Receiver specs - are they meaningful
 

Receiver test data from
S = Sherwood
P = Passport
Q = ARRL QST mag

5 KHZ THIRD ORDER INTERCEPT DYNAMIC RANGE

dB
100P Icom IC-R9500
93Q Flexradio SDR-1000
82S AOR7030
80S Icom R7800
78S Icom R781
78Q/75S Icom IC-R756 PRO III
77Q/75S Icom 756 PRO II
77P Drake R8A/B
77S NRD 515
75S Drake R7
75S WJ-1000
74P WJ-8711
71S Icom 756 PRO
71S Drake R8
68S/66P NRD545
67S Icom R75
67S Drake SW8
64S Yaesu 7700 (similar to FRG7)
62S Icom R70/R71
55P Eton E1 portable
46S Ten Tec 340
43P WinRadio 313i

The above data is supposed to indicate which of your dream receivers
will get you that ultimate DX catch above all other receivers. In
practice, life is different: one of my pals had a SDR-1000 and I
didn't notice his logs reflect anything much better than other
fella's. A top DXer John Bryant used a Eton E1 on a DXpedition to
Easter Island and logged some of the best catches I have ever seen.
See:
http://www.dxing.info/dxpeditions/easter_island_2007.dx

I have a pal who insists on DXing with an ancient battered Yaesu FRG-7
and i would rate his fantastic logs and high quality recordings
amongst the very best in the world, yet the FRG-7 is actually a very
poor receiver from a poor front end and sloppy bad filters point of
view. A few years ago a DXer won the prestigious Danish DC Club annual
contest with an equally modest receiver, a Yaesu FRG-7000.

A lot of my co DXer's are now using SDR-IQ's and achieving amazing
results, whilst the top rated AOR 7030 lads don't seem to be getting
much in the way of spectacular catches lately.

So what's the motto of this story; just this, don't worry about
receiver specs just concentrate on going on a decent DXpedition to a
good radio spot and make sure you get a decent antenna up.

Have fun and good DX

John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Sangean 803A.
Antenna's RF Systems DX 1 Pro Mk II, Datong AD-270
Kiwa MW Loop, PAORDT Roelof mini-whip
http://www.dxing.info/about/dxers/plimmer.dx

Receiver specs - are they meaningful
 

On Nov 25, 1:01 pm, wrote:
Receiver test data from
S = Sherwood
P = Passport
Q = ARRL QST mag

5 KHZ THIRD ORDER INTERCEPT DYNAMIC RANGE

dB
100P Icom IC-R9500
93Q Flexradio SDR-1000
82S AOR7030
80S Icom R7800
78S Icom R781
78Q/75S Icom IC-R756 PRO III
77Q/75S Icom 756 PRO II
77P Drake R8A/B
77S NRD 515
75S Drake R7
75S WJ-1000
74P WJ-8711
71S Icom 756 PRO
71S Drake R8
68S/66P NRD545
67S Icom R75
67S Drake SW8
64S Yaesu 7700 (similar to FRG7)
62S Icom R70/R71
55P Eton E1 portable
46S Ten Tec 340
43P WinRadio 313i

The above data is supposed to indicate which of your dream receivers
will get you that ultimate DX catch above all other receivers. In
practice, life is different: one of my pals had a SDR-1000 and I
didn't notice his logs reflect anything much better than other
fella's. A top DXer John Bryant used a Eton E1 on a DXpedition to
Easter Island and logged some of the best catches I have ever seen.
See:http://www.dxing.info/dxpeditions/easter_island_2007.dx

I have a pal who insists on DXing with an ancient battered Yaesu FRG-7
and i would rate his fantastic logs and high quality recordings
amongst the very best in the world, yet the FRG-7 is actually a very
poor receiver from a poor front end and sloppy bad filters point of
view. A few years ago a DXer won the prestigious Danish DC Club annual
contest with an equally modest receiver, a Yaesu FRG-7000.

A lot of my co DXer's are now using SDR-IQ's and achieving amazing
results, whilst the top rated AOR 7030 lads don't seem to be getting
much in the way of spectacular catches lately.

So what's the motto of this story; just this, don't worry about
receiver specs just concentrate on going on a decent DXpedition to a
good radio spot and make sure you get a decent antenna up.

Have fun and good DX

John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Sangean 803A.
Antenna's RF Systems DX 1 Pro Mk II, Datong AD-270
Kiwa MW Loop, PAORDT Roelof mini-whiphttp://www.dxing.info/about/dxers/plimmer.dx

right on john! i'm done searching for the holy grail of receivers - it
just doesn't exist - i am having more fun and catching the same dx
with my kaito 1103 than with my drake r8 or icom r75. infact there are
stations i can id with the kaito that i cannot make out on my drake r8
- go figure! the gap between portable and tabletop is closed. i am
patienty awaiting a new eton e1 - would not be suprised if my $50
kaito 1103 runs it neck and neck. good dx! john

Receiver specs - are they meaningful
 

On Nov 25, 6:01 pm, wrote:

snip

The above data is supposed to indicate which of your dream receivers
will get you that ultimate DX catch above all other receivers. In
practice, life is different: one of my pals had a SDR-1000 and I
didn't notice his logs reflect anything much better than other
fella's. A top DXer John Bryant used a Eton E1 on a DXpedition to
Easter Island and logged some of the best catches I have ever seen.
See:http://www.dxing.info/dxpeditions/easter_island_2007.dx

I have a pal who insists on DXing with an ancient battered Yaesu FRG-7
and i would rate his fantastic logs and high quality recordings
amongst the very best in the world, yet the FRG-7 is actually a very
poor receiver from a poor front end and sloppy bad filters point of
view. A few years ago a DXer won the prestigious Danish DC Club annual
contest with an equally modest receiver, a Yaesu FRG-7000.

A lot of my co DXer's are now using SDR-IQ's and achieving amazing
results, whilst the top rated AOR 7030 lads don't seem to be getting
much in the way of spectacular catches lately.

So what's the motto of this story; just this, don't worry about
receiver specs just concentrate on going on a decent DXpedition to a
good radio spot and make sure you get a decent antenna up.

Have fun and good DX

John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Sangean 803A.
Antenna's RF Systems DX 1 Pro Mk II, Datong AD-270
Kiwa MW Loop, PAORDT Roelof mini-whiphttp://www.dxing.info/about/dxers/plimmer.dx



I take some heat from my local SWL brotherhood because of my
unwillingness to "upgrade"
to a better receiver. I have been using a R2000 since the early 1980s.
And it is true that
Kenwood might choke on mu modifications, but after babysitting a
AOR7030+ for 9 months,
having a R8B for 2 months, and I still own a R390 and a R392 but
because of their odd
tunning, separate MHz(Mc) and KHz(Kc), and the fact that only a body
builder would enjoy
trying to rapidly tune from one frequency to another they seldom get
used by me. Both are
loaned out to people who value the precision and whom I know will take
good care of them.

At my location, and, if you think about it, at all locations, the
background noise or noise floor
sets the limit on what you can receive. The 7030+ and R8B have much
nicer features, but
the 7030+'s menuing system was really designed by a very demented 3rd
grader, but anything
I could receive on any of the better receivers, I could hear on a
stock R2000. True, better filters
and better audio and better noise filters make some signals better.

Don't get me wrong, I would sell my left n^^ for a 7030+ or R8B, but
for day to day listening,
the better receivers are like a limo compared to our Escort. Both do
the job, is the increased
ride worth the increased price.

There has been a one time power failure during December for 18 hours
and the AOR really
was impressive. But even then I couldn't find a signal that the AOR
received that the R2000
couldn't. It is true the better choice of filters makes the AOR more
fun during extremely quiet
RF conditions. But sadly it just isn't RF quiet enough for the better
receivers to win.

I accept that in wonderful, mythical (or is it mystical?), Greyland
the better receivers may well
receive signals that my lowly R2000 can't. But until I win the
lottery, not likely since I don't buy
tickets, I have to put up with the RF noise that I have.

