locked 3D2CR - odd 'Fox' behaviour #FoxAndHound


Martin G0HDB
 

3D2CR is currently QRV from Conway Reef, which is a pretty difficult DXCC entity to work from here in the UK.

I received a tip-off at approx 0730z today (Sun 19th Sept) that 3D2CR was operating as a DXpedition-mode 'Fox' on 18095kHz so I took a look and sure enough I was getting reasonable copy so I selected my FT8 'Hound' configuration and gave a call (above 1000Hz of course!).  I eventually got a call from 3D2CR who gave me a report of -08; my system responded accordingly by QSY'ing my Tx cursor down onto the Fox's frequency (around 300Hz IIRC) and sending a report of R-14.  I then expected to receive either an RR73 from the 3D2CR Fox or a repeat of my report but I copied neither, despite me copying other transmissions from 3D2CR.

My system then QSY'ed my Tx frequency up by 300Hz and continued re-sending my report of -14 until everything timed out; at no point did the 3D2CR Fox either re-send my report of -08 or send me an RR73.

I continued watching the activity and could see that the same thing was happening with many other Hound callers - the 3D2CR Fox would send an initial report to a Hound but would then fail to either re-send the report or to send an RR73 to indicate the QSO exchanges had been successfully completed.  I saw the 3D2CR Fox send very few RR73s - I would guess to maybe 1 in10 Hounds.

Interestingly, a few minutes after my apparent QSO with 3D2CR on 17m I managed to work them on 20m; in this QSO the sequencing worked exactly as expected both for me and for several other Hounds who I could copy sending their reports to the 3D2CR Fox - we all received an RR73 from the Fox.

Can the development team suggest why the 3D2CR Fox operation on 17m didn't appear to send either a repeat of a Hound's report or the final RR73 - could the Fox's failure to send either a repeat report or an RR73 to a Hound be caused by the 17m Fox operator perhaps logging QSOs before they'd run through the complete sequence, in an attempt to maximise the QSO rate?

TIA
--
Martin G0HDB


Ronnie Hull - W5SUM
 

I’m totally confused by the DXpedition (fox/hound) mode and have yet to make a single contact like that. Have missed some great ATNO’s because of it
Ron W5SUM

On Sep 19, 2021, at 1:56 PM, Martin G0HDB <marting0hdb@...> wrote:

3D2CR is currently QRV from Conway Reef, which is a pretty difficult DXCC entity to work from here in the UK.

I received a tip-off at approx 0730z today (Sun 19th Sept) that 3D2CR was operating as a DXpedition-mode 'Fox' on 18095kHz so I took a look and sure enough I was getting reasonable copy so I selected my FT8 'Hound' configuration and gave a call (above 1000Hz of course!). I eventually got a call from 3D2CR who gave me a report of -08; my system responded accordingly by QSY'ing my Tx cursor down onto the Fox's frequency (around 300Hz IIRC) and sending a report of R-14. I then expected to receive either an RR73 from the 3D2CR Fox or a repeat of my report but I copied neither, despite me copying other transmissions from 3D2CR.

My system then QSY'ed my Tx frequency up by 300Hz and continued re-sending my report of -14 until everything timed out; at no point did the 3D2CR Fox either re-send my report of -08 or send me an RR73.

I continued watching the activity and could see that the same thing was happening with many other Hound callers - the 3D2CR Fox would send an initial report to a Hound but would then fail to either re-send the report or to send an RR73 to indicate the QSO exchanges had been successfully completed. I saw the 3D2CR Fox send very few RR73s - I would guess to maybe 1 in10 Hounds.

Interestingly, a few minutes after my apparent QSO with 3D2CR on 17m I managed to work them on 20m; in this QSO the sequencing worked exactly as expected both for me and for several other Hounds who I could copy sending their reports to the 3D2CR Fox - we all received an RR73 from the Fox.

Can the development team suggest why the 3D2CR Fox operation on 17m didn't appear to send either a repeat of a Hound's report or the final RR73 - could the Fox's failure to send either a repeat report or an RR73 to a Hound be caused by the 17m Fox operator perhaps logging QSOs before they'd run through the complete sequence, in an attempt to maximise the QSO rate?

