I'm looking for FST4W signals


Rob Robinett
 

I have started to debug FST4W decoding in the WD 3.0 alpha but so far I can't find any signals at KPH on 630, and WSJT-x doesn't seem to identify such signals, if they exist, on other bands
I am using WSJT-x to decode audio from a browser session to KPH but I can find no signals on 630,  Can anyone suggest a source of FST4W signals I can use?
Thanks

--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Jim Lill
 

On 9/11/21 11:19 AM, Rob Robinett wrote:
I have started to debug FST4W decoding in the WD 3.0 alpha but so far I can't find any signals at KPH on 630, and WSJT-x doesn't seem to identify such signals, if they exist, on other bands
I am using WSJT-x to decode audio from a browser session to KPH but I can find no signals on 630,  Can anyone suggest a source of FST4W signals I can use?
Thanks

--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Jim Lill
 

I meant to say I could get something going on my "local" TX as I did for John with 2G ALE if that would help

On 9/11/21 1:16 PM, Jim Lill wrote:
On 9/11/21 11:19 AM, Rob Robinett wrote:
I have started to debug FST4W decoding in the WD 3.0 alpha but so far I can't find any signals at KPH on 630, and WSJT-x doesn't seem to identify such signals, if they exist, on other bands
I am using WSJT-x to decode audio from a browser session to KPH but I can find no signals on 630,  Can anyone suggest a source of FST4W signals I can use?
Thanks

--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Rob Robinett
 

One 2 minute wav file which has a FST4W signal in it would be enough for me

On Sat, Sep 11, 2021 at 10:17 AM Jim Lill <jim@...> wrote:

I meant to say I could get something going on my "local" TX as I did for John with 2G ALE if that would help

On 9/11/21 1:16 PM, Jim Lill wrote:
On 9/11/21 11:19 AM, Rob Robinett wrote:
I have started to debug FST4W decoding in the WD 3.0 alpha but so far I can't find any signals at KPH on 630, and WSJT-x doesn't seem to identify such signals, if they exist, on other bands
I am using WSJT-x to decode audio from a browser session to KPH but I can find no signals on 630,  Can anyone suggest a source of FST4W signals I can use?
Thanks

--
Rob Robinett
AI6VN
mobile: +1 650 218 8896

--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Glenn Elmore
 

If you run two instances of WSJT-X and a virtual audio cable/mixer can't you generate all the files and types possible?


On 9/11/21 12:00 PM, Rob Robinett wrote:
One 2 minute wav file which has a FST4W signal in it would be enough for me

On Sat, Sep 11, 2021 at 10:17 AM Jim Lill <jim@...> wrote:

I meant to say I could get something going on my "local" TX as I did for John with 2G ALE if that would help

On 9/11/21 1:16 PM, Jim Lill wrote:
On 9/11/21 11:19 AM, Rob Robinett wrote:
I have started to debug FST4W decoding in the WD 3.0 alpha but so far I can't find any signals at KPH on 630, and WSJT-x doesn't seem to identify such signals, if they exist, on other bands
I am using WSJT-x to decode audio from a browser session to KPH but I can find no signals on 630,  Can anyone suggest a source of FST4W signals I can use?
Thanks

--
Rob Robinett
AI6VN
mobile: +1 650 218 8896
--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Rob Robinett
 

Hi Glenn,

Why didn't I think of that?  Too much bash on the brain, I guess.
Rather than use a loopback audio path, I am running WSJT-x on one laptop and connecting an audio jumper cable to the input audio on another laptop.

Thanks!

Rob


On Sat, Sep 11, 2021 at 11:30 AM Glenn Elmore <n6gn@...> wrote:

If you run two instances of WSJT-X and a virtual audio cable/mixer can't you generate all the files and types possible?


