- Problems during previous test 26jan17:
- tx 5 arcing from tx output 5 MHz filter. This was worked on
- tx 2 and 4 were tripping on reverse power. at 5 and 8 Mhz.
- tx4 had driver a/c power trip running 8MHz.
What we did:
- 10:20 start
- mesh at 5 MHz position. tx at 5.125 Mhz
- 11:06 6 tx brought up to 40KW (each tx). for 10 minutes
- 11:18 start to raise power to 80KW (each tx)
- tx 4 trips with driver A/C error (need to check this error).
- tx4 remains off for about 1 hour
- 11:24 tx 2 output power goes from 80KW down to 50KW without
changing the drive level.
- the broad band output was showing 50W with syn drive level
of -9.1dbf. The other tx were around 150-400.
- 12:00 cycled hv on tx 2. syn drive -9.3dbf, broad band
90W and output power 80KW. So it was back to normal.
- Note sure what caused the drop.
- the input drive level was normal (we checked the input to
- 12:18 tried bringing tx 4 back up. Came up for 15
minutes then tripped. Saw arcing in the power supply vault.
- 12:36 ran 5 tx (1,2,3,4,6) at 80 KW
- 13:24 bringing up 430 Tx, start datataking recording.
echotek [5.5,5.5] gr,ch -> testhf_ file. ch -> usrp
- az=285,zach=8.83 zagr=11 .. so ch,gr were pointing out
of the heating beam (+/- 7deg).
- 13:55 start auto toggle 3 sec on, 3 sec off. 80 KW on
- 14:06 stopped cycling. readjusted output power to around 75 KW
- had drifted up to 90KW.
- restarted auto toggle
- 14:24 stopped auto toggle, rf off. Move mesh to 8Mhz position
(15 feet low).
- switched grplasmaline to 7.0 Mhz cfr for
- 14:44 start bringing up 8 mhz on tx [1,2,3,5,6] at 8.175
- sit at 50KW for about 10 minutes
- 15:00 80 KW on 5 tx (400KW total output power). tx 4 is
- 15:36 tx 6 trips on driver a/c 3 times. turned off 16:06 to
- 16:00 tx 4 brought back up (after cleaning things in the
- 16:24 all 6 tx now up at 80 KW each.. 480 KW total output
- 16:33 turn off transmitters, done with test.
Plots of output
and drive power:
The plots show the data we took
while the hf was on (.ps) (.pdf)
- Each page has 3 frames:
- each color is a different transmitter (1 through 6).
- top frame: rf power (in dbm) measured at the output of
the rf coupler.
- middle frame: the same output power, but displayed in KWatts
- bottom frame:
- The synthesizer drive amplitude used
- The dashed green line shows when the rf was on
- the red line at the bottom is the total power from the
carriage house 430 receiver (polA 425-435 MHz). When we have
arcing, there are jumps in this power (rfi can also make
- Page 1: 11:00 to 14:30 5MHz testing
- tx4 (blue) trips with driver a/c. stays off for most of the
5 Mhz test.
- tx2 (red) drops from 80KW to 50 KW around 11.5 hrs. after
resetting twice, it came back to 80KW with the same drive
- the jump in the ch tp monitor at 13.4 was when the 430
Tx was turned on.. The 430 tx setup changed the levels.
- around 14:00 we started the auto toggling..
- Page 2: 14:42 to 16:30 8MHz testing
- tx 4 (dark blue) remains down until 16:00
- tx 6 (light blue) starts tripping around 15.6
- all back up at 16.4
line movies while hf on
- 13:28 to 14:50 transmitting 5MHz
- 13:55 to 14:24 auto toggle
- 14:50 to 16:29 transmittting 8 MHz
- we did not see any arcing on the ch total power monitor
- Looking at the clp data, we can see arcing. especially with
the 8 mhz.
- tx 4 and tx 6 had trouble with arcing in the HV fault
- people were cutting out slabs of cement in the tx room floor
during this test.
- We need to check that the cement dust was not getting into
the HV vault, causing these problems.
- tx 2 (running at 5 Mhz) dropped it's power from 80KW to 50KW
without changing the drive levels.
- the broad band dropped from 90 to 50 Watts.
- We checked the input drive level to the broadband, and it
did not change.
- 5 Mhz. we ran 80*5 =400 KW for 1 hour
- 8 Mhz we ran 80*6 = 480 KW for 10 minutes.
- tx 6 broad band was running at 400 Watts with 80KW output
- Alfredo adjusted the biases, it then had 300+ Watts output
- For a long run, we may have heating problems with the broad
bands running at this level.
- The recommended broadband level for 100KW output is 70
to 140 Watts.
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