Re: A simplistic explanation (SCOTT!)



Thanks for the warm welcome. I've been reading through all the articles in the file area and at Looks like a lot of fun projects.

Even though there was no Ultralight DX group around when we designed the 473x chip, I did a lot of internet research on portable AM and SW radios. Dating back several years, I have an SRF-59 and SRF-S84, both modified according to Xin Feng's recommendations. I've also heavily modified my Kaito 1103 (based on a Russian site) and ICF-SW7600GR. My Eton E5 is kept stock. I also have a Radio Plus Q-Stick and Sony AN-LP1 shortwave loop. If you were to poke around the labs at Silabs, you'd find the guts of lots of radios, including 70s-era HiFis and automotive radios.

Although the architecture of the Si47xx receivers is very different than these other designs, I've always found a lot to learn in studying each of them, especially in the antenna interfaces and general parameters such as AGC performance and filter bandwidths. The Si47xx chips were originally designed for cell-phone applications, but we aimed very high in the performance and features departments.

I'm enjoying seeing the Si47xx-based radios going head-to-head with many of the past designs I've found inspiring.


--- In ultralightdx@..., "John H. Bryant" <bjohnorcas@...> wrote:


Let me add my name to the Welcoming Committee. You and the other
folks at SiLabs have turned a serious segment of radio on its head!
Bravo. I swear that the 47xx family of chips will go far to
revolutionize analog AM and FM as we know it. In truth SW and LW are
dying/dead bands from anything but an enthusiasts point of view, but
AM and FM still have a long run ahead of them. Doing what you guys
did, at the price point you managed, ought to continue to send out
ripples for a long time to come. I too, look forward to one or more
of the major manufacturers bringing out a full-sized portable that
will use more of the potential of the chip and that will give the
enthusiast operator more control of the parameters... especially the
soft mute function on AM.

The Sony 2010 ruled the world as the top portable radio for a full 20
years (until about 4 years ago) and sold a bunch of radios for Sony
over the years. They finally dropped that unit from the line, after
trying for a decade to successful replace it. They never really did.
The 2010 was supplanted at the top of the portable heap by the
current champ.... the Eton E1. It is really ruling the roost right
now, but it does not offer that much more than the now 25 year-old
2010. A big portable based on the 4734 chip would be a wonderful
thing, at some point. In the meantime, I'm coming to love the PL-380.

We realize that you all don't have control of what the radio
manufacturers build, but SiLabs does influence such, I wager.

For yourself, we certainly hope that you will give ultralight DXing a
try. You might really enjoy it. The way to get started is to listen
and keep a list of stations heard... the time, date, call, location
and a few program details (optional.) You ought to click on the Files
reference at the end of this message. It usually says something like
Five(5) new files, or some such. Just click into the files and you
will find a number of folders, organized by subject area. That
contains the 100 or so formal articles that have been written by
Ultralighters in the past two years. The best place to start is in
the folder called "Start Here" with the article "An Introduction to
Ultralight DXing." That article discusses what you expect, but it
also keys in to more detailed articles elsewhere in the Files.

Anyway... thanks to you and the rest of the folks at SiLabs for doing
such a great job!!!

John Bryant

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