Re: [digitalradio] Re: Question for experts

[José A. Amador]

El 09/03/2010 03:55 p.m., rein...@ix.netcom.com escribió:
> Hello All,
>
> Suppose I would build an transmitter with a x-tal oscillator, lets say
> running at 7040.000 Hz
>
> Part of the system was a balanced modulator and just to make sure a
> a high quality crystal filter, with a 1:1.05 shape factor, was added
> in the driver stages for the final amplifier.
>
> With  a lot of tweaking a carrier suppression of the balanced
> modulator was reached of  67.3 dB and the balanced modulator
> was kept temperature stabilized within .1 degree Fahrenheit.
>
> On the modulation section, I constructed a tone generator which could
> be changed in steps of 7.3 Hz starting from 1354 Hz to all the way up
> to 1646 Hz.
>
> I went out and got the xtal filter ordered for a lot of money.
>
> Center frequency of xtal filter ordered and delivered for 7041.500 Hz
> filter at - 80 dB BW 500 Hz.
>
> My question is what would the modulation be of this transmitter?
>
> The amount of audio was set in such a way that the output of
> the transmitter had no distortion what so ever totally
> linear!
>
> 73 Rein W6SZ
>

All that trouble for MFSK ? :-)

73,

Jose, CO2JA

Re: [digitalradio] Re: 1976 FCC - Delete all Emission Types from Part 97

[José A. Amador]

El 09/03/2010 02:08 p.m., KH6TY escribió:


Using FSK instead of AFSK means you can run a big amp Class-C and get 
more power output. Also, you do not have to worry about preserving 
linearity on a Class-AB or Class-B amplifier if running FSK,or figure 
out how to interface the computer to the rig for AFSK.


You can also run a saturated amplifiers chain with AFSK, if the envelope 
does not vary. FSK, OQPSK, whatever has a flat envelope.

And not only class C, but also class D, E, F...

73,

Jose, CO2JA

Re: [digitalradio] Re: Statement on Withdrawal of Support for ROS (K3UK Sked Pages)

[José A. Amador]

In spite of temperaments (my roots are spanish somewhere in the past) it 
has gone to extremes it never should  have got even near to. Statements 
like "FCC will have to pay me to see my code", the threat of legal 
action to someone who just was looking for his own spectrum management 
administration approval, the threat of banning certain callsigns, plus 
the following spanish statement in his web page:


 ---


   FCC: ROS LEGAL IN USA
   

2 March, 2010 by José Alberto Nieto Ros


 It ended the controversy about whether ROS is legal in USA or not.
 For which they insisted on it was illegal: "A mamarla"

---

I understand he meaning of the final part like "Suck my p" , which 
is not exactly nice or well mannered.


From my point of view, just stating "It ended the controversy about 
whether ROS is legal in USA or not" was enough.


Jose, CO2JA

---

El 03/03/2010 11:16 a.m., Toby Burnett escribió:



Marc,
I'm not saying that,  I'd be happy to support ROS and I do think it's 
a rather good experimental mode.  Ok so it is wide but as I said 
"experimental"
I think Jose did a fantastic job of making a software package for a 
completely new type of ham radio mode.  BUT,

The debate is getting out of hand (period)
There are reports of much QRM with the mode as no one seems to know 
where to operate.  Or they just don't give a damn where they operate.
Have you checked your messages?   How many on this subject since the 
software came out a few weeks ago. 1000+?

Is there nothing else we can talk about.
People are worried about their operating privileges in certain 
countries. And why not if there is a problem.
There shouldn't be and I don't think there are real ROS haters, just 
those who probably want nothing more to do with it, this discussion 
and I can see some people un subscribing from the group or sticking it 
to the junk filter 
In keeping with ham radio, I think everyone should calm down a bit and 
maybe do a bit of operating now that cycle 24 is in progress, rather 
than worrying about this.
Oh and I just had a listen and I cant hear the beacons due to ROS and 
a packet station.  14.101 is just too close I think.

Listen on 14.100 and you will hear.
Toby mm0tob
/---Original Message---/
/*From:*/ pd4u_dares 
/*Date:*/ 03/03/2010 15:59:33
/*To:*/ digitalradio@yahoogroups.com 
/*Subject:*/ [digitalradio] Re: Statement on Withdrawal of Support for 
ROS (K3UK Sked Pages)




--- In digitalradio@yahoogroups.com 
, "Toby Burnett"  
<..> But to be honest I don'' t think I shall bother too now as there 
seems much to much grief happening from this.

> Like I say, it seemed a fair experimental mode but it is wider than <..>
> It'd be nice to see something other than ROS comments on the digi 
reflector

> group. For a change.
>

Yeah let's stop our support for ROS on this group as well as on K3UK's 
sked page... Let us created two camps: the ROS haters and the ROS 
lovers...the good guys and the bad guys, and all in the name of the 
ham radio spirit of course!!


:-O

Marc, PD4U










--
MSc. Ing. José Angel Amador Fundora
Profesor Auxiliar
Departamento de Telecomunicaciones
Facultad de Ing. Eléctrica, CUJAE
Calle 114 # 11901 e/119 y 127
Marianao 19390
Ciudad de la Habana, Cuba
Tel: (53 7) 266-3445
Mail: amador at electrica.cujae.edu.cu

Re: [digitalradio] ROS carrier pattern when idle

[José A. Amador]

Warren,

Please allow me put my two cents. I would not expect so if the spreading 
code is the same.


The adventage of CDMA is code orthogonality, each user has a different 
chipping code that has little correlation with other user's codes., and 
so, there is little mutual QRM.


As far as I have seen, ROS uses a 3 kHz fixed bandwidth, irrespective of 
signalling speed. ROS 16 is affected by packet, pactor 2 and other ROS 
users QRM,

printing only garbage in such cases.

ROS 16 looks good on a clear channel, but crumbles under QRM. Not to be 
surprising when confined to just 3 kHz. Anyone can figure out just by 
listening on 14101.


Perhaps ROS 1 fares better, but so far I can't tell.

To me, so far, Olivia is the toughest chat mode, and includes a lot 
(perhaps, too much!) flexibility. Likewise, JT65A if you want to 
"squeeze QSO's out of thin air", but is hardly conversational at all. 
You can, in very short sentences (believe it is 13 characters), but you 
lose the adventage of some special hard coded short hand sentences (RRR, 
RO, 73 and such). Not a big penalty, but nevertheless, a penalty.


