How it's related? Jamming is just drowning signal in noise, how does it help locating the source of the signal?

Because ostensibly, whoever engineered the jammer (especially at these wavelengths) is capable of designing a capable-enough receiver.

Pumping out a lot of noise is usually easier than locating a source of a weak signal. That said, Russians likely have the necessary technology. The question would be do they feel like selling it to Iran and are Iranians capable of using it properly?

> Pumping out a lot of noise is usually easier than locating a source of a weak signal.

Not at the frequencies in question - this isn't 2.4GHz where a magnetron ripped out of a microwave oven will wreak havoc, these are highly-directional, beamformed signals. Also, ostensibly, there should be zero unapproved energy whatsoever in those bands.