Return-Path: Received: from mtain-dd08.r1000.mx.aol.com (mtain-dd08.r1000.mx.aol.com [172.29.64.148]) by air-me02.mail.aol.com (v129.4) with ESMTP id MAILINME022-8ba54c1ea2581d; Sun, 20 Jun 2010 19:20:56 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dd08.r1000.mx.aol.com (Internet Inbound) with ESMTP id 44FA638000130; Sun, 20 Jun 2010 19:20:52 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OQTn5-00019b-8i for rs_out_1@blacksheep.org; Mon, 21 Jun 2010 00:19:03 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OQTn4-00019S-5X for rsgb_lf_group@blacksheep.org; Mon, 21 Jun 2010 00:19:02 +0100 Received: from smtp5.freeserve.com ([193.252.22.151] helo=smtp6.freeserve.com) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OQTn2-00031C-CB for rsgb_lf_group@blacksheep.org; Mon, 21 Jun 2010 00:19:02 +0100 Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3531.me.freeserve.com (SMTP Server) with ESMTP id 50ED81C01F9D for ; Mon, 21 Jun 2010 01:18:54 +0200 (CEST) Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3531.me.freeserve.com (SMTP Server) with ESMTP id 421191C01FD6 for ; Mon, 21 Jun 2010 01:18:54 +0200 (CEST) Received: from AGB (unknown [91.109.61.157]) by mwinf3531.me.freeserve.com (SMTP Server) with SMTP id 496231C01F9D for ; Mon, 21 Jun 2010 01:18:53 +0200 (CEST) X-ME-UUID: 20100620231853300.496231C01F9D@mwinf3531.me.freeserve.com Message-ID: <1A277397AD72498D97B7D9CD2F7B3CA5@AGB> From: "Graham" To: References: <002401cb1076$f4620140$0401a8c0@xphd97xgq27nyf><005b01cb109e$58400960$0401a8c0@xphd97xgq27nyf> In-Reply-To: Date: Mon, 21 Jun 2010 00:18:46 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 X-Antivirus: avast! (VPS 100620-1, 20/06/2010), Outbound message X-Antivirus-Status: Clean X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Re: 137.500 kHz ROS beacon Content-Type: multipart/alternative; boundary="----=_NextPart_000_0115_01CB10D7.50C211E0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_20_30,HTML_MESSAGE, MISSING_OUTLOOK_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G x-aol-sid: 3039ac1d40944c1ea2547662 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_0115_01CB10D7.50C211E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ok Roger=20 Well as you will of noted Mr Ros had a bit of a bumpy ride with= our friends over the pond , so having a data system coded fo= r MF was , perhaps a bit of a unexpected out come from my initia= l request , however ... we have one ..... 2) Spread spectrum .. well that is where it all started to fall= apart ...... yes the term is reasonably close , but not close= enough to fully qualify , for example F5WK is working on a pic= based translator to enable a dds to be driven directly from= the ros software .. the tx tones are defined by a look up tab= le .. not exactly spread spectrum in the military sense ..yes there= is a mixing of digital noise with the tx data stream , but as= everyone is using the same prog free , then its not particularly= secret ...unlike say jolly windows , that every one uses without= access to the source code ....mfsk with fec may of been a more= fitting description .. but the post is history as was/is the = ensuing flap ..=20 The mode deploys full power to each tone burst , ie a mfsk, phase= continues modulation scheme , the average power is less than 10= 0% peak as the system seems to tx short ms pulses ..may be slightl= y wrong on that , but gaps do appear causing my carrier led to= flicker on tx 2) bandwidth is as advertised , the ros -mf 1 & 7 is approx 98= Hz wide , coded to fit inside the (new ?) 100 Hz data allocati= on on 500 .. by inspection the modulation seems to be very clean wi= th no over shoot , unlike mfsk that seems to spread quite badl= y , I note that 137K band plans talk of 200 hz data bw=20 3) Non linear PA is required , the smart x2 harmonic amplifier= Gary and my self deployed gives a work-round to the logic drive = problem , Gary is transverting to 137 khz from HF with a linear= transverter ... however the class d/e amp would half the frequ= ency and modulation , so picking the x2 harmonic produced a dr= ive carrier of 274 khz , which then reduced to 137 at the Ae ..= ....