Astronomers

Receivers

Name	Code	Frequency (GHz)	Feeds	N. of polarizations	Polarization type	Focal Position	Tsys(K)	Sefd(Jy)	Details
LP	PPP	0.305 - 0.410	1	2	Linear or Circular	Primary	65	125	see here
	LLP	1.3 - 1.8	1	2	Linear or Circular	Primary	20	36	see here
	PLP	0.305 - 0.410 1.3 - 1.8	2	2	see here	Primary	-	-	see here
C Band	CCB	5.7-7.7	1	2	Circular	Beam Waveguide	26 (*)	43 (*)
K Band	KKG	18-26	7	2	Circular	Gregorian	90(**)	138(**)

(*) at 6.7 GHz
(**) at 22.3 GHz with opacity τ=0.1 and air temperature on ground Tg=293 K.

The FWHM beam size, as a function of the frequency f, can be approximated by the following rule:

FWHM(arcmin)=19.7/ f(GHz)

SRT receiver changes are quick allowing an efficient frequency agility. The selected receiver is set in its focal position within few minutes (at most).

The LP receiver

Although it is a coaxial receiver package, the contol system sees it as a group of three different receivers, each one with its own code.
RF filters can also be applied.

For the PPP receiver the filters available are:

all band, 305-410 MHz (no filter)
310-350 MHz
305-410 MHz (band-pass filter, sharper band edges).

These are available for the LLP configuration:

all band, 1300-1800 MHz (no filter)
1320-1780 MHz
1350-1450 MHz (VLBI band)
1300-1800 MHz (band-pass)
1625-1715 MHz (VLBI band)

For simultaneous LP configuation all the combinations of the above configurations are allowed. For further details see the DISCOS user manual.