Thoughts on FST4


Jim Lill
 


Seems like at the moment we may be in a chicken and egg or Yogi Berra situation.  No transmits there anymore because everybody gave up listening.  There's darn few stateside TX stations so listening bears little fruit.

The RX crowd has it easy as our wspr-capable receivers can do it with no issue.  But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.

  • TX antennas on the 630/2200 bands are already a challenge and keeping them in tune while the matching components heat up will be a challenge. Commercial NDB antennas matching units have surveillance tuning
  • The TX itself may be challenged for lengthy TX periods.
  • Its use on other bands may provide a new unique or logging but likely nothing propagation relevant.

Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.

-Jim

WA2ZKD




Edward (W3ENR / K3WRG)
 

If it's not too technically difficult (I have no idea), somebody should convince Harry Zachrisson - or similar small scale hardware maker - to make an affordable little 1w FSTW4 transmitter.  Is a watt enough?

I think that would encourage / enable a lot of  experimentation.  Alligator clip it to your gutter or a fence rail and see what happens ... and similar.  Or hook it up to the beverage antenna when not otherwise in use.

Set it up as kickstarter type thing so enough orders could be (hopefully) collected to make it economically feasible for Harry.

EH

On 6/30/22 11:22 AM, Jim Lill wrote:


Seems like at the moment we may be in a chicken and egg or Yogi Berra situation.  No transmits there anymore because everybody gave up listening.  There's darn few stateside TX stations so listening bears little fruit.

The RX crowd has it easy as our wspr-capable receivers can do it with no issue.  But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.

* TX antennas on the 630/2200 bands are already a challenge and
keeping them in tune while the matching components heat up will be
a challenge. Commercial NDB antennas matching units have
surveillance tuning
* The TX itself may be challenged for lengthy TX periods.
* Its use on other bands may provide a new unique or logging but
likely nothing propagation relevant.

Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.

-Jim

WA2ZKD




Jim Lill
 

Having operated a 630M ZachTek TX plus amplifier last winter I can say that 1W into an unmatched antenna will not do much. "If it was that easy, everybody would do it" :-)

On 6/30/22 11:48, Edward Hammond wrote:
If it's not too technically difficult (I have no idea), somebody should convince Harry Zachrisson - or similar small scale hardware maker - to make an affordable little 1w FSTW4 transmitter.  Is a watt enough?

I think that would encourage / enable a lot of  experimentation. Alligator clip it to your gutter or a fence rail and see what happens ... and similar.  Or hook it up to the beverage antenna when not otherwise in use.

Set it up as kickstarter type thing so enough orders could be (hopefully) collected to make it economically feasible for Harry.

EH



On 6/30/22 11:22 AM, Jim Lill wrote:


Seems like at the moment we may be in a chicken and egg or Yogi Berra situation.  No transmits there anymore because everybody gave up listening.  There's darn few stateside TX stations so listening bears little fruit.

The RX crowd has it easy as our wspr-capable receivers can do it with no issue.  But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.

  * TX antennas on the 630/2200 bands are already a challenge and
    keeping them in tune while the matching components heat up will be
    a challenge. Commercial NDB antennas matching units have
    surveillance tuning
  * The TX itself may be challenged for lengthy TX periods.
  * Its use on other bands may provide a new unique or logging but
    likely nothing propagation relevant.

Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.

-Jim

WA2ZKD








KD2OM
 

Ed,
Take a look at RFZero. The link is https://rfzero.net. Output is +13dBm, not a watt but enough to use or drive an amplifier.

73,
Steve KD2OM

On Jun 30, 2022, at 11:48, Edward Hammond <manager@...> wrote:

If it's not too technically difficult (I have no idea), somebody should convince Harry Zachrisson - or similar small scale hardware maker - to make an affordable little 1w FSTW4 transmitter. Is a watt enough?

I think that would encourage / enable a lot of experimentation. Alligator clip it to your gutter or a fence rail and see what happens ... and similar. Or hook it up to the beverage antenna when not otherwise in use.

Set it up as kickstarter type thing so enough orders could be (hopefully) collected to make it economically feasible for Harry.

