Last month we posted about an RTL-SDR experimenter who shielded his RTL-SDR dongle using an aluminium case. Shielding the RTL-SDR helps to reduce out of band interference which can enter the device through the PCB itself.
Now Melih, another RTL-SDR experimenter has recently posted on his blog about his simpler shielding method that uses cheap copper tape. The copper tape was purchased from ebay, and is the type that is commonly used for creating a slug barrier in the garden.
Over on the Reddit thread discussing his work, there are some concerns about excessive crystal drift due to there being no ventilation holes. However, it seems that the general consensus is that lack of ventilation will not significantly affect crystal drift and may actually help to stabilise the crystal over time by keeping the internal temperature more constant.
You may also be interested in Melih’s previous post where he replaces the MCX connector on the dongle with an SMA female connector.