In the pedestal

• 211122: power levels were measured on, off the sun in the postamp chassis in the pedestal
• the sband cable was not connected to the postamp chassis
• the power meter was centered at 8.5 GHz.
• In the post amp chassis only polB was measured.
• 220323: power levels measured on,off the sun in the postamp chassis.
• The sband cable was installed and the new filter was in
• the levels were measured at:
• the input to the sband postamp chassis
• the input to the foTx
• with the 3 combinations: sbin,xbin  .. sbin,xbout .. sbout,xbin
• we have the s-parameters for the sband chain so we can compute the levels along the chain from the input value.
  

Power levels on,off the sun in the pedestal

date	rcv	polA			polB
		onSun dbm	offSun dbm	delta db	OnSun dbm	OffSun dbm	delta db	Location	notes
211122 sband disconnected	xb	-65.8	-69.5		-66.6	-73.6		input to the  lna	1
		-25.8	-29.5		-26.6	-33.6		output lna
		-35.8	-39.5		-36.6	-43.6		input hub amp
		-24.3	-28.0		-25.1	-32.1		output hub amp
								below values measured, above computed
		-31.8	-35.5	3.7	-32.6	-39.6	7	xb input to pedestal chassis (before the xb filter)	2
		-			-40.7	-58.0	17.3	output of xband filter. 8100 to 9130 mhz We measured after the 5db pad. I've removed 5db from the measured  values to get the output of the filter	3
					-7.4	-26.3	18.9	at input to fiber optic transmitter	4
220323 sband in sbfilter in	sb	-25.0	-25.0	0	-26.1	-25.1	0	sband input to pedestal chassis	5
					-5.4	-25.6	20.2	at input to fiber optic transmitter sb connected, xb connected
					-13.9	-32.7	18.8	at input to fiber optic transmitter sb connected, xb not connected
					-6.3	-26.1	19.8	at input to fiber optic transmitter sb not connected xb connected	5A

• 1. the values in the hub were computed using the measured power at the input to the postamp chassis and then using the measured component gain/losses
• moving upstream from the measurement at the postamp  chassis input.
  
• output 11.5 db amp (using 7.5 db loss cable from amp to pedestal input.
• input 11.5 db amp (using 11.5 db gain of amp)
• output lna (using 10db loss cable amp input to lna output
  
• 2. most of the power in the band is coming from 4.2 to 8 Ghz which is outside the xband filter
  
• 3: power after the xb filter.
  
• The filter has an in band loss of about 2db. Most of the power decrease is from removing the 4.8->8ghz power.
• 4. fiber optic transmitter input
• the data sheet says the 1db compression is 11dm .. so no compression is about 1 dbm.
  
• We are 8db below this 1dbm so the sun should not saturate (but we had sband unplugged).
  
• So the fiber optics will not saturate while on the sun.
• 5. Sband input to postamp chassis, on,off the sun shows no difference for both polA and B
• This is before the sband filter, so all of the sband rfi 1700 ->2600 MHz in being measured
• the rfi is dominating the on,off sun value.
• after we go through the sband filter, the sun,on,off values jump back up to a delta of 19db since most of the rfi is not gone.
  
• foTxInp with sband not connected.  The various polB on,off sun measurements agree
• 5A. foTxInp  with sband not connected.  The various polB on,off sun measurements agree
• 220223: -6.3,-26.1 dbm (on, off sun) xband only
• 211122: -7.5,-26.3 dbm (on,off sun) xband only
  

At the fiber optic receiver output, udc input.

    The power levels downstairs were measured on,off the sun.

• at the  fiber optic receiver output
• at the udc input
• 15,20 db attenuators (polA,B) were placed  between the FoOutput and the udc input
• on 5apr22 these attenuators placed on switches so that could be moved in or out.