73,

Jose, CO2JA


El 26/02/2010 01:42 p.m., Warren Moxley escribió:

Hi Skip,

Does ROS have any flexibility like Olivia where you can change the 
Bandwidth? I am thinking it must not. SS modes that we all have 
experience with ( Cells, WiFi, etc ) seem to work well on top of each 
other and seem not to interfere with each other (for the most part). I 
was wondering if several hams using ROS that are one top of each 
other, does it work better than say, Olivia?


Warren - K5WGM

Re: [digitalradio] ROS carrier pattern when idle

[José A. Amador]

Astonishing... astonishing language barrier and also an astonishing lack 
of clues...


What a pity. He is not a ham and it seems that understanding the facts 
is harder for him than applying the proper equations.


You can fool all a part of the time, fool a few all the time but not 
everybody all the time.


Jose, CO2JA

El 26/02/2010 09:59 a.m., jose alberto nieto ros escribió:



KH, are you a Ham Radio or a FCC member?
If you are Ham Radio you should waste your time in help new modes 
would be used. Only a fool throws stones at your own roof. So, if you 
are not a FCC member, then we know what you are.



*De:* KH6TY 
*Para:* digitalradio@yahoogroups.com
*Enviado:* vie,26 febrero, 2010 15:27
*Asunto:* Re: [digitalradio] ROS carrier pattern when idle

Hi Warren,

I have already captured a spectrum of Olivia 32-100 (i.e., FSK32) and 
posted it in a reply, but glad do it again.. You can see the fixed 
frequencies at idle and then the new frequencies added when data is 
sent (in the "seared" middle part). I have not combined that on one 
uploaded page with the ROS spectrum analysis, but you can easily 
compare the two yourself, using the ROS spectral analysys with MFSK16. 
I wanted to confirm that both MFSK16 and Olivia 32-100 had the same 
signature of FSK, and they do, which is far different from the 
signature of ROS. It is very clear that ROS is using Frequency 
Hopping, as the frequencies are not a function of the data, and that 
is a unique characteristic of frequency hopping, at least according to 
everything I could find.


Olivia 32-1000: http://home. comcast.net/ ~hteller/ OLIVIA32- 1000.JPG

73 - Skip KH6TY

   



Warren Moxley wrote:


Skip, can you show some more spectral comparison examples? This time 
add the widest Olivia mode and other very wide modes.


Thanks in advance,

Warren - K5WGM


--- On *Fri, 2/26/10, KH6TY //* wrote:


From: KH6TY 
Subject: Re: [digitalradio] ROS carrier pattern when idle
To: digitalradio@ yahoogroups. com
Date: Friday, February 26, 2010, 8:11 AM

Jose, my attempted help is to let you understand that the FCC
believed you when you said ROS is FHSS, so you will fail in any
attempt to reclassify ROS as just FKS144. The FCC will not
believe you. What will probably succeed is for you to continue to
describe ROS as FHSS and let the FCC permit it in the USA as long
as it can be monitored, the bandwidth does not exceed the wide of
a SSB phone signal, and it is not used in either the phone bands
(data is illegal there anyway) or in the band segments where
narrow modes, such as PSK31 are used because it is as wide as the
entire PSK31 activity area.

Look at the spectral comparison http://home. comcast.net/
~hteller/ SPECTRUM. JPG. In the middle, I am sending data by
MFSK16 (the letters "N"), and you can see that the frequencies
are being determined by the data, which means it is not FHSS.
But, in the middle of the ROS spectral display, I am doing the
same thing, and there is no change to the frequencies being
transmitted, obviously because the frequencies are independent of
the data, which is requirement #2 in the ROS documentation for
FHSS. This definitely implies ROS is FHSS.

If you really want ROS to be legal here, just support a petition
to the FCC to allow it.

73 - Skip KH6TY

   




jose alberto nieto ros wrote:

If you are waste time in try demostrate ROS is a SS, i think you
are not trying help.


*De:* KH6TY 
*Para:* digitalradio@ yahoogroups. com
*Enviado:* vie,26 febrero, 2010 14:36
*Asunto:* Re: [digitalradio] ROS carrier pattern when idle

> jose alberto nieto ros wrote:
> I propose to moderator you will be banned if you continue
saying stupid things in this group.

Moderated for stupidity? Now that will be a first!

Good luck with trying to fool the FCC. Spectral analysis
suggests ROS really is FHSS, no matter what you now try to claim.

This picture does not lie: http://home. comcast.net/ ~hteller/
SPECTRUM. JPG

Too bad - ROS is a fun mode and I cannot use it in USA except on
UHF.

I have only tried to help find a way for US hams to use ROS. It
will be an honor to be banned for my stupidity! :-) Please go
ahead as you wish.

73, Skip KH6TY SK

   



jose alberto nieto ros wrote:

My friend, one thing is what i wrote, and other different is
what ROS is.
If recommend you waste your time in doing something by Ham
Radio, instead of criticism ROS.
I propose to moderator you will be banned if you continue
saying stupid things in this group.


*De:* KH6TY 
*Para:* digitalradio@ yahoogroups. com

Re: {Disarmed} [digitalradio] Which Digi Program ??

[José A. Amador]

I am using a similar interface with two transformer and an optocoupler. 
I DO RECOMMEND an optocoupler
for avoiding problems with high induced EMF's due to thunder EMP. It is 
important down here.

The solution for those old rigs is to use an external "digital" VFO, say 
a PLL or a DDS, I would favor the DDS.
There are kits for 5-6 MHz that fit the Kenwoods. I saw another one for 
the Collins S Line built by AOR.
You just need to google for available solutions and prices, and see what 
is best if buying a better VFO or buying a whole new rig.
I still like those old Kenwoods, but they were built more than a quarter 
of a century ago.

The original VFO drift rate can be way too high for the rules of the 
"ballgame"we are playing nowadays.
I suffered that with a Swan 700 and HF packet.