Instead of "wasting" money on a "better" receiver, I have decided to
tackle the RF noise our
own home generates. For less then $200 and way too many hours in
research and work,
I can't tell the difference when the meter is pulled.

Picking the correct antenna, feeding it correctly, getting rid of,, or
suppressing RF noise sources
can make every day listening as rewarding as a trip to the country.

If you like the stock PAORDT mini-antenna, you might want to take a
look at the Kongsfjord
web page, http://www.kongsfjord.no/,http://www.kongsfjord.no/dl/
Antennas/Simplified%20Complementary%20Push-Pull%20Output%20Active
%20Whip%20Antennas.pdf.
Dallas Lankford has made some serious changes that greatly improve the
PARDT IMD performance.
I have an unusual situation in that I have 2 MW stations that drive
most active antennas nuts.
Dallas's active antennas are the only ones that survive my harsh RF
environment..

Terry

Receiver specs - are they meaningful
 

On Nov 25, 1:01 pm, wrote:

"A lot of my co DXer's are now using SDR-IQ's and achieving amazing results, whilst the top rated AOR 7030 lads don't seem to be getting much in the way of spectacular catches lately."

Dear John,

It seems that you really have a "thing" against the AOR AR7030 'Plus'
receiver. Frankly, I don't know why. You have very limited experience
with it and that was more than ten years ago. Did that so color your
impressions that you cannot accept the fact that virtually all of the
"negatives" written at that time (and even today repeated in some
publications) have been totally overcome or have become commonplace?
(I also note that you do not quote the IP3 for the RF Space SDR-IQ
model.)

I think that it is a shame that relatively few SWLs have purchased
this receiver solely because of those negative comments regarding its
operating scheme, and that of menu-driven products in general. Menu-
driven products were relatively uncommon in 1996, but they are quite
common, and are used by an increasing number of people (think DVD
players, GPS units, and cell-phones), today. People reading these
comments were/are frightened away from this receiver and continue to
be frightened today. For a number of years I myself, having read these
comments by professional testers and some early users, was scared away
from purchasing this radio.

But those AR7030 'Plus' specifications (all of them, not just one)
kept coming back to haunt me. I finally "bit the bullet" in 2004 and
bought a unit which was customized for me by the factory. The only
regret I have is that I didn't buy this radio sooner! Those
"negatives" regarding the operation of the receiver are just not true
nor even applicable today. And it should be noted that, should an
owner desire, full and effective (and easy!) computer control, which
did not exist in 1996, or even 2000, of this radio can now be achieved
and for FREE!

You will never see me achieving "spectacular catches" with it,
however. I am a program listener. I listen to a relatively few
stations that have news, opinions, and other similar political and
economic commentaries that concern me. I personally have little
interest nowadays in trying to hear "exotic" signals.

But this radio does allow me to hear the programs to which I listen to
absolute best advantage. I can tell you that I can definitely hear
things on this radio that I can hear on no other receiver I own. For
example, I own a Grundig Satellit 800, which is a pretty good
receiver. as well as the AR7030 'Plus." It is "fed" by one of my two
Wellbrook ALA 330S Active Loop Antennas, both of which are mounted in
my attic approximately twenty feet away from each other. Both are also
mounted on identical Radio Shack rotators. There is a great deal of
difference in the quantity and quality (more important to me) of
signals receivable on those radios. Frankly, the AR7030 'Plus' runs
rings around the Satellit 800 both in terms of the signals I can hear
and the sound quality of those signals. (It should, after all, as it
cost about five times as much!) The sound quality of a radio broadcast
is better via the AR7030 'Plus' than any other radio I have ever
heard, and that goes back to the console radio days. (This doesn't
even mention my portable SW receivers. Note that it is my opinion that
all of these types of receivers have a place in one's armamentarium.)

I wonder what John Bryant might have achieved had he had an ICOM
IC-756 Pro III instead of the Eton E1 on Easter Island. Or an AOR
AR7030 'Plus.' Or a Redsun RP-2100. Or even a GE Superadio III, all
assuming the same antenna system. Would he have heard more signals?
Would what he heard have sounded better? We'll never know for sure
but, based on the specifications of the radios mentioned, we can
guess. (Not that any of it matters one way or another - his results,
as achieved with his Eton E1, were indeed spectacular!)

I don't know how many true DXers have bought the AR7030 'Plus' but I'd
be willing to bet quite a number have been scared away as I was. I'd
also bet that any "top" DXer using this radio would achieve results at
least equal to, and maybe better than, what he/she can achieve with
most other radios, including your ICOM.

Your point that a good DXer, even with somewhat inferior (for want of
a better term) equipment can easily outperform someone who isn't quite
as experienced, even if the latter is using the latest and most
expensive radio and the best antenna is, of course, quite correct and
has been known for as long as I have been a SWL..

But you really can't ignore those specifications (all of them). Given
otherwise identical conditions, a radio with better specs, in the
hands of someone qualified, will indeed outperform a radio with
inferior specifications. Specs aren't the whole thing, but they are
one of the most important things in choosing a receiver.

I must mention that, in your previous terminology, I am not defending
the AOR AR7030 'Plus" "to the death." It is one of the "top" receivers
in that rarefied level of other "top" receivers. Each of them has
certain relative strengths and certain relative weaknesses. There has
never been, and there probably never will be, a "perfect" radio. All
one can do when choosing a receiver (assuming he/she can only purchase
one or two "top" receivers) is to determine, from the specifications
and reviews, which will satisfy him/her based on his/her own listening
habits, needs, and desires.

But I really wish you would stop "knocking" this receiver, or any
other receiver for that matter, unless there is a definite and well-
known weakness in the design, performance, or construction quality of
that particular radio of which a prospective purchaser should.be made
aware. Pejorative comments such as the one quoted above, which
actually do not enhance the premise of your otherwise interesting
posting, are not helpful to someone seeking information on tabletop SW
receivers, in my opinion.

It is well-known that you are a top DXer and, frankly, I feel that if
you had an AR7030 'Plus' instead of your ICOM IC-756 Pro III, your
results would be identical.

And, again in my opinion, there are a number of really good ("top")
receivers and the AOR AR7030 'Plus' is one of them.

Best,

Joe

Receiver specs - are they meaningful
 

On Nov 25, 12:24 pm, Joe Analssandrini
wrote:
On Nov 25, 1:01 pm, wrote:

"A lot of my co DXer's are now using SDR-IQ's and achieving amazing results, whilst the top rated AOR 7030 lads don't seem to be getting much in the way of spectacular catches lately."

Dear John,

It seems that you really have a "thing" against the AOR AR7030 'Plus'
receiver. Frankly, I don't know why. You have very limited experience
with it and that was more than ten years ago. Did that so color your
impressions that you cannot accept the fact that virtually all of the
"negatives" written at that time (and even today repeated in some
publications) have been totally overcome or have become commonplace?
(I also note that you do not quote the IP3 for the RF Space SDR-IQ
model.)

I think that it is a shame that relatively few SWLs have purchased
this receiver solely because of those negative comments regarding its
operating scheme, and that of menu-driven products in general. Menu-
driven products were relatively uncommon in 1996, but they are quite
common, and are used by an increasing number of people (think DVD
players, GPS units, and cell-phones), today. People reading these
comments were/are frightened away from this receiver and continue to
be frightened today. For a number of years I myself, having read these
comments by professional testers and some early users, was scared away
from purchasing this radio.

But those AR7030 'Plus' specifications (all of them, not just one)
kept coming back to haunt me. I finally "bit the bullet" in 2004 and
bought a unit which was customized for me by the factory. The only
regret I have is that I didn't buy this radio sooner! Those
"negatives" regarding the operation of the receiver are just not true
nor even applicable today. And it should be noted that, should an
owner desire, full and effective (and easy!) computer control, which
did not exist in 1996, or even 2000, of this radio can now be achieved
and for FREE!

