UBC Theses and Dissertations

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UBC Theses and Dissertations

Search for galactic H2+ Sloan, David Scott 1969

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A SEARCH FOR GALACTIC H  + 2  by  DAVID S. SLOAN B.Sc., The U n i v e r s i t y  of B r i t i s h  C o l u m b i a , 1967  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE  i n the Department of Phys i c s  We a c c e p t t h i s to  thesis  the required  as c o n f o r m i n g standard  THE UNIVERSITY OF B R I T I S H COLUMBIA April,  1969  In  presenting  an  advanced  the  Library  I further for  this  thesis  degree shall  agree  scholarly  at the University make  that  purposes  his representatives.  of  this  written  i t freely  permission  by  thesis  may  of  April  gain  Columbia  Columbia,  f o r reference copying  b y t h e Head  It i s understood  Physics  1969  of British  f o r extensive  be g r a n t e d  for financial  The University of British V a n c o u v e r 8, C a n a d a  f u l f i l m e n t of the requirements f o r  available  permission.  Department  Date  in partial  shall  that  n o t be a l l o w e d  and  thesis  Department or  that  Study.  of this  o f my  copying  I agree  or  publication  without  my  ii  ABSTRACT The d e s i g n and c o n s t r u c t i o n correlation It  is  IMiHz,  spectometer  a 16 c h a n n e l Extensive  for  device  use was  The use  of  the  molecular  covered  a frequency  sources  NML Cygnus and the  T  K.  0.25  with  hydrogen range  integrated  spectrometer (Hg*) 1404 to  a digital  astronomy  an o v e r a l l  made o f  ionized  fe  radio  of  is  is  described.  bandwidth  of 2  circuitry.  in a search  described.  1409 MH:z f o r  Omega Nebula  auto-  down to  The the  for  singly  search radio  a level  of  iii  TABLE OF CONTENTS Chapter I  II  Page Introduction (i) Hydrogen Ions i n Space (ii) S p e c t r o m e t e r and R e c e i v i n g  System  S p e c t r o m e t e r Development (i) R e c e i v i n g System B l o c k D i a g r a m (ii) Spectrometer Block Diagram (iii) S i m p l i f i e d A n a l o g to D i g i t a l Converter (iv) A c t u a l A n a l o g to D i g i t a l Converter (v) M u l t i p l i e r Accumulator (vi) Readout Gates (yii) Programmer and T e l e t y p e Code Converter ( v i i i ) Teletype Driver  III  Physics (i) (ii)  and Astronomy o f H o T r a n s i t i o n s R a d i a t i o n From H 2 * L i n e S t r e n g t h s and Number of H Ions  V  +  L i n e S e a r c h Program and R e s u l t s (i) Equipment T e s t i n g (ii) O b s e r v i n g Program (iii) Data P r o c e s s i n g (iv) C o r r e c t i o n for False D.C. Component (v)  van V l e c k  and Hamming C o r r e c t i o n s  C o n c l u s i o n s and R e c o m e n d a t i o n s  Bibliography  5 6 7 8 10 11 12 15  +  2  IV  1 2  16 17 21 22 23 24 26 28 30  iv  LIST OF ILLUSTRATI0NS Figure  Pa ge  1  Block  2  Spectrometer  3  Simplified  4  A c t u a l A n a l o g to D i g i t a l  5  Multiplier  6  Readout  7  Programmer  8  Teletype  Driver  38  9  Receiver  I.F.  39  10  Diagram o f  Receiving  Block  System  Diagram  A n a l o g to  Digital  32 Converter  Converter  Accumulator  33 34 35  Gates  Resulting  31  36  and T e l e t y p e  Response  Spectra  Code C o n v e r t e r  37  40  V  ACKNOWLEDGEMENTS I Dr,  W.  L.  would  H.  like  Shuter  for  to e x p r e s s his  my s i n c e r e  h e l p and g u i d a n c e  gratitude  to  throughout  this  work. I  wish  Astrophysica1  to  thank  Observatory  the for  staff  of  the D o m i n i o n R a d i o  generously  providing  their  facilities. I discussions  wish on the  to  thank  Prof.  spectrometer  F.  K.  design.  Bowers  for  helpful  1  CHAPTER  I  INTRODUCTION  (i)  Hydrogen  Ions  in  Space  The h y d r o g e n m o l e c u l a r radio the  amount  that of  astronomy of  a large  the  gen.  in  the  a knowledge so t h a t  inside  the  many s p e c t r a l  suitable  sources  might  determining  It  as  amount  is  accounts)  have  observations.  molecular  be e x c i t e d ,  been  hydro-  not r a d i a t e  windows  i n the  hydro-  h y d r o g e n can  h y d r o g e n does  lines  to  believed  molecular  of  atmospheric  hand has  hoped t h a t  in  amount o f m o l e c u l a r  total  other  is  use  in space.  the  we may make a s t r o n o m i c a l  it  interest  hydrogen o b s e r v a t i o n s  of  the  of  of  might e x i s t  which  band and  potential  molecular  any  is  +  much as 40% by some  the g a l a x y  Unfortunately  wavelengths  (as  21 cm a t o m i c  is, important  fixed.  its  hydrogen  proportion  hydrogen Since  of  molecular  so s u c c e s s f u l , gen  because  ion H g  H2  radio  be at  through on  +  the  frequency  hydrogen s u r r o u n d i n g perhaps  in  a manner  anagous  to OH. Two r e g i o n s Nebula  is  a s t r o n g HII  OH e m i s s i o n , known to  the  r e g i o n which  other,  be a s t r o n g  were o b s e r v e d  were s t u d i e d ,  NML Cygnus  OH s o u r c e .  from 1404 to  one o f is  is  these  thought an  to  have no  infra-red  The two s e l e c t e d  1409 Mhz i n  the Omega  five  star regions  overlapping 2  MHz b a n d s . The o b s e r v i n g  program was  p r e c e d e d by  test  2  observations  of  167  Omega s o u r c e .  in  the  the  hydrogen r e c o m b i n a t i o n  Palmer  and Zuckerman  of  instrument.  the  (ii)  1)  Receiving  The paraboloidal Observatory  near  varactor  diode  by U.  C.  of  B.  for  to  the  (fourier  2)  Dominion Radio The r e c e i v i n g  amplifier  25.6  permit  meter  Astrophysical  s y s t e m was a  radiometer  telescope.  