EH



On 6/30/22 11:22 AM, Jim Lill wrote:


Seems like at the moment we may be in a chicken and egg or Yogi Berra situation. No transmits there anymore because everybody gave up listening. There's darn few stateside TX stations so listening bears little fruit.

The RX crowd has it easy as our wspr-capable receivers can do it with no issue. But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.

* TX antennas on the 630/2200 bands are already a challenge and
keeping them in tune while the matching components heat up will be
a challenge. Commercial NDB antennas matching units have
surveillance tuning
* The TX itself may be challenged for lengthy TX periods.
* Its use on other bands may provide a new unique or logging but
likely nothing propagation relevant.

Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.

-Jim

WA2ZKD








Rob Robinett
 

I am in the queue to buy a RFZero, but there is no estimate of when it will be available.

On Thu, Jun 30, 2022 at 9:54 AM KD2OM <steve@...> wrote:
Ed,
Take a look at RFZero. The link is https://rfzero.net. Output is +13dBm, not a watt but enough to use or drive an amplifier.

73,
Steve KD2OM
> On Jun 30, 2022, at 11:48, Edward Hammond <manager@...> wrote:
>
> If it's not too technically difficult (I have no idea), somebody should convince Harry Zachrisson - or similar small scale hardware maker - to make an affordable little 1w FSTW4 transmitter.  Is a watt enough?
>
> I think that would encourage / enable a lot of  experimentation.  Alligator clip it to your gutter or a fence rail and see what happens ... and similar.  Or hook it up to the beverage antenna when not otherwise in use.
>
> Set it up as kickstarter type thing so enough orders could be (hopefully) collected to make it economically feasible for Harry.
>
> EH
>
>
>
>> On 6/30/22 11:22 AM, Jim Lill wrote:
>>
>>
>> Seems like at the moment we may be in a chicken and egg or Yogi Berra situation.  No transmits there anymore because everybody gave up listening.  There's darn few stateside TX stations so listening bears little fruit.
>>
>> The RX crowd has it easy as our wspr-capable receivers can do it with no issue.  But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.
>>
>>  * TX antennas on the 630/2200 bands are already a challenge and
>>    keeping them in tune while the matching components heat up will be
>>    a challenge. Commercial NDB antennas matching units have
>>    surveillance tuning
>>  * The TX itself may be challenged for lengthy TX periods.
>>  * Its use on other bands may provide a new unique or logging but
>>    likely nothing propagation relevant.
>>
>> Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.
>>
>> -Jim
>>
>> WA2ZKD
>>
>>
>>
>
>
>
>
>
>
>








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


Jim Lill
 

KD2OM has an RFzero and I have the amplifier for 630M. We intend to have something on the air for the fall "LF season".  Last season, my poor setup reached 1000 km on wspr. This time around, we'll have a better antenna.

-Jim

On 6/30/22 14:22, Rob Robinett wrote:
I am in the queue to buy a RFZero, but there is no estimate of when it will be available.

On Thu, Jun 30, 2022 at 9:54 AM KD2OM <steve@...> wrote:
Ed,
Take a look at RFZero. The link is https://rfzero.net. Output is +13dBm, not a watt but enough to use or drive an amplifier.

73,
Steve KD2OM
> On Jun 30, 2022, at 11:48, Edward Hammond <manager@...> wrote:
>
> If it's not too technically difficult (I have no idea), somebody should convince Harry Zachrisson - or similar small scale hardware maker - to make an affordable little 1w FSTW4 transmitter.  Is a watt enough?
>
> I think that would encourage / enable a lot of  experimentation.  Alligator clip it to your gutter or a fence rail and see what happens ... and similar.  Or hook it up to the beverage antenna when not otherwise in use.
>
> Set it up as kickstarter type thing so enough orders could be (hopefully) collected to make it economically feasible for Harry.
>
> EH
>
>
>
>> On 6/30/22 11:22 AM, Jim Lill wrote:
>>
>>
>> Seems like at the moment we may be in a chicken and egg or Yogi Berra situation.  No transmits there anymore because everybody gave up listening.  There's darn few stateside TX stations so listening bears little fruit.
>>
>> The RX crowd has it easy as our wspr-capable receivers can do it with no issue.  But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.
>>
>>  * TX antennas on the 630/2200 bands are already a challenge and
>>    keeping them in tune while the matching components heat up will be
>>    a challenge. Commercial NDB antennas matching units have
>>    surveillance tuning
>>  * The TX itself may be challenged for lengthy TX periods.
>>  * Its use on other bands may provide a new unique or logging but
>>    likely nothing propagation relevant.
>>
>> Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.
>>
>> -Jim
>>
>> WA2ZKD
>>
>>
>>
>
>
>
>
>
>
>








