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RX-888 MKII above 32MHz?

Posted: Sat Mar 06, 2021 2:28 pm
by ukdx
When the MKII is tuned above 32MHz what tuner is being used, I know the antenna port switches at 64MHz and see mention of 64MHz bandwidth but from what I can see it's the R828D, is that correct? I've tried it in both Console and using the extio with similar results. I've made some screengrabs with the gains cranked up to demonstrate what I see.

Paul
RX888BW.jpg

Re: RX-888 MKII above 32MHz?

Posted: Sat Mar 06, 2021 8:02 pm
by PD3LK
Not the answer you hoped for i think:
viewtopic.php?f=57&t=860

Re: RX-888 MKII above 32MHz?

Posted: Sun Mar 07, 2021 7:03 pm
by ukdx
I'm not sure Leon but then I don't how this beast actually works. I know it's capable of 32MHz of visible bandwidth but is that only 0-32MHz or should it be capable of, lets say 10-42MHz as a viewable chunk?

I see Justin pushed it to 64MHz but his I5 PC couldn't process the FFT quick enough although IK1XPV's I7 did run it OK. I'm using an I9-10850 so I should have enough power to run it at 64MHz then decimate it down to 32MHz to cover 32-64MHz which is the bit of band I'm really interested in.

If none of this can't be done then it's not the end of the world, I bought the 888MKII to cover HF and I now have enough 'spare' SDRs to cover Low VHF as well but if the 888 can do upto 64MHz in one go on the HF port then I'd like to try.

Paul

Re: RX-888 MKII above 32MHz?

Posted: Mon Mar 08, 2021 2:57 am
by bagmouse7
The RX-888 is built off of the original BBRF103 design.
You can see a block diagram of how it works here:
http://www.steila.com/blog/index.php?co ... id_post=18

More good info about related receivers can be found here:
https://sdr-prototypes.blogspot.com/

Thanks

Re: RX-888 MKII above 32MHz?

Posted: Tue Mar 09, 2021 9:03 pm
by ukdx
After some discussion on the nextgen group along with some tweets I've now got the 888MKII working with 70MHz bandwidth from the ADC and all on the HF port. Using the extio in either HDSDR or Sharp simply set the sample rate to 140000000 and IF BW to 70MHz or one of the smaller options.

I'm hoping to use it this Es season to monitor FT8 and phone on 10, 8, 6 and 5M so getting 35MHz from it would be ideal.

I guess this wider bandwidth option isn't available in Console, how do I go about requesting it?

Paul