complete survey  Minor  system  developed  modifications  connecting  with s p e c i a l  advantages  of  digital  given  and the  easy  digital  spectrometers  achievement  input  sign  of  that  significant  input  the  the  spectro-  is  1964 i s on  given  this  line  clipped until  preserved.  Bowers  in s i g n a l  are  anomalies  so c a l l e d only  the  (Ref.  6)  to  analog  techniques.  bandwidths.  the  by  review,  in a u t o c o r r e l a t o r s  of delay  of  autocorrelation  to d i g i t a l  of v a r i a b l e  improvement  techniques  Since  have been o f  noise is  way  methods  and e l i m i n a t i o n  where  emphasis  spectroscopy.  have l a r g l y  type  of  s p e c t r o s c o p y up to  techniques  the  the  on t h i s  transform)  from d r i f t s  of  the  Spectrometer  astronomical (Re,  calibration  System  were made w i t h  were made t o  A very  Argyle  a  system.  2)  radio  as  by  System  Penticton.  use  and s e r v e d  and R e c e i v i n g  parametric  the r e c e i v e r  meter  7)  observations  telescope  166 ©t^ and  These have been o b s e r v e d  (ref.  Spectrometer  lines  noise  freedom (Ref.  Nearly "1  The  2) all  bit"  algebraic has  shown  ratio  can  3  be o b t a i n e d of  the  by p r e s e r v i n g  input  Number  signal  of  as  more t h a t  shown  bits'  in  table  Signal  to  Ratio  Noise  the  quantizing  Relative  1.57  2.56  2  a.  1.28  3  1.04  1.08  Oo  1.00  1.00  to  complexity  be p a i d  especially  The D o m i n i o n R a d i o in a "low  for  noise"  experiment  in  13  which  1  this  improvement  the  "multipliers"  Astrophysica1  spectrometer they  described  spectrometer  for  this  experiment.  "2  bit"  as w e l l  to  hoped t h a t  test  the  "2bit"  improvement  in  use  grew  as  feasibility  quantization  observing  time,  (see  below).  were  The d e s i g n  out  of  This one b i t  of  increased  interested  i n a Super  were p l a n n i n g .  spectrometer  so t h a t  is  Observatory  for  herein  Observing  Time  1  The p r i c e  be used  in  one:  Relative  Table  built  one b i t  this  Synthesis for  the  discussions  spectrometer  was  quantization approach.  It  which  provides  a  would  be a s u i t a b l e  of a  could was  XX trade  off. The d e v i c e the  (cosine)  an o b s e r v i n g  described  autocorrelation  below  computes  function.  program w i t h an o v e r a l l  16 p o i n t s  The u n i t  bandwidth  was  used  of 2 Mhz.  of in  4 Bandwidths possible pass  from 6 Mhz to any  simply  filter  by c h a n g i n g  ahead  of  The o u t p u t teletypewriter general the  purpose  fourier  and  the of  smaller the  "clock"  transform  to  rate  should  and the  be band-  spectrometer. the  spectrometer  punched on paper  digital  bandwidth  computer. produce  tape This  the  is  typed  on a  for  input  to a  computer  power  computed  spectrum.  5  CHAPTER  SPECTROMETER  (i)  Receiving  by  the  antenna  electrical directional This  ( £ ^ 1 7 0 K)  to  the  is  an o c t a v e  to  overcome  bandwidth the  losses  1,  into  the  feed  horn is  the  about  the  signal  "feed  fed  collected The  through  the  parametric  noise  14 db g a i n .  amplifier.  temperature The next  amplifier  first  is  horn".  diode  system  transistor in  the  varactor  establishes  and p r o v i d e s  Diagram  figure  from the  coupler  amplifier  in  and f o c u s e d  signal  DEVELOPMENT  System B l o c k  As o u t l i n e d  II  amplifier  w i t h enough  gain  mixer. 4  A plasma d i s c h a r g e signal  which  is  attenuated  by the d i r e c t i o n a l  a calibration  erature  when d e s i r e d . The f i r s t  generated  in  the  wave o s c i l l a t o r .  This  signal  local  control This  generates  and added t o  coupler.  provide  tube  tube  the  a 10 input  signal  (L.O.)  antenna  signal  room by a p h a s e - l o c k e d  can be s e t  noise  can be o p e r a t e d  o f 25K e f f e c t i v e  oscillator  K  to any  to temp-  is  backward  frequency  in  the  9 range  1 t o 4 GHz w i t h a b o u t  accuracy. the  The f i r s t  transistor  intermediate  amplifier  frequency  a preamplifier control  L.O.  at  the  1 part  signal  in  beats  to g e n e r a t e  (I.F.) focus  10  signal.  resolution  w i t h the  a 35 MHz This  is  and  signal  from  (nominal) amplified  and a main a m p l i f i e r  in  by  the  room. The 35 MHz I.F.  is  further  mixed w i t h a 4 5 . 7 MHz  6  L.O.  to generate an 11,0 MHz  Several 10,7 MHz selected  (nominally 10.7 MHz)  I.F.  bandpass f i l t e r s are provided and can be  by a front panel switch.  These f i l t e r s  determine  the radiometer bandwidth and have passbands ranging from 5 KHz  to 6 MHz.  For operation with the spectrometer, a  special 2 MHz wide f i l t e r with sharp band edge's was  used.  This f i l t e r has been described elsewhere  The  bandshaped 11,0 MHz and passed to 4 MHz  (  signal was  through a 6 MHz  (Ref. 2),  mixed with an 8 MHz  L.O.  low pass f i l t e r to provide a 2  signal for the spectrometer.  ( i i ) Spectrometer  Block Diagram  The input signal from the receiver  enters the  analog to d i g i t a l converter where i t is sampled at the clock rate.  The samples are quantized and changed to binary numbers.  The d i g i t a l signal is s p l i t into two paths.  The f i r s t , the  "prompt" l i n e , goes to the f i r s t multiplier and the second, the "delayed" l i n e , goes to the f i r s t multiplier and the f i r s t s h i f t register stage.  The s h i f t register stores the  binary number present at i t s input during one s h i f t pulse u n t i l the next s h i f t pulse.  The sampling pulses and the  s h i f t pulses are synchronized and therefore the s h i f t register functions as a d i g i t a l equivalent of an analog delay line.  