  In low temperature transport measurements, there is frequently a need to
protect a device at cryogenic temperatures from thermal noise originating in
warmer parts of the experiment. There are also a wide range of experiments,
such as high precision transport measurements on low impedance devices, in
which a twisted-pair wiring configuration is useful to eliminate magnetic
pickup. Furthermore, with the rapid growth in complexity of cryogenic
experiments, as in the field of quantum computing, there is a need for more
filtered lines into a cryostat than are often available using the bulky low
temperature filters in use today. We describe a low cost filter that provides
the needed RF attenuation while allowing for tens of wires in a twisted pair
configuration with an RF-tight connection to the sample holder. Our filter
consists of manganin twisted pairs wrapped in copper tape with a light-tight
connection to the shield of the sample holder. We demonstrate agreement of our
filter with a theoretical model up to the noise floor of our measurement
apparatus (90 dB). We describe operation of our filter in noise thermometry
experiments down to 10 mK.
