In article , Matt wrote:
1. Sync detector. The sync detector on my Sony 2010 really helps me
dig out stations that my other non-sync radios cannot. How much per
unit would a sync detector cost?

The sync detector on the 2010 was born because Sony had tons of AM stereo
demultiplexor chips and nothing to do with them. By the time the 2010
came out AM stereo was dead.

Anyone out there with a AM stereo receiver? (mine was stolen in 1989).

A brilliant engineer figured out that with a slight circuit modification,
he could add a sync detector (unheard of on a consumer radio) and get
rid of those chips.

With the demise of the SW77, I doubt those chips are still available.

Now, to throw my own two cents in. :-) I'd like to see the unit
"EMP hardened" to the point that a nearby lightening strike would not
damage it. I live 3,000 feet up in the desert and we get some very strong
lightening storms.

Geoff.


--
Geoffrey S. Mendelson 972-54-608-069
Icq/AIM Uin: 2661079 MSN IM: (Not for email)
Carp are bottom feeders, koi are too, and not surprisingly are ferrets.

"Geoffrey S. Mendelson" wrote in message
...

The sync detector on the 2010 was born because Sony had tons of AM stereo
demultiplexor chips and nothing to do with them. By the time the 2010
came out AM stereo was dead.


It's true that AM stereo isn't the big deal that it's promoters claimed it
was,
but it's hardly dead. It certainly wasn't when the 2010 was introduced.

By the mid 80's, I'd say the AM stereo receiver market was still growing.
AM stereo was approved in 82.

There's three AM stereo stations here.

Anyone out there with a AM stereo receiver? (mine was stolen in 1989).

Two. One's the car radio.

[snip]


Geoff.



Frank Dresser

Okay, gotcha, RHF. My thought on the thing is that the
Ten - Tec RX320D model has DRM capability, and is
priced right for that application. I wonder when or if we
will ge DRM for mediumwave?

At any rate, point taken.

73,

Steve

"RHF" wrote in message
om...
| SMHL,
|
| IIRC: DRM requires 12kHz or 15kHz.
| So the first two are A-OK at 2.5kHz and 6kHz; but a third at 12/15kHz
| would made the radio's IF Section up-grade-able to DRM is desired.
|
|
| jm2cw ~ RHF
| .
| .
| = = = "Stephen M.H. Lawrence"
| = = = wrote in message
link.net...
| "Gregg" wrote:
|
| | IF BW of 2.5KHz 6KHz and 10KHz per side band for itelligibillity
through
| | audio quality.
|
| I dunno about the 10 kc, Gregg. I'd go for
| something really tight, at NRSC BW. Anything
| wider than that, you're just asking for noise.
|
| 73,
|
| Steve Lawrence
| Burnsville, MN
|
|
| ---
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I wish they all would, Gregg!

73,

Steve


"Gregg" wrote in message
news:WZM7b.105483$kW.105432@edtnps84...
| Behold, Stephen M.H. Lawrence signaled from keyed 4-1000A filament:
|
|
| "Gregg" wrote:
|
| | IF BW of 2.5KHz 6KHz and 10KHz per side band for itelligibillity
| through | audio quality.
|
| I dunno about the 10 kc, Gregg. I'd go for something really tight, at
| NRSC BW. Anything wider than that, you're just asking for noise.
|
| Besides the DRM noisemakers, there's still a few stations smart enough to
| use Khan ;-)
|
| --
| Gregg
| *Perhaps it's useful, even if it can't be SPICE'd*
| Visit the GeeK Zone - http://geek.scorpiorising.ca


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I did present all of your comments yesterday, and it seems that a small desk
top unit might be the first way to go, with a rotating loopstick on top,
similar to the way Palomar does it with their antenna. Depending on price,
we may go with an LCD graphics type of display, so that BW, tuning step,
RSSI, and frequency will be displayed. Tone controls could also be an
option. If we can find a reliable source of Sync Detector chips, that could
also be an option, but usually, these types of devices are on allocation
with the larger radio manufacturers. I went through just this type of thing
when I was working for one of the research divisions at Motorola. If we
weren't buying 10,000 devices a week, vendors of some of these specialty
items were not interested.
It was interesting; you look at some of these vendors such as CTS, our in
Sandwich, Illinois. I needed some OCXOs for a critical project. I was told
by one of their engineers (I am not going to name him) that they were not
interested in selling us only 30 units, at 400 dollars each. Same thing
with the Oak Frequency Group.
Murata pulled the same thing on one of the smaller radio manufacturers in
this country; their rep told that company that they were going to
discontinue all ceramic filter production. I called their headquarters down
in Smyrnia, Georgia, and asked them about this. I asked them if they had
another source where we could purchase our ceramic filters from (Motorola),
since they were discontinuing their filter line. They changed their tune.
The point of all of this is that unless you are a very large entity, most
companies don't want to deal with you. Exceptions are Analog Devices,
Mini-Circuits, Phillips, Coilcraft, and a few others. The companies that DO
want to deal with smaller entities will provide us with the wherewithall to
put this radio into production. I still need to find a reliable source of
4kHz and 6kHz ceramic filters. A couple of you mentioned the use of
Mechanical Filters...............this is a possibility, but we are talking
about 86 dollars each for these filters, unless you buy at least a couple
hundred at a time. The price then goes down to 50 dollars each. An example
of this is Palstar.....................when Paul provides the optional
Mechanical Filter for his radio, at a slightly higher price, he isn't making
any money on that filter. I know what he pays for those filters. Another
thing, these are the same filters that some of the other manufacturers are
selling as options in the $120.00 plus range.
In conclusion, I want to thank all of you for your input...........I am
listening, and presenting this information to my employer. We will be
moving carefully on this project; we want to make sure that we come out with
a product that people want to buy. I do believe that a portable unit will
also be on the horizon, but that will probably be our next product.
I have also contacted the National Radio Club, to see what some of their
members might be looking for. My next move is to
put my feelers out on my website.