The inputs to the N*th s h i f t register are binary  numbers corresponding to the present value of the input signal and the signal (N-l) s h i f t periods e a r l i e r , an analog delay,line, the delay time of the s h i f t  Unlike registers  7  can be v a r i e d  by c h a n g i n g  The m u l t i p l i e r numbers p r e s e n t accumulator. integration  the  3 octal  carriage  sum t h e s e  numbers  the  of 5£, 1, end o f  to  the  characters codes the and  bit"  The  input  This  circuit  1 state if  signal  the  at  its  input  put  signal  for  10 n s e c .  time  has  is  of is  sample  to  the  has  the  stored  teletype  code c o n v e r t e r .  This  to a 8 l e v e l  at  code used by  circuit the  the  spaces  the  the groups  line  feed  and  end o f  each  line.  is  free  A n a l o g to D i g i t a l  for  typing  t o an  if  the  This  that  it  input "1  flop  flip  shown  provide  and  input  of  to  to  delay flop's  flip  3,  circuit. a  logical  logical  0 state  the  of  the  flip  sampled v a l u e  the  the  in F i g ,  comparator  will  the  digital  similar  representation  the  holds  and t h e  is  is^0  bit"  The o u t p u t  register  taken  A to D)  integrated  property  flip  Converter  A to D ( f u n c t i o n a l l y  sampled by g a t i n g  been  period  out  required  •< 0 ,  shift  one  numbers and g a t e d  and g e n e r a t e s  fed  between s a m p l e s .  input  for  the  octal  the a c t u a l  the  This  to  the  remarks.  output  is  integration  teletypewriter  Simplified  operation  number  of  or 4 m i n u t e s .  formatting  A simplified "1  2,  character  A page  data  an  3 digit to  octal  Between o u t p u t s ,  (iii)  product  The a c c u m u l a t o r s  return  additional  binary this  teletypewriter, of  the  and f e e d s  by c h a n n e l  converts  produces  frequency.  inputs,  converted  channel  its  period At  sum i s  at  the c l o c k  flop  in-  flop for  is  the  the  line.  After  output  has  the  stabilized,  8  the  pulse  sample the  is  into  shift  output.  applied the  various  "delay  registers This  Actual  the  to  permit  input  circuit  to  voltage,  Bowers  has  the the  Analog  y,  shown  that  the  The c o m p a r a t o r above. delay  a pulse  samples  6) the  value  outputs  are  be a 1 or  Input  and  logic  gates  a 0 according  to  than  that  0<y<x •x <y<0 y<-x  the  and  to  flip  is  fed  -x,  the  4,  it  0 and  of  the  voltage  is  sampled and h e l d output  determine table  2:  Table  2  Comparator  0 0 0 10  0  extra  let flop  through  if  Output  if  the  respectively.  input not in  similar  circuitry  voltage,  becomes the  is  decide  +x  reference  rms v a l u e the  fig.  comparators  the  A B C x<y  in  but w i t h  Three  of  delay  new  Converter  shown  The s e c o n d c o m p a r a t o r ' s bit  pulse  the  multipliers.  above  greater  (Ref.  actual  a further  A to D i s  s h o u l d be a p p r o x i m a t l y but  16  to s h i f t  After  "prompt"  operation. is  registers  to D i g i t a l  discribed  "2bit"  shift  line".  is  The a c t u a l to  the  stabilize,  pulse  amplifiers  (iv)  to  x,  signal  critical. flip the  first  flops second  bit  Delay 12 0 0 10  1 1 0  0  1 1 1  11  1  as  should  Bit  9  As d e s c r i b e d sequentially  in  time  are  single  prompt p u l s e was  to  controlled  pulses  are  a second three  input  from the  from the output  clock  of  this  tribution  input  shown  in  the  clock  is  is  nsec)  circuit other to the  gate  the  to  input  clock  three  pulses  three  time of  the  has  three  g a t e and an  pulse  and i s  fed  inhibit  pulse width.  are  fed  input The  to  dis-  the d i v i d e  one s t a t e  by  circuit  time  the  three  the  three and  the  relation  the  clock  A, B,  by  pulse  and C.  circuit  divide  become  is  termed  three  pulses  that  shift  registers. were used to  as were r e q u i r e d pulses  so t h a t  the  pulses  by  of  TTL i n v e r t e r s  This  This  with  staggered  p r o c e s s e d to  volts.  flops.  sampling  a divide  strobed with  further  A test  to  the  below.  The o u t p u t  insure  3 times  fed  pulses  cycle".  delays  is  is  from TTL f l i p  timing diagram  pulses.  +3.8  This  input  prompt p u l s e  clock  This  RTL and TTL s h i f t  5  a three  as  These  the  Various (  gate.  case.  gate  (4 MHz) o u t p u t  the  above  These  just  to c o n t r o l  generate  become the  circuit  the  flops  circuit  These  "one  flip  period;  programmer a n d a s t r o b e  fashioned  gates  The  clock  and C o c c u r  readout  12 MHz).  logic  to  in  A, B,  amplifiers.  (le.  circuit  by t h r e e  combined i n  The a c t u a l rate  pulses  d u r i n g each  pulses  separate  below,  had the  switch forces  in various  proper  connects all  circuit  provide  three  time  the  parts  relation  comparator  comparators  operation  small of  the  with inputs  t o be  can be c h e c k e d .  in  10  (v)  Multiplier  Accumulator  The b i n a r y plier  are  delayed is  present  number  stored  for  The o t h e r prompt  are  ses  0,  Shift to  pass  positive  1,  2 or  toggle  2.  are  ored w i t h gated  accumulator  1 and  logic  gates  the  remaining  a number of  39 f l i p  as w e l l are  flops  stage  scales  of as  the  and s h i f t  pulses  flop. the  clock  Similarly  prompt  Rl  of  and  The  the  flip  register  high speed.  register  and  accumulator  binary  shift  pul-  accumu-  prompt p u l s e s  ie,  for  2.  the  prompt  by C I ,  2.  two  TTL l o g i c  on  The t r a n s i t i o n  transitions of  the  allows  differentiated  input  form and  d u r i n g one  1 flip  are  stages  2 are  flops.  