On 9/11/21 12:00 PM, Rob Robinett wrote:
One 2 minute wav file which has a FST4W signal in it would be enough for me

On Sat, Sep 11, 2021 at 10:17 AM Jim Lill <jim@...> wrote:

I meant to say I could get something going on my "local" TX as I did for John with 2G ALE if that would help

On 9/11/21 1:16 PM, Jim Lill wrote:
On 9/11/21 11:19 AM, Rob Robinett wrote:
I have started to debug FST4W decoding in the WD 3.0 alpha but so far I can't find any signals at KPH on 630, and WSJT-x doesn't seem to identify such signals, if they exist, on other bands
I am using WSJT-x to decode audio from a browser session to KPH but I can find no signals on 630,  Can anyone suggest a source of FST4W signals I can use?
Thanks

--
Rob Robinett
AI6VN
mobile: +1 650 218 8896
--
Rob Robinett
AI6VN
mobile: +1 650 218 8896



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Rob Robinett
 

WD is now decoding FST4W, but I am confused about how to label those spots by the discussion at: https://www.wsprnet.org/drupal/node/8500#comments
As I read it, all two minute long WSPR packets should be labeled as mode '2' in the spots uploaded to wsprnet.org.
If that is the case, then I will follow that rule but upload 2 minute FST4W extended spots to wsprdaemon.org as mode 12 so they can be distinguished from legacy WSPR spots.

On Sat, Sep 11, 2021 at 2:17 PM Rob Robinett via groups.io <rob=robinett.us@groups.io> wrote:
Hi Glenn,

Why didn't I think of that?  Too much bash on the brain, I guess.
Rather than use a loopback audio path, I am running WSJT-x on one laptop and connecting an audio jumper cable to the input audio on another laptop.

Thanks!

Rob


On Sat, Sep 11, 2021 at 11:30 AM Glenn Elmore <n6gn@...> wrote:

If you run two instances of WSJT-X and a virtual audio cable/mixer can't you generate all the files and types possible?


On 9/11/21 12:00 PM, Rob Robinett wrote:
One 2 minute wav file which has a FST4W signal in it would be enough for me

On Sat, Sep 11, 2021 at 10:17 AM Jim Lill <jim@...> wrote:

I meant to say I could get something going on my "local" TX as I did for John with 2G ALE if that would help

On 9/11/21 1:16 PM, Jim Lill wrote:
On 9/11/21 11:19 AM, Rob Robinett wrote:
I have started to debug FST4W decoding in the WD 3.0 alpha but so far I can't find any signals at KPH on 630, and WSJT-x doesn't seem to identify such signals, if they exist, on other bands
I am using WSJT-x to decode audio from a browser session to KPH but I can find no signals on 630,  Can anyone suggest a source of FST4W signals I can use?
Thanks

--
Rob Robinett
AI6VN
mobile: +1 650 218 8896
--
Rob Robinett
AI6VN
mobile: +1 650 218 8896



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Jim Lill
 

I had similar confusion when looking at FST4W for my page

On 9/11/21 11:37 PM, Rob Robinett wrote:
WD is now decoding FST4W, but I am confused about how to label those spots by the discussion at: https://www.wsprnet.org/drupal/node/8500#comments
As I read it, all two minute long WSPR packets should be labeled as mode '2' in the spots uploaded to wsprnet.org.
If that is the case, then I will follow that rule but upload 2 minute FST4W extended spots to wsprdaemon.org as mode 12 so they can be distinguished from legacy WSPR spots.

On Sat, Sep 11, 2021 at 2:17 PM Rob Robinett via groups.io <rob=robinett.us@groups.io> wrote:
Hi Glenn,

Why didn't I think of that?  Too much bash on the brain, I guess.
Rather than use a loopback audio path, I am running WSJT-x on one laptop and connecting an audio jumper cable to the input audio on another laptop.

Thanks!

Rob


On Sat, Sep 11, 2021 at 11:30 AM Glenn Elmore <n6gn@...> wrote:

If you run two instances of WSJT-X and a virtual audio cable/mixer can't you generate all the files and types possible?


On 9/11/21 12:00 PM, Rob Robinett wrote:
One 2 minute wav file which has a FST4W signal in it would be enough for me

On Sat, Sep 11, 2021 at 10:17 AM Jim Lill <jim@...> wrote:

I meant to say I could get something going on my "local" TX as I did for John with 2G ALE if that would help

On 9/11/21 1:16 PM, Jim Lill wrote:
On 9/11/21 11:19 AM, Rob Robinett wrote:
I have started to debug FST4W decoding in the WD 3.0 alpha but so far I can't find any signals at KPH on 630, and WSJT-x doesn't seem to identify such signals, if they exist, on other bands
I am using WSJT-x to decode audio from a browser session to KPH but I can find no signals on 630,  Can anyone suggest a source of FST4W signals I can use?
Thanks