TIA
--
Martin G0HDB


Brian Stucker
 

I think you answered your own question there.

"the 17m Fox operator perhaps logging QSOs before they'd run through the complete sequence, in an attempt to maximise the QSO rate"

73,
B


On Sun, Sep 19, 2021 at 11:56 AM Martin G0HDB <marting0hdb@...> wrote:
3D2CR is currently QRV from Conway Reef, which is a pretty difficult DXCC entity to work from here in the UK.

I received a tip-off at approx 0730z today (Sun 19th Sept) that 3D2CR was operating as a DXpedition-mode 'Fox' on 18095kHz so I took a look and sure enough I was getting reasonable copy so I selected my FT8 'Hound' configuration and gave a call (above 1000Hz of course!).  I eventually got a call from 3D2CR who gave me a report of -08; my system responded accordingly by QSY'ing my Tx cursor down onto the Fox's frequency (around 300Hz IIRC) and sending a report of R-14.  I then expected to receive either an RR73 from the 3D2CR Fox or a repeat of my report but I copied neither, despite me copying other transmissions from 3D2CR.

My system then QSY'ed my Tx frequency up by 300Hz and continued re-sending my report of -14 until everything timed out; at no point did the 3D2CR Fox either re-send my report of -08 or send me an RR73.

I continued watching the activity and could see that the same thing was happening with many other Hound callers - the 3D2CR Fox would send an initial report to a Hound but would then fail to either re-send the report or to send an RR73 to indicate the QSO exchanges had been successfully completed.  I saw the 3D2CR Fox send very few RR73s - I would guess to maybe 1 in10 Hounds.

Interestingly, a few minutes after my apparent QSO with 3D2CR on 17m I managed to work them on 20m; in this QSO the sequencing worked exactly as expected both for me and for several other Hounds who I could copy sending their reports to the 3D2CR Fox - we all received an RR73 from the Fox.

Can the development team suggest why the 3D2CR Fox operation on 17m didn't appear to send either a repeat of a Hound's report or the final RR73 - could the Fox's failure to send either a repeat report or an RR73 to a Hound be caused by the 17m Fox operator perhaps logging QSOs before they'd run through the complete sequence, in an attempt to maximise the QSO rate?

TIA
--
Martin G0HDB



Jim Brown
 

On 9/19/2021 11:59 AM, Ronnie Hull wrote:
I’m totally confused by the DXpedition (fox/hound) mode
The manual is a great place to start, but it confused me at first too.

Here's the concept. The Fox owns the channel (and it's always a non-standard FT8 dial frequency), and always operates at small offsets, sometimes multiple streams (that is, two or three offsets.) Hounds always transmit at offsets about 1,000 Hz, and can call constantly (in the right sequence).

When the Fox works a station, WSJT-X allows the Fox to take over that Hound's radio, moving that Hound down into the protected space below 1,000 Hz, where there should be no QRM.

All this happens automagically if you have set up Fox/Hound mode per the WSJT-X manual. All we Hounds have to do is pick a calling frequency above 1,000 Hz offset.

73, Jim K9YC


Jim Brown
 

On 9/19/2021 11:59 AM, Ronnie Hull wrote:
Can the development team suggest why the 3D2CR Fox operation on 17m didn't appear to send either a repeat of a Hound's report or the final RR73
MAYBE because the Fox must reduce power if running multiple streams, we may not decode the RR73 because of our local noise. I've not operated as the Fox, so don't know how it works on that end, but when we don't copy RR73, good practice is to send our report again, in which case the Fox should send our RR73 again.

73, Jim K9YC


Jim Brown
 

On 9/19/2021 12:51 PM, Jim Brown wrote:
Hounds always transmit at offsets about 1,000 Hz
Bad fingers -- I meant to say ABOVE 1,000 Hz.

73, Jim K9YC


Ronnie Hull - W5SUM
 

I don’t use SO2R so guess I’m just out of luck

On Sep 19, 2021, at 2:57 PM, Jim Brown <k9yc@...> wrote:

On 9/19/2021 12:51 PM, Jim Brown wrote:
Hounds always transmit at offsets about 1,000 Hz
Bad fingers -- I meant to say ABOVE 1,000 Hz.