73,

Jose, CO2JA

Barry Michels escribió:
> I have a TS-520 (no S or SE) that I use with a homebrew interface.  The 
> interface is a simple audio transformer for TX audio and a 1 transistor 
> serial port PTT switch.  RX audio goes straight into the Line-In with no 
> isolation.  Linux is my OS of choice, so I use fldigi most of the time 
> (in Windows and Linux).  WSJT7 for the weak signal modes.  I've made 
> over 500 contacts using Winmor on this rig.  Drift is bad and 
> calibrating the dial isn't accurate enough to run Winmor without 
> constant tweaking, so I have to listen first and center someone else's 
> signal before replying.  Tried the WSPRnet on it once.  It had drifted 
> 200hz by the next morning.
>
> Recently I built a Softrock RXTX v6.3 SDR and have been using the TS-520 
> only as a signal generator (low power into a dummy load) to align the 
> SDR to improve image rejection.
>
>
> Barry - KE4JUC
>
> Music Maker wrote:
>   
>> .
>> .
>> Hello Happy Hams
>>
>> After returning to Amateur Radio after a very long absence, I am 
>> 'messing about' with digital modes - all of which are totally new to 
>> me, and at almost 75 years of age,  my one very slow remaining braincell.
>>
>> I have downloaded and appraised all the programs I could find mainly 
>> for PSK 31, that will work with my little M0AQC (Alan) Interface.
>>
>> All seem to have their own individual merits and de-merits.   
>> MutltiPSK for example for its many supported modes - DigiPan or MixW 
>> for their simplicity.But for facilities, information, sheer 
>> complexity (for me!)Ham Radio DeLuxe.  Sadly, it doesn't seem to 
>> integrate well with my aged but well loved Kenwood TS 520 SE !!
>>
>> However, the program that appeals to me the most at the moment (this 
>> may change as my experience and knowledge improves), is certainly 
>> Airlink Express - I rarely see any stations using this, and the 
>> numerical favou rite on air seems to be MixW.
>>
>> There obviously can't be a program that is 'One size fits all' - but 
>> for me, not one of them has all the elements I want, without loads of 
>> features I don't !!
>>
>> I would be very interested to hear what programs others use - 
>> particularly with 'Boat Anchor' Kenwood Transceivers (520, 530, 820, 830)
>>
>> For reference - and to save hunting around for Digi Software - I think 
>> most of it is available for download at this site -
>>
>> http://www.xs4all.nl/~nl9222/digisoft.htm 
>>  
>>
>> I am at present writing up my experiences in detail on my 'Amateur 
>> Radio Blog'  on the Web Page at :-
>>
>>  www.John4Music.TV   
>>
>> Kind regards and 73's to all from this white, windy and cold country 
>> called 'England'.   'Gl obal Warming' - I think not !!!  HI
>>
>> de
>>
>> John  G3OBU
>> 




Participe en Universidad 2010, del 8 al 12 de febrero de 2010
La Habana, Cuba 
http://www.universidad2010.cu


-

SEGUNDO SEMINARIO INTERNACIONAL LEGADO Y DIVERSIDAD. ARQUITECTURA Y URBANISMO.

El rescate de los valores urbanos y arquitectónicos en tiempos de 
globalización

Colegio de San Gerónimo, La Habana Vieja, noviembre 24-27, 2009

-

Re: [digitalradio] Digital on 2M FM: Audio settings ?

[José A. Amador]

I used a Radio Shack scanner and tapped the demodulator (MC3359) output 
to an scope.
Used another synthesized radio to calibrate, first on channel (0 Hz 
difference...hopefully), then 5 kHz up and 5 kHz down.
It gives proper reference to baseline and peak to peak deviation.

Then modulate the radio you are calibrating so peaks do not go beyond 
calibration.
It is IMPORTANT that you do not clip the audio and preserve proper 
preemphasis.

John Ackermann's www.febo.com had a good explanation about caring for 
Layer 1 on packet.

I did not have the fine instruments he had and devised my own way. It works.

73,

Jose, CO2JA

James French escribió:
> On Monday 16 November 2009 08:10:08 Andy obrien wrote:
>   
>> Thanks for the feedback guys.  I will play around with the settings...once I
>> find a person to contact on 2M.
>>
>> Andy K3UK
>>
>>
>>
>> On Sun, Nov 15, 2009 at 11:28 PM, Tony  wrote:
>>
>> 
>>> Andy,
>>>
>>> I believe you have a Kenwood TS2K(?). If so, there is a way to control the
>>> digital mode audio level on FM. If you're feeding the audio through the
>>> microphone connector, menu 41 has a low, medium and high setting. If your
>>> using the 13 pin DIN plug, the audio input can be adjusted via menu # 50.
>>>
>>> Tony -K2MO
>>>
>>>   
>
> Andy,
>
> If you have done packet at the start of the packet craze back in the late 
> 80's,
> you probably would remember that AEA (at the time) came out with a nice 
> FM deviation meter that was used to determine if you were over modulating
> your signal. Don't remember the model number as it has been a LONG time
> since I have even seen one..:)
>
> Do a google search for 'FM deviation meter' and you'll come up with a few
> nice links for either building your ownmeter or modifying a Motorola Maxtrak
> to use along with some test equipment for checking your deviation. I think
> the Maxtrak idea is probably going to be the simplest and cheapest way to
> do it.
>
> MFJ makes a 2m FM signal Analyzer, the mfj-224. A little pricey at 180 dollars
> but the manual says it has a output that goes to a scope to monitor.
>
> The top three google links for 'FM deviation meter' are the what I am refering
> to for the above.
>
> Hope this helps some. If you were on SSB, I would give it a try as we are only
> roughly 200 miles apart across Lake erie.
>
> James W8ISS
>   




Participe en Universidad 2010, del 8 al 12 de febrero de 2010
La Habana, Cuba 
http://www.universidad2010.cu


-

SEGUNDO SEMINARIO INTERNACIONAL LEGADO Y DIVERSIDAD. ARQUITECTURA Y URBANISMO.

El rescate de los valores urbanos y arquitectónicos en tiempos de 
globalización

Colegio de San Gerónimo, La Habana Vieja, noviembre 24-27, 2009

-




Suggested frequencies for calling CQ with experimental digital modes =
3584,10147, 14074 USB on your dial plus 1000Hz on waterfall.

Announce your digital presence via our Interactive Sked Pages at
http://www.obriensweb.com/sked
Yahoo! Groups Links

<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/digitalradio/

<*> Your email settings:
Individual Email | Traditional

<*> To change settings online go to:
http://groups.yahoo.com/group/digitalradio/join
(Yahoo! ID required)

<*> To change settings via email:
digitalradio-dig...@yahoogroups.com 
digitalradio-fullfeatu...@yahoogroups.com

<*> To unsubscribe from this group, send an email to:
digitalradio-unsubscr...@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/

Re: [digitalradio] Re: An open letter: W1AW and 80m psk31 interference

[José A. Amador]

I was about to reply to the question of why the choice of frequency for 
PSK31. I could not at the moment, but I see noone has addressed this point.

It happens that 3.579545 MHz (NTSC color burst) were aboundant and 
rather cheap in the age of analog TV.
So, they have been used in some designs I have seen of simple PSK 
equipment using the cristal for both carrier oscillator and
pass band filters.

If you have a "normal ham transceiver", that is tunable, well, just rock 
the dial, and that is all about it.

Buth those simple rock-bound PSK transceivers cannot QSY.