--
Rob Robinett
AI6VN
mobile: +1 650 218 8896
--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Gwyn Griffiths
 

Rob, Jim
I hope to bring some light and not add to the confusion. There are, to my mind, three sources of confusion:
1. The wsprnet database team repurposed an existing field to signify the new modes, so the meaning of the numbers in the database field 'code' has changed.
2. Reporters running older wsjt-x software will still be uploading numbers into the code field that reflect its previous usage.
3. It is only Gary's post #13 in the thread  that gives the mapping between the database value for code and the mode (which is what one searches for on the wsprnet.org page), he wrote:

"So that code:1 means WSPR-2. I need to update the doc on the github, but it's still a bit of moving target and I don't want to create more updates when it changes. It's code = 1,2,4,8 for WSPR-2, WSPR-15, /300, /1800 respectively.

Since we are using the column `code` to avoid a schema change I am mapping it to the mode values and there are more changes coming. I know it's not ideal, but it will work for us. It is in the CSV daily dumps, too, and at least for now I have no plans to remap them."

So, for FST4W /300 for example querying the wsprnet database table spots on one of the wsprdaemon servers with 

select * from spots where wd_band='630' and code =4 order by wd_time desc limit 1;

gives

       wd_time       |  Spotnum   |    Date    | Reporter  | ReporterGrid | dB  |   MHz    | CallSign |  Grid  | Power | Drift | distance | azimuth | Band |  version   | code | wd_band | wd_c2_noise | wd_rms_noise | wd_rx_az | wd_rx_lat | wd_rx_lon | wd_tx_az | wd_tx_lat | wd_tx_lon | wd_v_lat | wd_v_lon 

---------------------+------------+------------+-----------+--------------+-----+----------+----------+--------+-------+-------+----------+---------+------+------------+------+---------+-------------+--------------+----------+-----------+-----------+----------+-----------+-----------+----------+----------

 2021-09-11 13:45:00 | 3403461808 | 1631367900 | N6LF/B    | CN83lt       | -29 | 0.475779 | JH1OFX   | PM95ql |    30 |     0 |     7904 |      49 |    0 | 2.4.0      |    4 | 630     |      -999.9 |       -999.9 |      301 |    43.812 |  -123.042 |       49 |    35.479 |   139.375 |   43.812 | -123.042

while on wsprnet.org, for an MF search with mode=5 

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az Mode
 2021-09-11 13:46   JH1OFX   0.475779   -29   0   PM95ql   1   N6LF/B   CN83lt   7904   49   5 

matches up
So it is the 'code' that has to be uploaded to the database, and wsprnet.org database then uses their 'mode' equivalent in their query.

To check for mode 30 on wsprnet.org on 2200 I get:
Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az Mode
 2021-09-14 06:30   JA1RWI   0.137520   +1   0   PM95tm   0.1   JA1NQI   QM05dv   73   55   30

and the query on wsprdaemon database

select * from spots where wd_band='2200' and code=8 order by wd_time desc limit 1;

returns

       wd_time       |  Spotnum   |    Date    | Reporter | ReporterGrid | dB |   MHz   | CallSign |  Grid  | Power | Drift | distance | azimuth | Band |  version   | code | wd_band | wd_c2_noise | wd_rms_noise | wd_rx_az | wd_rx_lat | wd_rx_lon | wd_tx_az | wd_tx_lat | wd_tx_lon | wd_v_lat | wd_v_lon 

---------------------+------------+------------+----------+--------------+----+---------+----------+--------+-------+-------+----------+---------+------+------------+------+---------+-------------+--------------+----------+-----------+-----------+----------+-----------+-----------+----------+----------

 2021-09-14 06:30:00 | 3411217293 | 1631601000 | JA1NQI   | QM05dv       |  1 | 0.13752 | JA1RWI   | PM95tm |    20 |     0 |       73 |      55 |   -1 | 2.3.0      |    8 | 2200    |      -999.9 |       -999.9 |      235 |    35.896 |   140.292 |       55 |    35.521 |   139.625 |   35.896 |  140.292