73, Jim K9YC



Jim Brown
 

On 9/19/2021 1:01 PM, Ronnie Hull wrote:
I don’t use SO2R so guess I’m just out of luck
Nothing SO2R about it. All this happens with one radio on both ends of the QSO.

73, Jim K9YC


Martin G0HDB
 

On Sun, Sep 19, 2021 at 09:02 PM, Ronnie Hull wrote:
I don’t use SO2R so guess I’m just out of luck
If you've got CAT implemented, so that WSJT-X can control your rig, then that's all you need for successful operation as a Hound.  It *is* possible to operate as a Hound without CAT but it's far from the ideal solution.

The key point to remember when you're trying to work a Fox is that you MUST initially call with your Tx cursor set above the 1,000Hz point on the waterfall - the Fox will *never* respond to Hounds' initial calls below that point.

Once your call has been received by the Fox and the operator has added you to the list of stations to be worked, the Fox will respond by sending you a report; when this is received by your system the WSJT-X software will automatically shift your Tx cursor down to the Fox's transmit frequency below 1,000Hz - typically around 300 - 400Hz - and your system will then send a report back to the Fox.  All being well you'll then receive an RR73 from the Fox and you'll be prompted to log the QSO.  The documentation to the Fox & Hounds DXpedition mode explains what happens when retries are needed - ultimately everything times out and you need to start again, calling as a Hound above 1,000Hz.

It's straightforward enough as long as you've got your system configured appropriately.

--
Martin G0HDB


Martin G0HDB
 

On Sun, Sep 19, 2021 at 08:56 PM, Jim Brown wrote:
MAYBE because the Fox must reduce power if running multiple streams, we
may not decode the RR73 because of our local noise. I've not operated as
the Fox, so don't know how it works on that end, but when we don't copy
RR73, good practice is to send our report again, in which case the Fox
should send our RR73 again.
Hi Jim, I've certainly experienced Fox & Hounds situations in which I haven't copied the Fox's RR73 because of QSB, QRM or whatever but in the 3D2CR scenario on 17m this morning I was copying the Fox's transmissions on the 1 or 2 other streams so I should have been able to copy either a repeat of my report from the Fox or the Fox's RR73 but neither of these appeared, hence my suspicion that the Fox operator was doing something that curtailed the normal sequencing of a QSO with a Hound.

I've also never operated as a Fox so I don't know the intricacies of how the software behaves; the documentation for the DXpedition (Fox & Hounds) mode states:

"Fox will call a specific Hound up to 3 times, waiting for an “R+rpt” response. If a Hound repeatedly sends an “R+rpt” message, Fox will send RR73 up to 3 times."

In my 17m situation this morning, I received a report of -08 from the 3D2CR Fox so he shouldn't have had much difficulty in copying the report of R-14 that I sent back to him; if he hadn't received the report then he should have re-sent his -08 report to me but I didn't see this.  If he did receive my report then he should have sent the RR73 but I didn't see this either!

The documentation also states:

"After receiving “R+rpt” from a Hound previously called, Fox will send “RR73” to that Hound and log the QSO."

However, there's nothing in the documentation to indicate whether the Fox operator can elect to log a QSO before the RR73 has been sent, hence my original request for a comment from the developers.

--
Martin G0HDB


Jim Shorney
 

I've worked many foxen with a 40 year old radio and no CAT. No problem. It works just the same, you just need to be a little more mindful of where the low end is on your SSB filter.

I would go so far as to say that it easier than CAT because I have never had to troubleshoot rig control errors... :)

73

-Jim
NU0C


On Sun, 19 Sep 2021 14:29:25 -0700
"Martin G0HDB" <marting0hdb@...> wrote:

On Sun, Sep 19, 2021 at 09:02 PM, Ronnie Hull wrote:


I don’t use SO2R so guess I’m just out of luck
If you've got CAT implemented, so that WSJT-X can control your rig, then that's all you need for successful operation as a Hound.  It *is* possible to operate as a Hound without CAT but it's far from the ideal solution.

