Broadcast AM Reject High Pass Filter (2.6 MHz HPF) by RTL-SDR Blog

I purchased a genuine RTL-SDR dongle which worked very well right through the HF radio frequencies through VHF and up to UHF. Decent enough sensitivity but it was plagued with interference from very powerful AM broadcast transmitters which saw spurious signals appear in various parts of the radio spectrum. It was still usable but annoying. Except for the 11 metre CB bands and the 10 metre Ham band. These were completely swamped with broadcast breakthrough. So I purchased this high pass filter which blocks signals below 2 Mhz and passes signals above. This completely cured the problem and made the RTL-SDR dongle even better. Well worth adding to your SDR setup.

This item works very well, so far as I can see in my short tests. I have a massive AM station a couple of miles to my north, at 50KW during the day, and it splattered all over the bands, with harmonics everywhere.As long as I connect this filter *directly* to my SDR (an SDRPlay2) with the included adapter, the station is just gone, and I can hear other signals (except in the filter's blocked range) quite nicely.If I connect it via a balun or feedline, the interference is back: I'll try various shielding strategies, but as long as the shield is there after the filter, all is well.Shipped promptly, arrived in good order (had one tiny screw on the case loose, easily fixed)

This filter does a great job at reducing strong AM Broadcast signals. It's very inexpensive compared to a filter I bought a few years ago. It's works great. Don't hesitate, it's worth it.

I live about a mile from a 5kW AM radio station. Without this filter, the radio station shows up all across the HF bands, but this filter completely clears it up! This should take care of all but the strongest MW signals. My only complaint is that the nuts on the SMA connectors were loose when I got it, but I tightened those up. This is definitely worth having in your RF equipment arsenal if you do any kind of HF work with SDR.

Seems to do its job fine, but it is not a panacea for suddenly getting clean 80m ham band signals for me like others have reported. I cannot tell a difference on that band with it in place or removed on any ham band, using a Airspy HF+ Discovery SDR and a magnetic loop antenna. So this is not a silver bullet, and may not solve your interference issues. But it does attenuate the AM band as it claims to do. May be most beneficial to proper third harmonics of AM frequencies. Also with it in place it does attenuate the 160m band as it says in the title (2.6MHz HPF, 160m band is 1.8-2.0MHz). Would be better if it had a sharper rolloff closer to the edge of the AM band like 1.4MHz so that 160m could still be used. But, it does what it says it does, and is high quality and inexpensive, so 5 stars.

For any ham or shortwave listener experimenting with Software Definable Radios (SDR), this little item is a must. Strong broadcast band signals can make a sensitive SDR essentially useless. This little filter significantly attenuates these broadcasts and enables the SDR to achieve its full dynamic range over the rest of the bands. As pointed out by the seller, this unit will attenuate the 160 meter ham band, but its -3dB cutoff of 2.6 MHz allows for good performance on 80 meters and up. Hard to beat the price!Added a network analyzer evaluation of the unit (see figure). Insertion loss ~ 0.15 dB, -3dB @ 2.7 MHz and -40dB @ 1.98 MHz. Ultimate out of band loss is on the order of 45 to 55 dB.