10 Meter FM Data USA Par97 limitations ?. #Intro


Graham
 

Can someone clarify the position on sending   data using FM on 10 meters , inside USA 

used to be  1200 packet on 29.250 , using FM , many moons ago  in Europe , rest of world 
but, is data allowed  at that end of the band in the part97

Are there limits for FM data on the band,  300 baud still apply ? Inside data segment ?
Max b/with ?

Tnx  Graham
G0nbd


Ev Tupis <w2ev@...>
 

On Saturday, November 3, 2018, 5:28:10 PM EDT, Graham <g0nbd@...> wrote:


Can someone clarify the position on sending   data using FM on 10 meters , inside USA 

used to be  1200 packet on 29.250 , using FM , many moons ago  in Europe , rest of world 
but, is data allowed  at that end of the band in the part97

Are there limits for FM data on the band,  300 baud still apply ? Inside data segment ?
Max b/with ?

Tnx  Graham
G0nbd


Ev Tupis <w2ev@...>
 

In a nutshell...

There is no US allocation on the 10 meter band within which DATA and FM is concurrent.

"SSB-based" data transmission is allowed, however.

Ev, W2EV


On Sunday, November 4, 2018, 6:35:29 AM EST, Ev Tupis via Groups.Io <w2ev@...> wrote:


On Saturday, November 3, 2018, 5:28:10 PM EDT, Graham <g0nbd@...> wrote:


Can someone clarify the position on sending   data using FM on 10 meters , inside USA 

used to be  1200 packet on 29.250 , using FM , many moons ago  in Europe , rest of world 
but, is data allowed  at that end of the band in the part97

Are there limits for FM data on the band,  300 baud still apply ? Inside data segment ?
Max b/with ?

Tnx  Graham
G0nbd


M5AKA
 

Ev, could you clarify what you mean when you say - "SSB-based" data transmission is allowed, however. 
Are you suggesting "SSB-based" data modes are permitted in the phone bands??

My interpretation of Part 97 is that Data modes in 10m are only permitted between 28.000 and 28.300 MHz and are subject to a 1200 baud symbol rate restriction.

73 Trevor M5AKA



On Sunday, 4 November 2018, 11:42:50 GMT, Ev Tupis via Groups.Io <w2ev@...> wrote:


In a nutshell...

There is no US allocation on the 10 meter band within which DATA and FM is concurrent.

"SSB-based" data transmission is allowed, however.

Ev, W2EV


On Sunday, November 4, 2018, 6:35:29 AM EST, Ev Tupis via Groups.Io <w2ev@...> wrote:


On Saturday, November 3, 2018, 5:28:10 PM EDT, Graham <g0nbd@...> wrote:


Can someone clarify the position on sending   data using FM on 10 meters , inside USA 

used to be  1200 packet on 29.250 , using FM , many moons ago  in Europe , rest of world 
but, is data allowed  at that end of the band in the part97

Are there limits for FM data on the band,  300 baud still apply ? Inside data segment ?
Max b/with ?

Tnx  Graham
G0nbd


Ev Tupis <w2ev@...>
 

Sure, Trevor.  Set your mode switch to SSB and operate 1200 baud packet in the USA data sub-bands (not the voice sub-bands).  Perfectly legal.

In the early days of the PropNET project, we used this approach to fantastic success (in fact, the speed of the transmission allowed occasional meteor scatter...despite those that predicted otherwise).

Cheers,
Ev, W2EV


On Sunday, November 4, 2018, 6:55:31 AM EST, AKA via Groups.Io <m5aka@...> wrote:


Ev, could you clarify what you mean when you say - "SSB-based" data transmission is allowed, however. 
Are you suggesting "SSB-based" data modes are permitted in the phone bands??

My interpretation of Part 97 is that Data modes in 10m are only permitted between 28.000 and 28.300 MHz and are subject to a 1200 baud symbol rate restriction.

73 Trevor M5AKA



On Sunday, 4 November 2018, 11:42:50 GMT, Ev Tupis via Groups.Io <w2ev@...> wrote:


In a nutshell...

There is no US allocation on the 10 meter band within which DATA and FM is concurrent.

"SSB-based" data transmission is allowed, however.

