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Re: vara #Software

KC9SGV
 

Excellent digital mode.
As fast as Pactor 3


KC9SGV


On Sep 1, 2019, at 1:16 PM, David Michael Gaytko // WD4KPD <wd4kpd@...> wrote:

hey youall......what happened to the new vara (any version) software ?

was hoping to at least get a look at it.

david/wd4kpd

Re: vara #Software

KC9SGV
 

Sorry,




On Sep 1, 2019, at 3:54 PM, KC9SGV <kc9sgv@...> wrote:

Excellent digital mode.
As fast as Pactor 3


KC9SGV


On Sep 1, 2019, at 1:16 PM, David Michael Gaytko // WD4KPD <wd4kpd@...> wrote:

hey youall......what happened to the new vara (any version) software ?

was hoping to at least get a look at it.

david/wd4kpd

For Sale: Funcube Pro Plus #FS Funcube Pro Plus #fs

Tony
 

All:

I have a Funcube Pro Plus Dongle for sale. Covers 150 kHz ~ 1.9 GHz.

Best offer shipped CONUS.

Tony -K2MO
Re: For Sale: Funcube Pro Plus #FS Funcube Pro Plus #fs

Barney
 

any takers yet?
Re: For Sale: Funcube Pro Plus #FS Funcube Pro Plus #fs

Tony
 

Barney et all:

The Dongle was sold.

Thank you.

Tony -K2MO



On 9/6/2019 4:16 PM, Barney wrote:
any takers yet?


Over-Driven FT-8 QRM #FT8 QRM #FT8

Tony
 

All:

The interference caused by over-driven FT-8 signals is concerning. The distortion that shows up on either side of the FT8 watering hole is often stronger than the signal one is trying to copy down the band.

The attached image shows an example of the bandwidth occupied by distortion products that are well beyond FT8 operating frequencies.

This has been going on for some time now and it seems most prevalent on weekends when there's lots of activity.

Am I the only one noticing this?

Tony -K2MO
Re: Over-Driven FT-8 QRM #FT8 QRM #FT8

Wa4kfz
 

I suspect too many hams are operating with the SSB compressor on. One advantage of the newer gear is that it supports a defined digital mode where the compressor is always off.

73,
Mark wa4kfz

On Sep 21, 2019, at 4:50 PM, Tony <DXDX@...> wrote:

All:

The interference caused by over-driven FT-8 signals is concerning. The distortion that shows up on either side of the FT8 watering hole is often stronger than the signal one is trying to copy down the band.

The attached image shows an example of the bandwidth occupied by distortion products that are well beyond FT8 operating frequencies.

This has been going on for some time now and it seems most prevalent on weekends when there's lots of activity.

Am I the only one noticing this?

Tony -K2MO




<20000813_201058.bmp>
PA1SDB uses 200 uW over QO100 Sat link #opera #sat #ao100

Graham
 
Edited

Posted to the Opera  facebook  page's 

 

Today SV8RV did copy my 0.2mW signal in OP05 via QO100. Dish is 2 meter :-) 
It was not possible to become decoded with less power   [21/9/2019]

 

Peter, reports the  200 uW  carrier power  was measured at the  feed point  of his  2 meter  dish,  

[noting , that  in terms of  energy expended ,  power deployed  equates to  100 uW ]

SV8RV , taking  the signal off air  at 10GHz 

 

Quite outstanding  , taking the  frequency and path involved  , not to  mention the  AO100  sat !
In terms of actual power deployed,  due to the  50%  mark/space ratio , this equates to 100uW
- noting that  when the  TX is 'off;' power is no  being  supplied , so. only power  deployed is 
actually  used  . 

Test with  longer  timelines  , op1  are planned  soon,  all the band  decoders , benefited  from the  ea5dom
eme  tests ,  the  main concern ,being  the ability of the  AFC to  track the  signal ,  faster times are 'simpler'
seemingly .  over the  Sat , stability is  good, so , longer times should function .... 

