Background:

• Getting ready for the jun19 heating campaign.
• see if we could get an enhanced plasma line from the fregion (previous attempts couldn't get through the e-region
  

What we did:

• The mesh was in the 5 MHz position
  
• we started transmitting  at 5.125 MHz rcp.
• hf tx 2 was down with a water leak.
  
• The 430tx ran at 1.2 MW clp with 440 usec rf pulse and 10ms ipp
• The sps  ipp was synchronized to the 1 sec tick.
  
• echotek data at [5.5,9.5] and usrp data taken.
• interim correlator was not run.
• 
  
• 09:45  430tx up around 1.2 MWatts
  
• 10:00  start bringing up hf tx.
• 10:14   50KW each of 5 tx
• 10:33   raise power to 75 KW each tx.
• 10:38   try autotoggle 4 sec on , 6 sec off
• 10:52   stop autotoggle.
• 11:00   turned off 430 tx. went under the bowl to look at rf levels.
• 11:50   430 tx back on
• 12:05   autotoggle 4,6
• 12:33   back to cw.
• 12:42   autotoggle 4 sec on , 6 sec off
• 13:01   back to cw
• 13:12   50KW each of 5 hftx,
• 13:19   start vlad's two tone exp. h3255/prog3.cmd
  
• 13:26:01 3 tx had tripped. reset.
• 13:56   back to cw to kick up power. 60KW each tx (2 still down)
• 14:02   start freq dual freq hop.
• 14:30:34  to cw to measure power.. 322.8KW.. 64.5,62.7,64.4,65.5
  
• 14:33 done

HF output power

Plots showing hf tx drive and output power (.ps) (.pdf)

• page 1:
• Top: hf rf coupler output vs hour of day
• Each color is a different tx.
• middle: output power in KW
• bottom: synth drive amplitude (in dbf)
• page 2: hf drive power vs hf output power
• the output power (in KW) vs input drive power (in dbf) is plotted for each tx.
• values that lie below the trend, occur when an rf off occurs during a spectrum analyzer power average.
  
• 
  

• dbf Drive for 50 KW output.. 5MHz

  tx	dbf drive
  1	-6
  2	--
  3	-9
  4	-14
  5	-6
  6	-9

Measuring rf power levels close to cables under the dish.

    On 22may19 we found a trolley td cable under the dish (close to td12) arcing. Using the rf meter, the trolley d cable had about 50mw/cm^2. Other dish/trolley td cables had fields of less that 1mw/cm^2
On 03jun19 luis and i checked the field strength for a  number of cables under the dish. If a cable had a high field, it might arc.

• trolley cables. terminations by edge of dish, north side.
  
• close to where they were terminated levels were < 1mw/cm^2
  
• road as it goes under the dish
• nw1a29 .. trolley cable 2.5mw/cm^2
• other cables < 1mw/cm^2
• td12 area.
  
• checked trolley, dish td cables (including repaired cable that was arcing 22may19).
  
• no large fields
• platform td cable grounds . next to block. 30-40 mw/cm^2
• td4 area
• platform td cable ground (by base) 10,16 mw/cm^2
• se206 30mw/cm^2. main  dish td cable (not trolley).
• se2a07 10mw/cm^2 main dish td cable.
• Around opening in center.
• ne corner. long cable from north corner to ground (north, and east): 17mw/cm^2
  
• AROUND DIPOLE TOWERS
• Note: heliax cables have a stw in them. Field changes as you move a fraction of a wavelength.
• So some of the measurements below were probably not the maximum.
  
• tower 1: 5mhz
• heliax  A 2 to 80mw/cm^2
  
• heliax B  .. lower
• tower 2: 8 mhz
• heliax 200 mw/cm^2 max
• area around crank 100 - 160 mw/cm^2
  
• tower 3: 5mhz
• heliax close to balun. 1.7,4 mw/cm^2
• tower 6: 8mhz
• heliax:170 mw/cm^2
• crank: 20mw/cm^2
• safetyline: 3mw/cm^2

Other rf field measurements:

• 430 Mhz with 430 tx on . (clp , 440 usec rf pulse, 1.2 MW), az=285, za=1.06deg.
  
• under the dish: .001 mw/cm^2
• balcony in front of control room: .003mw/cm^2
• visitor center balcony: .027mw/cm^2
• hf:
• visitor center balcony (5tx) : .04 -> .17 mw/cm^2

2 tone test

• started with 50kw/tx (only 5tx used)
• little arcing
• 60-65 kw/tx
• little more arcing , but probably ok to use (unless adding the 6th tx causes more trouble.)

Generator power vs hf output.

    The data from the 3 running generators was used to measure how much generator power was needed to drive the 6 hf transmitters.

Generator output power vs hf output power (.ps) (.pdf)

• Top: generator output power vs time.
• middle: total rf output from 6  hf tx
• bottom: gen power vs hftx output power

Summary:

• saw an enhanced plasma line in the E and F regions
• measured  field of some cables. (see above)
• 2 tone test ran with 50kw/tx ok.. 60-65kw some arcing .. but not to bad (but only 5 tx).

home_~phil