stage The  RTL  logic  cost. For  0 state  line,  stage  The  1 and  pulses  whether  a g a t e which stage  binary  may o c c u r  1 controls  2 controls  three  "1  or  and t h e r e  clock  bandwidths  bit"  and the  1 pulse  circuit  3 pulses  multi-  forms.  registers  by s e r i a l  accumulator  The f i r s t  either  in s h i f t  represented  of  the  by a p a r a l l e l  cycle  by the  two d i f f e r e n t  1 output  to t h e  low  in  is  consistes  for  input  to a c c u m u l a t o r  stage  to be m u l t i p l i e d  represented  register  register  to  lator  fed  number  allowed  shift  is  its  one c l o c k  line.  cycle.  at  numbers  Description  speeds  operation  shift  prompt p u l s e s  none. are as  only  Since 1/3  h i g h as  o f 6 Mhz o b t a i n e d  are  shift as  register either  2 is  1 or  register  many p u l s e s  0  held ie.  1 is  a TTL  on the  prompt  12 Mhz s h o u l d be p o s s i b l e although  this  has  not  in  and  been  tested. The m u l t i p l i e r  accumulators  are  a s s e m b l e d two  per  11  board  on e i g h t e t c h e d  mounting  frame  circuit  so that  boards.  the circuits  These  may  into  plug  be e a s i l y  a  changed  forservicing.  accumulator to  allow  For  the tests  with  was  modified  t o sum  below.  connection  from  controlling allowed  This  in effect  although  the first  made  type  last  physically  t o be r e a d  address that  input gates  selection  out.  D.  C.  line,  term  the  accumulator. device  to F i g . 6)  boards.  are  These  the contents  two  boards  o f t h e most  out s e q u e n t i a l l y to the generates  a 16  ( A , B, C, D ) a n d t h e i r sequence  i n p u t nand  o f four  lines  When  t h e nand  open.  a 15 c h a n n e l  programmer  This  are enabled.  gate  channels.  permit  lines  A four  this  of the accumulators  which  the  to the gate  to enter  16  (refer  channel.  occurs,  pulses  pulses  The r e a d o u t  combination  channel  flop  and holding  t o be g a t e d  on f o u r  for that  flip  on t h e r e a d o u t  (X,"TF, T7, T T ) .  appropriate  2  digits  sequence  plements is  Gates  ten stages  converter.  f o r the false  the spectrometer  contain the gates  binary  line  e t c . remained  (vi ) Readout  significant  delay  a l l the prompt  readout  The  on t h e prompt  The m o d i f i c a t i o n c o n s i s t e d o f removing  the prompt  This  also  t h e number  t h e c o r r e c t i o n t o be made  explained  mounted  2 b i t operation, the sixteenth  gate  which  comchannel  i s wired  to recognize  unit  to the  the binary  the appropriate address f o r  gate  These  selects  tele-  goes gates  (x, y , z ) t o e n a b l e  high allow  and the three the character  the readout  gates.  as  12  These p u l s e s starting  with  the  three  are  ored  to  all  read the  least onto  three  the  Note  the  lowest  output by the  (z).  busses three  input  the  A to D d e s c r i p t i o n a b o v e .  can r e s u l t  generates flops as  to  the  a single  a completely  At  the end o f  a p u l s e which  determined  this  time  one  (vii)  the  line  of  (refer  The t i m i n g  for  by  two  a two  in a b i n a r y stage  converted gate. for  the  to  shift  the  flop  counter.  a narrow  The r e s u l t i n g programmer.  is  taking  as  cycle,  last  common  place,  described  lasts  in  because  the  nine  the  readout out.  programmer  accumulator  about  printing  seven  flip  seconds  speed and d u r i n g  printed,  levels  Code  Converter  is  derived  wave i s  by a S c h m i d t  from  and f u r t h e r  by g a t i n g  10 Hz p u l s e that  is  the  in  divided  trigger  by  divided  three  10 Hz waveform the  the b a s i c model ASR  two  input  timing 33  the  converted  The 60 Hz square wave i s  The r e s u l t i n g  pulse  Note  gates  number b e i n g r e a d  V.,, 60Hz s i n e  gate.  flip  are  flop during  programmer  TTL l o g i c  made from an RTL l o g i c  these  with  7)  The 6 . 3  to a s q u a r e wave a t  cycle  of  required  and T e l e t y p e w r i t e r  to F i g .  line.  is  flip  the  is  and e n d i n g  which  inhibited  each r e a d o u t  output  1),  cycle  This  resets  (x)  flops,  expanders.  teletypewriter  Programmer  60 Hz power  2,  erronious  The r e a d o u t by  is  accumulator  in  zero.  (4,  input  accumulators  flip  The o u t p u t s  t h a t when a r e a d o u t  the  changing of  accumulator  most s i g n i f i c a n t  significant  channels,  to  out  in is  nand  pulse  teletypewriter  13  accepts  characters  for  printing  The 10 Hz p u l s e s C JJ  L 9958 d e c a d e  produce to  one p u l s e  p r o d u c e one p u l s e  per  4 minutes  which  rate  gration  will  per  time  2)  at  the  turns  3 controls  the  teletype  is  on f l i p  driver  two  gates,  64,  The n e x t  the  and t u r n s  to a two s t a g e  in  and one  A switch  of  selects  the  inte-  print  of  a reset  stages  the D waveform turns  on f l i p  counter  off flop  which  is  flip 1.  with  feed"  The  Flip  binary  by  16)  (in  out.  flop  provide  the At  flop  a  gate  counter.  the  readout the  end of and a  flop 2 (stopping  the  readout  control  differentiated  Flip  and  appropriate  z and s p a c e  to be r e a d  and a  f l o p 2 opens  and the  which  of  teletypewriter  stage  (divide  C, D s i g n a l s  manner:  Flip  y,  a line  pulse.  f l o p 3.  by f o u r ) x,  print  a "line  the  a six  a sequence  characters  following  to r e a c h  the  1)  three  line,  the  (divide  occurs,  follows:  operation  channel  p r o d u c e d which  counter)  to  divided  and hence  trigger  description).  