You will never see me achieving "spectacular catches" with it,
however. I am a program listener. I listen to a relatively few
stations that have news, opinions, and other similar political and
economic commentaries that concern me. I personally have little
interest nowadays in trying to hear "exotic" signals.

But this radio does allow me to hear the programs to which I listen to
absolute best advantage. I can tell you that I can definitely hear
things on this radio that I can hear on no other receiver I own. For
example, I own a Grundig Satellit 800, which is a pretty good
receiver. as well as the AR7030 'Plus." It is "fed" by one of my two
Wellbrook ALA 330S Active Loop Antennas, both of which are mounted in
my attic approximately twenty feet away from each other. Both are also
mounted on identical Radio Shack rotators. There is a great deal of
difference in the quantity and quality (more important to me) of
signals receivable on those radios. Frankly, the AR7030 'Plus' runs
rings around the Satellit 800 both in terms of the signals I can hear
and the sound quality of those signals. (It should, after all, as it
cost about five times as much!) The sound quality of a radio broadcast
is better via the AR7030 'Plus' than any other radio I have ever
heard, and that goes back to the console radio days. (This doesn't
even mention my portable SW receivers. Note that it is my opinion that
all of these types of receivers have a place in one's armamentarium.)

I wonder what John Bryant might have achieved had he had an ICOM
IC-756 Pro III instead of the Eton E1 on Easter Island. Or an AOR
AR7030 'Plus.' Or a Redsun RP-2100. Or even a GE Superadio III, all
assuming the same antenna system. Would he have heard more signals?
Would what he heard have sounded better? We'll never know for sure
but, based on the specifications of the radios mentioned, we can
guess. (Not that any of it matters one way or another - his results,
as achieved with his Eton E1, were indeed spectacular!)

I don't know how many true DXers have bought the AR7030 'Plus' but I'd
be willing to bet quite a number have been scared away as I was. I'd
also bet that any "top" DXer using this radio would achieve results at
least equal to, and maybe better than, what he/she can achieve with
most other radios, including your ICOM.

Your point that a good DXer, even with somewhat inferior (for want of
a better term) equipment can easily outperform someone who isn't quite
as experienced, even if the latter is using the latest and most
expensive radio and the best antenna is, of course, quite correct and
has been known for as long as I have been a SWL..

But you really can't ignore those specifications (all of them). Given
otherwise identical conditions, a radio with better specs, in the
hands of someone qualified, will indeed outperform a radio with
inferior specifications. Specs aren't the whole thing, but they are
one of the most important things in choosing a receiver.

I must mention that, in your previous terminology, I am not defending
the AOR AR7030 'Plus" "to the death." It is one of the "top" receivers
in that rarefied level of other "top" receivers. Each of them has
certain relative strengths and certain relative weaknesses. There has
never been, and there probably never will be, a "perfect" radio. All
one can do when choosing a receiver (assuming he/she can only purchase
one or two "top" receivers) is to determine, from the specifications
and reviews, which will satisfy him/her based on his/her own listening
habits, needs, and desires.

But I really wish you would stop "knocking" this receiver, or any
other receiver for that matter, unless there is a definite and well-
known weakness in the design, performance, or construction quality of
that particular radio of which a prospective purchaser should.be made
aware. Pejorative comments such as the one quoted above, which
actually do not enhance the premise of your otherwise interesting
posting, are not helpful to someone seeking information on tabletop SW
receivers, in my opinion.

It is well-known that you are a top DXer and, frankly, I feel that if
you had an AR7030 'Plus' instead of your, your
results would be identical.

And, again in my opinion, there are a number of really good ("top")
receivers and the AOR AR7030 'Plus' is one of them.

Best,

Joe

One of the problems with the 7030 is when someone sees you run it, it
looks like magic.You can flip through the menus pretty fast. It is
similar to watching someone run say a CAD program, where you do a few
clicks and the magic appears, but the other person can't follow what
you did.

My only regret about the 7030+ is the price hasn't dropped over the
years. I'd like a second one for stuff like hfdl, but can't justify
the expense. The NB options is kind of pricey since all I ever use is
the notch.

If you take a 7030+, add the NB, daughter board and say one extra
filter, you are at $2k. THe icom is about $700 more, or about a 1/3
premium. Then again, it has a built in pan adapter.The nice thing is
you know there will be a Pro IV eventually, so you can pick up the III
used eventually. AOR has done minor revs over the years (documented on
their website), but don't see the need to change the basic radio.

Receiver specs - are they meaningful
 

Hi John,

Good to hear from you again on the newsgroup, and to read your observations.

A few thoughts:

The RF environment where a receiver is used definitely figures into the
equation. I believe it's Vince or Gary in your country that uses the FRG-7,
and he has said that his DXing location is far from local transmitters. That
can make a big difference.

In the same way, John's use of the Eton E1 on Easter Island is fully
appropriate, as there are no local MW stations there, and only 1 low-power
FM. Easter Island's nearest concentration of MW stations is 2300 miles away
on the South American continent, and Australia/NZ is about 4300 miles
distant! It doesn't take a crunch-proof receiver front end to perform well
in such a location.

The scarceness of local noise and nearby powerful stations is also a reason
the early pioneers in radio and DXing had such phenomenal catches in the
1920s-1940s, despite their very simple receivers.

I chose the SDR-1000 largely on the strength of its front end and close-in
dynamic range/IP3, for use here in the greater Seattle/Tacoma area. I have
many MW frequencies registering S9+50db, and a number of them are at S9+60dB
or greater. The strongest I've seen was -13dBm on the SDR-1000's very
accurate and calibrated (dBm) signal meter. This is when I was using the
Beverage antennas in the greenbelt (forested) area behind my house. In
direct tests at my home, the SDR-1000 clearly heard weak DX that was
inaudible or muffled in the noise on a Ten-Tec RX-340 (two different units).
However, the same rigs side-by-side at the Grayland DXpedition location
performed equally as well. I've heard a number of 9 kHz "splits" at home
with the SDR-1000, such as 1475 kHz RTM Malaysia in Kota Kinabalu, that may
not have been quite as clear and strong with another radio used in the "RF
alley" here.

With the Perseus receiver I have on the way, the front end may be slightly
less "stout," but it has operational advantages over the SDR-1000 that make
it very worthwhile for both home and DXpedition use.

73,

Guy Atkins KE7MAV
Puyallup, WA USA


wrote in message
...
Receiver test data from
S = Sherwood
P = Passport
Q = ARRL QST mag

5 KHZ THIRD ORDER INTERCEPT DYNAMIC RANGE

dB
100P Icom IC-R9500
93Q Flexradio SDR-1000
82S AOR7030
80S Icom R7800
78S Icom R781
78Q/75S Icom IC-R756 PRO III
77Q/75S Icom 756 PRO II
77P Drake R8A/B
77S NRD 515
75S Drake R7
75S WJ-1000
74P WJ-8711
71S Icom 756 PRO
71S Drake R8
68S/66P NRD545
67S Icom R75
67S Drake SW8
64S Yaesu 7700 (similar to FRG7)
62S Icom R70/R71
55P Eton E1 portable
46S Ten Tec 340
43P WinRadio 313i

The above data is supposed to indicate which of your dream receivers
will get you that ultimate DX catch above all other receivers. In
practice, life is different: one of my pals had a SDR-1000 and I
didn't notice his logs reflect anything much better than other
fella's. A top DXer John Bryant used a Eton E1 on a DXpedition to
Easter Island and logged some of the best catches I have ever seen.
See:
http://www.dxing.info/dxpeditions/easter_island_2007.dx

I have a pal who insists on DXing with an ancient battered Yaesu FRG-7
and i would rate his fantastic logs and high quality recordings
amongst the very best in the world, yet the FRG-7 is actually a very
poor receiver from a poor front end and sloppy bad filters point of
view. A few years ago a DXer won the prestigious Danish DC Club annual
contest with an equally modest receiver, a Yaesu FRG-7000.