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


Glenn Elmore
 

I think you are probably right about it being chicken and egg but with WD capable of simultaneously decoding multiple modes perhaps the advantages of FST4x over WSPR and JT9 could come to the fore pretty quickly.  I ran mode 5 last night on 20m and already we are picking up some new spotters vs. a few days ago. Thanks for those that have modified their schedules to include FST4W.

UTC   (y-m-d) TX txGrid RX rxGrid MHz W SNR drift km Az° mode km/W spotQ version
2022-07-01 06:25:00 N6GN DN70ll W3ENR FM28jh 14.097104 5 -26 0 2563 86 5 513 143 WD_3.0.3.1
2022-07-01 06:25:00 N6GN DN70ll ZL2005SWL RE68mx 14.097105 5 -30 0 12254 233 5 2451 409 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll KPH CM88mc 14.097103 5 -12 0 1561 266 5 312 208 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll OE9GHV JN47wk 14.0971 5 -27 0 8323 39 5 1665 416 WD_3.0.3
2022-07-01 06:15:00 N6GN DN70ll N6GN/K DN70jo 14.097105 5 18 0 20 315 5 4 6 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll EA8BFK IL38bo 14.0971 5 -33 0 8085 67 5 1617 135 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll KFS CM87tj 14.097105 5 -22 0 1535 263 5 307 119 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll AI6VN/KH6 BL10rx 14.097105 5 -10 0 5291 262 5 1058 764 WD_3.0.3.1

It does seem that there are several dB of improvement in spot depth, e.g. EA8BFK's spots in the low -30's seem real. I don't think we'd see that with WSPR.

I was transmitting on 14.097105 ( I meant to be 100 Hz lower at WSPR  band bottom)  and it can be seen that not all these spotters yet have Rob's new code that gives 1 Hz resolution.

Reading the docs for it, it would seem that the code designers very much want to see uptake of FST4 over previous modes . I think those of us with WD might really help this. The more spotters there are and the more the advantages become known perhaps the more transmitters there will be.

Glenn n6gn

On 6/30/22 09:22, Jim Lill wrote:


Seems like at the moment we may be in a chicken and egg or Yogi Berra situation.  No transmits there anymore because everybody gave up listening.  There's darn few stateside TX stations so listening bears little fruit.

The RX crowd has it easy as our wspr-capable receivers can do it with no issue.  But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.

  • TX antennas on the 630/2200 bands are already a challenge and keeping them in tune while the matching components heat up will be a challenge. Commercial NDB antennas matching units have surveillance tuning
  • The TX itself may be challenged for lengthy TX periods.
  • Its use on other bands may provide a new unique or logging but likely nothing propagation relevant.

Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.

-Jim

WA2ZKD




Jim Lill
 

when FST4 came out I thought Joe stated it was aimed at the low(er) bands and then perhaps UHF. What advantage does it have on 20M etc.?

-Jim

On 7/1/22 09:53, Glenn Elmore wrote:

I think you are probably right about it being chicken and egg but with WD capable of simultaneously decoding multiple modes perhaps the advantages of FST4x over WSPR and JT9 could come to the fore pretty quickly.  I ran mode 5 last night on 20m and already we are picking up some new spotters vs. a few days ago. Thanks for those that have modified their schedules to include FST4W.

