Hello,

I would like to add a XPHASE 2 Qrm Eliminator to the rx chain of my PRO2.
The Qrm Eliminator provides a PTT system that bypass the filter when the rig is transmitting but I I would like to connect it like in the schematic below.

My first question is about the connection: is it fine or can it damage the rig?
The second is mostly a clarification: the manual states "The ADC IN connector is the direct receiver input, bypassing Band Pass Filters (BPFs)".
Does it means that the rx signal will never go through the BPFs or somewhere the signal will go back in the normal RX chain? From the Pro2 main schematic it seems the signal from RX-OUT has already passed out the BPF filter, but I would like to be sure.

Thank you very much
73' Enzo, iw7dmh

Hi, Enzo.
First of all, we'd like to point out that it's a very inventive way to use the QRM eliminator.
1. It's fine to use it, but of course, it depends on the output signal level from the eliminator.
2. The signal goes through BPF and ATT first, then it goes out from RX OUT, thus on ADC IN you apply the signal after BPFs and ATT.

Is the function of the QRM Eliminator also to be realized as a software solution?
RX 2 as receiver vor the unwanted signal.. That would be very nice

Hello,
I am wondering if RX-OUT and ADC-IN ports need to be enabled when external filter is used. I am doing some tests with the XPhase-2 and, when I select ADC in the rx antenna box, the signal is almost totally attenuated. The same happens when I just connect a bypass cable from RX-OUT to ADC-IN like in the picture.
I am pretty sure the filter if working fine because I tested it with another rig, but I am not sure how to use the ADC rx antenna.
Can you help me please?

73' Enzo
iw7dmh

Hi enzo
I am very interested in the QRM eliminator, and I would like to know what it gives to you and if your connection scheme works, because Roman's answer is not clear enough. My problem is an electric fence and NB is not enough. I see the same thing by connecting RXout to ADCin, on A2. Try on A3 it works without problem so it's a bug! 73 Jean-Marie

I use one simply on the ANT 1 input with a mobile whip as the noise antenna. It eliminates the electric fence QRM here together with power pole transformer noise, both which used to plague me on 160m and 80m. The the best 75 euro I ever spent on a receiver accessory. Mine is made by Anton RA9SMS.

Erik.

Hi Jean-Marie and Erik, thank you very much for your answer.
I would like to reduce the overall noise in the 80m band. As you can see in a video published on the RA0SMS page (https://www.youtube.com/watch?v=amUwCGh31Uc) he doesn't have a "particular" offending noise, it just reduce the qrm on the whole passband spectrum. It is the same result I would like to have.
I addition I would like to insert the filter in the RX chain trying to avoid the dangerous PTT line and it annoying clicks effect.
I understand the Jean-Marie answer, and I'll do a test this evening, but now I have another doubt: when you select the DAC-IN input, how can you say to the rig "receive from A2 vs A3 antenna"? Is there any "sensing" circuit? Or am I missing some other setting!?
@Erik: you selected ANT 1 because you have a MB1 (if I am not wrong)

73' Enzo

Hi Erik and Enzo.Tu connect your antenna to A2 or A3. You connect RXOut to ADCin directly or through a filter. You choose A2 or A3 or ADC that will receive the signal from A2 or A3.

Merci Erik. Tu l'as trouvé sur ebay?

Mine is on ebay
and a more detailed page is here
It should be the same Erik was talking about.
73'
P.S.: i forgot to say that Anthon (RA0SMS), for a small additional price, can solder all the SMD components. Just ask him before.

www.ebay.co.uk/itm/QRM-Eliminator-X-Phase-1-30-MHz-HF-bands-BNC-connectors/201895639042?hash=item2f01eaf802:g:m8wAAOSwWntcwTZz

It is supplied pre-assembled. You only have to connect power (12V), coax from radio, coax from main antenna, noise antenna,and PTT lead from radio and enable PTT in software. It has BNC connectors so I used adapters. I could not detect any insertion loss so I'd say Anton does a good job in building them.

Erik.

F1DJY wrote: HI,
in the mean time I had a clarification by Roman about the relation between A2, A3 and the ADC-IN inputs.
By design, when you select ADC IN in ESDR2, A3 ANT is still working for exactly such cases, but A2 ANT is disabled.
And it matches perfectly with your finding.
73'

OK, thank you friends. For ADCin and A3 but not A2, I did not understand that it was a choice of the manufacturer. Thanks for the links for the eliminator.

I understand then that the scheme proposed by iw7dmh in the first post to connect the noise canceller is valid with our sunsdr?

Hi
it should work but I hadn't tried. I ditched QrM eliminator for the fence, but I think it should be useful for decreasing noise on the 80m band. The important thing: use A3 for TRX in the Rxout / ADCin configuration. Ask Enzo the question. 73