A lot of my co DXer's are now using SDR-IQ's and achieving amazing
results, whilst the top rated AOR 7030 lads don't seem to be getting
much in the way of spectacular catches lately.

So what's the motto of this story; just this, don't worry about
receiver specs just concentrate on going on a decent DXpedition to a
good radio spot and make sure you get a decent antenna up.

Have fun and good DX

John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Sangean 803A.
Antenna's RF Systems DX 1 Pro Mk II, Datong AD-270
Kiwa MW Loop, PAORDT Roelof mini-whip
http://www.dxing.info/about/dxers/plimmer.dx

Receiver specs - are they meaningful
 

wrote in message
...
Receiver test data from
S = Sherwood
P = Passport
Q = ARRL QST mag

5 KHZ THIRD ORDER INTERCEPT DYNAMIC RANGE

This is one spec. That's like comparing cars soley on the transmission or
engine size. It tells you next to nothing about the receiver's overall
performance.
And for those of us with rotatable, directional antennas and no MW broadcast
stations in the same county, IP3 is probably the least important spec.
Dale W4OP

Receiver specs - are they meaningful
 

To reply to some of these posts:
r2000sw - I too have awful RFI at my home QTH and I found much of the
answer was to turn nearly everything OFF in the house so that I can
get a bit of noise free DX in in the wee hours of the morning. Of
course, in the evenings I can't intrude on my ball and chains TV/DVD/
VCR's that put out a hellava RFI racket. As for antenna's, I think my
RF Systems DX1 professional MK II I superb and reduces the local RFI
substantially - the PAORDT mini-whip was just horrible. Enjoy your
R2000!

to Joe A., I think the old adage "methinks the maiden doth protest too
much" applies to you and your defence of the 7030+. I have said before
it is a great radio, but not everyone's cup of tea. I don't know the
SDR-IQ specs but it is a very modest device and I doubt it's specs are
any better than the quoted WinRadio 313. As for John Bryant on Easter
Island, I think with any radio he would have done just as well, but
here is where the SDR-IQ is a big plus, because you can monitor 190
Khz of spectrum just before and after the TOH top of hour and thus get
more positive ID's, hence that is why DXer's are getting such good
results from their SDR-IQ because of the ability to get multiple
catches at the same time. Something you can't do on an ordinary radio.

to m...sushi, I agree totally with you about the 7030's menu system. I
can't even operate the menu on my cellphone let alone the DVD's, so my
wife does that. I like one button one knob RX's with a very large
display like the Drake R8B/NRD545/756Pro3 to mention just a few.

to my pal Guy - thanks for that input. I must admit putting in the
original post with a bit of tongue in cheek, as I am a lover of top
end RX's with the more bells and whistles the better and the bigger
and better screen. If I ever win the Lotto I will upgrade to an Icom
IC 7700 = huge and superb. No computer radio's for me in my dotage!

I do believe like you that in some very tight situations the really
very top end RX's do deliver the goods that radio's with lesser specs
can't do, but the thrust of my post was really, does it actually
matter in the wholeness of who gets what with what RX and the actual
quantum of results achieved??? I don't think so.

I once demonstrated to my co-DX friends Vince with his R8A and Gary
with his Frog how I could get perfectly readable copy of Reunion on
666 using all the bell's and whistles on my Icom and Kiwa Loop
regeneration, whereas they couldn't get readable copy, but in the
wholeness of things they achieve just as much as I do and sometimes
more.

You are moving now from a superlative SDR-1000 to a much more modest
Perseus, the reason being that it can copy a huge 400 Khz of spectrum
at TOH for later playback, and however modest the specs of the Perseus
might be, this facility is going to get you lots more catches and
positive ID's.

ZS6011, John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Sangean 803A.
Antenna's RF Systems DX 1 Pro Mk II, Datong AD-270
Kiwa MW Loop, PAORDT Roelof mini-whip
http://www.dxing.info/about/dxers/plimmer.dx


On Nov 26, 6:18 pm, "Guy Atkins" wrote:
Hi John,

Good to hear from you again on the newsgroup, and to read your observations.

A few thoughts:

The RF environment where a receiver is used definitely figures into the
equation. I believe it's Vince or Gary in your country that uses the FRG-7,
and he has said that his DXing location is far from local transmitters. That
can make a big difference.

In the same way, John's use of the Eton E1 on Easter Island is fully
appropriate, as there are no local MW stations there, and only 1 low-power
FM. Easter Island's nearest concentration of MW stations is 2300 miles away
on the South American continent, and Australia/NZ is about 4300 miles
distant! It doesn't take a crunch-proof receiver front end to perform well
in such a location.

The scarceness of local noise and nearby powerful stations is also a reason
the early pioneers in radio and DXing had such phenomenal catches in the
1920s-1940s, despite their very simple receivers.

I chose the SDR-1000 largely on the strength of its front end and close-in
dynamic range/IP3, for use here in the greater Seattle/Tacoma area. I have
many MW frequencies registering S9+50db, and a number of them are at S9+60dB
or greater. The strongest I've seen was -13dBm on the SDR-1000's very
accurate and calibrated (dBm) signal meter. This is when I was using the
Beverage antennas in the greenbelt (forested) area behind my house. In
direct tests at my home, the SDR-1000 clearly heard weak DX that was
inaudible or muffled in the noise on a Ten-Tec RX-340 (two different units).
However, the same rigs side-by-side at the Grayland DXpedition location
performed equally as well. I've heard a number of 9 kHz "splits" at home
with the SDR-1000, such as 1475 kHz RTM Malaysia in Kota Kinabalu, that may
not have been quite as clear and strong with another radio used in the "RF
alley" here.

With the Perseus receiver I have on the way, the front end may be slightly
less "stout," but it has operational advantages over the SDR-1000 that make
it very worthwhile for both home and DXpedition use.

73,

Guy Atkins KE7MAV
Puyallup, WA USA

wrote in message

...



Receiver test data from
S = Sherwood
P = Passport
Q = ARRL QST mag

5 KHZ THIRD ORDER INTERCEPT DYNAMIC RANGE

dB
100P Icom IC-R9500
93Q Flexradio SDR-1000
82S AOR7030
80S Icom R7800
78S Icom R781
78Q/75S Icom IC-R756 PRO III
77Q/75S Icom 756 PRO II
77P Drake R8A/B
77S NRD 515
75S Drake R7
75S WJ-1000
74P WJ-8711
71S Icom 756 PRO
71S Drake R8
68S/66P NRD545
67S Icom R75
67S Drake SW8
64S Yaesu 7700 (similar to FRG7)
62S Icom R70/R71
55P Eton E1 portable
46S Ten Tec 340
43P WinRadio 313i

The above data is supposed to indicate which of your dream receivers
will get you that ultimate DX catch above all other receivers. In
practice, life is different: one of my pals had a SDR-1000 and I
didn't notice his logs reflect anything much better than other
fella's. A top DXer John Bryant used a Eton E1 on a DXpedition to
Easter Island and logged some of the best catches I have ever seen.
See:
http://www.dxing.info/dxpeditions/easter_island_2007.dx

I have a pal who insists on DXing with an ancient battered Yaesu FRG-7
and i would rate his fantastic logs and high quality recordings
amongst the very best in the world, yet the FRG-7 is actually a very
poor receiver from a poor front end and sloppy bad filters point of
view. A few years ago a DXer won the prestigious Danish DC Club annual
contest with an equally modest receiver, a Yaesu FRG-7000.

A lot of my co DXer's are now using SDR-IQ's and achieving amazing
results, whilst the top rated AOR 7030 lads don't seem to be getting
much in the way of spectacular catches lately.

So what's the motto of this story; just this, don't worry about
receiver specs just concentrate on going on a decent DXpedition to a
good radio spot and make sure you get a decent antenna up.