UTC   (y-m-d) TX txGrid RX rxGrid MHz W SNR drift km Az° mode km/W spotQ version
2022-07-01 06:25:00 N6GN DN70ll W3ENR FM28jh 14.097104 5 -26 0 2563 86 5 513 143 WD_3.0.3.1
2022-07-01 06:25:00 N6GN DN70ll ZL2005SWL RE68mx 14.097105 5 -30 0 12254 233 5 2451 409 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll KPH CM88mc 14.097103 5 -12 0 1561 266 5 312 208 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll OE9GHV JN47wk 14.0971 5 -27 0 8323 39 5 1665 416 WD_3.0.3
2022-07-01 06:15:00 N6GN DN70ll N6GN/K DN70jo 14.097105 5 18 0 20 315 5 4 6 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll EA8BFK IL38bo 14.0971 5 -33 0 8085 67 5 1617 135 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll KFS CM87tj 14.097105 5 -22 0 1535 263 5 307 119 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll AI6VN/KH6 BL10rx 14.097105 5 -10 0 5291 262 5 1058 764 WD_3.0.3.1

It does seem that there are several dB of improvement in spot depth, e.g. EA8BFK's spots in the low -30's seem real. I don't think we'd see that with WSPR.

I was transmitting on 14.097105 ( I meant to be 100 Hz lower at WSPR  band bottom)  and it can be seen that not all these spotters yet have Rob's new code that gives 1 Hz resolution.

Reading the docs for it, it would seem that the code designers very much want to see uptake of FST4 over previous modes . I think those of us with WD might really help this. The more spotters there are and the more the advantages become known perhaps the more transmitters there will be.

Glenn n6gn

On 6/30/22 09:22, Jim Lill wrote:


Seems like at the moment we may be in a chicken and egg or Yogi Berra situation.  No transmits there anymore because everybody gave up listening.  There's darn few stateside TX stations so listening bears little fruit.

The RX crowd has it easy as our wspr-capable receivers can do it with no issue.  But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.

  • TX antennas on the 630/2200 bands are already a challenge and keeping them in tune while the matching components heat up will be a challenge. Commercial NDB antennas matching units have surveillance tuning
  • The TX itself may be challenged for lengthy TX periods.
  • Its use on other bands may provide a new unique or logging but likely nothing propagation relevant.

Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.

-Jim

WA2ZKD




Glenn Elmore
 

I suppose this is still TBD and a good reason for getting more transmitters and spotters. 

All things equal (they aren't) I'd guess that the advantage over mode 2 would be the ratio of energies or  roughly 10*log(mode/2).  For the mode 5 I ran last night that would only be about 4 dB. This matches with the -29 -4 = -33 dB SNR I saw last night, if the SNR reporting at this level is to be believed.

Probably the SNR reporting becomes suspect as one gets close to the lower limit and perhaps HF/ionospheric propagation doesn't stay constant for the longer modes, again TBD. Joe shows:

which pretty well matches the energy estimate. 

So IF 20m or other HF propagation is stable AND the decoders make similar use of received energy I guess we might see as much as 12 dB deeper spotting out of mode 30.  That could be really interesting.

I would wonder whether we get 30 minutes of stable propagation just as the MUF is going through a particular band,  or maybe even grayline might not be this long, I'm not sure, but as a practical matter I doubt that the spots I received last night would all have occurred with a 2m WSPR transmission. Even for a mode 2 FST4W it looks to me like there may be a couple of dB or so improvement.

It seems worth investigating.

Glenn n6gn


On 7/1/22 07:58, Jim Lill wrote:

when FST4 came out I thought Joe stated it was aimed at the low(er) bands and then perhaps UHF. What advantage does it have on 20M etc.?

-Jim


Jim Lill
 

Here is a key statement from that same document....

achieving the sensitivities listed in the table requires that oscillator drifts and path-induced Doppler shifts must be less than the tone spacing, over the full sequence length.

-Jim

On 7/1/22 13:29, Glenn Elmore wrote:

I suppose this is still TBD and a good reason for getting more transmitters and spotters. 

All things equal (they aren't) I'd guess that the advantage over mode 2 would be the ratio of energies or  roughly 10*log(mode/2).  For the mode 5 I ran last night that would only be about 4 dB. This matches with the -29 -4 = -33 dB SNR I saw last night, if the SNR reporting at this level is to be believed.