four  C, D and A , B, select  as  each  generate  10 Hz p u l s e s ,  pulse  Fairchild  counter,  2 minutes,  rate  f l o p 2 and f l i p  printing  two s t a g e s  input  readout  goes  done  The f i r s t  boards)  two  further  dividers.  symbol and g e n e r a t e  10 Hz p u l s e s  B,  100 i n  is  one per  readout  consisting  to a l l o w  A,  by  This  binary  the  end o f  return" This  signals.  minute,  the  which  each word  "carriage  (see  30 s e c o n d s .  control  begins  16 w o r d s ,  trigger  divided  rate.  time.  events  space.  a 10 Hz  and by 3 i n a s h i f t  by a d d i t i o n a l  Each of  are  dividers per  at  the  1 opens a  appropriate  gates  gate  14  generate  the l i n e  The r e s e t and r e s e t s  signal  feed, turns  carriage off flip  the a c c u m u l a t o r .  differentiated  and t u r n s  return flop  and r e s e t  3 ( and t h e  signals. teletype)  The o u t p u t waveform H i s  off f l i p  flop  1 and t h e  cycle  generates  the p r o p e r  ends . The t e l e t y p e outputs bit  on s i x l i n e s  A S C I I code w h i c h  other  two l e v e l s  code c o n v e r t e r  which  become s i x b i t s  the t e l e t y p e w r i t e r  a r e always  the  right  hand s i d e  six  lines  according to table  1 and 0 .  of f i g u r e  o f the e i g h t  recognizes. The l o g i c  7 generate  gates  outputs  The at  on t h e  3:  Table 3 Character  Level  G  123456 000011  1  100011  * 8  000111  9  100111  L.  F.  010100  C.  R.  101100  Space  000001  The readout  gates  representation  i n f o r m a t i o n on l i n e s go d i r e c t l y o f numbers  to l i n e s is binary  1, 2 and 4 from the 1, 2,  and 3 qs t h e A S C I I  weighted.  The programmer  15  is  located  in a shielded  box t o  the  right  The T e l e t y p e  Driver  (refer  of  the  plug  in  cards.  (viii)  The ASR33  teletypewriter  conductors is  teletype  required  commanded t o  relay. the  isolation  from t h e  of  flop  3 in  This  lamp c a u s e s  on t h e  the  is  cuits  and t h e  operate  shown a t  power  power  line  high  the  top o f  figure  the  teletype trip)  8 accomplishes  circuit  logic  levels  command ( f r o m long l i f e  flip lamp.  to c o n d u c t which  and o p e r a t e s  and problems  into  semi-  (reader  c o n n e c t i o n between  getting  power  a 115 v o l t  lights a miniature  circuit  model  The  The p r i n t  thyristor  the  teletype.  photo-transis tor  no e l e c t r i c a l relay  all  integrated  line.  programmer) the  inside  the  the  8)  located  by o p e r a t i n g  bi-directional  There  the  to  the d e l i c a t e  115 v o l t  is  and c o n t a i n s  print  The c i r c u i t  driver  to F i g .  the  the of  integrated  turns  relay.  logic  cir-  transients circuits  from  are  avo i d e d . The model ASR33 data ing  by g r o u n d i n g one or to  the A S C I I code  transistors  are  and t h e  teletype  teletype  signal  this any  is  of  other  used  teletype  more of  interface  voltages. power  supply  no c o n c e r n as purpose.  the  (tape reader to  Note is  l o n g as  has  provision  eight  input  input). between  that  the  entering  lines  accord-  Eight the  PNP  logic  normally  grounded at the  for  this  teletype  is  power  levels floating  point  but  not used  for  16  CHAPTER I I I  PHYSICS AND ASTRONOMY OF Hn  (i)  Radiation  from H  Somerville for  Hg  +  as  the  form F_2 and £2  The rotational  3) has g i v e n  b^j  simplified (the  level  lowest  and the V=0  the  c o u p l i n g scheme  s c h e m e , where J_ and S_ c o u p l e  and N_ c o u p l e t o  state  transitions)  2—  (Ref.  so c a l l e d  TRANSITIONS  form F»  diagram for  state  state,  to  is  Hg+ i n  giving radio sketched  the  N=l  frequency  below  £2  •4  Somerville ilities  for  intense w i l l  the be  has c a l c u l a t e d  possible transitions  the  Va.  transition  and shown t h a t  probabthe  most  17  and  that  the  Einstein  A coefficient -IS  The expressed  spin  Somerville's  value  for  the  l  7  best  based  Vp  z  their  for  is  the  b & c and (  system  can  be  ref.  the  range  for  d  ~*  experimental  12)  IMHJ,  then  C 1 Yy  0  is  -i>  Jefferts  * '*4  value  The value  for  C z ( Z ? . 0  frequency  Vo * 6  the  by  7  000.  predicted  using  values  d obtained  r  transition  j  Using  y  this  -I  Hamiltonian  as  for  '<L  SIHj,  gives  searched  1 4 0 5 MHz u p o n w h i c h  includes Penzias  this et  value  al.  and  (ref.  the  8)  search.  (i i) For  Line  Strengths  a cloud  of  and  Number  tempterature  7"^  of  ions.  H2  +  t  a n ( j  optical  depth  f  18  the  expected  If  t h e  cloud  To  f i n d  e q u a t i o n  an  antenna  i s  temperature  o p t i c a l l y  e x p r e s s i o n  f o r the  f o r  "7"  we  a b s o r p t i o n  Y*0??7x  i s  0  oi f{y)  T"  the  7"V<  (  t h i n  use  I  )  Barret's  ( R e f .  5)  c o e f f i c i e n t :  k r  c  where  i s  a b s o r p t i o n  c o e f f i c i e n t  per  i s the  number  c c .  i n the  i s  the  E i n s t e i n  i s  the  1i n e shape  is  the  observing  i s  the  cloud  per  B  of  ions  i o n  c o e f f i c i e n t f u n c t i o n frequency  temperature.  s i n c e  ' we  -fvc*)jut.  have  c where  N *  i s  the  column.  t o t a l  k  r number  ions  i n  the  upper  s t a t e  i n a  s t a t e  19  From Condon and S h o r t l e y  P°' where two  ~ <r  f_!L i s  -  the  hyperfine  ratio  is  of  the  statistical  the E i n s t e i n  have  putting  in  equation ( 1 ) ,  no-  TT  ' «  weights  for  =3.  we  f  have:  Rio  Substituting  this  4) we  ,  levels  AJO  (Ref.  V c  A  T  A coefficient.  -  S  T—: >0  if  we assume the  line  to be a g a u s s i a n ,  I where/iV We g e t  is  the  gaussian  full  width  at  a value  of A J Q from S o r n m e r v i l l e  Pi to  3 i 63  ~  X  lO* * 1  h a l f maximum. (ref.  3 ) of  the  20  If the  i s t h e number number  Hi.  i n the s t a t e  i n the ground  6  w h e r e V'-i?  state  ( F , F)  (3/2,  2  i s given  5/2)  thei  by:  -  i s the energy  gap b e t w e e n  the N  =0  and N - 1 l e v e l s .  substituting for  and  therefore  we g e t f o r  r  21  CHAPTER  FOUR  LINE SEARCH PROGRAM AND RESULTS (i)  Equipment In  it  is  variation the  order  necessary  a function  of of  system  Testing  to  frequency  flat.  noise  background  (£^200  to 0 . 1 % .  etc.,  amplitude In  order  10 t i m e s ) K)  helps  the  a good f r e q u e n c y  but  features,  response  as  that a  compared w i t h  The o b s e r v i n g  spectrum)  spectral  frequency technique  because  response  is  of  resused  equip-  still  a  concern.  the  effects  it  would r e q u i r e  1400 Mhz R . F .  important  ponse of  the  R.F.  over  measured.  the  added  Figure  stages  a two  stages  The a m p l i t u d e  including  output  very (say  a difference  for  time.  is  K be l a r g e  Since Q*s  intensity  0.2  ment d r i f t s major  low  have a s y s t e m whose  ponse must be f l a t (taking  to r e s o l v e  was  9 shows  the  the  spectrometer.  frequency  was  adjusted  the  were a t t e n u a t e d B)  of  the  by a t  least  that  tests  gassband  in d e t a i l I.F.  with  res-  at  this  amplifiers was  from 35 Mhz i n p u t information  to be 12 Mhz so t h a t and a l l  circuit  the s p e c t r o m e t e r  From t h i s  point  high  frequency  receiver  response  20 d b .  Other  the  the  not measured  system for  to  occured at  to a f f e c t  Mhz r a n g e ,  response I.F.  unreasonably  aliasing  folded spectral  amount.  the  to  sampling  (Ref.  1)  components  22  The s p e c t r o m e t e r amplitude  sine  was  further  waves  into  spectrometer  attached.  10 Khz s t e p s  were u s e d .  c a s e was below. peak  processed to  ponse  (fig,  testing  9)  the  35 Mhz I.F.  Frequencies  from 33 to  were i n s p e c t e d  and were  depicted  free  to  the  f r o m any  whole r e c e i v e r  constant  system with  The s p e c t r o m e t e r  correctly  used the  by f e e d i n g  the  36 Mhz,  output  p r o d u c e a s p e c t r u m as  These s p e c t r a  amplitudes  tested  in  each  described  insure I.F.  that  the  amplitude  anomalies.  s y s t e m and  in  is  res-  Further  described  below.  ( i i ) Observing  Program  As a p r e l i m i n a r y profiles this  line  jo'f the is  21 cm a t o m i c  typically  the  overall  its  usefulness  for  Palmer  lines  a test  (nyn-1)  of  (Ref,  our  had a n t e n n a  the  was  7)  we began our  search  for  The s e a r c h and 20 minutes  of  low  0.4  the  spectrometer,  were t a k e n .  in  no i n d i c a t i o n  intensity  of  of  lines. recom-  the Omega N e b u l a . these  lines  1399.4 Mhz and H166 source.  Since  p r o v i d e d a measure  made by l o o k i n g f o r  frequency  These range,  two  at  at  lines  and s i n c e  K and were c l e a r l y  they  resolved,  Hg*.  consisted  with the  line  have o b s e r v e d  Omega N e b u l a  temperatures  this  hydrogen  planned search  testing  s y s t e m but  We o b s e r v e d H16<7< a t  1 4 2 4 . 7 Mhz i n bracketd  the  observing very  and Zucherman  Harvard,  of  of  hydrogen  100 K,  performance  Therefore bination  stage  antenna  of  20 minutes  on the  moved one d e g r e e  source  north  in  23  declination. subtracted spurious minutes in  of  from t h a t  responses of  and t h e  bandwidth  from 1404 to  occasions. this  The  manner  To f u r t h e r tions  nearly  obtained.  infrared only  eliminate  Data  as  on the  desired.  also  into  the  lines  D.  C.  the of  data.  (see the This  above) data  was  Since  the  on two  spectro-  obser-  separate  also  the  two  observed taken. observa-  by 300 K h z .  data  every  a line  tape  by the any  of  teletype  and  taken and the  off  the  were p e r f o r m e d .  was  and the  The c o s i n e  the  16 a u t o c o r r e l a t i o n  the  and the  the  off  subtracted Hamming fourier  computed u s i n g a program w r i t t e n  program took  In  are  tape  from each  made f o r  s o u r c e was  van V l e c k  this  processing.  computed and s u b t r a c t e d correction  to 4 minutes  coefficients )  on the s o u r c e were a v e r a g e d  A similar  output  30 s e c o n d s  (autocorrelation  computer w i t h o u t  on s o u r c e d a t a  40  1 Mhz h i g h e r  s p e c t r u m was  frequency  provides  teletypewriter  The o u t p u t  The d a t a  manner  responses,  in  each  Processing  component was  efficient.  tuned  NML Cygnus was  spurious  punched on paper  fed  eliminate  The Omega N e b u l a was  one c o m p l e t e  The s p e c t r o m e t e r printed  to  then  2 Mhz, a 50% o v e r l a p p i n g  this  star  of Omega were s h i f t e d  (iii)  was  s o u r c e was  After  repeated.  1409 Mhz i n  but  source  the r e c e i v e r  very  the  equipment.  pattern  is  off  on the  from the  e a c h s p e c t r u m was  ved  in  taken  observing,  frequency  meter's  The s p e c t r u m t a k e n  was  computer false cosource  from  the  corrections transform  by A. C.  coefficients  of  Gower. and  24  computed a 31 spectra  and  t a p e and  The  The  on and  off  source  t h e d i f f e r e n c e s p e c t r u m were punched on  p r i n t e d by  done on s i t e further  p o i n t power s p e c t r u m .  a t D.  the computer. R. A.  processing  was  0.  The  using  c o m p u t e r p r o g r a m s were n o t  above p r o c e s s i n g  their  done a t t h e  U,  paper  P.  B.  D.  C.  u n i q u e and  P.  9 computer,  computing  are  was  not  center.  