Have fun and good DX

John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Sangean 803A.
Antenna's RF Systems DX 1 Pro Mk II, Datong AD-270
Kiwa MW Loop, PAORDT Roelof mini-whip
http://www.dxing.info/about/dxers/plimmer.dx- Hide quoted text -

- Show quoted text -

Receiver specs - are they meaningful
 

On Nov 26, 12:00 pm, Joe Analssandrini
wrote:
On Nov 26, 1:30 pm, wrote:





To reply to some of these posts:
to Joe A., I think the old adage "methinks the maiden doth protest too
much" applies to you and your defence of the 7030+. I have said before
it is a great radio, but not everyone's cup of tea. ...
... but here is where the SDR-IQ is a big plus, because you can monitor 190
Khz of spectrum just before and after the TOH top of hour and thus get
more positive ID's, hence that is why DXer's are getting such good
results from their SDR-IQ because of the ability to get multiple
catches at the same time. Something you can't do on an ordinary radio.

to m...sushi, I agree totally with you about the 7030's menu system. I
can't even operate the menu on my cellphone let alone the DVD's, so my
wife does that. I like one button one knob RX's with a very large
display like the Drake R8B/NRD545/756Pro3 to mention just a few.

to my pal Guy - thanks for that input. I must admit putting in the
original post with a bit of tongue in cheek, as I am a lover of top
end RX's with the more bells and whistles the better and the bigger
and better screen. If I ever win the Lotto I will upgrade to an Icom
IC 7700 = huge and superb. No computer radio's for me in my dotage!

I do believe like you that in some very tight situations the really
very top end RX's do deliver the goods that radio's with lesser specs
can't do, but the thrust of my post was really, does it actually
matter in the wholeness of who gets what with what RX and the actual
quantum of results achieved??? I don't think so.

Dear John,

"I see, said the blind man as he picked up his hammer and saw." NOW I
understand where you're coming from, John. Obviously if you cannot
operated menu-driven products, the AOR AR7030 'Plus' would definitely
NOT be for you. That explains, in part, your review of it.

I had to learn how to operate this receiver which was much different
from anything that I had used previously. But I have to say, as a
retired old geezer, I just didn't have that much, if any, trouble
learning how to operate it. I hate to say this, John, but I'm afraid
that, more and more, menu-driven products will become the norm and
that is solely due to cost. We're all going to have to learn to use
them. Switching electronically is much less expensive for the
manufacturers to produce than switching mechanically. That is why the
AR 7030 'Plus' can offer performance equal to or superior than much
more costly receivers with mechanical controls at a far lower price
and is one of the reasons that it has had such a long production life.
(And I too love radios with lots of buttons and knobs. They surely do
impress your relatives, friends, and neighbors! These people always
exclaim, upon being shown one of these radios, "Wow. You really know
how to work this?" But really, in fact, I'm much more interested in
performance than "show.")

Your comment about being able, with SDRs, to "monitor" many
frequencies at the same time is well-taken and something about which I
had not thought previously. For a dedicated DXer this would be a boon
BUT the manufacturers have got to 1) get the performance of these SDR
radios up to the level of current shortwave receivers and 2) "future-
proof" them so that when Microsoft or Apple introduce new operating
systems, these radios will continue to operate. This latter problem is
one to which I have given a great deal of thought and is the reason
why, at least at the present time, I am not considering purchase of
one. And I'm not just talking about a change from Windows XP to
Windows Vista. What will Microsoft produce ten or fifteen years from
now? Will today's SDRs still function with your computer of the future
or will you have just an expensive paperweight? Yes, I know you can
hold on to an older computer, but, when that goes, what do you have?
For me, at least, this is something to seriously consider.

If I won the lottery, I would buy a Watkins-Johnson WJ-8711A with all
its factory options plus a Sherwood SE-3 MK IV as described in
PASSPORT TO WORLD BAND RADIO. (I would also buy another house
somewhere, preferably near the ocean, on a very large property so I
could put up a Beverage antenna or two. I'd have my resident employees
maintain these antennas for me.) But, you know what? I would ALSO buy
two more AR7030 'Plus' receivers - one, configured the same as my
current one, to replace my Grundig Satellit 800 and one, configured
with the internal NiCd battery option, for travel, replacing my Sony
ICF-SW7600GRs.

Ah, dreams ...

All the best to you John,

Joe- Hide quoted text -

- Show quoted text -


My Answer to the My Tired/Weak Old Eyes and
My Big Old Fingers is the Grundig Satellit
800 Millennium Radio for every day Shortwave
Radio Program Listening (SWL).

The Grundig Satellit 800 Millennium Radio has
Big Widely Space Number Buttoms; a good size
Tuning Knob that feels right; and a Large LCD
Display with Numbers I can read without my Eye
Glasses. Plus the Wonderful Sound that comes
out of it is Pleasing to my worn-out Old Ears too.

Grundig Satellit 800 Millennium Radio
Icom IC-R75 Receiver with Kiwa Mods
Kenwood R-5000 Receiver
Eton E1 Radio

~ RHF

Receiver specs - are they meaningful
 

On Nov 26, 12:00 pm, Joe Analssandrini
wrote:
On Nov 26, 1:30 pm, wrote:





To reply to some of these posts:
to Joe A., I think the old adage "methinks the maiden doth protest too
much" applies to you and your defence of the 7030+. I have said before
it is a great radio, but not everyone's cup of tea. ...
... but here is where the SDR-IQ is a big plus, because you can monitor 190
Khz of spectrum just before and after the TOH top of hour and thus get
more positive ID's, hence that is why DXer's are getting such good
results from their SDR-IQ because of the ability to get multiple
catches at the same time. Something you can't do on an ordinary radio.

to m...sushi, I agree totally with you about the 7030's menu system. I
can't even operate the menu on my cellphone let alone the DVD's, so my
wife does that. I like one button one knob RX's with a very large
display like the Drake R8B/NRD545/756Pro3 to mention just a few.

to my pal Guy - thanks for that input. I must admit putting in the
original post with a bit of tongue in cheek, as I am a lover of top
end RX's with the more bells and whistles the better and the bigger
and better screen. If I ever win the Lotto I will upgrade to an Icom
IC 7700 = huge and superb. No computer radio's for me in my dotage!

I do believe like you that in some very tight situations the really
very top end RX's do deliver the goods that radio's with lesser specs
can't do, but the thrust of my post was really, does it actually
matter in the wholeness of who gets what with what RX and the actual
quantum of results achieved??? I don't think so.

Dear John,

"I see, said the blind man as he picked up his hammer and saw." NOW I
understand where you're coming from, John. Obviously if you cannot
operated menu-driven products, the AOR AR7030 'Plus' would definitely
NOT be for you. That explains, in part, your review of it.

I had to learn how to operate this receiver which was much different
from anything that I had used previously. But I have to say, as a
retired old geezer, I just didn't have that much, if any, trouble
learning how to operate it. I hate to say this, John, but I'm afraid
that, more and more, menu-driven products will become the norm and
that is solely due to cost. We're all going to have to learn to use
them. Switching electronically is much less expensive for the
manufacturers to produce than switching mechanically. That is why the
AR 7030 'Plus' can offer performance equal to or superior than much
more costly receivers with mechanical controls at a far lower price
and is one of the reasons that it has had such a long production life.
(And I too love radios with lots of buttons and knobs. They surely do
impress your relatives, friends, and neighbors! These people always
exclaim, upon being shown one of these radios, "Wow. You really know
how to work this?" But really, in fact, I'm much more interested in
performance than "show.")