=20 4) Well its a free system ...... its running better as time go's= on and evolving , some beacon modes are now available , cut and pa= ste , and the e-mail qsl seems to work nicely=20 5) I would say it already is , running 1 watt to my Ae I can= obtain 100% decodes from the delft web-sdr on 500 Khz in mf-1= mode , 2 to 3 watts for mf-7 , that's 350 miles , on 7 meg in= qso with co2dc I have taken 100% print with him running 250 mW= to the Ae with 50 mW drive to my Ae on 500 , print was 100%= in Harrogate, in tests last month , Grays test on 137 as reported= by F5WK , was under the visible level on the spectrum plot , but= was decoding.=20 1) facts and figures ..well I don't really know .Mr Ros has the= info .. but its not for publication .... this is perhaps a sticky= point .. but while it lasts its showing what can be achieved .= wspr is a time locked array processed system , using best fit= matching , ros is a free running live data system, that is= using digital noise reduction / cancellation to recover the data= and as such are not really compatible , it looks to be on the= lines of the noise reduction used in the military satellite syste= ms of the 1980/1990 .. but in a much reduced bandwidth, making us= e of modern pc power ... reception of the initial sync frame is= essential .. this process is much more robust than the main= data flow , but dose present a problem with long qsb , unlik= e wspr that is partitioned=20 >From my own experience as was Michel , I have seen the low baud= rate ros system produce 100% print , when the signal could no= t be viewed on spec lab or detected by headphones .. so I think= 'we' are working below the noise , co2dc has intimated that the= system provides a increase of 20 dB over the psk31 system over= the path co/vk , high immunity to phase distortion is also pro= vided by the modulation system.=20 Ok Roger , I hope that fills in the gaps ... at the moment you st= ill need the traditional audio to rf translation , however f5wk= is working on a pic system and the x2 harmonic amp provides a= work round for classe/d amps .. but you do need to generat= e on the intended Ae frequency to use the amp. 73 - G ..=20 Nb .. There may be some mileage in using a logic gate digital= mixer to get on to frequency ........ would need a x2 doubler= (logic) to get over the logic drive .. but if it works .. opens= up 500/137 to a lot more data com's , bit of a odd concept . bu= t if it works .. ? From: Roger Lapthorn=20 Sent: Sunday, June 20, 2010 9:41 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Re: 137.500 kHz ROS beacon Graham, I'm behind on ROS progress so have a few questions please, if you've= time: 1.. How does ROS compare on a weak signal "effectiveness" factor wit= h modes like QRSS3, 10 etc and with WSPR? Is there a "dB better than"= estimate for ROS in its various forms? 2.. What sort of bandwidths does ROS occupy on these LF tests? I app= reciate it is spread spectrum, so there's not much power at any time= on any frequency. 3.. What sort of TX PA is needed - linear or non-linear?=20 4.. Is the software less clunky than when I looked a few months back= ?=20 5.. Is it going to be a serious contender for real QRP buffs like me= ? 73s Roger G3XBM On 20 June 2010 20:46, Graham wrote: ''''for instance the French stn F5WK cannot hear you''''' Well , yes , that's the point of it all , no noise, no trace= just 100% pure digital data rolling over the land , like the un-= seen fog of progress =20 IARU - R-1 plan .. 137.4 to 137.6 digital modes , with the note tha= t CW is 'not allowed' =20 I think the test and the frequency went fully to 'to plan' and= paves the way for a magnitudinal increase in data use on 137 , to= date limited by bandwidth to psk31 , ros-mf by design occupying= on 50% of the allowable space on 137 and 99% of the 100Hz allo= cations for 500K. and passing via a non linear system , how lon= g will it before the first live data qso over the pond ? G .=20 From: mal hamilton=20 Sent: Sunday, June 20, 2010 6:30 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Re: 137.500 kHz ROS beacon Gary There are too many variables with these experiments for instance the= French stn F5WK cannot hear you but you are S5 solid on 137.5 here at= my qth The RX stations antennas need to be analyised otherwise it misrepres= ents what you are doing. Can u pse use frequencies below 136.5 kcs otherwise there is a probl= em with EU and Russian stations using the area 137 - 137.778 kcs for= QRS acty. also this is the DX window area for the USA and others. 