included  here. Typically baseline with The  individual  points  o f the  subtacted t h e end no  an  approximatly  straight  spectra are  line  individual  total  s p e c t r u m was  line  adjacent  the  shown i n f i g u r e  166  i s the  resent  the  values  0 or  or  less  input voltage 1 according  same a r g u m e n t h o l d s  and  the  The  and  end  routine and  "rejected" by  50%  computer  subtracted The  pro-  a  best  resulting  167 •< r e c o m b i n a t i o n  lines  C.  Component  in this  type  of  spectro-  a r i t h m e t i c i s used t o  samples.  rep-  The  samples are g i v e n  the  to whether the  sample i s g r e a t e r  to  (This  i s f o r t h e "1  f o r the  "2  hardware r e q u i r e m e n t s .  of the  counter"  type.  b i t " case but  b i t " case).  reduce the "up  slope.  overlapped  spectrum.  concern  that positive  than z e r o .  Mhz  A computer  lost.  F a l s e D.  considerable fact  a sloping  the e n d p o i n t s  spectra  and  had  10.  ( i v ) C o r r e c t i o n For  meter  eye  spectra  from the t o t a l  along with  Of  through  Since  gram t h e n j o i n e d up fit  d e g r e e K/  p a r t were p i c k e d .  a straight  p a r t of the  one  s p e c t r a were e x a m i n e d by flat  data.  the d i f f e r e n c e s p e c t r a  This  the  i s done  Simple accumulators  "Up-down" c o u n t e r s  which  can  to  are  25  subtract  counts If  for  noise  width)  is  fed  into  formed  in  the  first  the  input  to  negative  the  inputs  with a f l a t  are  spectrum  the a u t o c o r r e l a t o r channel  delay  much more  input,  multiplier  and prompt  (over  will  lines  chance and 0, a  G and  of  a 1 is  1 would 0,  0,  1 are  each  1 would  If  occur  with equal  is  has  the  the  large  fourier signal  sinx/x width  form and of  quency.  important  a low  It  undesirable  More  ring  the  is  these  this  sidelobes  necessary  (correlation  the  throughout  expected s p e c t r a l is  for  that  the  i n each  This  is  applications the  t h e whole  the  nature  First,  the  of a low  of  fre-  were  this  frequency  term  band and  amplitude  features  not  be  this  they  could  term be s u b t r a c t e d before  The  fourier  transform  term and  it  was  decided that  false  C. was  the is  fourier very  it  term has a  that  sidelobes  and  t r a n s f o r m to a  two r e a s o n s : information  of  channel  present, It  0  products  the  coefficients)  For  for  the  would be many times  performed.  D.  ie,  probability  term w i l l  (D.C.).  spectral  spectrometer,  level  the  information  this  the  had been u s e d ,  number grows  frequency  term masks  for  since  zero  1 )  D.C. component".  that  of  2 and  ie„  square  therefore  l i k e l i h o o d and  chance,  extra  "false  (0  product  be t h e  and  arithmetic  no s p e c t r a l  this  planned at  This  transform  at  true  have e q u a l  even when t h e r e  of  likely  0,5.  1 would be 0 . 2 5 .  been termed  equally  t h e 2Mhz b a n d -  the  2 products  expensive.  of  tolerated.  from the  data  transform  sensitive  to  some method of r e c o r d i n g  is this  the  required. the  tests  made w i t h "2  bit"  operation,  the  26  last of  ( 1 6 t h ) c h a n n e l was  the  delayed  prompt  line  machine,  and u n d e l a y e d  only.  description  it  half  to  the  value  q u i r e d was all  the  of  for  the  Since the  the  and the false  van V l e c k  two ways  prior  van V l e c k  effect  of  one-half  the  is  to  the  the  because  the  the  the  this  only  first  case  bit"  above  16th c h a n n e l was in  the  a "1  re-  is  one-  correction  coefficient  triangle  re-  from  wave.  wave s t a r t s  correlation  function  would  is  (Re.  6,  that  the  a reduction  9).  the  than any  other  of  the  to  the  noise  channel  has is  in-  amplitude  function  of a  function  con-  a cosine  wave the  d l i p p i n g had  a stationary  function  first  channel.  if  for  signal  the  a maximum) which  have been  The a u t o c o r r e l a t i o n  coefficient  at  for  The  constant  (actually  degradation in  input.  The van V l e c k  wave to a s i n e  The o n l y  processed  The need  The a u t o c o r r e l a t i o n  triangle  occured.  transform.  to a s q u a r e wave o f  a triangle  are  may be seen by c o n s i d e r i n g  the  larger  herein)  q u a n t i z i n g on a s i n e w a v e  clipped  s q u a r e wave i s  signal  on  in  used as  coefficients  fourier  by t h e A to D c o n v e r t e r .  not  numbers  and Hamming C o r r e c t i o n s  correction  one b i t  put s i g n a l  verts  was  D.C.  channel,  products  described  correlator  The a u t o c o r r e l a t i o n  the  the  the  coefficients.  (v)  in  is  not  work r e p o r t e d  first  to s u b t r a c t  count  modification  not r e q u i r e d  normal.  to  numbers but  When the  was  m o d i f i c a t i o n was turned  This  above.  (as  modified  ratio the as  The c o e f f i c i e n t s  noise ci.  property large can  or be  27  normalized of  the  therefore  first  by d i v i d i n g  channel.  all  channels  The so c a l l e d  can  then be p e r f o r m e d .  It  the  normalized c o e f f i c i e n t  consists C  by  van V l e c k (Ref.  the  be c o m p l i c a t e d  critically decision  involving  depend on t h e  level  in  the  two  the  the  sidelobes  cussed was  correlation of  in d e t a i l  chosen.  efficient  of  C  fourier  in r e f .  This  is  the  n'th  correction  of  replacing  point  "2  bit"  operation  waves and  of  the  will  second  1.  given  performed which  is  transform.  channel  C„  the  required This  The c a l l e d by t h e  is  Hamming  16.  