Your comment about being able, with SDRs, to "monitor" many
frequencies at the same time is well-taken and something about which I
had not thought previously. For a dedicated DXer this would be a boon
BUT the manufacturers have got to 1) get the performance of these SDR
radios up to the level of current shortwave receivers and 2) "future-
proof" them so that when Microsoft or Apple introduce new operating
systems, these radios will continue to operate. This latter problem is
one to which I have given a great deal of thought and is the reason
why, at least at the present time, I am not considering purchase of
one. And I'm not just talking about a change from Windows XP to
Windows Vista. What will Microsoft produce ten or fifteen years from
now? Will today's SDRs still function with your computer of the future
or will you have just an expensive paperweight? Yes, I know you can
hold on to an older computer, but, when that goes, what do you have?
For me, at least, this is something to seriously consider.

If I won the lottery, I would buy a Watkins-Johnson WJ-8711A with all
its factory options plus a Sherwood SE-3 MK IV as described in
PASSPORT TO WORLD BAND RADIO. (I would also buy another house
somewhere, preferably near the ocean, on a very large property so I
could put up a Beverage antenna or two. I'd have my resident employees
maintain these antennas for me.) But, you know what? I would ALSO buy
two more AR7030 'Plus' receivers - one, configured the same as my
current one, to replace my Grundig Satellit 800 and one, configured
with the internal NiCd battery option, for travel, replacing my Sony
ICF-SW7600GRs.

Ah, dreams ...

All the best to you John,

Joe- Hide quoted text -

- Show quoted text -


My Answer to the My Tired/Weak Old Eyes and
My Big Old Fingers is the Grundig Satellit
800 Millennium Radio for every day Shortwave
Radio Program Listening (SWL).

The Grundig Satellit 800 Millennium Radio has
Big Widely Space Number Buttoms; a good size
Tuning Knob that feels right; and a Large LCD
Display with Numbers I can read without my Eye
Glasses. Plus the Wonderful Sound that comes
out of it is Pleasing to my worn-out Old Ears too.

Grundig Satellit 800 Millennium Radio
Icom IC-R75 Receiver with Kiwa Mods
Kenwood R-5000 Receiver
Eton E1 Radio

~ RHF

Receiver specs - are they meaningful
 

On Nov 26, 1:01 pm, "Dale Parfitt" wrote:
wrote in message

... Receiver test data from
S = Sherwood
P = Passport
Q = ARRL QST mag

5 KHZ THIRD ORDER INTERCEPT DYNAMIC RANGE

This is one spec. That's like comparing cars soley on the transmission or
engine size. It tells you next to nothing about the receiver's overall
performance.
And for those of us with rotatable, directional antennas and no MW broadcast
stations in the same county, IP3 is probably the least important spec.
Dale W4OP

If you read the PDF file on Sherwood's site discussing the Performance
Chart, he concludes by stating, "You also have to like the operational
aspects of a radio, not just its numbers." I heartily agree. I've
had great performing receivers that were too much of a PITA to enjoy
using, so I ended up not using them, despite the great specs.

Receiver specs - are they meaningful
 

wrote in message
...

You are moving now from a superlative SDR-1000 to a much more modest
Perseus, the reason being that it can copy a huge 400 Khz of spectrum
at TOH for later playback, and however modest the specs of the Perseus
might be, this facility is going to get you lots more catches and
positive ID's.

Hi again John,

I would have to disagree that the Perseus is a "much more modest" receiver.
The SDR-IQ would fit that description, but Perseus has +31 dBm IP3 and 125
dBm blocking dynamic range (@ 14 MHz), assisted by a total of 9, 6-pole
bandpass filters and one 3-pole lowpass filter to help achieve this
performance. I know specs don't tell the whole story, but these are very
good to excellent numbers, not modest at all. In fact, the Perseus appears
to be roughly in the same league as the SDR-1000.

In my urban RF location I can use all the receive front end protection I can
get. Other than the SDR-1000, the best receiver here by far for this purpose
have been the two AR7030s I've owned. After some practice I didn't find the
ergonomics of the AORs to be an issue, and much of the time I operated them
via PC through ERGO control, which was even better.

More measurements and details of the Perseus are available he
http://www.microtelecom.it/perseus/ Granted, these are numbers from the
manufacturer himself. I'll be interested to read some independent tests in
the future, such as Sherwood Engineering.

Joe has concerns about outdated PC operating systems in the future, in
regard to SDR radios. I think this is a non-issue. All it means is that it
will be even less expensive to have a computer dedicated solely to operating
the radio down the road. I too am loathe to adopt Vista; fortunately Windows
XP is very usable. A few years down the road you'll be able to buy XP for
around $25-50 or so, just like you can get a Windows98 original disc for
that price now. The 1.0 GHz Pentium III machines selling at my local
computer surplus store for $50 now will be replaced with the likes of
Pentium 4 3.2 GHz PCs or maybe even 1.6 - 1.8 Ghz Core 2 Duos for $75.
Either of these setups will run SDRs OK. Today's "Cadillac" computers are
the old Chevys of tomorrow!

If you're concerned about parts availability, traditional radios from major
manufacturers have their share of orphaned and unavailable ICs and
transistors, too.

It took me a few years to embrace the SDR radio concept, as I've certainly
owned and enjoyed my share of traditional communications receivers.
Personally, I believe that receivers are way down the list of criteria
necessary for DXing success, but I like equipment and technology as much as
catching a new and distant station.

Here's my list of factors needed for hearing the DX, in descending order:

1. Antenna(s) - ya won't hear much without one! Perferably directional
and/or low noise designs.
2. A DXer with skill and experience
3. An RF-quiet environment
4. Luck!
5. The receiver

For me, the biggest advantage of SDRs are two main things: 1) fully
adjustable filters in any width desired, with performance better the
top-notch Collins filters I spent big bucks on over the years, and 2) a
detailed view of the DX being tuned, through spectrum displays or
panadapters. Once you "see" your DX at variable "zoom" levels, it's hard to
go back to a traditional radio! This is an especially neat feature for
split-frequency MW DXing, as you can keep an eye on very weak signals long
before they strengthen and break into audio.

73,

Guy

Receiver specs - are they meaningful
 

On Mon, 26 Nov 2007 23:06:39 -0800, Guy Atkins wrote:

wrote in message
...

You are moving now from a superlative SDR-1000 to a much more modest
Perseus, the reason being that it can copy a huge 400 Khz of spectrum
at TOH for later playback, and however modest the specs of the Perseus
might be, this facility is going to get you lots more catches and
positive ID's.

Hi again John,

I would have to disagree that the Perseus is a "much more modest" receiver.
The SDR-IQ would fit that description, but Perseus has +31 dBm IP3 and 125
dBm blocking dynamic range (@ 14 MHz), assisted by a total of 9, 6-pole
bandpass filters and one 3-pole lowpass filter to help achieve this
performance. I know specs don't tell the whole story, but these are very
good to excellent numbers, not modest at all. In fact, the Perseus appears
to be roughly in the same league as the SDR-1000.


Wow!

I just looked at the Perseus, it looks incredible. I was thinking of
getting an SDR-IQ but since I'm in north London, UK, the extra DR of the
Perseus could be useful. However it's more than double the price and I
could pick up a preselector for under £100. So now I can't decide - and
the wife would go nuts if she ever found out I'd spent £600 on "just a
radio"!

Alex

Receiver specs - are they meaningful
 

Dear Guy,

Joe has concerns about outdated PC operating systems in the future, in
regard to SDR radios. I think this is a non-issue. All it means is that it
will be even less expensive to have a computer dedicated solely to operating
the radio down the road. I too am loathe to adopt Vista; fortunately Windows
XP is very usable. A few years down the road you'll be able to buy XP for
around $25-50 or so, just like you can get a Windows98 original disc for
that price now. The 1.0 GHz Pentium III machines selling at my local
computer surplus store for $50 now will be replaced with the likes of
Pentium 4 3.2 GHz PCs or maybe even 1.6 - 1.8 Ghz Core 2 Duos for $75.
Either of these setups will run SDRs OK. Today's "Cadillac" computers are
the old Chevys of tomorrow!