(1 row)


where you see that the code field is 8  corresponding to mode 30 as in Gary's post.

regards
Gwyn G3ZIL


WILLIAM n SUSIE ENGELKE
 

Could someone please suggest to me what frequency I should set WSJT-x to, to run a 160m beacon on FST4W?
I just installed WSJTx v 2.5.0-rc6, which has  frequency settings of 1.8368 and 1.839 MHz for this mode. Should I use one of these, or another?    -73- Bill Engelke, AB4EJ


Rob Robinett
 

Hi Bill,

I posted questions about the FST4W bands and frequencies to the WSJT-x forum and heard back in this thread: https://wsjtx.groups.io/g/main/topic/85595606#28773

This is my first exploration of the 'frequency of bands' feature of the WSJT-x and I find band definitions for  2200M and 630M to be the same as WSPR, while the 160M band is in the 200 Hz immediately above the WSPR band.  It seems no wonder that FST4W isn't being widely used if there are only 3 bands defined for it;=)

Since WD users are likely to become the primary listeners to FST4W on all bands, and there seems no compelling technical reason to have separate bands, I would propose we add Mode FST4W bands to WSJT-x which overlap with the existing WSPR bands.  So for tonight I suggest we delete the existing 160M FST4W band in WSJT-x->Settings->Frequencies  and replace it with one which duplicates the 160M WSPR band.

What do you think?

73,

Rob


On Tue, Sep 14, 2021 at 7:46 AM WILLIAM n SUSIE ENGELKE <engelke77@...> wrote:
Could someone please suggest to me what frequency I should set WSJT-x to, to run a 160m beacon on FST4W?
I just installed WSJTx v 2.5.0-rc6, which has  frequency settings of 1.8368 and 1.839 MHz for this mode. Should I use one of these, or another?    -73- Bill Engelke, AB4EJ



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Rob Robinett
 

Reading the FST4 Quick Start Guide at:  https://physics.princeton.edu/pulsar/k1jt/FST4_Quick_Start.pdf
I see it suggested that FST4 transmissions occupy the same 1400-1600 Hz bands as WSPR signals.
So I don't know where the 1600-1800 Hz for the 160M band comes from, nor why only 2200,630 and 160 are defined in 2.5.0-x

On Tue, Sep 14, 2021 at 8:25 AM Rob Robinett via groups.io <rob=robinett.us@groups.io> wrote:
Hi Bill,

I posted questions about the FST4W bands and frequencies to the WSJT-x forum and heard back in this thread: https://wsjtx.groups.io/g/main/topic/85595606#28773

This is my first exploration of the 'frequency of bands' feature of the WSJT-x and I find band definitions for  2200M and 630M to be the same as WSPR, while the 160M band is in the 200 Hz immediately above the WSPR band.  It seems no wonder that FST4W isn't being widely used if there are only 3 bands defined for it;=)

Since WD users are likely to become the primary listeners to FST4W on all bands, and there seems no compelling technical reason to have separate bands, I would propose we add Mode FST4W bands to WSJT-x which overlap with the existing WSPR bands.  So for tonight I suggest we delete the existing 160M FST4W band in WSJT-x->Settings->Frequencies  and replace it with one which duplicates the 160M WSPR band.

What do you think?

73,

Rob


On Tue, Sep 14, 2021 at 7:46 AM WILLIAM n SUSIE ENGELKE <engelke77@...> wrote:
Could someone please suggest to me what frequency I should set WSJT-x to, to run a 160m beacon on FST4W?
I just installed WSJTx v 2.5.0-rc6, which has  frequency settings of 1.8368 and 1.839 MHz for this mode. Should I use one of these, or another?    -73- Bill Engelke, AB4EJ



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


WILLIAM n SUSIE ENGELKE
 

Rob - I just saw this - I was checking the wrong email earlier this AM. Please disregard my earlier email of today.