Ev, W2EV


On Sunday, November 4, 2018, 6:35:29 AM EST, Ev Tupis via Groups.Io <w2ev@...> wrote:


On Saturday, November 3, 2018, 5:28:10 PM EDT, Graham <g0nbd@...> wrote:


Can someone clarify the position on sending   data using FM on 10 meters , inside USA 

used to be  1200 packet on 29.250 , using FM , many moons ago  in Europe , rest of world 
but, is data allowed  at that end of the band in the part97

Are there limits for FM data on the band,  300 baud still apply ? Inside data segment ?
Max b/with ?

Tnx  Graham
G0nbd


Graham
 

Thank's Ev,

Right , that  look's  like the  same as  I found , your upto  1200  baud , with  fsk 1 Khz shift ,  [now that's  'buzzing' along  hihi]
There  is no  mention  of actual  transmission 'mode'  though ,  FSK by  hard keying ,  is base band  FM  

(4) Only a RTTY or data emission using a specified digital code listed in §97.309(a) of this part may be transmitted. The symbol rate must not exceed 1200 bauds, or for frequency-shift keying, the frequency shift between mark and space must not exceed 1 kHz.

There  used to  be  activity on  29.250   , 1200 packet FM  , ie  Voice  channel  B/W  , I see  from the  regulations  [part97]  that  only   'Voice  and  Image'  is  permitted  above  28.300 , I assume,  image  use to  mean  , Analogue  fax like  transmission and not  image  by  data  transfer , hence the  de-bar ?  The two  tone packet  modem, is , via , heterodyne , is producing  FSK , so  = ok ?

The  regulations  appear to define  content and not  method in this  case ,  with other pre limitations  ,  already defined.     . 


If  data can be  sent  under 28.300 MHz  using  FSK/FM  , then ,  its  possible to  deploy  the  VARA modem   'FM'  1200  baud  replacement  version  on  10 meter HF using  FM speech bandwidth  ???

Tnx-Graham.



NB: VARA FM is  
NOT replacement  for the   HF version ....But  , 
If stations  have  good  10 meter  link's  ,  its  possible  to  deploy the  FM version and  achieve  higher  data  throughput   
trial  deployment is  recommended , 

VAAR is provided  in two  versions ,  
HF  requires  SSB  and may be  deployed  via  FM  
FM requires FM and is  not  compatible  with SSB


M5AKA
 

Graham, if you are suggesting a 12 kHz bandwidth FM transmission on 10m it seems it would not be permitted in USA, see the definitions of "Data" and "RTTY":

(2) Data. Telemetry, telecommand and computer communications emissions having (i) designators with A, C, D, F, G, H, J or R as the first symbol, 1 as the second symbol, and D as the third symbol; (ii) emission J2D; and (iii) emissions A1C, F1C, F2C, J2C, and J3C having an occupied bandwidth of 500 Hz or less when transmitted on an amateur service frequency below 30 MHz. Only a digital code of a type specifically authorized in this part may be transmitted.


(7) RTTY. Narrow-band direct-printing telegraphy emissions having designators with A, C, D, F, G, H, J or R as the first symbol; 1 as the second symbol; B as the third symbol; and emission J2B. Only a digital code of a type specifically authorized in this part may be transmitted.


73 Trevor M5AKA

On Sunday, 4 November 2018, 14:52:49 GMT, Graham <g0nbd@...> wrote:


Thank's Ev,

Right , that  look's  like the  same as  I found , your upto  1200  baud , with  fsk 1 Khz shift ,  [now that's  'buzzing' along  hihi]
There  is no  mention  of actual  transmission 'mode'  though ,  FSK by  hard keying ,  is base band  FM  

(4) Only a RTTY or data emission using a specified digital code listed in §97.309(a) of this part may be transmitted. The symbol rate must not exceed 1200 bauds, or for frequency-shift keying, the frequency shift between mark and space must not exceed 1 kHz.

There  used to  be  activity on  29.250   , 1200 packet FM  , ie  Voice  channel  B/W  , I see  from the  regulations  [part97]  that  only   'Voice  and  Image'  is  permitted  above  28.300 , I assume,  image  use to  mean  , Analogue  fax like  transmission and not  image  by  data  transfer , hence the  de-bar ?  The two  tone packet  modem, is , via , heterodyne , is producing  FSK , so  = ok ?