I was unaware that one could still buy old operating system discs new.
Do you know of places one can buy them? And can one buy a very
inexpensive (new) notebook computer with no operating system installed
so that one could install an older operating system if desired?

Do any of these SDRs operate with Linux?

I'm still not keen on an SDR (I like a "real" radio on which I can put
my hands, though I have no problems with radios with menu-driven
operating systems) mostly because, at the present time, I do not feel
these SDRs are good value for money. Some of these cost much more than
the computer to which they will be attached and which supplies most of
the processing power! The "guts" inside these SDRs do not, in my
opinion, justify their relatively high prices. But I'm sure that you
and many others here will disagree with me.

Perhaps one of these days someone is going to design an open-source
"radio program" which will do everything these current SDR models do
and, if history is any guide, he/she will put it out on the internet
for free. Maybe you'd just have to buy a USB-compatible connector for
an antenna.

Am I dreaming too much?

Best,

Joe

Receiver specs - are they meaningful
 

On Nov 27, 12:36 pm, Joe Analssandrini
wrote:
Dear Guy,

Joe has concerns about outdated PC operating systems in the future, in
regard to SDR radios. I think this is a non-issue. All it means is that it
will be even less expensive to have a computer dedicated solely to operating
the radio down the road. I too am loathe to adopt Vista; fortunately Windows
XP is very usable. A few years down the road you'll be able to buy XP for
around $25-50 or so, just like you can get a Windows98 original disc for
that price now. The 1.0 GHz Pentium III machines selling at my local
computer surplus store for $50 now will be replaced with the likes of
Pentium 4 3.2 GHz PCs or maybe even 1.6 - 1.8 Ghz Core 2 Duos for $75.
Either of these setups will run SDRs OK. Today's "Cadillac" computers are
the old Chevys of tomorrow!

I was unaware that one could still buy old operating system discs new.
Do you know of places one can buy them? And can one buy a very
inexpensive (new) notebook computer with no operating system installed
so that one could install an older operating system if desired?

Do any of these SDRs operate with Linux?

I'm still not keen on an SDR (I like a "real" radio on which I can put
my hands, though I have no problems with radios with menu-driven
operating systems) mostly because, at the present time, I do not feel
these SDRs are good value for money. Some of these cost much more than
the computer to which they will be attached and which supplies most of
the processing power! The "guts" inside these SDRs do not, in my
opinion, justify their relatively high prices. But I'm sure that you
and many others here will disagree with me.

Perhaps one of these days someone is going to design an open-source
"radio program" which will do everything these current SDR models do
and, if history is any guide, he/she will put it out on the internet
for free. Maybe you'd just have to buy a USB-compatible connector for
an antenna.

Am I dreaming too much?

Best,

Joe

JA,

-IF- SDR Radios become like PCs expect that within
4 Years you will be able to buy one at Half-the-Price
with Twice-the-Power. Then within 2 Years you will be
able to buy one at Half-the-Price with Twice-the-Power.

But the 'key' is like "PC"s with a high enough Interest
in them {Consumer Demand for more Freatures} and a large
enough Sales Volume to bring the price down, Down. DOWN !

~ RHF

Receiver specs - are they meaningful
 

On Nov 27, 12:36 pm, Joe Analssandrini
wrote:
Dear Guy,

Joe has concerns about outdated PC operating systems in the future, in
regard to SDR radios. I think this is a non-issue. All it means is that it
will be even less expensive to have a computer dedicated solely to operating
the radio down the road. I too am loathe to adopt Vista; fortunately Windows
XP is very usable. A few years down the road you'll be able to buy XP for
around $25-50 or so, just like you can get a Windows98 original disc for
that price now. The 1.0 GHz Pentium III machines selling at my local
computer surplus store for $50 now will be replaced with the likes of
Pentium 4 3.2 GHz PCs or maybe even 1.6 - 1.8 Ghz Core 2 Duos for $75.
Either of these setups will run SDRs OK. Today's "Cadillac" computers are
the old Chevys of tomorrow!

I was unaware that one could still buy old operating system discs new.
Do you know of places one can buy them? And can one buy a very
inexpensive (new) notebook computer with no operating system installed
so that one could install an older operating system if desired?

Do any of these SDRs operate with Linux?

I'm still not keen on an SDR (I like a "real" radio on which I can put
my hands, though I have no problems with radios with menu-driven
operating systems) mostly because, at the present time, I do not feel
these SDRs are good value for money. Some of these cost much more than
the computer to which they will be attached and which supplies most of
the processing power! The "guts" inside these SDRs do not, in my
opinion, justify their relatively high prices. But I'm sure that you
and many others here will disagree with me.

Perhaps one of these days someone is going to design an open-source
"radio program" which will do everything these current SDR models do
and, if history is any guide, he/she will put it out on the internet
for free. Maybe you'd just have to buy a USB-compatible connector for
an antenna.

Am I dreaming too much?

Best,

Joe

My understanding is you can use the SDRs as panadapters. Granted, an
expensive panadpter.

There is a home brew group that makes a board or kit sdr. Google
SoftRock-40

Receiver specs - are they meaningful
 

On Tue, 27 Nov 2007 12:36:29 -0800, Joe Analssandrini wrote:

I was unaware that one could still buy old operating system discs new.
Do you know of places one can buy them? And can one buy a very
inexpensive (new) notebook computer with no operating system installed
so that one could install an older operating system if desired?

Do any of these SDRs operate with Linux?


Yes, the SDR-1000, SDR-5000, SDR-14 and SDR-IQ are all supported by
Linrad.

http://www.nitehawk.com/sm5bsz/linuxdsp/linrad.htm

Anything that outputs I/Q audio will able to be used with Linrad in fact,
eg the Softrock.

Leif also produces his own hardware for Linrad, specialising in EME and
very weak signal.



I'm still not keen on an SDR (I like a "real" radio on which I can put
my hands, though I have no problems with radios with menu-driven
operating systems) mostly because, at the present time, I do not feel
these SDRs are good value for money. Some of these cost much more than
the computer to which they will be attached and which supplies most of
the processing power! The "guts" inside these SDRs do not, in my
opinion, justify their relatively high prices. But I'm sure that you and
many others here will disagree with me.

Perhaps one of these days someone is going to design an open-source
"radio program" which will do everything these current SDR models do
and, if history is any guide, he/she will put it out on the internet for
free. Maybe you'd just have to buy a USB-compatible connector for an
antenna.

Linrad is open-source.


Am I dreaming too much?


A little - you can't just connect an antenna to a USB port or the like -
you either need something to downconvert the RF to audio frequencies so it
can be sampled by your sound card (like the SDR-1000/5000/Softrock), in
which case you can see a band segment equal to the sampling rate of your
soundcard, or instead sample the whole band with an A-D convertor. The
latter approach is used by the SDR-14/IQ/Perseus.

The advantage of the latter system is that you can have a Panadaptor
covering as much of the HF spectrum as you like. The disadvantage is that
when you want to select a particular "band" to listen to, you need a
digital downconvertor to get rid of the extraneous data (so you don't
exceed the bandwidth of your USB port.) The DDCs tend to be quite
expensive - eg in the case of the Perseus they use Altera FPGAs, which are
not cheap by any means and require very specialised knowledge to program.

However, since SDR is rapidly becoming "de facto" in commercial situations
(especially mobile phones) there will be more and more devices and ICs
coming onto the market, which will keep driving prices down.

Cheers

Alex

Receiver specs - are they meaningful
 

Wow! - Guy I certainly got the wrong idea about that Perseus, I should
have known if you are committing yourself to one it would be top end
cutting edge technology. Enjoy it when it comes and good DX with it.
Am I right in saying that you need a fairly top end computer/laptop
with Intel Duocore plus a good soundcard to run it? And then there is
the fact that if you want to enjoy the full benefits of it's enormous
capabilities you are going to need something like a 1 Terabyte
outboard hardisk to record the vast amount of info it generates?
That's all going to add up to quite a lot of moolla! Anyway, I can see
that's the way the MW DX hobby is going and the lads with Perseus are
going to outperform us old dodderers with our single catch sets by
quite a way in both volume and quality of exotic catches.

