Hello, I have designed a set of 7 filters on ELAD-BPF-boards for the whole range up to 30MHz. This are suboctave-filters with nearly constant ratio of upper/lower frequency. The band edges do not cut

#pre-selector

Paul, dear friends, I am surprised that the unmounted B3 filter cards from Franco are so poorly utilized and perceived by customers as mysterious or impractical. I gladly share my own component values

#fdm-duo #pre-selector

Impressive! However, I would like to have an inverted effect as a MW/AM DX listener. To the band-full of Trans-Atlantic signals, e.g. from Arizona! Seriously speaking, schematics of band-pass filters

#fdm-duo #pre-selector

Thanks for the suggestion, Klaus. A bit too ambitious for my low-level skills, unfortunately.

#fdm-duo #pre-selector

:).

#fdm-duo #pre-selector

I'm sure you're right, Clint, but the individual filter boards are relatively cheap and I don't suppose Elad is making a loss on these? But your eBay link is interesting, and that could be a cost-effe

#fdm-duo #pre-selector

Paul Jones, You are a star!

#fdm-duo #pre-selector

If you are 'ok' with a manually-tuned low-cost preselector, it might be worthwhile to have a look at the BCC (Bavarian Contest Club) preselector (design dated from ca. 1998). There is a brief descript

#fdm-duo #pre-selector

Hi Paul, This is a test to see if JPG pictures come through in an email on the groups.io site. Here is a spectrum display of the AM broadcast band at my QTH in Phoenix, AZ. I get ADC overload on my Du

#fdm-duo #pre-selector

Hi Paul White, I suspect that there would not be enough demand for the special filters to warrant Elad’s financial investment in the project. The current Elad ham band filters, while effective, do not

#fdm-duo #pre-selector

Sounds like an opportunity for someone to design and make filter boards for other specific uses. I'd like a narrow one for 136kHz for example. Neil G4DBN #notvolunteering

#fdm-duo #pre-selector

Paul I have requested a few months ago new filters to also cover the main broadcast bands that swl users can make use of. Also a dedicated am 520-1800 notch filter Paul EladUSA

#fdm-duo #pre-selector

Hi, Clint Isn't it a little disappointing that the available filters are designed for the amateur bands only? I wouldn't have the skills to build on the unpopulated boards.

#fdm-duo #pre-selector

Hi Patrick, Some SDR radios have built-in front end bandpass filters on the receivers and some do not. The S2 and Duos radios have no front-end filters. The main purchase of the pre-selector is to red

#fdm-duo #pre-selector

Who really notices a big positive change with the preselectors available at Elad? Which ones and why? 73, Patrick KM5L

#fdm-duo #pre-selector