How do you connect 2 in series?

@@prizeking1647 possibly the cable from one of these filters that normally would go from one of these filters into the radio, goes instead into the second filters, then the cable from the second filter goes into the antenne input of the radio. if there is 2 strong QRM-Phases, then that would probably help to use 2 of these filters, one for each of the QRM-Phases. disadvantage could be that weak signals get attenuated to much and blotted out, whatever added into the antenna cable will have some sort of attenuation to the desired signals.

What do you use for a noise antenna?

@@nathanpetrovski7525 something tiny, something that can pick up the interference, but not the transmissions you're wanting to receive. I've seen people use a tiny short wire hooked up to the AUX/interference connector, or a tiny telescopic antenna if said interference is from your home. I've seen people run quite a long wire to get close to the source of the interference outside the home (like a few houses down from them kind of long). It all really depends where the interference is coming from on what you'll need to get for the antenna.

It really is an awesome option for local noise. Let me know how it goes for you.

Where's place to buy for 25??

@@charlessalard4636 aliexpress but lasted 2 weeks and gave up so back in box on shelf

Sounds like what is called diversity receive?

@@1OFGODSOWN Yes the Anan has two receivers. You use one to subtract from the other in basic terms. You can also adjust phase.

7300 doesn’t have Roofing Filters because it’s an SDR.Analog radios use Roofing Filters.

Yep, Clear speech works pretty well. And yes, it sounds like I turned on an attenuator, but the difference is the signal-to-noise ratio. The signal sounds weaker, but the noise is lower by more than the signal. Different ways to skin the cat.

It's actually very easy. The far-right control you'd want to leave all the way counterclockwise to have the most gain. Then just adjust the other two for the lowest noise. They will both have dips. Just play because it's not like you will blow finals if you take too long tuning. (grin). Then turn the right control up and see what happens. The signals will drop a little, but you can bring the noise down even more.

@@DaveKelleyphotography Wow Dave, that was the fastest reply I ever got on KZfaq, thanks so much! So u start the gain fully counter-clockwise to the left (full gain) and work ur way clockwise to the right (reducing gain gradually)? I actually bought the Wimo QRM Eliminator (comparable) except the gain is highest fully clockwise. So the key is to start with the most gain and work ur way down while tweaking the phase knobs. OK, I'll give it a try. I subscribed because ur so fast to answer :) 73 KJ6ER

@@gregmihran8616 Yep, I just tweak the left two and usually leave the gain open since it reduces the noise so much as it is. If you have a decent noise antenna (aux) the dip can be nice and deep. I've uses a 17' vhf/uhf and antenna on the roof and it does really well. I've also used a 40 meter portable antenna, just a whip and small coil for things like the FT-817 or KX3, and it did a much better job than I would have expected. You'll get the hang of it.

@@DaveKelleyphotography Thanks Dave, I understand this will take some practice so I'll keep at it. Ur right about two key points: 1) u need a good 'noise antenna', I will try using my VHF/UHF antenna on the roof, and 2) yes, this simple circuitry should be built-in on all HF radios - imagine if it could be automatic - e.g. like the built-in auto-tuner. Thanks again for all ur prompt responses, much appreciated. 73 KJ6ER

I doubt it will remove it all. It may help to some degree. The idea is that it takes a sample of the noise and counters the main RF coming in with an out-of-phase version of the same noise. That might be a pretty massive amount of noise to try to counter. Certainly worth a try. But don't think you'll get a nice quiet S2 noise floor with it.

@@DaveKelleyphotography Got one of these, it does a great job, I can hear daytime MW signals where there was noise before. You're right it wont give s2 noise floor but when the "sweet spot" is found in the phasing between the two antennas the difference is quite remarkable, a very clever design.

@@tonymagnier9846 Good deal, Tony. I have a vertical and a CCD dipole at my small lot. The dipole is always quieter than the vertical, of course, so I've changed things up totally here. I transmit on the vertical, sometimes with 800 watts. I receive on the dipole by going into the receive only antenna jack on the back of my K3S. A lot of the larger radios have RX only jacks on the back. I added a DX engineering 'receiver guard' to keep the 800 watts from blowing the front end on the RX. So, the vertical was over S9 noise. The dipole was S7 noise, and with the phase unit it is S3-S5. Of course the phasing unit drops the strength of the desired signal, but the noise goes down much farther. I see about a 4 to 5 S unit gain in signal to noise. I'm glad it's working well for you. It has made my station operational again.

Like any filter, there are never any absolutes. The idea is, if your antenna is picking up signal and some power line noise, and you can get a secondary smaller antenna to just pick up the power line noise, it should be able to null it out.

I just have a little 40 meter whip that I use when I take my FT-817 out and about. But I've used a simple wire that's a few meters long as well as my VHF vertical on the roof and they all did fine. As long as the aux antenna picks up the local noise but not the signal you are trying to hear, it'll work fine.

It is connected just like an amplifier would be. A simple cable with an RCA plug on both ends. One end in the amp jack on the radio and the other in either of two RCA jacks on this phasing box. And if you have an amp then you use the second RCA jack to go to the amp. Daisy chain.

@@DaveKelleyphotography thank you dave ,2 port over there, but which one? alc port or send port?

@@bagasteguh6414 it would be the SEND jack.

@@DaveKelleyphotography okay, thank you very much, and regard's dave