Pete


RHF wrote in message
om...
MJC,

You ar right the CCRadio (Grundig S350?) are nice size radios.
- - - The Sangean ATS-909 and Grundig YB-400 are simply to small.


Pete,

If a Portable Radio, I would prefer something the Size and layout of
an Panasonic RF-2200 and nothing smaller than a Sony ICF-2010.

If a Desk Top Radio, then I would prefer something the Size and layout
of a JRC NRD-515 (Drake SW2?).

TBL: Basically, a Radio that's Size and layout is "Human Engineered"
for Big Old Fingers and Tired Old Eyes.


~ RHF
.
.
= = = "MJC"
= = = wrote in message ...
To answer your first question about size and portability, take a look at
the CCRadioPlus. It is a perfect mixture of size, portability, reception
and
sound quality. It works off both AC and battery, and it's battery life
is
exceptional off of C cells. It's sound is as good as any table top radio
(or
better).
As for all the rest, I think everyone else here has already listed
all
the desired technical features and if you manage to incorporate them all
into the package as I described (like the CCRadioPlus), you'll have a
winner.
The only concern then is if you will be able to offer it at anything
reasonable in cost. We all know you can't set something for nothing so,
as
the designer, you're the one who'll have to figure out the best
compromise
of cost and features that will sell well on the open market.

MJC

"Pete KE9OA" wrote in message
...
My employer has given me the go ahead to design a new product. If
there is
enough interest, I will design a new MW receiver for the market. What
would
you be more interested in......................a small table top type,
or
a
portable?
Performance wise, I am talking about something like that of an
AOR7030.
I don't think that I would be inplementing Sync Detection, but a
couple of
I.F. bandwidths could be possible. Definitely, double conversion, and
digital readout, with good audio quality.
Would you want any presets? How about target price? Do you want a
built
in
antenna, or external antenna only? High and low impedance antenna
inputs?
How about a built in tunable preselector?
E-mail me directly, and we will see what happens. Any of you who have
built
any of me receivers know what I am talking about...............I plan
to
take the design to the next couple of steps up in performance.

Pete

Hi Frank,
No, it won't weigh that much, but I can fill it with some
very dense ballast, if you like! Seriously, you will be able to expect the
kind of RF handling performance that you get out of an R390. One of the
things that some of the people at Rockwell-Collins commented on was the AGC
performance. Some of those folks have actually built one of the earlier
designs.
I took a couple of my units to work yesterday, in an all metal building. The
AM-FM radios that they have been using will not pull in even the local
Chicago stations without quite a bit of noise. When I was able to show them
WTMJ, in Milwaukee, coming in pretty clearly, they were convinced. When they
asked me to tune in a distant station, I tuned in WLW, on 700kHz. This was
at 4:00 yesterday afternoon. Granted, the signal was at a low level, but
were were able to discern the audio, even in that metal building. Thanks
for your comments!

Pete

Frank Dresser wrote in message
...

"Pete KE9OA" wrote in message
...
That's the amazing thing about this design; it does have that tube like
sound. As far as performance, we are talking about 18 tube performance,
not
6 or 7 tube performance. I do understand your doubts, but I think that
you
will be pleasantly surprised.

Pete


18 tube performance? Now you've got my attention. Will it weigh at least
60 lbs? Will it have more knobs and controls than a Wurlitzer theater
organ? Will the wrinkle paint be tight and even? When I ask what it
costs,
will you say "Dollar a pound, maybe less, just don't start whining about a
strained back."?

Frank Dresser

Thanks, Gary. I think that a portable will definitely be on the horizen, and
the tone control circuit is beginning to sound like a better and better
idea. I think that this can be implemented into the design. The main thing
is the choice of turnover frequencies of the tone control circuit, for the
best sound. Back in the early to mid 90s, I used to design and build custom
acoustic instrument amplifiers, so I've got a bit of experience with tone
control circuitry.
Thanks for those comments!