73,

Jose, CO2JA

PS: Who uses a tunable  radio


Participe en Universidad 2010, del 8 al 12 de febrero de 2010
La Habana, Cuba 
http://www.universidad2010.cu


-

SEGUNDO SEMINARIO INTERNACIONAL LEGADO Y DIVERSIDAD. ARQUITECTURA Y URBANISMO.

El rescate de los valores urbanos y arquitectónicos en tiempos de 
globalización

Colegio de San Gerónimo, La Habana Vieja, noviembre 24-27, 2009

-

Re: [digitalradio] Re: PSK-ARQ versus ALE-400

[José A. Amador]

Rick W escribió:

>  Say, John, you also use Pactor 2 and 3 which are always 100 baud PSK
>  modes.

Pactor and Pactor 2 can work at 200 baud. Buit it requires little 
multipath and good SNR.

>  Do you find that these modes work through the ionospheric
>  conditions when sound card modes, even those with similar modes do
>  not?

ARQ is a great adventage. If not acknowledged, repeat it. That is what 
helps to hold the link under marginal conditions.

>  I find PSK to be rather poor at times here at 44 degrees N latitude,
>  unless you are close to the MUF with a stable ionosphere. I have
>  never seen any published information or other comparisons of P2 and
>  P3 in terms of how much multipath or Doppler can be tolerated, but I
>  suspect that it is not all that much, and there are going to be times
>  that some sound card modes work (albeit slowly) and P2 and P3 simply
>  will not.

I have never compared them, but again, ARQ is a great adventage. If some 
mode could compete, is at least Olivia 16/500.
I had a scheduled QSO on 40 with HB9, and even when the waterfall was 
very faint, print was perfect.

Lenghthening the symbols (lowering the speed) helps with multipath. With 
Doppler, I believe that differential PSK is what makes it tick
on HF, otherwise, Doppler.can be very destructive on the link integrity.

73,

Jose, CO2JA



VI Conferencia Internacional de Energía Renovable, Ahorro de Energía y 
Educación Energética
9 - 12 de Junio 2009, Palacio de las Convenciones
...Por una cultura energética sustentable
www.ciercuba.com 




Announce your digital presence via our Interactive Sked Pages at
http://www.obriensweb.com/sked

Recommended digital mode software:  Winwarbler, FLDIGI, DM780, or Multipsk
Logging Software:  DXKeeper or Ham Radio Deluxe.



Yahoo! Groups Links

<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/digitalradio/

<*> Your email settings:
Individual Email | Traditional

<*> To change settings online go to:
http://groups.yahoo.com/group/digitalradio/join
(Yahoo! ID required)

<*> To change settings via email:
mailto:digitalradio-dig...@yahoogroups.com 
mailto:digitalradio-fullfeatu...@yahoogroups.com

<*> To unsubscribe from this group, send an email to:
digitalradio-unsubscr...@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/

Re: [digitalradio] The usual OS Flame war thread....

[José A. Amador]

Per,

I use BOTH.

I just meant a joke, because "the dark side of the force is always lurking"

I did not mean to hurt anyone, and I do operate on the air as well, 
perhaps not as much as I would like.

73,

Jose CO2JA



Per escribió:
> These threads just do not end. Pse just use what you like and stop bad 
> mouthing all the other systems.
> I only use linux but I'm not going to tell you that windows and macs 
> suck, if you like any of those then good for you. Have some fun on the 
> air instead.
>
> 73 de Per, sm0rwo
>


VI Conferencia Internacional de Energía Renovable, Ahorro de Energía y 
Educación Energética
9 - 12 de Junio 2009, Palacio de las Convenciones
...Por una cultura energética sustentable
www.ciercuba.com 

Re: [digitalradio] PSKMail Windows server?

[José A. Amador]

Once upon a time, in a very distant galaxy, there was an ace pilot named 
Anakin Skywalker...

> > Linux has not been very successful here in the U.S. with most ham
> > computer users.
> > But it just has not been very practical at this point because like
> > so many things in life, the trade-offs are too great:(
>
>  Because too many refuse to think??
>

VI Conferencia Internacional de Energía Renovable, Ahorro de Energía y 
Educación Energética
9 - 12 de Junio 2009, Palacio de las Convenciones
...Por una cultura energética sustentable
www.ciercuba.com 

Re: [digitalradio] Re: Bandwidth v Shift in RTTY ?

[José A. Amador]

Dave Bernstein escribió:

>  I understand, Jose. My question is whether the "inner tones" -- the
>  ones between the ensemble's highest and lowest tones -- contribute to
>  the bandwidth if their magnitudes are identical to those of the
>  lowest and highest tones.

I expect little contribution from them to occupied bandwidth. The 
significant ones are the extreme tones.

>  Asked another way, is the bandwidth of 300 baud 1 khz 4-tone FSK
>  greater than the bandwidth of 300 baud 1 khz 2-tone FSK? (where the 1
>  khz is the frequency difference between the ensemble's highest and
>  lowest tones). Based on the superposition approach suggested by an
>  earlier poster, one would suspect that the inner tones make little
>  contribution to bandwidth unless the tones are spaced quite closely.

Without the backing of any simulations or calculations, this makes sense 
at first sight.

73,

Jose, CO2JA



VI Conferencia Internacional de Energía Renovable, Ahorro de Energía y 
Educación Energética
9 - 12 de Junio 2009, Palacio de las Convenciones
...Por una cultura energética sustentable
www.ciercuba.com 

Re: [digitalradio] MT63 Operating Tips

[José A. Amador]

I use a PEP output meter and back off power a little to avoid clipping. 
I think that works too for people that know their way around.

73,

Jose, CO2JA

---

Tony escribió:
> All,
>  
> Had several QSO's with first-time MT63 OPs this week. 
> Some had a difficulty getting used to the software settings 
> so I thought I'd pass along a few tips.
>  
> Peak Power:
>  
> Peak power will be substantially higher than the average with this 
> mode so it's best to use the software's tune feature to set the 
> transmitters output. The most common mistake is setting the RF output 
> power with the MT63 signal itself. This can cause distortion 
> / throughput issues. A typical peak setting of 25 watts will show 
> about 5 watts average on your rigs meter.
>  
> Software: 
>  
> Fldigi, MultiPSK and Mixw all work well. Nino Porcino's MT63 Terminal 
> has signal report and tune features that are useful for the beginner. 
> It also has a couple of nifty "analog" gauges that measure confidence 
> and SNR. It works well and is easy to setup. Use the asterisk * in the 
> transmit buffer to allow the type-ahead feature.
>  
> See  http://xoomer.virgilio.it/aporcino/MT63/index.htm 
>  
>  
> Reception:
>  
> Use the markers in the waterfall and keep the signal centered between 
> them. Nino's MT63 software has a two-tone transmit marker that helps 
> the other party tune your signal. It shows the receiving station where 
> the top and bottom edge of the MT63 signal is. This feature is 
> especially helpful when signals are weak.
>  
> Fast Chat Mode:
>  
> It will take some getting used to MT631K if your typing is slow; it's 
> best to use the type-ahead buffer to keep things rolling along. The 1K 
> mode does 100 wpm so text files can be sent at a fair pace. The 
> cut-and-paste works well for sending emails and other small files.
>  
> The mode resists QRM / QRN very well and will usually print with a 
> fair chunk of the signal overlapped by another MT63 signal. Use common 
> sense when running a wide mode like MT63. Listen carefully to make 
> sure your not causing interference. The 1K, long interleave mode gives 
> the best bang-for-the-buck.
>  
> Tony -K2MO
>  
>  
>
>
> 