to  reduce is  is  replaced  dis-  function  o p e r a t i o n where t h e  C  from 1 to  grading  point  co-  by  ^ * [ o . S ¥ + 0-i6 x c , s ( "~' *  where n r a n g e s  magnitude  A to D c o n v e r t e r .  coefficients  the  for  triangle  operating  The s e c o n d c o r r e c t i o n of  9)  the  function  The c o r r e s p o n d i n g c o r r e c t i o n will  by  1  lr  )  J  28  CHAPTER  CONCLDSIONS  FIVE  AND RECOMMENDATIONS  ( i ) H? + S e a r c h Figure the  Omega N e g u l a  upper  limit  i n a cm nor  in  its  to  these  of  processes  in  Penzias  et  al  might have i n interstellar to r e f i n e  as  will  reduce  and p e r m i t  (ii)  were of  This the  period which  later  it  deviations)  it  is  felt  an can  because  of  that  the  u n d e r s t a n d i n g of  space.  the  the  8)  It  is  frequency  frequency  more s o u r c e s  noted  to  which  further  importance  physical  that  prediction  range  at  first  more  is  theo-  important  must be  be s t u d i e d .  to be a r e s u l t The  as  interfacing to  of  after  an  Some component  to component  a power  failures,  supply going  of TTL to RTL l o g i c  l o a d i n g by  by a d d i n g an RTL b u f f e r  two c i r c u i t s .  expected  completed.  were a t t r i b u t e d  be s e n s i t i v e  cured  worked  o f " d e b u g g i n g " was  shown  found to was  than  Spectrometer  regulation.  was  standard  (Ref.  the  The s p e c t r o m e t e r initial  suggest  for  T h i s i s e q u i v i l e n t to 3.3jt>e i o n s + A l t h o u g h no Hg was found i n t h i s s e a r c h  work  searched  obtained  regions.  retical this  spectra  Theses  s h o u l d be made to d e t e c t  detection  faults  final  and NML C y g n u s .  column.  that  efforts  the  of T^ = 0.25 K ( ^ - 5  be a s s i g n e d 2  10 shows  The T T L c i r c u i t  the  RTL f l i p  amplifier  which  ored t h e  out  levels flops.  between differ-  29  entiated  pulse  and  the  f o u n d to be s e n s i t i v e this  gate  was  prompt p u l s e w i d t h . the  been t e s t e d  in  the  well  powerline  Simple  R.C.  trends  in  low  circuits future  pass  integrated  TTL c i r c u i t s  so c l e a r .  the  upper  multipliers  gate  This  was  frequency  circuit  and was  for  circuit  that it  using TTL c i r c u i t s  the  not  programmer and t e l e t y p e  into  circuits  from  the 60 Hz t r i g g e r  filtering  advantages of  to  might  has  removed the  noise.  have been towards advantages  for  RTL  this  o f speed and n o i s e  type  exclusively.  would  driver  noise  generator. Recent  lower is  C o n s i d e r i n g the wide r a n g e o f a v a i l a b l e  instruments  for  have com-  sensitive  some i n t e r f e r e n c e  so the c o s t  and t h e i r  because  limit  had to  very  was  circuit.  gates,  getting  the  shown below a l t h o u g h  actual  except  in  amplitude.  A TTL l o g i c  problem is  on t h e  for  near  selected  The r e a d o u t worked v e r y  pulse  The d i f f e r e n t i a t o r  individually  alleviate  to  operating  TTL c i r c u i t s . ponents  prompt p u l s e  prices  no l o n g e r TTL  immunity,  probably benefit  from  30  BIBLIOGRAPHY 1)  Blackman,  R.  B.  and Tukey J .  Power S p e c t r a " 2)  A r g y l e , P.  3)  Somerville,  4)  Condon,  E.  Ph.D.  W.  (1968)  E.  D.  B. ,  Y.  C.  (1958).  Dover  Mon. N o t .  R.  C. ,  (1964).  astro.  G. H . ,  Soc,  1 3 9 . 163  "The Theory of Atomic  Cambridge U n i v e r s i t y P r e s s ,  Barrett,  6)  Bowers,  7) 8)  P a l m e r , P., Z u c k e r m a n , B. , N a t u r e , 2 0 9 . 118, ( 1 9 6 6 ) . P e n z i a s , A. A . , J e f f e r t s , K. B., D i c k i n s o n , D. F . , L i l l e y , A. E . , and P e n f i e l d , H. A p . J . , 154. 389, (1968).  9)  van V l e c k ,  12)  Radio Res. (1943).  S.,  Proc.  W.  L.  H.,  Press.  Jefferts,  K.  IRE,  46. 250.  (1958).  P r i v a t e Communication.  #51, 10) W e i n r e b , 11) S h u t e r ,  K.,  Proc.  (1964).  5)  F.  H.,  Measurement o f  T h e s i s 0. B.  and S h o r t l e y ,  Spectra", A.  N.  W,"The  B. ,  Lab.,  IRE,  Sloan, Phys.  £9, D. Rev.  Harvard  1099, S.  University  Rept.,  (1961).  Can. J .  Letters,  Phys., 2_0, 3 9 ,  In  the  (1968).  DIODE  25. G M PARAB.  >  PAR-AMP  PRE  O C T A V E TRWS. AMP  1 i 1 |  \ ST  L.O.  AMP .  F T  ATT EN. V A  1ST U . O .  S5  I.F.  MIXER  2  \-.o. NOMINAL  o  \0.7.MH^ I.F.  MHfl  AMP T O E*\ST. RECEIVER  PLASMA NOVSE  T U B E  _ . .  7.7 M H ^ osc. 10.7 B P F  TO  I  PULSE <3cN 6WlH-j. L P r  S P E C T R O M T R  TT  Y  SPECTROMIET^  S H I F T  R E G I S T E R S  M U L T I P L I E R S  ACCUMULATORS  READOUT  £>ATES  SELECTOR  CODE  CONVERTOR  T T Y  T T Y DRIVER  <j0  R F  .  INPUT  DELAY  -O  PULSE-  -o  4 MHi  0 -  -o-o-  PROMPT LINE.S TO EACH ORCUIT CARD  READOUT . \HH\B\T E>  S.f?.  S H I F T  P U L S E  Ik  o 0 o  w ^—  :+  Q U-  0  h D 0-  z  Actual  A  to  D  Figure h  Converter  35 SHIFT REGISTERS  > > >—1  >  r  ->  MPS  SS2.  "PROMPT L\HE  -{>-  L  cc  Vc  V TO READOUT  SATES Figure  5 Multiplier  Accumulator  36 7ACCI  \N  V  0-  S u-  On  0 — M  I  0; J  0  —  >  2  o—  0  1>  D  0 0  A  A BB c c  DD  , i t i i i  > i •i  <KJ=—<Y  A  SET Readout fioure  gates . 6  ii  I I  37  A  i  Z  0  .  A  A  A  Q  O  O  O  1  —W—  f t  ui V  v<rx  IUJIU-  h  h 3 0  Q  0  < UJ  V V CD  i_jr 10- " D — P — 0 -  m  -K -i>—1  U-  IT*  UJ  -VVHi' LI)  L-L~  9  .|10  0  •cr  o. 0 -»  u CO  c-jnurp figure  7 /  Programmer and fcode Converter  Teletype '  4)—p—p—  N  38 F P T - IOO  MAC-5 R E A D E R T R I P  -WAr  rW  JLSJb  1  US  VA-.C.  W  4  r r  T E L E T Y P E  DRWER  Figure 8 Teletype Driver  8  T.ELETYP_E  39  R e s u l t i n g I.F. R e s p o n s e Figure 9  

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