All the post is very informative for designer's, I had transfered all
to my forum bbs.leowood.net, sorry it's Chinese version. the designer
is also a community moderator in this Chinese radio fan's forum, he
has reviewed all the thread, I will keep all in the loop

some link here
http://bbs.leowood.net/web/leowood/f...=0&ClassID =0

Dear Sir,

At the risk of posting too much, may I say that I understand that Degen
is one of China's leading radio manufacturers. As such, I hope that the
design of this radio is a "no-holds-barred" short wave receiver of
absolute top quality. Ergonomics especially should be user-friendly.
Menu-driven radios are perfectly acceptable IF the owner's manual is
comprehensive and complete. (I own an AOR AR7030 Plus, the best
performing radio I have ever owned, which I find very easy to use due
in part to its superb owner's manual. Though menu-driven, its
ergonomics are superb.) NO "FRILLS" (such as a "fake" analog dial)
should be on this radio; everything incorporated should be there for a
distinct purpose: the best possible reception of the signals desired.

I sincerely hope you will take into consideration my suggestion to
incorporate the various new terrestrial digital reception modes. It is
not necessary (nor, in my opinion, desirable) to incorporate XM or
Sirius satellite "pay" reception into this forthcoming radio. Satellite
radio can better be served by another separate receiver.

As I stated above, ABSOLUTE TOP QUALITY in DESIGN, COMPONENTS, and
CONSTRUCTION QUALITY are of PARAMOUNT importance.

Degen should market this radio in the USA under its own name. If the
radio is a great one, this will give impetus to awareness of the Degen
name in the United States.

I believe that, if any company can design and market a near-perfect
short wave radio, Degen is that company.

Best,

Joe

Dear Sir,

I should also like to add one more item to my list posted previously:
all memories and the firmware should be non-volatile. Should battery
and AC power be disconnected, all information should be retained
permanently (until changed by the user).
All my best wishes for the success of this forthcoming receiver.

Joe

Thanks, Joe, for spec'ing out an excellent radio - I'd like one of those!

now for one additional nit...

"Joe Analssandrini" wrote in message
ups.com...
Clocks should be RADIO-CONTROLLED (and operated independently from
radio and powered via 2 AA or AAA batteries). Two times zones should be
available, one of which should be UTC. Local time should be adjustable
for daylight-savings time (via radio control) if required; UTC should
NOT be affected by DST change. One of the clocks (including seconds)
should ALWAYS be visible, radio on or off.


Regarding the clocks, I suggest making it possible for the user to disable
the automatic time-setting based on the radio time signal.

Every once in a long while, radio-controlled clocks can mis-read the signal.
I had a radio-controlled clock radio misread the DST information, and it was
exactly 1 hour off for the next day! If you're relying on the radio to wake
you up in the morning, this could be a problem (not likely, I'll admit, but
I've seen it happen). Alternatively, design the radio controlled clock
logic so that it makes a couple attempts to read the signal, and only update
the clock if the results are consistent.



Stephen

Re-reading my first post I noticed two silly errors I made: the slew
buttons on FM should offer 100 kHz tuning (not MHz)- and possibly 50
kHz tuning also - and the internal ferrite antenna for MW and LW should
be 260 mm minimum length (not 130). An auxiliary external removeable
MW/LW antenna, which could plug into a receptical on the top of the
radio, and be rotated would be extremely nice; only the antenna would
have to be rotated for best MW/LW reception, not the whole radio.

By the way, really "tight" (multiple) filters for FM reception would be
a plus.

One other suggestion: make the radio BIG - more on the order of the
Grundig Satellit 800. Smaller radios involve too much compromise in my
opinion. There are certainly enough smaller compromised radios on the
market already but very few "great" ones. (The Satellit 800 is close,
but the improvements suggested here on this post would result, I
believe, in one of the all-time great radios.)

Sorry about the errors. Senility ...

Best,

Joe

Joe Analssandrini schrieb:

One other suggestion: make the radio BIG - more on the order of the
Grundig Satellit 800.

