[ADXA] N5J background

[Bill Priakos]

Hello, ADXA;

Some info on N5J condx.

https://groups.io/g/wsjtgroup/message/3112

from Glenn, AF8C


________________________________
[https://s3-us-west-1.amazonaws.com/groupsiotestprofilephotos/profilephoto.380351?AWSAccessKeyId=AKIAJECNKOVMCCU3ATNQ&Expires=1723412338&Signature=4LKxv0DrTz68z2m4neZ%2B0U8Lmb8%3D] Ned Stearns <https://groups.io/g/wsjtgroup/message/3112>
Aug 10   #3112   <https://groups.io/g/wsjtgroup/message/3112>


de AA7A here. I am the digi team lead on N5J and have been behind the piles for over 24 hours so far. Let me give everyone some background info.

We manage the PC clocks to balance the DT error between tx and rx . There is an annoying tx audio delay caused by DSP activities in SmartSDR. We check time error daily and make minor time adjustments at times to keep the SuperFox's contribution to timing errors to the minimum on both tc and rx intervals.

There is also an issue with TX offsets in the Flex. Again, we run daily tests with my home station used as truth in order to keep the Fox sync tone as close to 750 Hz on every band. With frequent band changes, it might be off for a short while while we re-adjust.

We are concerned about the completion rates. Using my home station as a quality control tool, it decodes Fox transmissions 100% for signals down to -16. It appears that we are not decoded by Hounds anwhere near as well as we can decode Hounds. My thoughts on why. Take your pick

1. Extremely quiet on Jarvis. We can hear better than Hounds by many dB.

2. We are running only 10 w at times to dodge interference to other Jarvis stations caused by salt spray corrosion on the multiband antennas. Hounds are running much more power. We are working procedures to deal with corrosion effects, but everyone needs to be patient while they get their magic moment. We will bee here another week or so.

3. Some Hounds are still using version RC5

4. We are getting reports of DQRM in EU.

We are hoping to get ahead of the corrosion business and try to get to full output power on the Fox transmitters. It will take time to sort thru all the variables.

73 and see you all on the screen.

Ned / AA7A
On 8/10/2024 8:49 AM, Joe WB9SBD wrote:
Hide quoted text<https://groups.io/g/wsjtgroup/message/3112#quoted-241628374>
I have never understood why anyone would not be really close to dead on with the clock. EVEN if you do not have access to any good time source.

Just look at the freaking waterfall!

look at the average start and stop times of the hundreds of stations transmitting.

are those signal evenly spaced with the TX/RX divider lines? No? adjust your clock till it is.

No external clock needed!

Joe WB9SBD

On 8/10/2024 10:42 AM, JP Tucson, AZ wrote:
Hi Mike,

I can tell you folks the REAL PROBLEM is that there are a bunch of yahoo's out there!

First and worst is the DELIBERATE QRM idiots!  These knuckleheads have been flooding both 15m & 20m with MUSIC, which of course is quite illegal!

On 30m there are folks south of the border who are pirates and they are cab drivers who are using VOICE on 30m, which is CW & DATA only! Also very illegal, but unfortunately nothing we can do, since the FCC has no control down there.

I have also noticed 1 other possible issue. On the FT8 SF, N5J is consistently running with a DT of .3 seconds. Hmmm, you would think they would have a GPS disciplined clock.  Now, there may be an issue there of this RIB (Remote In Box) having a delay effect... don't know. But somewhere I thought one of you dev. team members said the timing was a bit more critical with SF... is that true?

73



On Sat, Aug 10, 2024 at 8:31 AM Mike Black W9MDB via groups.io<http://groups.io/> <mdblack98=yahoo.com at groups.io<mailto:yahoo.com at groups.io>> wrote:
They were 4.4 QSOs/min on the 1st day for FT8.

They now show 3.7/min for FT8 (average over all days so their rate now is notably less then 3.7/min)

Over all QSO rate for the dxpedition has dropped a bit from 8.26/min on 1st day to 6.5/min on the 8th.
This data comes from the statistics tab here https://jarvisisland2024.com/qsl-info-log-search/log-oqrs

[Inline image]

Mike W9MDB



On Saturday, August 10, 2024 at 10:12:56 AM CDT, Saku OH1KH <nylsak at ...<mailto:nylsak at ...>> wrote:


HI!
I have been watching (and trying) N5J now on Friday and Saturday and qso rate seems to be very poor.
I have seen many N5J periods without any completed qsos (no RR73s) and where they exist there are only one or two of them on one period.

Problem on hound side are tons of tuning stations that break up sensitive superfox signal and so RR73 may not be copied by hound that leads to unneeded retries over and over again.

Looked from hound side it looks like fox's problem may be too long callsign queues.
Conditions on band are changing and hounds may change their TX frequency rolling over other, already queued, callsigns.
For that reason fox should keep the queue as short as possible (maybe around 10 calls) so that response for caller could happen quite fast after his over is received by fox.
I do not know how the queue is handled, but as said, from hound's view it should not have many calls (old ones) to avoid changes of fox's receiving conditions while queue is spooled.



--
73 - John - N7GHZ

[https://ci3.googleusercontent.com/mail-sig/AIorK4zuz6j4Flbr9E5LEbJEZoXs-c7IFQ3H3fXC8flgut38lUYAm_8nxeU-wHDULT4Vv70bG4qESfkXa42s]


trying to catch the crew at OH0AM, too!

73, Bill

Bill Priakos – W5SJ
10 Free Ferry Heights
Fort Smith, AR 72903
479.461.8368

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