Pete

Gray Shockley wrote in message
...
On Wed, 10 Sep 2003 11:25:58 -0500, Gary wrote
(in message ) :

I'm getting excited about this new MW receiver. I have the CCRadio
and believe it's reception is only fair, with poor selectivity
compared to my Grundig Satellit 800. Even my Grundig S350 is better
than the CCRadio.

My biggest problem with MW is interference from hologen lamps,


Generally, there is no interference from halogen lamps themselves, I have
two
in my radio room and there is no interfernce whatsoever from them.

However (and you knew this was coming, right? grin) these have off-lo-hi
switches. I have one in the living room which has a dimmer switch and it
tears up anything that gets close. Some of this latter design will even
interfere when they're turned off.


dimmers, etc. I don't know if there is any NB that will eliminate
this type of interference.

What I would like to see is:
A portable with a large enough quality speaker to get a decent bass
response, separate tone controls (or even better, a graphic equalizer

Over the years, I've used from one tone control to nine and the simplest
that
worked well was three controls, the standard trebel and bass and a
"midrange"
that covered (typically) from 300 to 3000cps/Hertz.


tailored to reduce certains frequencies associated with different
types of interference), at LEAST two GOOD bandwidths, a superior
built-in directional antenna, and of course a selectable sideband
option would certainly be nice.

If your set is a real step up from what I currently have, I will
definitely be a buyer!


Gray

Hi Gregg,
That is exactly what I plan to use..............I have been
using that topology for several years now, so I've got the Diplexer design
nailed down pretty well. Take a look at my website, and you can see how
I've got this implemented. I've got a few downloadable zip files of some of
my designs (no, I won't hide the schematic from the final product).
I am not sure why more manufacturers don't use doubly-balanced mixers,
especially when you can purchase a Mini-Circuits ADE-3 mixer for around 3
dollars. We are talking about a mixer with an SSB conversion loss of around
4.7dB, which, since this is a passive topology, translates approximately to
a noise figure of around 5dB. Since this is a Level 7 mixer, the IP3 should
be around +14dBm. Compare this to an Analog Devices AD831 mixer, which has a
+20dBm IP3, but has a 12dB NF. To reduce the NF to that of the ADE-3, you
need to have an RF amplifier ahead of that mixer. Let's say that we need
10dB of takeover gain from the RF amplifier; we now have an IP3 of only
+10dBm from that AD831, and we still need all of those external support
components for that mixer.

Pete

Gregg wrote in message
t...
Behold, Pete KE9OA signaled from keyed 4-1000A filament:

You do have some good ideas, and I am listening. A DX switch won't be
necessary; we will have a great dynamic range.

Am I to assume then that you plan a double-balanced diode ring mixer?

--
Gregg
*Perhaps it's useful, even if it can't be SPICE'd*
Visit the GeeK Zone - http://geek.scorpiorising.ca

"Pete KE9OA" wrote in message
...
Thanks, Gary. I think that a portable will definitely be on the horizen,
and
the tone control circuit is beginning to sound like a better and better
idea. I think that this can be implemented into the design. The main thing
is the choice of turnover frequencies of the tone control circuit, for the
best sound. Back in the early to mid 90s, I used to design and build
custom
acoustic instrument amplifiers, so I've got a bit of experience with tone
control circuitry.
Thanks for those comments!

Pete

Do you have any experience with the Motorola tone control chips? Those are
quite nice, and just fit right in the normal audio chain with just a few
external components (capacitors, mostly). IIRC, they have about a 12 or 16
dB boost/cut, and I would imagine that you could tailor the crossover
frequencies with the external components..

That wide bandwidth would be pretty nice, but what I am shooting for is a
DXing machine. With that wider bandwidth, I am not sure if we would need
good group delay characteristics, but I do know that the IP3 of the 2nd
mixer would suffer from out of bandpass signals. I do like the idea of the
2.5kHz bandwidth, but right now, Murata has discontinued production of the
CFJ/CFR series of filters that have that bandwidth. I would surmise that
the larger manufacturers have made a lifetime buy of those filters. I think
that the only option for a narrow bandwidth filter is the Mechanical FIlter.

Pete

RHF wrote in message
om...
SMHL,

IIRC: DRM requires 12kHz or 15kHz.
So the first two are A-OK at 2.5kHz and 6kHz; but a third at 12/15kHz
would made the radio's IF Section up-grade-able to DRM is desired.


jm2cw ~ RHF
.
.
= = = "Stephen M.H. Lawrence"
= = = wrote in message
link.net...
"Gregg" wrote:

| IF BW of 2.5KHz 6KHz and 10KHz per side band for itelligibillity
through
| audio quality.

I dunno about the 10 kc, Gregg. I'd go for
something really tight, at NRSC BW. Anything
wider than that, you're just asking for noise.

73,

Steve Lawrence
Burnsville, MN


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