 

73-Graham 
g0nbd

 

 

 

Spots in the  EA data base, show  a series  of  -20  /  -21  dB  spots  from  SV8 

 

2019-09-22 10:44:19 PA1SDB JO33KH SV8RV KM07KS 2.035 1.296.600 -11 Op05_||||||||||||||||||_~11dB

2019-09-22 10:44:19 PA1SDB JO33KH SV8RV-1 KM07KS 2.035 1.296.600 -11 Op05_||||||||||||||||||_~11dB

2019-09-21 16:48:14 PA1SDB JO33KH SV8RV KM07KS 2.035 1.296.600 -20 Op05__~21dB

2019-09-21 16:48:14 PA1SDB JO33KH SV8RV-8 KM07KS 2.035 10.368.000 -21 Op05__~21dB

2019-09-21 16:47:41 PA1SDB JO33KH SV8RV-8 KM07KS 2.035 10.368.000 -20 Op05__~20dB

2019-09-21 16:47:41 PA1SDB JO33KH SV8RV KM07KS 2.035 1.296.600 -19 Op05__~20dB

2019-09-21 16:47:41 PA1SDB JO33KH SV8RV-1 KM07KS 2.035 1.296.600 -18 Op05_||_~19dB

2019-09-21 16:47:07 PA1SDB JO33KH SV8RV-1 KM07KS 2.035 1.296.600 -18 Op05_||_~19dB

 

2019-09-21 16:47:07 PA1SDB JO33KH SV8RV KM07KS 2.035 1.296.600 -18 Op05_||_~19dB
Re: Over-Driven FT-8 QRM #FT8 QRM #FT8

Graham
 

Its only  single tone , no  intermod  products , don't matter where the  alc is set,  that's  harmonics  , due to the  aggressive  tone switching ,  mfsk  produces a  similar set of sidebands ,  but not  as bad ,,  wspr2  makes the same , but the  rate is  slow, so no one notices ..interesting  arrl  have issued a statement  , stating its not  compatible  with there  data  award's ?

73-Graham
G0NBD
Re: Over-Driven FT-8 QRM #FT8 QRM #FT8

Chuck K4RGN
 

I check my transmitted digital signals (FT8, etc) with a US$30 SDR USB dongle and SDRSharp freeware. The cheapest dongles don't receive below 25 MHz, but that doesn't matter. Put a dummy load on your transceiver, select 10 meters, send CQ's or VVV's in your chosen mode, and view your transmitted spectrum in SDRSharp. (This is a poor-man's spectrum analyzer.) Avoid overloading the dongle; if the dongle is close enough to your dummy load, you won't need to connect a whip antenna to the dongle.  

If you're splattering, it will be obvious in the SDRSharp waterfall display. With this setup a ham can easily adjust the audio levels between the computer and the transceiver to achieve a proper RF signal -- without having to wait for other hams to tell you that you're splattering. 

These SDR dongles are Swiss army knives for hams. I encourage everyone to get one, unless you have the luxury of a real spectrum analyzer in your shack. The dongles don't make calibrated measurements, but I seldom need calibration. Relative measurements are good enough. 

73, Chuck, K4RGN
Re: Over-Driven FT-8 QRM #FT8 QRM #FT8

Graham
 
Edited

Chuck,

If you  run one of the  RTL $10  dongles,  you  can select  ,  direct conversion in the  driver , and the  device  will  Rx from  ~~ 0 to  25  MHz  ish ,  it  cuts out the  front  end and just uses the  back  a/c convertor  

Usually  enough  stray  coupling to  work,  if not , you  can  attach a line to  the  board ,  if  you  google  RTL direct  conversion,  there are  various shots  of where to  connect  to  

Perhaps a  better  display  is the Spec-Lab  software ,  justlink the  SDR sharp  detector  audio  with  virtual  audio  cable , then you  have a  choice of  decoder  , I think  the  audio  b/w of the  sdr  sharp  system is  constricted , not  wide enough to  monitor  say VARA  FM 9600  mode ,  , which is often deployed  via constricted audio  b/w 

Scope probe and pc sound-card , with  Spec-lab , makes a very good audio  measuring  tool as well  , check the  data input audio  b/w against the  recovered off  air 
73-Graham
g0nbd
Re: Over-Driven FT-8 QRM #FT8 QRM #FT8

Tony
 

Graham:

Single-tone modulation shouldn't produce inter-mod products, but some of the FT8 signals behave that way as if there were 2-tones in play. Could you elaborate on aggressive tone switching and it's effect?

Tony -K2MO


On 9/22/2019 12:15 PM, Graham wrote:
Its only  single tone , no  intermod  products , don't matter where the  alc is set,  that's  harmonics  , due to the  aggressive  tone switching ,  mfsk  produces a  similar set of sidebands ,  but not  as bad ,,  wspr2  makes the same , but the  rate is  slow, so no one notices ..interesting  arrl  have issued a statement  , stating its not  compatible  with there  data  award's ?