Probably the SNR reporting becomes suspect as one gets close to the lower limit and perhaps HF/ionospheric propagation doesn't stay constant for the longer modes, again TBD. Joe shows:

which pretty well matches the energy estimate. 

So IF 20m or other HF propagation is stable AND the decoders make similar use of received energy I guess we might see as much as 12 dB deeper spotting out of mode 30.  That could be really interesting.

I would wonder whether we get 30 minutes of stable propagation just as the MUF is going through a particular band,  or maybe even grayline might not be this long, I'm not sure, but as a practical matter I doubt that the spots I received last night would all have occurred with a 2m WSPR transmission. Even for a mode 2 FST4W it looks to me like there may be a couple of dB or so improvement.

It seems worth investigating.

Glenn n6gn


On 7/1/22 07:58, Jim Lill wrote:

when FST4 came out I thought Joe stated it was aimed at the low(er) bands and then perhaps UHF. What advantage does it have on 20M etc.?

-Jim


Glenn Elmore
 

From previous experience, I think HF propagation may meet the Doppler shift requirement much of time  excluding  when the MUF is moving through the frequency when the ionosphere is moving vertically rapidly.  With GPS referenced systems even 10m Doppler may be OK to  to a fraction of a Hz much of the time and I think sporadic E which we've also seen on WSPR tests,  is not likely, to be too much of a problem. Joe was initially ruling out WSPR2 on 6m because he thought that Doppler shift and ACS (aircraft reflection) self-QRM would be a problem. As it turned out Doppler and reflections are virtually never a problem that way with stabilized systems, even on 6m which is perhaps the worst.

Some commercial radios have been shown to be usable for 70 cm WSPR, say 1-2 Hz drift as the RF deck would heat up, which might imply usable performance of this non stabilized equipment out to mode 15 through much of HF most of the time.  This is something we struggled with and conquered during 2m/70cm/23cm WSPR operations and documented on the 2m+ WSPR group. There are quite a few spectrograms of various kinds of Doppler and reflection on VHF on these pages, taken over the years.  It's interesting and easy to differentiate aircraft types (helicopters in particular!) and even individual aircraft vectors in some situations. We have graphs of these, meteor pings and wing-tip vortex paths which have been interesting but not  usually a deterrent to successful spots on 2m WSPR.

I think out to mode 15 worth trying given reasonable tx/rx equipment on HF. I am transmitting a GPS referenced with much sub ppb stability over these longer modes so if the WD receivers are adequate, we might have success on HF much of the time.  I'll try to run for a while on 20m  mode 5 as I am now and then perhaps move to mode 15 for comparison after a few days for comparison.

Again, the more spotters the better. GPS-stabilized Kiwis even may be adequate though they do have some short term variance that could be an issue.


Glenn n6gn


On 7/1/22 11:51, Jim Lill wrote:

Here is a key statement from that same document....

achieving the sensitivities listed in the table requires that oscillator drifts and path-induced Doppler shifts must be less than the tone spacing, over the full sequence length.

-Jim


Rob Robinett
 

To add to Glenn's response, Joe's paper on FST4 at https://physics.princeton.edu/pulsar/k1jt/FST4_Quick_Start.pdf says FST4W-120 has about a 1.4 dB efficiency advantage over WSPR-2.  The longer modes add up to 12 dB more SNR depth for -1800:

"FST4W-120 and the longer sequence lengths are proportionally more sensitive. FST4W-120 is about 1.4 dB better than standard WSPR, and with its 30-minute sequences FST4W-1800 reaches a threshold SNR of nearly -45 dB. We strongly recommend that users of JT9 and WSPR on the LF and MF bands should migrate to using FST4 and FST4W, instead"

I think that Joe thought that doppler shift on ionospheric propagated signals would limit the usefulness of FST4W on the HF bands, but Glenn and Gwyn's experiences with doppler measurements suggest that Joe may be wrong about that.  
So these experiments are to show how useful all the FST4W modes are on the HF bands.  I think these experiments will be a significant contribution to the WSJT-x effort, since using WSJT-x as the receiver is a very awkward one band / one mode.