VI Conferencia Internacional de Energía Renovable, Ahorro de Energía y 
Educación Energética
9 - 12 de Junio 2009, Palacio de las Convenciones
...Por una cultura energética sustentable
www.ciercuba.com 

Re: [digitalradio] Re: using WSPR

[José A. Amador]

Andrew O'Brien escribió:
> For JT65A it will not work trying to tune in a signal transmitted USB and 
> received in LSB.  I just tried it, the sync tones appear to be upside-down, 
> so like RTTY, it looks like you need a "reverse" button in the software, 
> there are none.  
>
> At least that is what I am finding, others ?
>
> Andy K3UK
>
>
>   
None of the programs I use for JT65 have reverse possibilities. As not 
all modes are created equally,
it can be understood that WSJT is meant to be used with good radios. :-)

Jose, CO2JA



VI Conferencia Internacional de Energía Renovable, Ahorro de Energía y 
Educación Energética
9 - 12 de Junio 2009, Palacio de las Convenciones
...Por una cultura energética sustentable
www.ciercuba.com 

Re: [digitalradio] HF packet

[José A. Amador]

I believe that nowadays 110 baud  (or 100 baud) should fare better.

Sadly, PAX only passes unproto in Multipsk as modem (but maybe UI 
packets are enough for TCPIP)

I would have to reinstall JNOS and try with Multipsk.

73,

Jose, CO2JA

Mark Milburn escribió:
> No...I was thinking of his actually using the program to connect to a BBS.  I 
> should have made that clear.
> 73  Mark
>
>   


VI Conferencia Internacional de Energía Renovable, Ahorro de Energía y 
Educación Energética
9 - 12 de Junio 2009, Palacio de las Convenciones
...Por una cultura energética sustentable
www.ciercuba.com 

Re: [digitalradio] Re: ALE400 and 141a - talk about JNOS ...

[José A. Amador]

Maiko, good to see you here.

MultiPSK already has a KISS interface. It has been used for APRS 
successfully so far.

73,

Jose, CO2JA

--

maiko4 escribió:
> Good day to everyone,
>
> I am new to this group - could not help but notice JNOS mentioned.
>
> Jose stated earlier :
>
>   
>> I believe that the simplest is not reinventing the wheel, and
>> using MultiPSK as a modem, using traditional BBS programs as
>> the mail application.
>> 
>
> Believe it or not, using MultiPSK as a modem for JNOS has been on
> my mind for quite some time now. It's on my TODO list, I just have
> not gotten to it yet. I have chatted with the author of MultiPSK
> about doing this as well.
>
> I'm not sure what mode I would want to use it for though. I even
> considered using JNOS as an IP bridge using the MultiPSK modem to
> transport RAW IP (more or less) frames over HF, as one example
> of what was on my mind.
>
>   
>> The store and forward part could mean a *LOT* of work ...
>> 
>
> Not really. JNOS has a S&F ability already, it would just be a
> matter of writing a new INTERFACE (PORT) for JNOS to communicate
> over. JNOS could use FBB, FBB compressed, or B2F (recently added
> in my attempt to keep uptodate with WinLink interoperability.
>
>   
>> I feel that a lot of the old packet legacy programs have a lot
>> to offer if the classic TNC is replaced for a better modem.
>> 
>
> I agree. That's why I spent the last few years writing hostmode
> drivers for a few types of pactor modems. Unfortunately, I seem
> to have stumbled across these needs long after the fact. In a way,
> the work has been a bit of a waste of time - maybe 3 users world
> wide that I know of, that are possibly playing with the code.
>
>   
>> net2kiss ...
>> 
>
> I wrote a kernel interface for the Linux version of JNOS, allowing
> you to directly attach JNOS to baycom boards via the linux kernel
> modules - WITHOUT the need for 'net2kiss' and 'pseudo-tty' devs.
>
>   
>> Could that be extended to ALE ?
>> 
>
> I'm sure it could be.
>
> Anyways, I just thought i would jump in.
>
> I don't think using MultiPSK as a modem will be difficult.
>
> BUT, this time to better make sure I don't waste precious time
> working on something no one will use, I need to know from more
> than just one person, what should I concentrate my efforts on
> then. That's the big dilemna for me. What do I focus on ?
>
> Too many protocols to choose from now, and lots of division
> between their camps. That frustrates the development part.
>
> But having something like MultiPSK would actually solve that
> for me, since all I'm doing is interfacing to a modem, so in
> a way I would not have to worry about the different modes,
> considering they all do the same thing in the long run.
>
> Regards,
>
> Maiko Langelaar / VE4KLM
>
> * http://www.langelaar.net/projects/jnos2
>
>
>
> 
>
> Announce your digital presence via our Interactive Sked Page at
> http://www.obriensweb.com/sked
>
>
>
> Yahoo! Groups Links
>
>
>
>   


-- 
MSc. Ing. José Angel Amador Fundora
Profesor Auxiliar
Departamento de Telecomunicaciones
Facultad de Ing. Eléctrica, CUJAE
Calle 114 # 11901 e/119 y 127
Marianao 19390
Ciudad de la Habana, Cuba
Tel: (53 7) 266-3445
Mail: amador at electrica.cujae.edu.cu


VI Conferencia Internacional de Energía Renovable, Ahorro de Energía y 
Educación Energética
9 - 12 de Junio 2009, Palacio de las Convenciones
...Por una cultura energética sustentable
www.ciercuba.com 

Re: [digitalradio] ALE400 and 141a

[José A. Amador]

I believe that the simplest is not reinventing the wheel, and using 
MultiPSK as a modem, using traditional BBS programs as the mail 
application.
Does anyone find this to be wrong?