The key point to remember when you're trying to work a Fox is that you MUST initially call with your Tx cursor set above the 1,000Hz point on the waterfall - the Fox will *never* respond to Hounds' initial calls below that point.

Once your call has been received by the Fox and the operator has added you to the list of stations to be worked, the Fox will respond by sending you a report; when this is received by your system the WSJT-X software will automatically shift your Tx cursor down to the Fox's transmit frequency below 1,000Hz - typically around 300 - 400Hz - and your system will then send a report back to the Fox.  All being well you'll then receive an RR73 from the Fox and you'll be prompted to log the QSO.  The documentation to the Fox & Hounds DXpedition mode explains what happens when retries are needed - ultimately everything times out and you need to start again, calling as a Hound above 1,000Hz.

It's straightforward enough as long as you've got your system configured appropriately.

--
Martin G0HDB


Butch Washer
 

Jim,

I have a nonCAT setup as well on my TS-450 and have not used Fox/ Hound mode due to the very low frequency (below 500hz sometimes).
Do you adjust your dial frequency down to move the Fox up in audio frequency then make certain that you call the Fox on would fall above 1000hz and once he calls and move you to his frequency you are transmitting within you good range?

I watch my TX power level closely when I get near 500hz or below since it falls off a lot down there.

I would like to chase F/H’s, but I don’t want to cause excessive noise by over driving below 500hz or just be wasting my time.

I too snicker when I see hams fighting CAT problems that I don’t have! KISS (Keep It Simple Stupid) mode is my favorite!!

Tnx es 73 N5SMQ Butch

On Sep 19, 2021, at 5:57 PM, Jim Shorney <jshorney@...> wrote:


I've worked many foxen with a 40 year old radio and no CAT. No problem. It works just the same, you just need to be a little more mindful of where the low end is on your SSB filter.

I would go so far as to say that it easier than CAT because I have never had to troubleshoot rig control errors... :)

73

-Jim
NU0C


On Sun, 19 Sep 2021 14:29:25 -0700
"Martin G0HDB" <marting0hdb@...> wrote:

On Sun, Sep 19, 2021 at 09:02 PM, Ronnie Hull wrote:


I don’t use SO2R so guess I’m just out of luck
If you've got CAT implemented, so that WSJT-X can control your rig, then that's all you need for successful operation as a Hound. It *is* possible to operate as a Hound without CAT but it's far from the ideal solution.

The key point to remember when you're trying to work a Fox is that you MUST initially call with your Tx cursor set above the 1,000Hz point on the waterfall - the Fox will *never* respond to Hounds' initial calls below that point.

Once your call has been received by the Fox and the operator has added you to the list of stations to be worked, the Fox will respond by sending you a report; when this is received by your system the WSJT-X software will automatically shift your Tx cursor down to the Fox's transmit frequency below 1,000Hz - typically around 300 - 400Hz - and your system will then send a report back to the Fox. All being well you'll then receive an RR73 from the Fox and you'll be prompted to log the QSO. The documentation to the Fox & Hounds DXpedition mode explains what happens when retries are needed - ultimately everything times out and you need to start again, calling as a Hound above 1,000Hz.

It's straightforward enough as long as you've got your system configured appropriately.

--
Martin G0HDB


Butch Washer
 

Sorry for the extra bandwidth on the reflector.

I meant to send this direct to Jim and I missed checking the email address on this. I’m hoping that he will convert it to direct to me when he responds.

Again sorry!!!

Butch N5SMQ

On Sep 20, 2021, at 7:51 AM, Butch Washer via groups.io <n5smqw4@...> wrote:

Jim,

I have a nonCAT setup as well on my TS-450 and have not used Fox/ Hound mode due to the very low frequency (below 500hz sometimes).
Do you adjust your dial frequency down to move the Fox up in audio frequency then make certain that you call the Fox on would fall above 1000hz and once he calls and move you to his frequency you are transmitting within you good range?

I watch my TX power level closely when I get near 500hz or below since it falls off a lot down there.

I would like to chase F/H’s, but I don’t want to cause excessive noise by over driving below 500hz or just be wasting my time.

I too snicker when I see hams fighting CAT problems that I don’t have! KISS (Keep It Simple Stupid) mode is my favorite!!