73-Graham
G0NBD


Re: Over-Driven FT-8 QRM #FT8 QRM #FT8

Graham
 



Hi Tony 

May be  aggressive is a subjective  assessment , 

If CW tx , could be  described  as  Hard/Aggressive  Keyed ,  that  would  give  the  same  results ,  Ie  , Soft keying / envelope shaping ,  produces ,  less  side bands or  Click's , less  envelope shaping ,  produces a  much harsher / aggressive / wider  signal 

A good  comparison   is the  original  MFSK  mode  and,  say, ROS-HF  ,

In terms  of the  on-air presence ,  MFSK and ROS  are  ''identical''  both  use  single  tone ,  both change  the  tone  frequency  and  duration, as directed  by the  resolve of the  mode coding and modem design , both are  'base band  heterodyned systems ', each may transit via, none linear  systems [ OLIVIA  has a  phase component to  the modem  modulation scheme , and as such , requires linear amplification ]

But, where  as the  MFSK mode , produces a  set of near in ‘side  band's’ , [ even marked on the  spectrum  plot  in Patrick’s Multi-psk, as additional B/W ]   ,  ROS-HF can be seen to  be  clean  and  producing only  the  on air  tone  set .

The modem in ROS is  Phase continuous , may be other systems  are  also, but  , the  ROS system , embodies design features that  are  missing/not as developed   from other systems , ''Gray noise''  is the general  term 

The audio  level  supplied to the  Transmitter  , remains  constant  ,

 However ,  fluctuations  may be  observed on the  TX power meter , these ,  appear to  be  a by product of the  filtering  in the  TX .  the  abrupt  changes in Tone ,  appear to  be  subjected to  the filter  characteristics , phase shift , group  delay etc, which  in turn , adds   phase / time  distortion , the resolve of which is amplitude variation

 Racal  listed  various option fit  filters , some , voice ,  some  data , so i suspect the  problem was  known about  some time  back , two filters  in the  tx/rx  path ,  40 MHz  roofing and the  1.4 MHz pass/band , using the  widest possible  filter , can  reduce the  ‘side bands’, the DSP  compensates  for  disturbance ,  but ,  from a transmission aspect, its better to  maintain the  ''waveform''   

That probably  explains the  different  on-air  signals ,  interims of additional  side  bands  , from a  single tone , or at least that’s my general  observation , Tx [ and  unseen RX issues] serve to  degrade the  signal  quality , the  claim,  no filter is required , hold quite true , if the  DSP is  correctly  designed .. 

73-Graham
g0nbd
GEO satellite for the Americas. #digital

KC9SGV
 

If you are interested to find out more about the efforts to secure our own GEOstationary satellite over the Americas, please join the new GEO IO group.
All digital modes will be possible through it.
Save those old Direct TV dishes...

https://groups.io/g/GEO

KC9SGV
Re: Over-Driven FT-8 QRM #FT8 QRM #FT8

Tony
 

Graham:

Thank you for that explanation. I can see how the CW hard-keying analogy could apply to digital. If this is something inherent in FT8, the side-bands would worsen with stations running high-power.

I was surprised to see that some hams run near legal limit with FT8 and I'm not sure if the developers intended the mode to be used that way. 

Tony -K2MO


On 9/23/2019 2:46 PM, Graham wrote:


Hi Tony 

May be  aggressive is a subjective  assessment , 

If CW tx , could be  described  as  Hard/Aggressive  Keyed ,  that  would  give  the  same  results ,  Ie  , Soft keying / envelope shaping ,  produces ,  less  side bands or  Click's , less  envelope shaping ,  produces a  much harsher / aggressive / wider  signal 

A good  comparison   is the  original  MFSK  mode  and,  say, ROS-HF  ,

In terms  of the  on-air presence ,  MFSK and ROS  are  ''identical''  both  use  single  tone ,  both change  the  tone  frequency  and  duration, as directed  by the  resolve of the  mode coding and modem design , both are  'base band  heterodyned systems ', each may transit via, none linear  systems [ OLIVIA  has a  phase component to  the modem  modulation scheme , and as such , requires linear amplification ]

But, where  as the  MFSK mode , produces a  set of near in ‘side  band's’ , [ even marked on the  spectrum  plot  in Patrick’s Multi-psk, as additional B/W ]   ,  ROS-HF can be seen to  be  clean  and  producing only  the  on air  tone  set .