73 de mal/g3kev ----- Original Message -----=20 From: Gary - G4WGT=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Sunday, June 20, 2010 4:31 PM Subject: Re: LF: Re: 137.500 kHz ROS beacon Hi Mal,=20 Thank you for your report & comments. The mail you replied to give= s all the details of equipment in use for the test beacon. I would like to be able to have a QSO using morse but I have to ad= mit to a complete loss of confidence as I have not used the mode for= 25 years which was one year after I passed the test in 1984. Looking= back, letting it go was a silly thing to do. I do enjoy testing out these "weak signal" modes & in the report= I received from Michel F5WK last night he wrote that he could not hea= r the signal or even see it on SpecLab but he got a complete decode.= So as a weak signal communication mode it works. Just to elaborate on the antenna, it is a 12 metre base loaded ver= tical with a small elevated inductor of 500uH at about 9 metres & a 1= x 3 metre capacity top with a 120uH spiral inductor. In my small gard= en I have no space to go outwards only upwards. 73, Gary - G4WGT. On 20 June 2010 13:48, mal hamilton wrote: Gary If that was you last nite on 137.5 kcs you were strong enough= for cw or qrs3 no need to struggle with decodes from elswhere. also I had a qso with G3XIZ this morning on 137.0 kcs and got 59= 9, he was 569. Not sure what antenna u were using but it was putting out a fair= signal to this qth. Your radiators are probably acting as an antenna= above earth. de mal/g3kev ----- Original Message -----=20 From: Gary - G4WGT=20 To: LF Group (RSGB)=20 Sent: Sunday, June 20, 2010 12:07 PM Subject: LF: 137.500 kHz ROS beacon Hi LF, Having successfully bench & on-air tested a x2 harmonic amplif= ier method of driving my G0MRF Class D LF transmitter, I ran a beacon= last night (Saturday 19th) on 137.500 kHz. An extract from my previous e-mail description is shown at the= end. Using the equipment & method described below, the ERP from my= 12 metre vertical antenna was around 150mW. The mode was ROS MF-1, 10= 0 Hz bandwidth. I received the following report from Michel, F5WK in JN18HP,= a distance of 410 miles (661 kilometres) in daylight. >> Not even a faint trace on a QRSS3 spectrum but: >> RX1: 19:23 @ 5.9 Hz: 9 -37 dB >> RX1: 19:28 @ 5.4 Hz: O4WGT -34 dB >> RX1: 19:33 @ 5.4 Hz: G4WGT -31 dB The x2 harmonic low level amplifier is a simple way of driving= a Class D type of transmitter which employs a divide by 2 drive chain= . My limitation with multi tone drive is that my DDS VFO will only pro= duce 2 frequencies ie. the main frequency & a CW/Rx offset which has= previously limited me to 2 tones as with RTTY & DFCW modes. Please bear in mind that it will not be suitable for modes lik= e PSK were tones are transmitted simultaneously. At the moment the 2 small PCB's are precariously lying on the= desk, when I have cased them I will publish the circuit & pictures. 73 Gary - G4WGT. *********************************************** After a few days experimenting & bench testing a method of= driving my G0MRF Class D Tx on the 137.000 kHz band from my linear tran= sverter I finally constructed a harmonic amplifier producing a 274.000 kHz sig= nal from 137.000 kHz input. An "on-air" trial was conducted resulting in a QS= O with Graham G0NBD on 137.000 kHz using ROS data mode software. =20 My thanks to Graham for his ideas & tests. =20 The mode used was ROS MF-7. The equipment used for the QSO= was as follows. Kenwood TS-440 to my LF-MF linear transverter produ= cing the 137.000 kHz signal, followed by a tuned harmonic circuit &= buffer amplifier whose output was 274.000 kHz therefore at x2 drive= for the Class D Tx. The x2 signal is then divided by the Tx driver chain= in the normal way to provide 137.000 kHz to the PA. =20 This method should also work well using WSPR & other similar= modes. ********************************************* --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 ------=_NextPart_000_0115_01CB10D7.50C211E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ok Roger
 