The  regulations  appear to define  content and not  method in this  case ,  with other pre limitations  ,  already defined.     . 


If  data can be  sent  under 28.300 MHz  using  FSK/FM  , then ,  its  possible to  deploy  the  VARA modem   'FM'  1200  baud  replacement  version  on  10 meter HF using  FM speech bandwidth  ???

Tnx-Graham.



NB: VARA FM is  
NOT replacement  for the   HF version ....But  , 
If stations  have  good  10 meter  link's  ,  its  possible  to  deploy the  FM version and  achieve  higher  data  throughput   
trial  deployment is  recommended , 

VAAR is provided  in two  versions ,  
HF  requires  SSB  and may be  deployed  via  FM  
FM requires FM and is  not  compatible  with SSB


Gary Chatters WA9ZZZ
 

On 11/4/18 9:52 AM, Graham wrote:

[...]
There  is no  mention  of actual  transmission 'mode'  though ,  FSK by  hard keying ,  is base band  FM
[...]

As I understand the regulations, RTTY and Data on 10m are permitted only from 28.000 MHz to 28.300 MHz.

To determine what transmission modes are referred to by "RTTY" and "Data" you have to look in section 97.3 "Definitions".

Then to learn what each of those emission designators refer to, look them up in section 2.201 "Emission, modulation, and transmission characteristics." Note: This is Part 2, not Part 97.



Many years ago (before maybe 1970) RTTY on 10m was permitted in the 29.0-29.7 MHz range using frequency modulation techniques (F1 or F2).

gc


Graham
 

Hi, Trevor 

The  VARA FM modem base band  is  about  3 KHz  bandwidth , will  pass  via  normal  FM voice  channel , the  9600  version is  wider of  course . 

Regulations  allow  for  FSK, which is a variation  of  FM  to  be   1200  baud  at  1 KHz  shift , as to the  effective  bandwidth   , has to be  over 3 KHz 
The modem should  work  with a  normal narrow  band  FM voice  channel on  10 meters ,  out side the  Union,  packet  used to  exist  , using FM  on  29.250 ,

If the  FM version  is not  possible,  then  HF remains the  only  option, at 7 K its  still   quick ..  users  may  not  of  linked the  FM version  with , HF , ie 10 meters  , The object of the  thread was to  explore  possible  deployments ,out side the accepted  norm ,  some  are possible , some not, the  graphic illustrates this 

The  badge FM did  cause some  confusion , the  modem  is  designed  to  be  conveyed  via   'ssb'   or  'fm , where  as the  FM version  can only be  conveyed , via  FM, the  HF version  is able to  accommodate  all transmission  modes  and paths.

73- Graham 

 



M5AKA
 

Sounds like the Packet operation you heard on 29.250 MHz didn't conform to the FCC license conditions.

You're correct the bandwidth for a 1200 baud FSK transmission with 1 kHz shift would be about 3 kHz but the "(7) RTTY" definition indicates you could only use it below 28.3 MHz if it had Emission Designator codes of either F1B or J2B.

Feeding 1200 baud FSK with 1 kHz shift into an FM transmitter would be an Emission Designator of F2B and this is not permitted for RTTY on 10m.

73 Trevor M5AKA



Graham
 
Edited

Hi Trev ,

Well used to operate 1200 packet on 29.250  fm
Using Belcom  ls 102  and pk232 , with BBC,B  as well
At 300 baud ssb  , was it 28103 ? 
Belcom has 5 KHz bw filter ,

Best dx  was a indonesian mail box , that was busy , not
Bad for 20 watts and a dipole ..

73 Graham ..


Chuck K4RGN
 

I concur that in the USA, "data" and "FM" are mutually exclusive on 10 meters regardless of data rate. I also concur that data can be sent 28.0-28.3 MHz if it's narrow FSK and no faster than 1200 baud. The easiest way to do that is modem audio into SSB.
 
Traditional packet radio is audio FSK (AFSK) over analog FM voice, using whatever FM bandwidth the radio happens to be set at or designed for. Typically at 2 meters and higher those signals are wide, like 20 KHz.  
 
As a practical matter, in urban settings the noise floor on 10 meters may be so high that data transmissions are unreliable. Certainly is at my QTH.

73, Chuck, K4RGN