The store and forward part could mean a *LOT* of work to be done, or 
actually, re-done...

For traditional ham mail, I find FBB is very good. And for e-mail, JNOS.

Would it be possible to extend the KISS mode interface to other modes 
and not only packet? I don't know right now, but sounds tempting.

I feel that a lot of the old packet legacy programs have a lot to offer 
if the classic TNC is replaced for a better modem.

Maybe it would be interesting to identify other interfacing software, 
i.e., KISS-WA8DED, 6PACK-KISS, etc

73,

Jose, CO2JA

---

John Bradley escribió:
>
> Maybe we can convince Patrick to look at possible “store and forward” 
> functions as well
>
> John
>
> VE5MU
>


VI Conferencia Internacional de Energía Renovable, Ahorro de Energía y 
Educación Energética
9 - 12 de Junio 2009, Palacio de las Convenciones
...Por una cultura energética sustentable
www.ciercuba.com 



Announce your digital presence via our Interactive Sked Page at
http://www.obriensweb.com/sked



Yahoo! Groups Links

<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/digitalradio/

<*> Your email settings:
Individual Email | Traditional

<*> To change settings online go to:
http://groups.yahoo.com/group/digitalradio/join
(Yahoo! ID required)

<*> To change settings via email:
mailto:digitalradio-dig...@yahoogroups.com 
mailto:digitalradio-fullfeatu...@yahoogroups.com

<*> To unsubscribe from this group, send an email to:
digitalradio-unsubscr...@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/

Re: [digitalradio] RE:Packet radio with sound card

[José A. Amador]

Howard Brown escribió:

>  GM Jose,
>
>  There is one point in your post I would like to bring up. Where you
>  say:
>
>  >"Multitasking cannot handle tight ARQ timing windows.
>
>  >It is a pity that noone has come forward (as far as I know) a real
>  >time OS (RTL, for instance) with a proposal usable on an old PC as
>  >packet engine with a sound card as modem. The problem is not the PC
>  >itself, but the prevalent OS's."
>
>  Why not challenge the need for the tight timing windows?  This
>  creates more wear and tear and the radio but what real benefit does
>  it provide?  I believe that the NBEMS package and the RFSM8000
>  package prove that you can have effective ARQ without the fast
>  switching.

Examples of tight timing and succesful implementation are P-II and 
P-III, not only AMTOR, with its hair raising clicking

I never tried SCAMP, which seemingly did well running under Windows. 
Actually, I have entrenched on my mind what
gave me good results, but certainly, that may not be the only way for 
success, I have to admit.

Examples of the success of tight timing are WSPR and WSJT, and  
certainly, knowing WHEN to expect input  is a bonus.
None of them generate such a high wear and tear. WHEN may be absolute, 
like in WSJT, related to the UTC time scale,
or relative, in some time measure after the last received packet.

I have had little luck with RFSM8000,  because of  my perennial lack of 
time in recent times and the little user mass it has generated.

>  I would love to see Linux used more and not need to deal with Windows 
but still, the quick switching seems to be of little value.

It was a way, which certainly, has been proven not to be the only one. 
You cannot entirely disegard trends, that may vary in time.

I was the sysop of three BBS's at a time, on MSDOS (even with Desqview 
"multitasking"),  Linux and Windows (the last one was a quick hack and 
an exercise in lazyness) and I liked BBS's.

Forwarding over radio links, with all the freedoms it provides, and some 
associated extra responsibilities too. But I fail to see the comeback of 
the BBS's.
Winlink may be useful, but it hardly substiututes the "packet" network 
the way it operated in the 90's.

I have very good memories of the Linux based systems I ran (node, FBB, 
JNOS, DXNET), both were highly resilient and almost bulletproof. Uptime 
was usually more than 30 days, and the PC's ran without battery backups. 
I always used hardware TNC's, Kantronics and SCS.

Pactor allowed 1 MB per day of forwarding on HF easily. Packet (300 
baud) hardly ever exceeded 100 kb per day.

73,

Jose, CO2JA

Re: [digitalradio] RE:Packet radio with sound card

[José A. Amador]

Rick W escribió:
> Similarly, I have used Multipsk's packet modes on both HF and VHF with 
> success. With the advance of technology, I moved away from packet around 
> 15 years ago! It is just not robust enough for HF and can only go a 
> short distance on VHF, compared with newer modes
>   
I moved from HF 300 baud packet to Pactor (PTC-II) ten years ago. It 
meant a tenfold increase in forwarding thruput,
with ten times less power. About a hundredfold improvement...
> What seems like an unfulfilled need is a framework similar to packet, 
> with the ability to insert different modes as they are developed. You 
> would not have to keep inventing the wheel over and over.
>   
My feeling is that even when the modulation/signalling speed was quite 
less than optimal, the network worked.
(Runing a network costs, but there existed a will to keep it going. Life 
is more expensive nowadays)

The Achilles heel has been the radio channel access method.
> This would mostly have practical value for groups that want to set up a 
> BBS system. For example, I have monitored the packets on an 80 meter BBS 
> here in my state where most of the transmissions are retries. And this 
> is during the day under NVIS conditions. 
NVIS has the longest time spread of all ionospheric propagation modes. 
Even 300 baud can be too fast at times.
> A much more robust mode needs 
> to be used.  Then you would be able to send and receive direct or time 
> shifted messages. This is the one thing we can not do with any other 
> system, but there does not seem to be any interest in developing such a 
> system.
>   
It is EASIER with the Internet...as long as it is up.
> At this time, it is true that a slower baud rate packet system could be 
> used, such as the software 110 baud speed available in Multipsk. This is 
> why hardware packet TNC's are a poor choice for our advancing technology 
> and why almost no one uses them anymore. 
Rick, I do not agree with this. My feeling is that manufacturers took the easy 
way out 
with a stagnant product, and the market fell on its knees because of lack of 
innovation.
With a market scale vision, hams are not a profitable market.

SCS has the merit of distributing easily flashable firmware updates. Who else 
has done so?

Of course, with a CPU running a single task... ("Real men use hardware 
TNC's..." 8-) ) 

MultiPSK has the merit of being a working option at less than 300 baud. 

The sound card itself is not a panacea, when used in a multitasking (or quick 
task switching) OS. 
Multitasking cannot handle tight ARQ timing windows.

It is a pity that noone has come forward (as far as I know) a real time OS 
(RTL, for instance) with a proposal 
usable on an old PC as packet engine with a sound card as modem. The problem is 
not the PC itself, but the 
prevalent OS's. 