Well  as you  will  of=   noted=20 Mr Ros had a  bit  of a  bumpy ride with  our = ; friends=20 over  the  pond , so  having a  data  system&= nbsp;=20 coded  for  MF was , perhaps a  bit  of a  un= expected=20 out come  from my  initial  request , however ... we ha= ve =20 one .....
 
2) Spread  spectrum .. well = ; that is=20 where  it all  started to  fall apart ......  yes= the =20 term is  reasonably  close , but  not  close= enough=20 to  fully  qualify , for  example F5WK is  working= on=20 a  pic based translator  to  enable  a  dds&n= bsp; to=20 be  driven  directly  from the  ros  software= .. =20 the  tx tones are  defined by  a  look up  ta= ble ..=20 not  exactly spread spectrum in the  military  sense ..= yes=20 there  is a  mixing  of  digital  noise with= the =20 tx data  stream , but  as everyone  is using the = same =20 prog free , then  its not  particularly secret ...unlike&nbs= p;=20 say  jolly  windows , that  every one uses  withou= t =20 access  to the  source code ....mfsk with  fec  ma= y of been=20 a  more  fitting  description .. but the  post&nbs= p; is=20 history  as was/is  the  ensuing flap  .. <= /DIV>
 
The  mode  deploys full&nbs= p; power to=20 each tone  burst , ie  a mfsk, phase continues   modula= tion=20 scheme , the  average  power is  less  than 100%= peak =20 as the  system seems to  tx short ms pulses ..may be&nb= sp;=20 slightly  wrong  on that  , but  gaps do  app= ear=20 causing my  carrier  led to  flicker  on tx=
 
2)  bandwidth  is as advert= ised ,=20 the  ros -mf 1 & 7  is  approx  98 Hz&nbs= p;=20 wide  , coded to  fit  inside the  (new ?) 100 Hz&= nbsp;=20 data  allocation on 500 .. by inspection the  modulation see= ms to=20 be  very  clean with  no  over  shoot = , unlike=20 mfsk  that seems to  spread  quite  badly , = I note=20 that  137K  band plans  talk of 200  hz data bw=20
 
3)  Non linear  PA  is=  =20 required , the  smart x2  harmonic  amplifier Gary and= my self=20 deployed gives a  work-round to the  logic  drive = problem ,=20 Gary is  transverting to  137 khz  from HF with a = =20 linear  transverter ... however the  class d/e  amp&nbs= p;=20 would  half  the  frequency  and  modulation= , so =20 picking the  x2  harmonic  produced  a  drive=  =20 carrier of  274 khz , which then  reduced to  137 = at=20 the  Ae  ......
 
4) Well  its a  free system= ......=20 its  running  better  as time  go's on and evolvin= g ,=20 some  beacon modes are now  available , cut and  paste= , and=20 the  e-mail qsl seems to  work  nicely
 
5)  I  would  say it&n= bsp; already=20 is , running  1 watt  to  my  Ae I can  obtai= n=20 100%  decodes  from the  delft  web-sdr  on= 500 Khz in=20 mf-1 mode , 2 to 3  watts  for  mf-7 , that's  350=  =20 miles , on  7  meg  in qso with  co2dc I have = ; taken=20 100% print  with  him running  250 mW to the  Ae&n= bsp; =20 with  50 mW  drive to  my  Ae on 500 , print = was 100%=20 in Harrogate, in tests  last  month , Grays test on 137 = ; as=20 reported by F5WK , was under the visible  level  on the = ;=20 spectrum  plot  , but  was decoding.
 
1) facts and  figures ..well&nbs= p; I=20 don't  really know  .Mr Ros  has the  info = .. but its=20 not  for  publication .... this is perhaps a sticky point ..= but =20 while it  lasts  its showing what  can be  achieve= d  .=20 wspr  is a  time  locked   array  proces= sed =20 system , using  best fit  matching  , ros  is a&nb= sp;=20 free  running  live  data  system, that  is= using =20 digital  noise  reduction / cancellation to  recover th= e =20 data and as  such  are  not  really  compatib= le ,=20 it  looks to be  on the lines of the  noise reduction&n= bsp; used=20 in the  military satellite  systems  of the  1980/= 1990 ..=20 but  in a much  reduced  bandwidth, making use  of=  =20 modern  pc  power ... reception of the  initial&nb= sp;=20 sync  frame is  essential  ..  this  process&= nbsp;=20 is  much  more robust than the  main data  flow ,= but =20 dose  present a  problem  with  long  qsb &nb= sp; ,=20 unlike wspr that  is partitioned
 
From my own experience  as was= Michel , I=20 have  seen  the  low  baud  rate = ros =20 system  produce  100% print  , when  the signal&nb= sp; could=20 not  be  viewed on spec lab or  detected by  headp= hones=20   .. so  I think 'we'  are  working  below th= e =20 noise , co2dc has  intimated that  the  system  pr= ovides=20 a  increase of  20 dB over the  psk31 system over the&n= bsp;=20 path  co/vk , high  immunity  to  phase  dist= ortion is=20 also  provided  by the  modulation  system.
 