==========

I have upgraded WD 3.0 at OE9GHV and EA7BFK so they too now print out the fill rx frequency of FST4W spots.
By using an i7 for the low bands and an i5 for the high bands, OE9BFK is listening for all modes on all bands all the time.
EA8BFK has only an i7, so he is decoding only F2:F5 on all bands.

Maui, KFS, KPH, KA7OEI-1, N6GN, WA2TP, EA7BFK, and OE9GHV are all listening through at least F5.
I'll try to put up a frequently updated table on wsprdaemon.org which displays a list of WD reporters and what modes they are listening for.


On Fri, Jul 1, 2022 at 6:59 AM Jim Lill <jim@...> wrote:

when FST4 came out I thought Joe stated it was aimed at the low(er) bands and then perhaps UHF. What advantage does it have on 20M etc.?

-Jim

On 7/1/22 09:53, Glenn Elmore wrote:

I think you are probably right about it being chicken and egg but with WD capable of simultaneously decoding multiple modes perhaps the advantages of FST4x over WSPR and JT9 could come to the fore pretty quickly.  I ran mode 5 last night on 20m and already we are picking up some new spotters vs. a few days ago. Thanks for those that have modified their schedules to include FST4W.

UTC   (y-m-d) TX txGrid RX rxGrid MHz W SNR drift km Az° mode km/W spotQ version
2022-07-01 06:25:00 N6GN DN70ll W3ENR FM28jh 14.097104 5 -26 0 2563 86 5 513 143 WD_3.0.3.1
2022-07-01 06:25:00 N6GN DN70ll ZL2005SWL RE68mx 14.097105 5 -30 0 12254 233 5 2451 409 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll KPH CM88mc 14.097103 5 -12 0 1561 266 5 312 208 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll OE9GHV JN47wk 14.0971 5 -27 0 8323 39 5 1665 416 WD_3.0.3
2022-07-01 06:15:00 N6GN DN70ll N6GN/K DN70jo 14.097105 5 18 0 20 315 5 4 6 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll EA8BFK IL38bo 14.0971 5 -33 0 8085 67 5 1617 135 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll KFS CM87tj 14.097105 5 -22 0 1535 263 5 307 119 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll AI6VN/KH6 BL10rx 14.097105 5 -10 0 5291 262 5 1058 764 WD_3.0.3.1

It does seem that there are several dB of improvement in spot depth, e.g. EA8BFK's spots in the low -30's seem real. I don't think we'd see that with WSPR.

I was transmitting on 14.097105 ( I meant to be 100 Hz lower at WSPR  band bottom)  and it can be seen that not all these spotters yet have Rob's new code that gives 1 Hz resolution.

Reading the docs for it, it would seem that the code designers very much want to see uptake of FST4 over previous modes . I think those of us with WD might really help this. The more spotters there are and the more the advantages become known perhaps the more transmitters there will be.

Glenn n6gn

On 6/30/22 09:22, Jim Lill wrote:


Seems like at the moment we may be in a chicken and egg or Yogi Berra situation.  No transmits there anymore because everybody gave up listening.  There's darn few stateside TX stations so listening bears little fruit.

The RX crowd has it easy as our wspr-capable receivers can do it with no issue.  But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.

  • TX antennas on the 630/2200 bands are already a challenge and keeping them in tune while the matching components heat up will be a challenge. Commercial NDB antennas matching units have surveillance tuning
  • The TX itself may be challenged for lengthy TX periods.
  • Its use on other bands may provide a new unique or logging but likely nothing propagation relevant.

Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.

-Jim

WA2ZKD





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


WA2TP - Tom
 

Rob,
My new server is online and set to decode 4w all bands, all modes except -30 above 80m.
I also sent you a few messages on telegram.