> You are locked into a mode 
> developed over 30 years ago with no FEC or ability to be adaptive for 
> conditions. And yet, I admit that if you want a BBS system today, what 
> other choices do you have?
>
> 73,
>
> Rick, KV9U
>
>
> Bev & Jerry Chambers wrote:
>   
>> I have used MixW for packet, both on 2 meters and on HF and found it 
>> to work fine.
>>  
>> Jerry - W6LQR
>>
>>
>> 

73,

Jose, CO2JA

Re: [digitalradio] ASCII ?

[José A. Amador]

It seems not so robust and more prone to errors. It requires the correct 
decoding of  7 bits vs 5 bits on Baudot.

I read the same in old QST's.

Jose, CO2JA

John Becker escribió:

>  I recall that when the FCC first authorized the use of ASCII code for
>  RTTY in addition to Baudot in 1980, the ham radio press made it
>  appear that this was a really big deal.
>
>  I've Googled information on ASCII RTTY, and find no indication that
>  is being used to any significant extent. ARRL states that their
>  teleprinter bulletins are transmitted in Baudot, AMTOR, and *in ASCII
>  only as time allows*. Why did ASCII fail to catch on? Just curious!
>
>  73,
>
>  John, K9MM

Re: [digitalradio] Re: High speed packet

[José A. Amador]

Going too fast on a serial port is not always a bonus. If there are 
errors,  it is another source of retries, without even reaching the air.

Go only as fast as it makes sense with very few or no errors. YMMV.

Jose, CO2JA

---

Bob Donnell escribió:

>  Martin:
>
>  I'd bet you were thinking of ISA instead of IDE - and probably the
>  dual opto-SCC card developed by your countrymen back then.
>
>  Ross:
>
>  JNOS is probably the most actively maintained version of NET which
>  became NOS, back in about 1990/1991 time frame.  Current versions of
>  it can be run under either Windows or Linux.  JNOS has KISS as one of
>  its historic interface methods.  As long as you have a more modern
>  serial communications chip in the computer you're using
>  (16550-compatible) you should be able to configure it to have
>  adequate communications with the TNC at either 57.6kbps or 115.5kbps,
>  if the TNC supports it.
>
>  The SV2AGW family of programs may also support that fast serial data
>  rate - I don't have an easy way to check where I'm entering this
>  email.  The AGW Packet Engine (AGWPE) definitly also understands how
>  to do KISS.  My home Airmail station is using a shim to talk to
>  AGWPE, which is talking to an AEA PK-96 using KISS, which is then
>  interfaced with the radio.
>
>  Perhaps I've not been watching the list carefully - what over-the-air
>  data rate are you using that makes performing serial communications
>  at 57.6kbps an advantage?  Unless you're sending quite large AX.25
>  packets (1k or 2k) on a radio link at 38.4kbps, there's probably not
>  much performance advantage to going that fast.  And if your on-air
>  data rate IS that fast, congratulations!
>
>  73
>
>  Bob, KD7NM
>
>  -Original Message- From: digitalradio@yahoogroups.com
>  [mailto:[EMAIL PROTECTED] On Behalf Of martin beekhuis
>  Sent: Tuesday, September 09, 2008 11:38 AM To:
>  digitalradio@yahoogroups.com Subject: [digitalradio] Re: High speed
>  packet
>
>  Hello Ross
>
>  Here we have already for years running the packetnode using ax25
>  drivers in linux.  http://sharon.esrac.ele.tue.nl (sorry in dutch)
>  Different speed up to 76800 however we use SCC IDE controlers I think
>  via the serial port ttyS0 ax0 will do also.
>
>  Before we switched from DOS-6.11 to linux we used NOS or NET
>
>  No GUI all very basic but reliable from 1987 till now
>
>  73 matin pa3dsc
>
>
> > I am looking for a packet program, which I can use to operate my
>  Symek TNC3S at 57600
> > but which has the kiss mode. Any one any ideas.
> >
> > Packet was in favour a few years ago and all the programs I can
> > find
>  are very old,  dont like the kiss mode,
> > or cant talk to the TNC3S at 57600.
> >
> > Regards to all Ross ZL1WN .
> >
>
>
>
>  
>
>  Announce your digital presence via our Interactive Sked Page at
>  http://www.obriensweb.com/sked
>
>  Yahoo! Groups Links
>
>
>
>
>
>
>  
>
>  Announce your digital presence via our Interactive Sked Page at
>  http://www.obriensweb.com/sked
>
>  Yahoo! Groups Links
>
>


-- 
MSc. Ing. José Angel Amador Fundora
Profesor Auxiliar
Departamento de Telecomunicaciones
Facultad de Ing. Eléctrica, CUJAE
Calle 114 # 11901 e/119 y 127
Marianao 19390
Ciudad de la Habana, Cuba
Tel: (53 7) 266-3445
Mail: amador at electrica.cujae.edu.cu

Re: [digitalradio] Re: Noise

[José A. Amador]

It is usually so, but there are also return channels to the headend 
below 54 MHz in some places.

A loose conector or a broken shield might allow it to leak out.

73,

Jose, CO2JA

--

John Taylor escribió:
> Ron, as a semi direct answer to your question, as a general rule 
> cable tv frequencies typically are well above hf radio. It is not 
> impossible for there to be interference, but generally it will be 
> some other source. One thing to remember with most cable systems is 
> that the line and trunk amps need to be powered and are usualy done 
> through the cable itself with pole mounted power supplies every so 
> often in the system. If there is a connection breakdown somewhere 
> near you, it"could" cause your symptoms. You did provide a clue to 
> your own situation. You mentioned a bucket truck in the area when the 
> noise suddenly stopped and then started again. If he was working at a 
> particular pole, you might try physically walking to that pole and 
> see if you hear any arcing, especially if this is also a power pole 
> carrying primary voltages. It is not uncommon for the insulators to 
> start breaking down due to dirt and grime in the air getting on the 
> insulators and forming a path for the current to travel. This 
> manifests itself frequently as strong intermittant static.
> Your noise blanker typically only works on "impulse" noise such as 
> ignition, etc. 
> Have you also eliminated all noise sources in your own home, such as 
> televisions, computers and  monitors, etc.?
> A great way to chase the source is to take a small portable shortwave 
> receiver with a small antenna and follow the noise to it's source. 
> You can usually get very close very quickly with a little leg work.
> Just some thoughts 
> Best of Luck
>
> --- In digitalradio@yahoogroups.com, w4lde <[EMAIL PROTECTED]> wrote:
>   
>> If this question is inappropriate for the reflector I apologize but 
>> 
> as 
>   
>> of last Friday I started to experience significant noise (S-9) on 
>> 
> all 
>   
>> bands from 160 through 15M with the lower frequencies much 
>> 
> stronger.  I 
>   
>> thought that it was due to power line noise but it appears to be 
>> intermittent in that it completely disappeared last Friday evening 
>> 
> but 
>   
>> once again showed up last Saturday and stayed this way.  On the 
>> 
> Ft1000mp 
>   
>> the noise blankers are completely ineffective.  At the same time I 
>> started having internet problems and the cable company indicated 
>> 
> they 
>   
>> should have the speed issue fixed by Tuesday.
>>
>> The cables are run on poles until they enter a subdivision which 
>> 
> then 
>   
>> run underground.  My question is can cable lines be the possible 
>> 
> problem 
>   
>> to HF frequencies?  The power and cable companies have been 
>> 
> installing 
>   
>> new poles and running new lines in the area which initially led me 
>> 
> to 
>   
>> believe it was a power issue however, while I was writing this 
>> 
> email the 
>   
>> noise completely disappeared for a few seconds and then 
>> 
> reappeared.  As 
>   
>> I was looking out my window I noticed a cable company buck truck  
>> through the woods towards the main road, I am off now to talk to 
>> 
> them 
>   
>> and see what I can discover.  Any suggestions?
>>
>> Thanks for the bandwidth if this question is inappropriate for this 
>> reflector.
>>
>> 73 de
>> Ron W4LDE
>>
>> 
>
>
>
> 
>
> Announce your digital presence via our Interactive Sked Page at
> http://www.obriensweb.com/sked
>
> Yahoo! Groups Links
>
>
>
>   