I have added the standard WSPR frequency of 1.836600 MHz to my WSJT-x instance for FST4W mode, and will use that for my beacon starting today; so I will check with you from time to time about possible detection of it.  -73- Bill , AB4EJ

On Tuesday, September 14, 2021, 10:37:35 AM CDT, Rob Robinett <rob@...> wrote:


Reading the FST4 Quick Start Guide at:  https://physics.princeton.edu/pulsar/k1jt/FST4_Quick_Start.pdf
I see it suggested that FST4 transmissions occupy the same 1400-1600 Hz bands as WSPR signals.
So I don't know where the 1600-1800 Hz for the 160M band comes from, nor why only 2200,630 and 160 are defined in 2.5.0-x

On Tue, Sep 14, 2021 at 8:25 AM Rob Robinett via groups.io <rob=robinett.us@groups.io> wrote:
Hi Bill,

I posted questions about the FST4W bands and frequencies to the WSJT-x forum and heard back in this thread: https://wsjtx.groups.io/g/main/topic/85595606#28773

This is my first exploration of the 'frequency of bands' feature of the WSJT-x and I find band definitions for  2200M and 630M to be the same as WSPR, while the 160M band is in the 200 Hz immediately above the WSPR band.  It seems no wonder that FST4W isn't being widely used if there are only 3 bands defined for it;=)

Since WD users are likely to become the primary listeners to FST4W on all bands, and there seems no compelling technical reason to have separate bands, I would propose we add Mode FST4W bands to WSJT-x which overlap with the existing WSPR bands.  So for tonight I suggest we delete the existing 160M FST4W band in WSJT-x->Settings->Frequencies  and replace it with one which duplicates the 160M WSPR band.

What do you think?

73,

Rob


On Tue, Sep 14, 2021 at 7:46 AM WILLIAM n SUSIE ENGELKE <engelke77@...> wrote:
Could someone please suggest to me what frequency I should set WSJT-x to, to run a 160m beacon on FST4W?
I just installed WSJTx v 2.5.0-rc6, which has  frequency settings of 1.8368 and 1.839 MHz for this mode. Should I use one of these, or another?    -73- Bill Engelke, AB4EJ



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Rob Robinett
 

Thanks Bill,

I'll set up KPH to listen on 160M FST4W overnight.  If KPHsuccessful you will see those spots in the wspr.live report pages.

Rob

On Wed, Sep 15, 2021 at 9:00 AM WILLIAM n SUSIE ENGELKE <engelke77@...> wrote:
Rob - I just saw this - I was checking the wrong email earlier this AM. Please disregard my earlier email of today.

I have added the standard WSPR frequency of 1.836600 MHz to my WSJT-x instance for FST4W mode, and will use that for my beacon starting today; so I will check with you from time to time about possible detection of it.  -73- Bill , AB4EJ

On Tuesday, September 14, 2021, 10:37:35 AM CDT, Rob Robinett <rob@...> wrote:


Reading the FST4 Quick Start Guide at:  https://physics.princeton.edu/pulsar/k1jt/FST4_Quick_Start.pdf
I see it suggested that FST4 transmissions occupy the same 1400-1600 Hz bands as WSPR signals.
So I don't know where the 1600-1800 Hz for the 160M band comes from, nor why only 2200,630 and 160 are defined in 2.5.0-x

On Tue, Sep 14, 2021 at 8:25 AM Rob Robinett via groups.io <rob=robinett.us@groups.io> wrote:
Hi Bill,

I posted questions about the FST4W bands and frequencies to the WSJT-x forum and heard back in this thread: https://wsjtx.groups.io/g/main/topic/85595606#28773

This is my first exploration of the 'frequency of bands' feature of the WSJT-x and I find band definitions for  2200M and 630M to be the same as WSPR, while the 160M band is in the 200 Hz immediately above the WSPR band.  It seems no wonder that FST4W isn't being widely used if there are only 3 bands defined for it;=)

Since WD users are likely to become the primary listeners to FST4W on all bands, and there seems no compelling technical reason to have separate bands, I would propose we add Mode FST4W bands to WSJT-x which overlap with the existing WSPR bands.  So for tonight I suggest we delete the existing 160M FST4W band in WSJT-x->Settings->Frequencies  and replace it with one which duplicates the 160M WSPR band.

What do you think?