Tnx es 73 N5SMQ Butch
On Sep 19, 2021, at 5:57 PM, Jim Shorney <jshorney@...> wrote:


I've worked many foxen with a 40 year old radio and no CAT. No problem. It works just the same, you just need to be a little more mindful of where the low end is on your SSB filter.

I would go so far as to say that it easier than CAT because I have never had to troubleshoot rig control errors... :)

73

-Jim
NU0C


On Sun, 19 Sep 2021 14:29:25 -0700
"Martin G0HDB" <marting0hdb@...> wrote:

On Sun, Sep 19, 2021 at 09:02 PM, Ronnie Hull wrote:


I don’t use SO2R so guess I’m just out of luck
If you've got CAT implemented, so that WSJT-X can control your rig, then that's all you need for successful operation as a Hound. It *is* possible to operate as a Hound without CAT but it's far from the ideal solution.

The key point to remember when you're trying to work a Fox is that you MUST initially call with your Tx cursor set above the 1,000Hz point on the waterfall - the Fox will *never* respond to Hounds' initial calls below that point.

Once your call has been received by the Fox and the operator has added you to the list of stations to be worked, the Fox will respond by sending you a report; when this is received by your system the WSJT-X software will automatically shift your Tx cursor down to the Fox's transmit frequency below 1,000Hz - typically around 300 - 400Hz - and your system will then send a report back to the Fox. All being well you'll then receive an RR73 from the Fox and you'll be prompted to log the QSO. The documentation to the Fox & Hounds DXpedition mode explains what happens when retries are needed - ultimately everything times out and you need to start again, calling as a Hound above 1,000Hz.

It's straightforward enough as long as you've got your system configured appropriately.

--
Martin G0HDB


K9RX - Gary
 

FYI to the person that said "he must reduce power if more than one stream" ... power isn't reduced! The total power is the same it is just divided between the streams. So there is a 6 db drop every time you double the number of streams. If there are 4 streams and they are say -16, -16, -17, -16 then that station would be roughly -4 if they were using a single stream. You can use this to estimate the chances of working (and more importantly completing) with the DX if they are weak with one stream and yet, because of THEIR conditions (the stations they're working) they are using multiple streams often. 

Also WSJT doesn't "allow the fox to take over" ... the local program just knows when your call is received with a report to move down to the frequency that you were called on. Note that if the FOX has a need to change from say 4 (or any) to 1 or 2 streams their response to you (RR73) might then 'shift' to one of those streams. 

Finally I worked 3D2CR no problem on 30M. Didn't see any unusual program issues. 

Gary 
K9RX


Bill Somerville
 

On 20/09/2021 13:17, K9RX - Gary wrote:
FYI to the person that said "he must reduce power if more than one stream" ... power isn't reduced! The total power is the same it is just divided between the streams. So there is a 6 db drop every time you double the number of streams. If there are 4 streams and they are say -16, -16, -17, -16 then that station would be roughly -4 if they were using a single stream. You can use this to estimate the chances of working (and more importantly completing) with the DX if they are weak with one stream and yet, because of THEIR conditions (the stations they're working) they are using multiple streams often.

Also WSJT doesn't "allow the fox to take over" ... the local program just knows when your call is received with a report to move down to the frequency that you were called on. Note that if the FOX has a need to change from say 4 (or any) to 1 or 2 streams their response to you (RR73) might then 'shift' to one of those streams.

Finally I worked 3D2CR no problem on 30M. Didn't see any unusual program issues.

Gary
K9RX
Gary,

although what you say about power spread between channels, the Fox *must* also reduce total power. This is necessary because once there are multiple slots the signal is no longer constant envelope and IMD becomes possible thus the Fox *must* ensure that their transmitter is operating in linear mode to keep sidebands to a reasonable level. We recommend a total power reduction of 10% below the maximum output of the transmitter for Fox stations if the number of slots is greater than 1.

73
Bill
G4WJS.


K9RX - Gary
 

Bill,

Sorry - what I meant was that there isn't a reduction when going from 1 stream to multiple streams, at least on the fly. So for a FOX it is a one time consideration - if they are running FOX and multiple streams they need to reduce it when they begin to use it. Correct?

