AM broadcast bands on all frequencies / bands (SDR2/SDRUno)

[kerchunk]

I imagine this topic has been beat to death but I didn't find anything specific using the search engine - not including the one on a very nice home built high pass filter.

My question/comment is two-fold:

a) my FT-950 receives nicely on 80 and 40 meters (all I've checked). Nicely meaning given my modest antenna situation. I can tune in on LSB voice transmissions just fine. However, the SDR2 is a different story altogether. Using the same antenna, I can see 10 KHz spaced AM signals on both the 80 m and 40m ham bands on the SDR2, even with the MW/FM filter selected (I"m using Ch A of the SDR2). The filter doesn't have any noticeable effect visually on the spectrum scope. I can select many of these AM signals and demodulate and hear the AM broadcasts - only slightly muffled. These AM broadcast signals are just burying any ham band signal reception. I could only barely hear one ham station transmitting on 3.915 MHz I think it was, but it was coming in a solid S9+ on my FT950. This is all just some observation for my upcoming question. I live near Dallas so I imagine there are lots of AM broadcast stations I guess.

Note: I can also select Ch B (with my antenna still connected to Ch A) and I can see the 10 KHz spaced signals on the spectrum scope but at a very low signal level (down below -140 or -180 on the spectrum display as I recall). I don't know if this is coupling from Ch B to Ch A internally inside the SDR2 or maybe I just need to terminate the Ch B input with a 50 ohm load. I also put some snap on type filters around the USB cable as well as the power cable to the mini pc right at the input to the pc DC input.

b) I plan to buy, if y'all can recommend it, a PAR BCST-HPF high pass filter. I know I could build something but I'm fine just purchasing something in the interest of time. If you have had success with this filter or one like it I'd appreciate your inputs.

Am I missing anything (besides reading the user's manual in more detail)? I believe I had low-IF selected but I haven't played around with much else.

Thanks for reading and any help you can offer.

[sdrom33]

1. What antenna you have?
2. Go to the MW broadcast band and check the levels of the AM stations you receive then you can have an idea of your problem

[kerchunk]

I have it hooked to an EF-QUAD end fed from PAR (LNR Precision). The EF-QUAD is designed to receive the 40/20/15/10 m bands. When the SDR2 is tuned to the AM bands (e.g. KRLD 1080 AM) the received signal level is approximately -25 dBm. The same station picked up on the 75m band is about 30 dB lower in received power level (I don't recall which frequency it showed up at in that band).

[g1hbe]

Hi Kerchunk. I have the RSP2 and a couple of big MW BC stations nearby. I use a Wellbrook loop antenna. The only way I can get overload is by turning the RF gain near full (or the RF attenuation to the bottom). Have you checked the setting of this slider? Remember that if it is in 'attenuation' mode it makes the signals STRONGER as you slide it downwards.
I'm wondering why the MW rejector isn't doing anything, it really ought to.
It's been a long time since I used the A/B inputs for HF so I can't recall if it was like this. I stick to the Hi-z input for HF these days.
I hope you get it working properly as I find it is a fine receiver, especially if you treat it to some high/low filters.

EDIT: I'm back again, Kerchunk. I've just been upstairs to see if I can reproduce your problem and I can - all too easily. Applying my Wellbrook loop to the A input, I get MW BC signals popping up all over the 2 to 3 MHz range (I didn't check beyond 3 MHz). The gain slider makes a difference but not enough and the MW rejector does almost nothing. Things are MUCH better on the Hi-z input,
I wonder could you try the Hi-z input, as I get clean results on it. There's clearly something odd going on (perhaps with the new 1.3 software) and it may be worth raising a ticket via support.

[sdrom33]

Hi kerchunk, bear in mind the processor starts overloading at -40 dbm so at - 25 input it cannot operate. You can start with a 20 db attenuator before the input, just to see it work. Later you can use a high pas filter (look at the posts here) to cut mw out.