Plots
    Table of high freq resolution plots
    2.7 to 12Ghz plots

•  25may23 with 12db pad in front of FoTx (.pdf)
• 29may23 no 12db pad, SolAttn (20db) in front of udc input (.pdf)

---

INTRO

    Cal on, cal off measurements were taken 25 and 29 may23 to see how large the cal deflection was.
On 25may23 the 12db pad in front of the fiber optic (FO) tx was installed.
On 29may23 the 12db pad in front of the FO tx  was removed.

---

Setup

Three different rf filters were used to go 2.7 to 12 GHz

• filter 3: 2775-3475 MHz
• filter 1: straight thru mode 3475 to 4600 MHz
• filter 5: 4600 MHz hipass: 4600 MHz to 12000MHz

    The mock spectrometers were used to record the data. Their setup was:

• 172.032 MHz bw, up to 7 mocks at a time. Spaced by 142MHz
• 8192 channels/ 172Mhzbw -->  20Khz rbw
• 1 second spectral integerations.
  
• 4 sec  cal off
• 4 sec cal on
• then loop 3 times on this cycle
• When stepping through the freq settings, the downstairs if/lo attenuators are occasionally being adjusted so the mock adjpwr says around 30 count for 1 sigma.
  

• 25may23
  
• 12db pad before FiberOptic tx was installed
• solar attenuator after FoRcv was not used
• 29may3:
• 12db pad was removed from in front of FOtx
  
• blank sky at ra=74722, dec=373000 (az=16,el=70) was tracked (started around 15:22.. some clouds).
• the 20db solar attenuator after the FoRcv was used for filter 3 and filter 5.
  

---

Processing:

• The median spectrum was computed for each 4sec calOn,calOff file
• The ratio calOn/calOff was then computed
• the median of the 3 calon,off cycles was used.
• the cal ratio spectrum for 2.7 to 12ghz was then interpolated to a 1 MHz rbw grid.

---

Plotting the results

    The table belo show the 20khz  resolution spectra for the acquired data:

• filter 3: 2775-3475 MHz
• filter 1: 2.7-14 GHz straight thru (with 15 db pad)
• filter 5: 4.6 hipass  filter
• Each page has  3 frames
• top: polA calOn, cal off spectra. darkBlue: calOn, light blue caloff.
  
• middle: polB calOn,calOff spectra
• bottom: calOn/calOff.. black=polA,red=polB
• Keys:
• udcC -> udc compression
• There is lots of rfi 2.7 to 12 GHz.
  

freq	filt#	25may29 12db pad In	29may29 12db pad  out solAttn in	notes
2775-3485	3	.pdf	.pdf
3475-4469	1	.pdf	.pdf	25May udcC 29May udcC
4469-4611	1	.pdf	.pdf	25May udcC 29May udcC
4600-4594	5	.pdf	.pdf
5594-6588	5	.pdf	.pdf
6588-7582	5	.pdf	.pdf
7582-8576	5	.pdf	.pdf
8576-9570	5	.pdf	.pdf
9570-10564	5	.pdf	.pdf
10564-11558	5	.pdf	.pdf
11558-11984	5	.pdf	.pdf	some aliasing from udc (max freq 12ghz)

The following plots have the 2.7 to 12GHz calOn/CalOff  plotted:

•  25may23 with 12db pad in front of FoTx (.pdf)
• 29may23 no 12db pad, SolAttn (20db) in front of udc input (.pdf)
  
• The median for each band was computed and the the spectra were interpolated to a 1 MHz freq spacing.
• The noise diode varies by less than .5 db across the band.
• 25may23:
• The calDeflection/Tsys is going from 1.6*Tsys to .03*Tsys
  
• 29may23:
  
• the calDeflection/Tsys goes 1.7 to .02*Tsys

---

Summary

• The cal deflection was measured vs Tsys on
• 25may23 with the 12db pad in front of the FoTx
• 29may23 no 12db pad in front of foTx , 20 db pad after foRcv
  
• 20db pad needed so udc doesn't overload (more info)
  
• The cal deflection in Tsys units fall much faster than the diode freq dependence.
• At higher freq, the calDeflection is not getting above the noise floor of the system. 

Processing: x101/230529/meassky.pro, 230525/meassky.pro