I was only explaining why there is a signal level change - I think the original poster was thinking this was due to power being dropped 'on the fly' when more than one stream was used. 

Gary 


Jim Nuytens
 

I don’t think there are enough fingers and toes on the planet to count the number of times that rule gets violated.

On Sep 19, 2021, at 5:29 PM, Martin G0HDB <marting0hdb@...> wrote:

The key point to remember when you're trying to work a Fox is that you MUST initially call with your Tx cursor set above the 1,000Hz point on the waterfall - the Fox will *never* respond to Hounds' initial calls below that point.


Martin G0HDB
 

On Sun, Sep 19, 2021 at 10:57 PM, Jim Shorney wrote:
I've worked many foxen with a 40 year old radio and no CAT. No problem. It works just the same, you just need to be a little more mindful of where the low end is on your SSB filter.

I would go so far as to say that it easier than CAT because I have never had to troubleshoot rig control errors... :)
Hi Jim, as you've found it's certainly posible to work a Fox when you don't have a CAT-controlled radio but IMO there are two issues.  You've mentioned one, about the bottom corner frequency of whatever filter is being used which could be a real problem when the Fox is operating around the 300Hz mark as many of them do, but there's also the issue of any harmonics of your audio being in-band and hence a cause of QRM when you're Tx'ing with a low audio offset.  This second issue is to all extents and purposes avoided when CAT is used because the Tx audio frequency is always maintained within the 'sweetspot' range of 1500 to 2000Hz, thus putting any harmonics outside the passband of any normal SSB-type filter.

--
Martin G0HDB


kbstackhouse
 

I also saw some "different" behavior.  Of course I didn't have the rig on the correct "base" frequency, which might explain it.  I called once and 3D2CR responded with my report.  The F/H firmware moved me down to his frequency (which was still above 1000Hz) and I sent his report.  No RR73 from him, but for some reason I was moved down to another slot and I resent his report.  I then got the RR73 from him on yet another slot.  If I get no RR73 I do expect to be moved, but not until at least 3 tries.

143715 Tx      2409 ~ 3D2CR K6UF CM97

143730 -9  0.2  934 ~ K7ZV 3D2CR -16

143730 -10 0.2 1114 ~ K6UF 3D2CR –08

143745 Tx      1114 ~ 3D2CR K6UF R-10

143800 –9  0.2  934 ~ JA6SUY RR73; RA1QD <3D2CR> -12
143815 Tx       814 ~ 3D2CR K6UF R-10

143830 -3  0.2  934 ~ K6UF RR73; OH7NGC <3D2CR> -22

143930 -19 0.4  932 ~ CQ 3D2CR RG78  Conway Reef

Ken, K6UF


Reino Talarmo
 

I also saw some "different" behavior.  Of course I didn't have the rig on the correct "base" frequency, which might explain it.  I called once and 3D2CR responded with my report.  The F/H firmware moved me down to his frequency (which was still above 1000Hz) and I sent his report.  No RR73 from him, but for some reason I was moved down to another slot and I resent his report.  I then got the RR73 from him on yet another slot.  If I get no RR73 I do expect to be moved, but not until at least 3 tries.

143715 Tx      2409 ~ 3D2CR K6UF CM97

143730 -9  0.2  934 ~ K7ZV 3D2CR -16

143730 -10 0.2 1114 ~ K6UF 3D2CR –08

143745 Tx      1114 ~ 3D2CR K6UF R-10

143800 –9  0.2  934 ~ JA6SUY RR73; RA1QD <3D2CR> -12
143815 Tx       814 ~ 3D2CR K6UF R-10

143830 -3  0.2  934 ~ K6UF RR73; OH7NGC <3D2CR> -22

143930 -19 0.4  932 ~ CQ 3D2CR RG78  Conway Reef

Ken, K6UF

Hi Ken,

According to the FT8 DXpedition Mode User Guide the 300 Hz shift is normal operation for the second R-10 report sending.

The 3 tries applies when you need to start from beginning by calling DX again above 1000 Hz.

73, Reino OH3mA