Guy wrote:
Here's my list of factors needed for hearing the DX, in descending
order:

1. Antenna(s) - ya won't hear much without one! Perferably directional
and/or low noise designs.
2. A DXer with skill and experience
3. An RF-quiet environment
4. Luck!
5. The receiver

Guy, thanks for publishing that again, it's always a good issue to
debate. I agree with you on all except for item 4: LUCK. Our famous
South African golfer Gary Player once replied to a reporter at the
Masters who said to him "That was a lucky shot!", to which Gary
replied: "The more I practise the luckier I get". I think this applies
to radio as well, as I find some of the best DXer's use their vast
experience and aquired skill to pull out signals from nowhere that
lesser mortals don't find or see. I learnt quite a lot from an amazing
DXer years ago who had that uncanny knack of finding rare and exotic
catches that no one else seemed to find until he pointed them out to
us. I like to think that with years more experience behind me and some
familiarity with the MW band that I too can now unerringly dig out
that exotic DX. But the real fun of this hobby is that you never get
tired of it, as just when you are getting bored with the same old
thing, conditions will change and a whole new lot of catches will pop
up and enthuse you again to go on far a few more years. I can see from
the MW logs that are coming in this year from all over the world that
it will go down as a vintage year, one of the best ever. That's the
fun of it, but you have to have the patience to hope for those good
years.

Alex wrote:
[and the wife would go nuts if she ever found out I'd spent £600 on
"just a radio"!]

I know the feeling very well - in my household my old ball and chain
insists that for every penny I spend on radio she gets one as well.
That makes buying even a modest MP3 recorder painful, let alone when I
got my big ticket Icom. Paying double for everything is a pain in the
ass and very limiting.............

Have fun and good DX

John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Sangean 803A.
Antenna's RF Systems DX 1 Pro Mk II, Datong AD-270
Kiwa MW Loop, PAORDT Roelof mini-whip
http://www.dxing.info/about/dxers/plimmer.dx

On Nov 27, 9:06 am, "Guy Atkins" wrote:
wrote in message

...

You are moving now from a superlative SDR-1000 to a much more modest
Perseus, the reason being that it can copy a huge 400 Khz of spectrum
at TOH for later playback, and however modest the specs of the Perseus
might be, this facility is going to get you lots more catches and
positive ID's.

Hi again John,

I would have to disagree that the Perseus is a "much more modest" receiver..
The SDR-IQ would fit that description, but Perseus has +31 dBm IP3 and 125
dBm blocking dynamic range (@ 14 MHz), assisted by a total of 9, 6-pole
bandpass filters and one 3-pole lowpass filter to help achieve this
performance. I know specs don't tell the whole story, but these are very
good to excellent numbers, not modest at all. In fact, the Perseus appears
to be roughly in the same league as the SDR-1000.

In my urban RF location I can use all the receive front end protection I can
get. Other than the SDR-1000, the best receiver here by far for this purpose
have been the two AR7030s I've owned. After some practice I didn't find the
ergonomics of the AORs to be an issue, and much of the time I operated them
via PC through ERGO control, which was even better.

More measurements and details of the Perseus are available hehttp://www..microtelecom.it/perseus/ Granted, these are numbers from the
manufacturer himself. I'll be interested to read some independent tests in
the future, such as Sherwood Engineering.

Joe has concerns about outdated PC operating systems in the future, in
regard to SDR radios. I think this is a non-issue. All it means is that it
will be even less expensive to have a computer dedicated solely to operating
the radio down the road. I too am loathe to adopt Vista; fortunately Windows
XP is very usable. A few years down the road you'll be able to buy XP for
around $25-50 or so, just like you can get a Windows98 original disc for
that price now. The 1.0 GHz Pentium III machines selling at my local
computer surplus store for $50 now will be replaced with the likes of
Pentium 4 3.2 GHz PCs or maybe even 1.6 - 1.8 Ghz Core 2 Duos for $75.
Either of these setups will run SDRs OK. Today's "Cadillac" computers are
the old Chevys of tomorrow!

If you're concerned about parts availability, traditional radios from major
manufacturers have their share of orphaned and unavailable ICs and
transistors, too.

It took me a few years to embrace the SDR radio concept, as I've certainly
owned and enjoyed my share of traditional communications receivers.
Personally, I believe that receivers are way down the list of criteria
necessary for DXing success, but I like equipment and technology as much as
catching a new and distant station.

Here's my list of factors needed for hearing the DX, in descending order:

1. Antenna(s) - ya won't hear much without one! Perferably directional
and/or low noise designs.
2. A DXer with skill and experience
3. An RF-quiet environment
4. Luck!
5. The receiver

For me, the biggest advantage of SDRs are two main things: 1) fully
adjustable filters in any width desired, with performance better the
top-notch Collins filters I spent big bucks on over the years, and 2) a
detailed view of the DX being tuned, through spectrum displays or
panadapters. Once you "see" your DX at variable "zoom" levels, it's hard to
go back to a traditional radio! This is an especially neat feature for
split-frequency MW DXing, as you can keep an eye on very weak signals long
before they strengthen and break into audio.

73,

Guy

Receiver specs - are they meaningful
 

Hi John,

I think you are spot-on with your comments on "luck". Most of the time, good
DXers "make their luck" based on their wealth of experience.

I've watch my friend John Bryant on many DXpeditions, pass by *common*
trans-Pacific MW signals of amazing strength during excellent propagation
conditions. Despite the allure and fun of enjoying a "near-local" quality
signal of regularly heard DX, he goes right to frequencies with interesting
jumbles of low-level audio to see what might rise above the din, or he
chases his personal "hitlist" of highly sought-after stations. John knows
not to waste his time on the common stuff during the excellent openings. In
this way, John makes his own luck. In the same way, on his Easter Island
DXpedition he didn't spend much time tuning Chinese MW stations which are
common at our Grayland DXpedition location. He went after DX that would be
more exotic for his interests, and more distant from Easter Island. He was
rewarded with catches like Radio Farda-UAE and BBC-Oman on medium wave.

You asked about the PC requirements of Perseus. I have not seen anything
published specifically listing the minimum requirements, but I've upgraded
to a laptop with a T7200 Core 2 Duo Processor and 2 Gb of PC-5300 SDRAM
memory. Based on what others have been using successfully, this will be more
than enough processing power. I'm hoping it will also handle recording
bandwidths 400 kHz when the Perseus designer implements this capability. My
500gb hard drive has an eSata interface, as well as my laptop. I plan to get
another large HD, and I am hoping the eSata format's faster data transfer
will handle the 400 kHz requirements when it comes to speed to/from the
buffers.

Guy

Receiver specs - are they meaningful
 

On Nov 28, 10:16 am, wrote:


I know the feeling very well - in my household my old ball and chain
insists that for every penny I spend on radio she gets one as well.
That makes buying even a modest MP3 recorder painful, let alone when I
got my big ticket Icom. Paying double for everything is a pain in the
ass and very limiting.............

Have fun and good DX

John Plimmer, Montagu, Western Cape Province, South Africa

Try to find a Creative Labs Zen V Plus, it is a 4GB MP3 player/
recorder with
mic and stereo !!line!! input. LithION battery that is recharged by
the USB
data transfer port and super, and I mean silent, RF quiet!
Flash drive or flash RAM, no hard drive to fail.

USA prices:
$100 for a 4GB
$69 0r $79 for 2GB.

128 or 168? encoding. Since I use mine for HF I haven't even tested
the higher
datarate. I would love a firmware patch to lower the capture rate to
64K. It will
run for at least 15 hours and, to me this is worthless, will also play
videos.

Best trade of the year.
Got one for my wife and me.
She will fight to keep hers!


Terry