Now that would be fairly huge. Sure sound could be very good, but
portability really suffers. I'd even have trouble fitting such a beast
on my desk or nightstand. It would, BTW, be advisable to use the largest
speaker that fits the case (unlike the '800, which only uses a 10 cm
speaker, a joke given the size of the thing).

Stephan
--
Meine Andere Seite: http://stephan.win31.de/
PC#6: i440BX, 2xP3-500E, 704 MiB, 18+80 GB, R9k AGP 64 MiB, 110W
This is a SCSI-inside, Legacy-plus, TCPA-free computer

Joe Analssandrini schrieb:

Synchronous-selectable sideband reception is a MUST.

I forgot this in my original post. Yup, a low-distortion AM detector of
some kind is virtually a must. Notoriously distorted diode detection
just doesn't cut it for serious listening. (Besides, the Sat 700 already
had synch detection.)

Should be designed
at least as well as that on the Grundig Satellit 800.

Quite tricky, given the folks at DEGEN have no experience building synch
detectors so far.

Full passband
tuning would be even better.

Sure, but I've never seen that in a portable.

Lock must be held as well as on AR7030
model

That would be great. It virtually never unlocks (and even if it does,
you don't notice much since the receiver is still using the very
low-distortion product detector). BTW, if synch audio quality were
anything close to that on the AR7030 this would be great. I was amazed
by how good AM can sound that way. (It's just that the AR7030 doesn't
match my usage pattern very well and usually resides in its box. Seems
silly, but maybe I'll be able to put up a decent antenna one day, and
then I'd be sorry to have sold the thing. It's unlikely to lose much in
value anyway.)

and must automatically turn off when tuning and then re-lock when
station is selected.

That would be the standard way of implementing it, I think.

A good notch filter (with at least 50 dB depth) with range of 0.1 - 5
kHz.

That sure would be nice, but did any other portable ever have one?

At least 3 IF filters (bandwidths) (preferably 4) of 2.2 kHz, 4 kHz, 6
kHz (and possibly 1 kHz for data/CW);

I don't know whether that's realistic in a portable. Still, a 2.2/4/6
kHz combo would work well.

operation of these filters should
be cascaded so that inexpensive ceramic filters will give much better
performance than usual.

However, you can't cascade indefinitely. Passband ripple will mess up
things at some point. The AR7030, BTW, uses a 4-element 12 kHz tail
filter along with some 6-element ceramics and a high-quality SSB filter
(Murata CFJ). If a good SSB filter is not within the budget, cascading
the 6 and 4 kHz filters might also work (which would give a caascade of
the 12, 6 and 4 kHz filters overall). The 12 kHz might also be useful
for DRM or really indisturbed AM reception. BTW, with good filtering
present, low oscillator phase noise is of high importance. That's one of
the reasons why the AR7030 achieves such good selectivity.

All shape factors should be less than 1:2.

Actually that's true even of the 6-element Muratas like the one used in
the 7600GR.

Dial illumination via LEDs, perhaps color-switchable (Red, Blue,
Green).

Now that would be nifty.

Dial light scheme similar to Grundig Satellit 800. (Always on or always
off with AC power, on for 15 seconds with any button push when using
battery power, or always off with batteries, as desired by user.)

This concept does not seem so uncommon, our Sony ICF-M60SRDS also uses
it.

Line outputs for external speaker(s) and stereo system. Excellent sound
quality is a must.

Shouldn't be that much of a problem, decent-quality opamps like 5532s
aren't expensive these days, and decent-quality electrolytics aren't
that much of a problem either.

Independent tone controls (Treble and Bass) should
be incorporated. Internal mono speaker of high quality is preferable to
mediocre stereo speakers.

ACK.

At least two external antenna inputs for AM/SW (high and low impedence)
as well as an FM antenna input.

That seems reasonable. Now the question is, what norm would the FM ant
input conform to?

