27may16: 6 ant on sky @ 80KW
We ran with 6 antennas on sky at 70 to 85
KW. Testing went from 8am to 11:20 am on 27may16.
- Data was recorded from the ch receiver using the interim
- the telescope was parked at:
- gr az=285, fch az=105, ch za=8.8, ch dome=10.
- ch was within 15 deg of td 4..
- to minimize arcing in receiver.. it would have been better
to put is at 270, 90.
- We phased the array using the file: rhcp_2.hfsynth
- 08:00 -started to bring up all tx (except tx4. it had an
air valve problem)
- 08:30 -tx up to around 15 dbm on coupler
- 08:40 tx 4 brought up.
- 09:30 raised the drive a little
- 09:51 raised the bias on tx 4 a little (and the output
power went up)
- 10:36 power recorded from ch jumps by about 3db..
- All tx (except tx4) was brought up together
- tx 4 had a problem with an air valve.. it was fixed and then
brought online. (8:40 am)
- 10:40 increment drive to get around 80-85 kw.
- 11:10 stopped
rf synth levels
and totpwr from ch receiver.
The log file from the gui driving the
rfsynth was input and plotted vs hour of day.
The plots contain:
Synlog and ch power (.ps) (.pdf):
- amplitude (db below full scale). Each tx in has a separate
- the phasing used
- The total power (computed from the 25 MHz,, 1 sec interim
correlator dumps) was over plotted (db above Tsys .. with an
offset for display)
- The dashed green line shows when the rf was cycled on and off.
- Page 1: entire run: 7:50 to 11:10
- Top antenna drive (db full scale).
- tx 4 came online at 8.6 (8:36)
- The red line shows the ch power (db scale)
- There was a jump in the ch power at 10.6 (10:36).
- bottom: phase for each tx.
- This was right hand circular. we did not change the phase
during the run
- Page 2: bloup of 9.5 to 11.2 hours
carriage house spectra and dynamic
over plotting the spectra:
25 MHz 1sec dump spectra were taken with the interim
correlator during the entire run.
The long range recievers were selected.
ch spectra 10.0 to 10.5
ch spectra 10.6 to 11.1
- the harmonics of 5.125 MHz are flagged.
- pol A and polB where averaged..
- This was before the total power jump at 10.59 hours.
- this is after to total power jump at 10.59.
- the jump was across the band (the noise floor increased by
- other strong birdies have also appeared
dynamic spectra 10.6 to 11. 1 hours
The first image shows the dynamic spectra
scaled to 5 sigma (.gif)
The 2nd image shows the dynamie spectra
scaled to 500 sigma (.gif)
- the horizontal lines at 10.65 and 11.0 correspond to the total
power jumps seen in the hfsynlog plots.
- the 5.125 mhz harmonics are visible as vertical lines at:
425.375,430.5,435.625, and 440.75 MHz
- a strong birdie at 429.5 is also visible
- around 11.0 there were strong bursts at 430.0, 431.0,431.5,
and 432 MHz. these look like periodic bursts.
rf drive and output power. tx output
drive and total output power (KW) where plotted for the 3
hour run (ps) (.pdf)\
- Each transmitter is plotted in a separate frame
- The black line is the kilo Watt output power (as measured from
the rf coupler).
- the red line is the rf drive (linear scale).
- I scaled it so that the maximum output value we used was 80.
- Page 1:
- top tx 1
- middle tx2
- at 30 minutes the output was 87 Kw. it then drifted down
to 65 Kw (without changing the drive).
- bottom: tx3
- Page 2:
- top: tx4
- tx 4 came online at 50 minutes.
- middle: tx5.
- at 30 minutes tx5 went to 68 Kw. it then drifted down to
55 Kw in 20 minutes.
- bottom: tx6
- at 30 minutes tx6 went to 80 Kw. It drifted down to 65 Kw
in about 30 minutes.
- We melted the end of the load cell cable on td 4.
- They unplugged the cable from the huffman box side. It was
left connected to the load cell
- It should have been disconnected at the load cell.
- drive when at max power (max for the day).
- We saw burst of noise.. when starting up, and again around
11.0 (maybe this was the cable end arcing).
- there was a 3db jump in level in the ch receivers around 10.6.
- tx 2,5, and 6 drifted down in power by 15-25% in
about 20 minutes after being brought to full power.
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