The modem in ROS is  Phase continuous , may be other systems  are  also, but  , the  ROS system , embodies design features that  are  missing/not as developed   from other systems , ''Gray noise''  is the general  term 

The audio  level  supplied to the  Transmitter  , remains  constant  ,

 However ,  fluctuations  may be  observed on the  TX power meter , these ,  appear to  be  a by product of the  filtering  in the  TX .  the  abrupt  changes in Tone ,  appear to  be  subjected to  the filter  characteristics , phase shift , group  delay etc, which  in turn , adds   phase / time  distortion , the resolve of which is amplitude variation

 Racal  listed  various option fit  filters , some , voice ,  some  data , so i suspect the  problem was  known about  some time  back , two filters  in the  tx/rx  path ,  40 MHz  roofing and the  1.4 MHz pass/band , using the  widest possible  filter , can  reduce the  ‘side bands’, the DSP  compensates  for  disturbance ,  but ,  from a transmission aspect, its better to  maintain the  ''waveform''   

That probably  explains the  different  on-air  signals ,  interims of additional  side  bands  , from a  single tone , or at least that’s my general  observation , Tx [ and  unseen RX issues] serve to  degrade the  signal  quality , the  claim,  no filter is required , hold quite true , if the  DSP is  correctly  designed .. 

73-Graham
g0nbd
Re: Over-Driven FT-8 QRM #FT8 QRM #FT8

Graham
 

Tony .

These modes  are  ' base band heterodyned'  as in the  generation  is  performed  at the  base band , in this case  audio  ,  the  ' waveform'   is then  heterodyned / mixed to the  wanted  frequency ,   the  opposite  of the  RX process ,  where  audio is  presented to the  DSP , after the  RX has recovered the  'Audio  wave' , Tx power should not  alter the  side band ratio  ,  as long  its  its linear , 

Alc could  provide a  leading edge over shoot  and tilt  of the  TX envelope , that's something,  the on/off  keying  , deployed in 
Opera  is  susceptible too , its necessary to  reduce the  drive to the  onset of  ALC to  prevent a  spike on the  leading  edge,if the  audio  keying  is used , 

Replacing the  CW-Key  on the  other hand ,  the  signal  utilises the  TX envelope  shaping , the  system was developed , using the  20 wpm  test signal from the  racal ma1723 as the  standard  'shape'  

Power wise ,  that's  a  unfortunate situation , the  concept of  narrow b/w  short burst signal is really  counter productive , as can be seen from the levels  deployed ,  multiple  access  at  low s/n  is best provided  by  the  appropriate  techniques , making  use  of the  SSB b/w channel ,  requiring a  second  layer in the  coding    applied to the  'modem' ie the  tone placement  routines . 

73-Graham
g0nbd 
Re: GEO satellite for the Americas. #digital

KC9SGV
 


Echostar 9

So, there is a proposal out from ORI (Open Resource Institude) for rented bandwidth on Echostar 9 at 121 deg West.
All the FLdigi modes will be able to be repeated by it.
The uplink is via an aggregator on commercial frequencies.
The downlink is direct on 12 GHz, but you must homebrew your receiver.
This could be a SDR dongle and SDR# Windows software.
Join the GEO.IO Group to read more.
https://groups.io/g/GEO
Re: GEO satellite for the Americas. #digital

Andrew OBrien
 

Very interesting, thanks for the info and the link . 

Andy


On Oct 1, 2019, at 6:16 PM, KC9SGV <kc9sgv@...> wrote:


<image.jpeg>

Echostar 9

So, there is a proposal out from ORI (Open Resource Institude) for rented bandwidth on Echostar 9 at 121 deg West.
All the FLdigi modes will be able to be repeated by it.
The uplink is via an aggregator on commercial frequencies.
The downlink is direct on 12 GHz, but you must homebrew your receiver.
This could be a SDR dongle and SDR# Windows software.
Join the GEO.IO Group to read more.
https://groups.io/g/GEO
QRPGuys DSB Digital Transceiver

Ken wa4mnt <wa4mnt@...>
 

Gang,

We are pleased to offer the QRPGuys DSB Digital Transceiver kit. It includes three easily changed FT8 band modules for 40/30/20m. The kit uses all thru hole components. Price is $40. We are also offering bare band module pcb's for those wanting to experiment with different bands and modes, 4 for $10. Come by and see it at <https://qrpguys.com/digital-transceiver>.

ken - wa4mnt
www.qrpguys.com
Re: GEO satellite for the Americas. #digital

Theodore A. antanaitis
 


aggregator on commercial frequencies

Not sure what this implies. Any guesses?

Ted WA7ZZB