190522:hf test
may19
Background:
- Getting ready for the jun19 heating campaign.
- A loose/bad cable from tx4 rf output coupler to control
room was repaired. We were probably reporting incorrect power
levels (reporting too low) previously,
What we did:
- The mesh was in the 5 MHz position
- we transmitted at 5.125 MHz rcp.
- The 430tx ran at 1.2 MW clp with 440 usec rf pulse and 10ms
ipp
- echotek data at [5.5,9.5] and usrp data taken.
- raw data deleted after movie made
- interim correlator was not run.
- 10:30 430tx up around 1.2 MWatts
- 10:35 start bringing up hf tx.
- 12:30 bring tx up to 75 KW/tx
- 12:55 80 KW/tx .. arcing..
- 13:10 bring down 430tx, leave hf up. go under the
dish looking for arcing
- found main cable td cable arcing at base near td12. carlo
tried to short around the arcing area with some wire
- 14:00 430tx back up.]
- 14:12 tried some auto toggling to generate an enhanced
line. no luck, fof2 too low.
- 14:30 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
|
-11
|
3
|
-9
|
4
|
-14
|
5
|
-6
|
6
|
-9
|
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:
- fof2 remained below 5.125 mhz for entire run
- had some bad arcing. You could make it go away by turning off
1 or 2 of many hf.. so probably a total power problem
- found main cable td cable close to td12 arcing at base. carlo
put a short around it.
- Using rf meter we were getting 60milliW/cm^2 close to arcing
cable. All other cables had less that 1mW/cm^2
- so this is a good test to if a cable might be close to
arcing..
processing: x101/190522/hftest.pro, hf_190522.pro
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