamic range for frequencies that manage to pass through the stage. That was a pain in the panties for the S3A sonobuoy receiver given its architecture. Fortunately their dynamic range requirement as not at science fiction levels.

And, yes, 6 meters is fairly noisy. By 60s and even 70s standards the noise figures we get by default were considered exotic and low. Pushing for tiny noise figures (<1dB) on 2 is sort of pushing reality a little bit, and can really cost you with dynamic range.

{^_^}

On 20220330 00:55:47, Conrad, PA5Y wrote:

I completely disagree.

 

If you have an LNA that will not overload and has sufficient headroom you can use a step attenuator after the LNA to ensure that the input levels to the subsequent stage are appropriate for the conditions. For EME you are concerned with sensitivity.  During a summer Es opening in Europe you will need to reduce sensitivity and accept a small noise figure hit. It is the best way to handle these enormous variation in signal levels. What I do not want is to take the hit in noise figure due to cable loss before the receiver.

 

This is not HF and the sensitivity is always the primary concern.

 

The dynamic range for VHF in EU means that dynamic range is certainly not optional. I put systems together based upon total system analysis which includes both noise figure and dynamic range. On 2m with a 1dB NF which is a little better than needed for terrestrial operation in my semi-rural location. The system dynamic range is 101dB on 2m when I use either my K3S or TS-890. I expect it will be 2-3dB worse with the Elad FDM-S3. However for 2m this is still very good.

 

On 6m the noise figure does not need to be that good even for EME due to sky temperature.

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of jdow via groups.io
Sent: 30 March 2022 09:18
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

A step attenuator plus LNA is not much of a solution for anything as it guarantees you a loss of dynamic range even for the no net change in noise figure case. It must be nice to live where dynamic range is optional.

{o.o}

On 20220329 06:43:54, Conrad, PA5Y wrote:

OK Simon.

 

I’m convinced.

 

My only comment would be that I do not use MDS as a metric as I always use an external preamp to set the system noise figure. Even on 6m where I sometimes do EME. While the NF requirements are quite low on 6m using an LNA allows the use of splitters for my transceiver and SDRs and also finding a sweet spot for any situation. It is easy to make a very high IIP3 LNA for VHF these days, just add enough gain to overcome cable/splitter losses and the receiver noise figure. During big Es openings I typically add 6-12dB attenuation, but this covers all eventualities. A step attenuator in the RX path is an essential accessory, does not matter if it is internal or external to the radio.

 

I must admit that I trust Elad and the photos of the innards of the FDM-S3 look very well implemented.

 

So I will buy one. 😊

 

I just remembered that I have a spare transverter for 2m so the downconverter may not be necessary, I will wait and see what Elad offer.

 

Regards

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 29 March 2022 15:27
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

Also,

 

I would just add that the S3 is a class product.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown
Sent: 29 March 2022 14:23
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

My 10 pence:

 

1.       I assume that you cannot overlap the VHF and HF ranges, you select one or the other?
Correct

2.       I see several VHF ranges in the manual, one of which is 108-147MHz under sampled at 98.304MHz, so for 2m I just need a good external band pass filter before the VHF input, correct? Of course I will need sufficient gain to make up for the relatively high noise figure, this is easy.
I think so but there’s a big downconverter coming – suffering from unobtainable parts atm.

3.       On HF how does it compare to the Perseus, especially with respect to dynamic range. I have always found the Perseus to be almost good enough, another 3dB would be enough
It’s excellent. Can’t give you any figures, but FWIW I think the Airspy Discovery has better MDS than Perseus. Perseus is good but we do have better now.

4.       How does the FDM-S3 compare to the FDM-DUO, I owned one and it was not as good as I expected based upon user feedback. However it would make a fine uwave transverter driver. I probably should have kept it.
NO comment really – I use the DUO on HF and to drive 4m / 2m / 70cms Q5 Signal transverters, BDR at least 110 dB. For microwave there’s always the Pluto with preamp etc.

5.       If I like it I may buy a second one,  to cover 50MHz and MUF duties simultaneously, it all boils down to dynamic range

 

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 29 March 2022 12:58
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Elad S3 versus Perseus and FDM Duo

 

I am seriously thinking of buying an Elad FSM S3. At first I was going to buy an ANAN-7000DLE but then I thought about it. The ANAN delays are variable and I don’t really need a transceiver. What I need are receivers.  I see the Elad being useful for tracking the MUF during the Es season and also creating multiple receivers connected to different instances of WSJT-X on 6m

 

A few questions to those who have them.

 

1.       I assume that you cannot overlap the VHF and HF ranges, you select one or the other?

2.       I see several VHF ranges in the manual, one of which is 108-147MHz undersampled at 98.304MHz, so for 2m I just need a good external band pass filter before the VHF input, correct? Of course I will need sufficient gain to make up for the relatively high noise figure, this is easy.

3.       On HF how does it compare to the Perseus, especially with respect to dynamic range. I have always found the Perseus to be almost good enough, another 3dB would be enough

4.       How does the FDM-S3 compare to the FDM-DUO, I owned one and it was not as good as I expected based upon user feedback. However it would make a fine uwave transverter driver. I probably should have kept it.

5.       If I like it I may buy a second one,  to cover 50MHz and MUF duties simultaneously, it all boils down to dynamic range

 

I assume that on 6m I can easily create what Flex call ‘slices’. For instance I use a 1536kHz sample rate and I can create multiple receivers, 2 attached to WSJT-X for FT8 and one for 50.110 for example.

 

73

 

Conrad PA5Y


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Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.

 



Re: Elad S3 versus Perseus and FDM Duo

Jim Smith G0OFE
 

Not necessarily.

Many are horizontal or mixed. Holland, Ireland are mostly vertical. A n excellent site to use is FM LIst for transmitter info, and you can also see in real time what Band 2 DXers are logging,. If you need more pointers them mail me directly or join the SkywavesDX forum on SkywavesDX.org

I also have the 8 ele Innovantennas, since 2013.  I'd like to use a Korner 9.2 as it has better front-to-back but it needs a bit of vertical space due to the reflector array, and I'd have to sacrifice an additional antenna for that.


================================
Need help with SDR Console? If you have a problem:
Go to https://www.sdr-radio.com/support
Please follow instructions in that link.
===================================
Jim, Bournemouth, Dorset. IO90BR.
Elad FDM-S2, Airspy HF+, SDRPlay and Funcube Dongle SDR Recievers
8-element OP-DES for Band 2, 8-element LFA for 2m, 3-element LFA for 6m, 20m Windom for HF,. Wellbrook 1530 Loop for LF


On 29/03/2022 19:51, Mag loop Simon wrote:

Hi Conrad

Yes most fm stations are vertical, but by time bounced a few times from “E” who knows polarisation..

Other Simon g0zen 





Re: Frequency Database - Display Only Entries For Current Time ??

Max
 

On Tue, Mar 29, 2022 at 10:45 PM, John Dusek wrote:
I was hoping SDRC could emulate that current-time filtering bit, my current limited listening station only has one PC screen and is hard to fit a SDR with spectrum scope and CSVUserBrowser on a single screen in a usable manner,
I agree it would be good if Simon could add a "current time" filter to the database. That would indeed be very useful. It's one of the best features of CSVUB and my guess is it would not be too difficult to implement in SDRC (spoken as a non-programmer!).

Don't know if Simon is reading these posts at the moment as he is planting his tomatoes!

Max