73,

Rob


On Tue, Sep 14, 2021 at 7:46 AM WILLIAM n SUSIE ENGELKE <engelke77@...> wrote:
Could someone please suggest to me what frequency I should set WSJT-x to, to run a 160m beacon on FST4W?
I just installed WSJTx v 2.5.0-rc6, which has  frequency settings of 1.8368 and 1.839 MHz for this mode. Should I use one of these, or another?    -73- Bill Engelke, AB4EJ



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Stefan HB9TMC
 

Hi Rob & group,

On Sat, Sep 11, 2021 at 11:37 PM, Rob Robinett wrote:
extended spots to wsprdaemon.org as mode 12 so they can be distinguished
from legacy WSPR spots.
WSJT-X currently reports FST4W-120 as mode "3", you might want to use that, too.
But it isn't supported by wsprnet yet. (Wsprnet rewrites all other values than 2, 5, 15 and 30 to "2".

Mode designation from WSJT-X (wsprnet.cpp):
QString WSPRNet::encode_mode () const
{
if (m_mode == "WSPR") return "2";
if (m_mode == "WSPR-15") return "15";
if (m_mode == "FST4W")
{
auto tr = static_cast<int> ((TR_period_ / 60.)+.5);
if (2 == tr || 15 == tr)
{
tr += 1; // distinguish from WSPR-2 and WSPR-15
}
return QString::number (tr);
}
return "";
}


After actively participating in FST4W activity for a year, a few remarks from my point of view:
- FST4W-Activity (in Europe) was >90% FST4W-300 (5 minute T/R) on the 630m band and FST4W-1800 (30 minute T/R) on the 2200m band. These two configurations seem to be the preferred applications for FST4W. Longer duration modes on 630m are difficult due to frequency stability requirements.
- FST4W-120 is only marginally better than WSPR and only under certain conditions. The big advantage of FST4W are the longer T/R modes (5, 15 and 30 minutes).
- FST4W is sensitive to doppler spread and drift (other than WSPR, it has no drift compensation). It is losing sensitivity very quickly with doppler spread, which makes it unsuitable for 80m and up (that's why in the documentation is written "designed particularly for the LF and MF bands").

73
Stefan


Rob Robinett
 

Hi Stefan,

Thanks for that information.  I am deep into implementing WD 3.0 and the first new feature is support for FST4W up to all lengths at the same  time.  I was aware of the mode number issue but not that '3' would mark 2 minute FST4W packets. The extended spots stored at wsprdaemon.org will preserve that mode number so users of wspr.rocks will be able to differentiate between 2 minute WSPR and 2 minute FST4W packets.

73,

Rob

On Sat, Sep 18, 2021 at 3:19 AM Stefan HB9TMC <hb9tmc@...> wrote:
Hi Rob & group,

On Sat, Sep 11, 2021 at 11:37 PM, Rob Robinett wrote:
> extended spots to wsprdaemon.org as mode 12 so they can be distinguished
> from legacy WSPR spots.
>

WSJT-X currently reports FST4W-120 as mode "3", you might want to use that, too.
But it isn't supported by wsprnet yet. (Wsprnet rewrites all other values than 2, 5, 15 and 30 to "2".

Mode designation from WSJT-X (wsprnet.cpp):
QString WSPRNet::encode_mode () const
{
  if (m_mode == "WSPR") return "2";
  if (m_mode == "WSPR-15") return "15";
  if (m_mode == "FST4W")
    {
      auto tr = static_cast<int> ((TR_period_ / 60.)+.5);
      if (2 == tr || 15 == tr)
        {
          tr += 1;              // distinguish from WSPR-2 and WSPR-15
        }
      return QString::number (tr);
    }
  return "";
}


After actively participating in FST4W activity for a year, a few remarks from my point of view:
- FST4W-Activity (in Europe) was >90% FST4W-300 (5 minute T/R) on the 630m band and FST4W-1800 (30 minute T/R) on the 2200m band. These two configurations seem to be the preferred applications for FST4W. Longer duration modes on 630m are difficult due to frequency stability requirements.
- FST4W-120 is only marginally better than WSPR and only under certain conditions. The big advantage of FST4W are the longer T/R modes (5, 15 and 30 minutes).
- FST4W is sensitive to doppler spread and drift (other than WSPR, it has no drift compensation). It is losing sensitivity very quickly with doppler spread, which makes it unsuitable for 80m and up (that's why in the documentation is written "designed particularly for the LF and MF bands").

73
Stefan







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Rob Robinett
AI6VN
mobile: +1 650 218 8896