Ok Roger , I hope that  fills in= the =20 gaps ...  at the  moment you  still  need the = ;=20 traditional  audio  to rf  translation  , however= f5wk=20 is  working  on a pic  system and the  x2 =20 harmonic  amp  provides a  work  round  for&n= bsp;=20 classe/d  amps  .. but  you  do  need = to =20 generate  on the intended  Ae frequency to  use the&nbs= p;=20 amp.
 
73 - G ..
 
Nb .. There may be  some = mileage  =20 in using a  logic  gate  digital  mixer to = get on=20 to  frequency ........ would need  a  x2  doubler= (logic)=20   to  get over the  logic  drive  .. but if= it works ..=20 opens up  500/137 to  a lot  more data  com's , bi= t of=20 a  odd  concept . but if it  works .. ?
 
 
 

Sent: Sunday, June 20, 2010 9:41 PM
Subject: Re: LF: Re: 137.500 kHz ROS beacon

Graham,

I'm behind on ROS progress so have a few= questions=20 please, if you've time:
  1. How does ROS compare on a weak signal "effectiveness" factor wit= h modes=20 like QRSS3, 10 etc and with WSPR? Is there a "dB better than" estima= te for ROS=20 in its various forms?
  2. What sort of bandwidths does ROS occupy on these LF tests? I app= reciate it=20 is spread spectrum, so there's not much power at any time on any=20 frequency.
  3. What sort of TX PA is needed - linear or non-linear?=20
  4. Is the software less clunky than when I looked a few months back= ?=20
  5. Is it going to be a serious contender for real QRP buffs like=20 me?
73s
Roger G3XBM

On 20 June 2010 20:46, Graham <g8fzk@g8fzk.fsnet.co= .uk>=20 wrote:
''''for instance the French stn F5W= K cannot=20 hear you'''''
 
Well  , yes , that's the = point =20 of it  all  , no  noise, no  trace just  10= 0%=20 pure  digital  data rolling over the  land , like the=  =20 un-seen  fog  of  progress 
 
IARU - R-1 plan .. 137.4 to 137.6&n= bsp; digital=20 modes , with the note that  CW is 'not allowed' 
 
I think the  test and  th= e =20 frequency  went fully  to  'to plan' and paves the wa= y =20 for a magnitudinal  increase in  data  use on 137 ,= to date=20 limited by bandwidth  to  psk31 , ros-mf  by  de= sign =20 occupying on 50%  of the  allowable  space on = 137 =20 and 99% of the  100Hz  allocations  for  500K.= and =20 passing via  a  non linear  system , how  long= will =20 it before the  first  live  data  qso  over= the =20 pond ?
 
G .
 
 

Sent: Sunday, June 20, 2010 6:30 PM
Subject: Re: LF: Re: 137.500 kHz ROS=20 beacon

Gary
There are too many variables with= these=20 experiments for instance the French stn F5WK cannot hear you bu= t you are=20 S5 solid on 137.5 here at my qth
The RX stations antennas need to be= analyised=20 otherwise it misrepresents what you are doing.
Can u pse use frequencies below 136= .5 kcs=20 otherwise there is a problem with EU and Russian stations using the= area 137 -=20 137.778 kcs for QRS acty.
also this is the DX window area for= the USA and=20 others.
73 de mal/g3kev
 
 
 
----- Original Message -----
F= rom: Gary - G4WGT
Sent: Sunday, June 20, 2010= 4:31=20 PM
Subject: Re: LF: Re: 137.50= 0 kHz ROS=20 beacon

Hi Mal,=20

Thank you for your report & comments. The mail you replie= d to gives=20 all the details of equipment in use for the test beacon.

I would like to be able to have a QSO using morse but I have= to admit=20 to a complete loss of confidence as I have not used the mode for= 25 years=20 which was one year after I passed the test in 1984. Looking back,= letting it=20 go was a silly thing to do.

