408MHz

In the range 405 to416MHz depending on the type of antenna, direction of observation and sources of narrowband interference. SARA Quagi (Yagi) antennas are used at this frequency. In addition the 3m dia dish is used with a  3 element Quagi feed.
Radio Astronomy Supplies 408MHz  0.37dB NF LNAs are used in this band.
Both Total Power measurements and Interferometric measurements are made at this frequency

1420MHz

In the range 1419 to 1435MHz . 1419 to 1421 MHz covers the frequency spread of the Doppler shifted H line with a base frequency of 1420.4MHz
The principal antenna for these frequencies is a 3m dia dish with cylindrical waveguide feeds.
Radio Astronomy Supplies 1420MHz  0.37dB NF LNAs are used in this band.

A pyramidal horn of ~ 1m2 physical aperture feeding  a waveguide to coax coupler is also used in this frequency range

Two helical antennas have been constructed to operate around 1GHz and 2GHz

~4GHz

Two C Band TV LNBs  ((0.35dB NF) have been purchased and enclosed in temperature controlled  enclosures as feeds for the 3m dia dish.

~11GHz

Several commercial TV LNBs are used as feeds for a 60cm and  80cm diameter offset dishes.

30-2000MHz

An Icom-R7000 communications receiver has been modified to deliver an output signal from the AGC level circuit that can be processed and recorded. Amplitude and frequency stability is  maintained by an active temperature control system attached to the receiver.