On Jul 1, 2022, at 4:54 PM, Rob Robinett <rob@...> wrote:


To add to Glenn's response, Joe's paper on FST4 at https://physics.princeton.edu/pulsar/k1jt/FST4_Quick_Start.pdf says FST4W-120 has about a 1.4 dB efficiency advantage over WSPR-2.  The longer modes add up to 12 dB more SNR depth for -1800:

"FST4W-120 and the longer sequence lengths are proportionally more sensitive. FST4W-120 is about 1.4 dB better than standard WSPR, and with its 30-minute sequences FST4W-1800 reaches a threshold SNR of nearly -45 dB. We strongly recommend that users of JT9 and WSPR on the LF and MF bands should migrate to using FST4 and FST4W, instead"

I think that Joe thought that doppler shift on ionospheric propagated signals would limit the usefulness of FST4W on the HF bands, but Glenn and Gwyn's experiences with doppler measurements suggest that Joe may be wrong about that.  
So these experiments are to show how useful all the FST4W modes are on the HF bands.  I think these experiments will be a significant contribution to the WSJT-x effort, since using WSJT-x as the receiver is a very awkward one band / one mode.

==========

I have upgraded WD 3.0 at OE9GHV and EA7BFK so they too now print out the fill rx frequency of FST4W spots.
By using an i7 for the low bands and an i5 for the high bands, OE9BFK is listening for all modes on all bands all the time.
EA8BFK has only an i7, so he is decoding only F2:F5 on all bands.

Maui, KFS, KPH, KA7OEI-1, N6GN, WA2TP, EA7BFK, and OE9GHV are all listening through at least F5.
I'll try to put up a frequently updated table on wsprdaemon.org which displays a list of WD reporters and what modes they are listening for.


On Fri, Jul 1, 2022 at 6:59 AM Jim Lill <jim@...> wrote:

when FST4 came out I thought Joe stated it was aimed at the low(er) bands and then perhaps UHF. What advantage does it have on 20M etc.?

-Jim

On 7/1/22 09:53, Glenn Elmore wrote:

I think you are probably right about it being chicken and egg but with WD capable of simultaneously decoding multiple modes perhaps the advantages of FST4x over WSPR and JT9 could come to the fore pretty quickly.  I ran mode 5 last night on 20m and already we are picking up some new spotters vs. a few days ago. Thanks for those that have modified their schedules to include FST4W.

UTC   (y-m-d) TX txGrid RX rxGrid MHz W SNR drift km Az° mode km/W spotQ version
2022-07-01 06:25:00 N6GN DN70ll W3ENR FM28jh 14.097104 5 -26 0 2563 86 5 513 143 WD_3.0.3.1
2022-07-01 06:25:00 N6GN DN70ll ZL2005SWL RE68mx 14.097105 5 -30 0 12254 233 5 2451 409 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll KPH CM88mc 14.097103 5 -12 0 1561 266 5 312 208 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll OE9GHV JN47wk 14.0971 5 -27 0 8323 39 5 1665 416 WD_3.0.3
2022-07-01 06:15:00 N6GN DN70ll N6GN/K DN70jo 14.097105 5 18 0 20 315 5 4 6 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll EA8BFK IL38bo 14.0971 5 -33 0 8085 67 5 1617 135 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll KFS CM87tj 14.097105 5 -22 0 1535 263 5 307 119 WD_3.0.3.1
2022-07-01 06:15:00 N6GN DN70ll AI6VN/KH6 BL10rx 14.097105 5 -10 0 5291 262 5 1058 764 WD_3.0.3.1

It does seem that there are several dB of improvement in spot depth, e.g. EA8BFK's spots in the low -30's seem real. I don't think we'd see that with WSPR.

I was transmitting on 14.097105 ( I meant to be 100 Hz lower at WSPR  band bottom)  and it can be seen that not all these spotters yet have Rob's new code that gives 1 Hz resolution.

Reading the docs for it, it would seem that the code designers very much want to see uptake of FST4 over previous modes . I think those of us with WD might really help this. The more spotters there are and the more the advantages become known perhaps the more transmitters there will be.

Glenn n6gn

On 6/30/22 09:22, Jim Lill wrote:


Seems like at the moment we may be in a chicken and egg or Yogi Berra situation.  No transmits there anymore because everybody gave up listening.  There's darn few stateside TX stations so listening bears little fruit.

The RX crowd has it easy as our wspr-capable receivers can do it with no issue.  But TX brings on new issues. Sure, you can run the 2 minute mode and that's no harder the wspr but as you go for the longer TX times, new issues arise.

