- 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
- 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
- 14:02 start freq dual freq hop.
- 14:30:34 to cw to measure power.. 322.8KW..
- 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
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
- trolley cables. terminations by edge of dish, north side.
- close to where they were terminated levels were <
- 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).
- 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
- 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),
- under the dish: .001 mw/cm^2
- balcony in front of control room: .003mw/cm^2
- visitor center balcony: .027mw/cm^2
- visitor center balcony (5tx) : .04 -> .17 mw/cm^2
2 tone test
- started with 50kw/tx (only 5tx used)
- 60-65 kw/tx
- little more arcing , but probably ok to use (unless adding
the 6th tx causes more trouble.)
Generator power vs
The data from the 3 running generators was
used to measure how much generator power was needed to drive the 6
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
- 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).
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