I do enjoy testing out these "weak signal" modes & in the= report I=20 received from Michel F5WK last night he wrote that he could not he= ar the=20 signal or even see it on SpecLab but he got a complete decode. So= as a weak=20 signal communication mode it works.

Just to elaborate on the antenna, it is a 12 metre base loade= d vertical=20 with a small elevated inductor of 500uH at about 9 metres & a= 1 x 3=20 metre capacity top with a 120uH spiral inductor. In my small garde= n I have=20 no space to go outwards only upwards.

73,

Gary - G4WGT.

On 20 June 2010 13:48, mal hamilton <g3kevmal@talktalk.net> wrote:
Gary
If that was you last nite on&nb= sp; 137.5 kcs=20 you were strong enough for cw or qrs3 no need to struggle= with=20 decodes from elswhere.
also I had a qso with G3XIZ thi= s morning on=20 137.0 kcs and got 599, he was 569.
Not sure what antenna u were us= ing but=20 it was putting out a fair signal to this qth. Your radiators are= probably=20 acting as an antenna above earth.
 
de mal/g3kev
 
----- Original Message -----=
= From:=20 Gary - G4WGT
Sent: Sunday, June 20,= 2010 12:07=20 PM
Subject: LF: 137.500 kH= z ROS=20 beacon

    Hi LF,
Having successfully bench & on-air tested a x2 harmon= ic=20 amplifier method of driving my G0MRF Class D LF transmitter,= I ran a=20 beacon last night (Saturday 19th) on 137.500 kHz.

An extract from my previous e-mail description is shown= at the=20 end.

Using the equipment & method described below, the ERP= from my=20 12 metre vertical antenna was around 150mW. The mode was ROS= MF-1, 100=20 Hz bandwidth.

I received the following report from Michel, F5WK in JN18= HP, a=20 distance of 410 miles (661 kilometres) in daylight.

>> Not even a faint trace on a QRSS3 spectrum=20 but:

>> RX1: 19:23 @ 5.9 Hz: 9 <STOP> -37= =20 dB
>> RX1: 19:28 @ 5.4 Hz: O4WGT <STOP> -34=20 dB
>> RX1: 19:33 @ 5.4 Hz: G4WGT <STOP> -31 dB<= /DIV>

The x2 harmonic low level amplifier is a simple way of dr= iving a=20 Class D type of transmitter which employs a divide by 2 drive= chain. My=20 limitation with multi tone drive is that my DDS VFO will only= produce 2=20 frequencies ie. the main frequency & a CW/Rx offset which= has=20 previously limited me to 2 tones as with RTTY & DFCW modes= .

Please bear in mind that it will not be suitable for mode= s like PSK=20 were tones are transmitted simultaneously.

At the moment the 2 small PCB's are precariously lying on= the desk,=20 when I have cased them I will publish the circuit & pictur= es.

73

Gary - G4WGT.
    ***********************************************
    After a few days experimenting & bench testing a metho= d of=20 driving my
    G0MRF Class D Tx on the 137.000 kHz band from= my linear=20 transverter I finally
    constructed a harmonic amplifier pr= oducing a=20 274.000 kHz signal from 137.000
    kHz input. An "on-air" tr= ial was=20 conducted resulting in a QSO with
    Graham G0NBD on 137.000= kHz using=20 ROS data mode software.
     
    My thanks to Graham for= his ideas=20 & tests.
     
    The mode used was ROS MF-7. The eq= uipment=20 used for the QSO was as
    follows. Kenwood TS-440 to my LF-= MF linear=20 transverter producing the
    137.000 kHz signal, followed by= a tuned=20 harmonic circuit & buffer
    amplifier whose output was= 274.000=20 kHz therefore at x2 drive for the Class
    D Tx. The x2 sign= al is then=20 divided by the Tx driver chain in the
    normal way to provi= de 137.000=20 kHz to the PA.
     
    This method should also work wel= l using=20 WSPR & other similar modes.
    *********************************************
<= /BLOCKQUOTE>






--
http://g3xbm-qrp.blogspot.c= om/
http://www.g3xbm.co.uk=
http://www.you= tube.com/user/g3xbm
G3XBM=20    GQRP 1678      ISWL G11088


------=_NextPart_000_0115_01CB10D7.50C211E0--