  • TX antennas on the 630/2200 bands are already a challenge and keeping them in tune while the matching components heat up will be a challenge. Commercial NDB antennas matching units have surveillance tuning
  • The TX itself may be challenged for lengthy TX periods.
  • Its use on other bands may provide a new unique or logging but likely nothing propagation relevant.

Don't overspend on your hardware to do F30 as I think it will be sometime before you'll see much activity there.

-Jim

WA2ZKD





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


Erwin - PE3ES - F4VTQ
 

QRPlabs QDX will do all WSJT-x modes with 5 watts on 1 band out of 4 : 80/40/30/20, 60 is doable as well.
Maybe not enough by itself but certainly enough to drive an amp on 80 meters.


Glenn Elmore
 

Erwin,

Interesting option. I think 5W is likely just fine. I have some questions about the stability of the TCXO on long FST4 modes but I'm willing to try it, so I pre-ordred one. I can inject my own GPS referenced 25 MHz  o rpossibly phaselock his TCXO 9if I can get to it) if necessary to make mode 30 work.

Hans has done a lot of design work and measuring the incoming WSJT-X audio to set a Si5131 is a neat solution, throwing in a simple SDR is even better. 

I'll see what happens with it when I receive it, possibly this month.

Glenn n6gn


On 7/2/22 07:37, Erwin - PE3ES - F4VTQ via groups.io wrote:
QRPlabs QDX will do all WSJT-x modes with 5 watts on 1 band out of 4 : 80/40/30/20, 60 is doable as well.
Maybe not enough by itself but certainly enough to drive an amp on 80 meters.


Stuart Ogawa
 

Thanks for the heads up Erwin.

Just placed an order for 3 of these QDX units.  Once I have these, then I will begin fstw4 beacon transmitting on bands, non stop.

On Sat, Jul 2, 2022 at 7:22 AM Glenn Elmore <n6gn@...> wrote:

Erwin,

Interesting option. I think 5W is likely just fine. I have some questions about the stability of the TCXO on long FST4 modes but I'm willing to try it, so I pre-ordred one. I can inject my own GPS referenced 25 MHz  o rpossibly phaselock his TCXO 9if I can get to it) if necessary to make mode 30 work.

Hans has done a lot of design work and measuring the incoming WSJT-X audio to set a Si5131 is a neat solution, throwing in a simple SDR is even better. 

I'll see what happens with it when I receive it, possibly this month.

Glenn n6gn


On 7/2/22 07:37, Erwin - PE3ES - F4VTQ via groups.io wrote:
QRPlabs QDX will do all WSJT-x modes with 5 watts on 1 band out of 4 : 80/40/30/20, 60 is doable as well.
Maybe not enough by itself but certainly enough to drive an amp on 80 meters.


WA2TP - Tom
 

I am also Receiving all bands 2200-10 including 4w modes on 64rx channels. 

On Jul 2, 2022, at 3:27 PM, Stuart Ogawa <stuartogawa@...> wrote:


Thanks for the heads up Erwin.

Just placed an order for 3 of these QDX units.  Once I have these, then I will begin fstw4 beacon transmitting on bands, non stop.

On Sat, Jul 2, 2022 at 7:22 AM Glenn Elmore <n6gn@...> wrote:

Erwin,

Interesting option. I think 5W is likely just fine. I have some questions about the stability of the TCXO on long FST4 modes but I'm willing to try it, so I pre-ordred one. I can inject my own GPS referenced 25 MHz  o rpossibly phaselock his TCXO 9if I can get to it) if necessary to make mode 30 work.

Hans has done a lot of design work and measuring the incoming WSJT-X audio to set a Si5131 is a neat solution, throwing in a simple SDR is even better. 

I'll see what happens with it when I receive it, possibly this month.

Glenn n6gn


On 7/2/22 07:37, Erwin - PE3ES - F4VTQ via groups.io wrote:
QRPlabs QDX will do all WSJT-x modes with 5 watts on 1 band out of 4 : 80/40/30/20, 60 is doable as well.
Maybe not enough by itself but certainly enough to drive an amp on 80 meters.