IBOC reception (AM & FM) for the US. Canadian DAB. (Possibly European
DAB.) Self-contained DRM (or a 12 kHz IF output to connect to a
DRM-equipped computer).

I'd consider DRM as a world-wide standard to be more important than DAB.

Clocks should be RADIO-CONTROLLED

Good idea, but by which time signal station? Making this variable
requires considerably more efforts. (Typically a narrow-band LC tuned
front-end filter is used, which has to be laid out or at least adjusted
differently for the various frequencies, e.g. MSF 60 kHz for UK folks,
DCF77 77.5 kHz etc.)

(and operated independently from
radio and powered via 2 AA or AAA batteries). Two times zones should be
available, one of which should be UTC. Local time should be adjustable
for daylight-savings time (via radio control) if required; UTC should
NOT be affected by DST change. One of the clocks (including seconds)
should ALWAYS be visible, radio on or off.

Very reasonable suggestions.

No LEDs (except for dial illumination and possibly button
illumination). Properly calibrated digital bar graph S-meter of at
least 12 segments.

I guess most people would already be happy with a *useful* meter that
doesn't read full strength 95% of the time, yet also catches fairly weak
signals and has a pretty wide range.

A high-quality plastic cabinet or, preferably, a light-weight metal
(aluminum or magnesium) cabinet.

I don't know whether a metal case would do the sound aspect any good.
Plastic is more realistic anyway.

ALL internal components to be of TOP-QUALITY (formerly known as
MIL-spec).

Isn't that asking a bit too much?

Excellent sensitivity; a 3 or 4 step attenuator (or adjustable RF-gain
control) should be incorporated.

A 2-step attenuator would most likely also do. RF gain was more
necessary in the old days to get SSB demodulation with fairly lousy
detectors right. A switchable AGP time constant/behavior, however, would
be a nice touch.

All other specifications to be of Drake R8B/AOR AR7030 caliber,
especially blocking, ultimate rejection, image rejection, and, most
important, dynamic range.

I guess the receiver will be priced at around ~500USD/EUR, so not all of
this will be possible.

Excellent sensitivity (a 3 or 4 step
attenuator would be of help).

Depending on how sensitive the thing becomes, either a pre-amp for the
whip (as done in the Sat 700) or a pre-attenuated ext ant input (we
don't want anything to blow on large antennas) seems like the more
likely solution.

A carrying case (nylon or leather) should be optionally offered; this
should be able to carry AC adapter, batteries, and any other options,
as well as fully protecting the radio.

Seems like a good idea, though this kind of rig will never be as
portable as a DE105. (BTW, I sure would like to get my hands on a
DE1105. The '105 isn't bad for what it is, but doesn't perform as well
as I'd like. And since the '1105 isn't a lot bigger, this seems like the
perfect model to upgrade to.)

Servicing is important. All service information should be made
available on line.

That would be great indeed. At the very least there should be some way
of obtaining service docs at all.

Stephan
--
Meine Andere Seite: http://stephan.win31.de/
PC#6: i440BX, 2xP3-500E, 704 MiB, 18+80 GB, R9k AGP 64 MiB, 110W
This is a SCSI-inside, Legacy-plus, TCPA-free computer

Stephan Grossklass wrote:


Quite tricky, given the folks at DEGEN have no experience building synch
detectors so far.

I think we've reached the point where a good sync' detector is not
exactly rocket science anymore. However the problem is designing one
that doesn't infringe on someone elses design. That could be a big
problem.

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wrote:
The designer(also the main engineer of DE1103 & Grundig SAT800) now
ask
advise of the receiver function from BCLer, the DE1108 will be the
high-end receiver of DE 110X series, it comes with a large dot matrix
LCD display(128*64) two way speaker system, MP3 recorder, AM sync
detector, SSB, dual conversion, the reference basis is SAT700, it
should has better performance than sony 2001D, 7600G, SW77 even
SAT700,
the outline dimensions will be large than SAT700,pls post your
thougts
here, I will take the message to the design, thank you!