General coverage receivers, like dongles, often compromise on the front end.
So, yes some form of front-end filter would be desirable.
If it's a specific frequency you're interested in then a bandpass filter.
Or if you still want to tune a wide range then a low pass filter (eg a pi network) would help.
A pi network for 300 MHz will have much better attenuation at 100 MHz than one made for 120 MHz.
And because we're talking VHF frequencies our values of capacitance and inductance are small.
That means you wouldn't use a toroid for the inductor. Options include traces on a printed circuit board appropriately designed or (easier for experimenting) air wound coils comprising a few turns of wire.
Small disc ceramics should be OK for the capacitors, with their value depending on the cut off frequency and impedance you want your filter for.
How could I make this? On my old computer I had a site that told you how to make coils or even figure out values just by counting turns. They need to make a way to make your book marks portable on SD card or file you can email.
So this is my problem I like to just play around and listen I don't really want a particular band or anything specific I just like hearing the signals and trying to identify them I often start at 1 MHz and listen up to 2000mhz over an evening researching them as I go. Any sites come to mind where you can put in values or frequencies? I have magnet wire and PCBs that I can mess with.
Perhaps a trip to the pool store to make HCl into ghetto ferric chloride boosted with grocery store H2O2. Masking tape for the traces. Wonder if hot glue would work? Or acrylic paint for masking.
Best course of action would be a pi net work that blocks 90-110 MHz? I don't ever remember having this problem when I lived in this town. Frustrating because while its near a city you get ALOT of signals but tune in a and hear FM on all of them. Even the airport when they transmit you hear FM broadcast then when they stop the signal goes back into the noise.
When the SDRPlay tunes over 2ghz what are you hearing; it says its range stops but the software goes up higher.