-- 
MSc. Ing. José Angel Amador Fundora
Profesor Auxiliar
Departamento de Telecomunicaciones
Facultad de Ing. Eléctrica, CUJAE
Calle 114 # 11901 e/119 y 127
Marianao 19390
Ciudad de la Habana, Cuba
Tel: (53 7) 266-3445
Mail: amador at electrica.cujae.edu.cu

Re: [digitalradio] Re: KV9U - Mode Sensitivity / Robustness

[José A. Amador]

I believe that both have a space under the sun. The charm of the 
simulator tests is _repeatability_,
even when the results on the air might be different.On the air, you 
cannot have repeatability, so, the results,
even when real, are harder to correlate.

Yesterday I attmoted to get some real noise samples at my QTH, but we 
are having rather quiet days
by the end of the week.

I have been thinking that a PRN generator triggering a sound card 
"static crash generator" would be a further good
approach to the real world, but the results might not be as repeatable 
as with gaussian white noise.

I have been recalling of some CW pileup generators used for training. 
The algorithm could be similar, but generating
"crashes" instead of Morse code. Ther random generator or generators 
could be representatuive of the lower bands, while
another repetitive with pseudo random period shifts could be 
representative of spark plug noise which is more prevalent
in urban environments on 10 or 6 meters.

73,

Jose, CO2JA

---

Tony escribió:
> Patrick,
>
>   
>> I for one would like to try different modes and compare them
>> under real conditions. There can be too many variables.
>> 
>
> I agree, I think the simulator can tell a lot about mode performance, but it 
> has it's limitations.
>
> It might be a good idea to test modes according to type. Seems fruitless to 
> compare a mode that's known to be extremely sensitive and robust against the 
> "average" chat mode.
>
> Good point about switching frequency when testing; need to mind the wide 
> modes in the narrow band segments etc.
>
> There was a lot more activity along these lines when sound-card modes were 
> first introduced. Wonder if anyone recalls digital beaconing?
>
> Station S59DOR had one on 10 meters that would transmit the different 
> Hellschreiber modes.
>
> Macros allowed the software (IZ8BLY's Hellschreiber) to switch modes 
> automatically. Have a screenshot of the beacon if anyone is interested.
>
> Glad to see the enthusiasm Patrick! It's the stuff that keeps the hobby 
> alive.
>
> Tony, K2MO
> Kings Park, NY
>
>   




Announce your digital presence via our Interactive Sked Page at
http://www.obriensweb.com/sked

Check our other Yahoo Groups
http://groups.yahoo.com/group/dxlist/
http://groups.yahoo.com/group/contesting
http://groups.yahoo.com/group/themixwgroup
Yahoo! Groups Links

<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/digitalradio/

<*> Your email settings:
Individual Email | Traditional

<*> To change settings online go to:
http://groups.yahoo.com/group/digitalradio/join
(Yahoo! ID required)

<*> To change settings via email:
mailto:[EMAIL PROTECTED] 
mailto:[EMAIL PROTECTED]

<*> To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]

<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/

Re: [digitalradio] Digital Voice -- US / Australian QSO -- programing skills needed.

[José A. Amador]

VERY interesting. At what time was that QSO?

Jose, CO2JA

Tony escribió:
> All,
>  
> Was nice to hear Graeme (VK4CAG) on digital voice last night. Mel 
> (K0PFX) and I were rag chewing on 14236 when Graeme popped in. We were 
> running FDMDV on 20 meters.
>  
> FDMDV did fairly well on the 10,000 mile path considering the 
> conditions at the time.
> Unfortunately, multi-path does take it's toll on FDMDV and long-haul 
> signals are especially prone to this. Decoding becomes choppy 
> and drop-outs more frequent with rapid fading.
>  
> This is not to say that the mode doesn't work well. It does a great 
> job fighting moderately unstable conditions and we certainly 
> do appreciate the hard work Peter (G3PLX) and Cesco (HB9TLK) have 
> done. Hams have enjoyed countless hours of noise-free phone over HF 
> thanks to there work. Peter's modem does remarkable things with 1.2 
> KHz of bandwidth.
>  
> What we need now is someone with the programming skills to take it to 
> the next level. The existing modem looks promising and I'm told that 
> modifications could improve performance quite a bit.
>  
> Obviously, asking someone to take on a project like this is a tall 
> order, but it would not go unappreciated. The popularity of digital 
> voice is growing and I think most would agree that a robust (spectrum 
> friendly) digital HF voice mode would benefit ham radio.
>  
> There's no doubt that a weak signal variant would do the same for 
> phone as PSK31 has done for digital. Certainly would be appreciated 
> by those without the resources for big power and antennas. It would be 
> quite an achievement.
>  
> Best regards,
>  
> Tony - K2MO
>  
>  
>  


-- 
MSc. Ing. José Angel Amador Fundora
Profesor Auxiliar
Departamento de Telecomunicaciones
Facultad de Ing. Eléctrica, CUJAE
Calle 114 # 11901 e/119 y 127
Marianao 19390
Ciudad de la Habana, Cuba
Tel: (53 7) 266-3445
Mail: amador at electrica.cujae.edu.cu