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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
I am not sure why contesters at multi-op stations
don't use rigs with the best TX signals they can get. With
adequate antenna separation you can place more operators on the
same band. It's a serious points increase opportunity. (But, I
don't do contests so what do I know? I just go back to an old and
maybe current military goal to have two radios on separate
antennas on a jeep and use them as ad hoc repeaters. And, yes,
jeep. It goes back that far.)
{^_^}
On 20220225 11:38:38, Larry Dodd wrote:
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Right on. Not many amateur radio operators or radio
enthusiasts are in a position to pay >$10k for a receiver or
transceiver. In reality they don't "need" that level of
precision even though its desired. Far surpasses the minimum
requirements of the FCC rules. Yes its great to pursue and more
power to those that are capable of doing so. Pure Signal is a
great achievement. Can't imagine the dollars spent on high end
microphones and audio equipment that are far beyond what is
necessary for voice communications. The ultimate is that 24k
Gold Plated CW key.
Larry K4LED
On 2/25/2022 18:06:02,
jdow <jdow@...> wrote:
There is an
economics pressure here. Who is going to be the first
company to give up being price competitive in a small
commodity market and will that company survive the hit
to its bottom line? A LOT of pressure from actual
customers will be required to advance the commodity
transceiver state of the art.
(And this thread is about the Hermes with it as a
proof of concept for more general improvements - and
their failures. It's been interesting.)
{o.o}
On 20220225 06:50:24,
Conrad, PA5Y wrote:
Hello I never meant to come
across as acrimonious, just insistent.
The plot is from a Rohde and
Swartz FSUP signal source analyser in this case.
https://scdn.rohde-schwarz.com/ur/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/FSUP_bro_en.pdf
The LO I used is from Kuhne
electronics and is known as the XO1, it was
intended as a 116MHz LO for use with 144 MHz
transverters. It is not a custom product. It is
simple Xtal oscillator with a narrow band PLL. The
plot shows its performance when locked to a Leo
Bodnar GPSDO at 10MHz.
It is normalised to 1Hz so in
an SSB BW you can add 68dB to this plot assuming
2400Hz BW for SSB. I do not agree that this
performance levels are only obtainable by special
equipment. In fact older equipment like the IC-202
used to fair better. New equipment is making a
pigs ear of this and transmitters are getting
worse. A K3S and a transverter is all you need, or
indeed a FDM Duo, Hermes, Flex or ANAN SDR.
These radios are all capable of
meeting the code of conduct which in practice does
have a positive effect. Not perfect but its
existence is useful.
Now that we have such excellent
receivers maybe we should pay attention to the TX
chain?
This thread was about the
Hermes, I apologise for hijacking it.
Regards
Conrad
Um, I am not sure I understand that picture.
That is the analyzer's specification or something
very custom you have put together? I'm answering
both emails here.
If that is the noise level you are insisting
everybody meet I suspect you are going to be a
very frustrated gentleman for the rest of your
life. (Some old rigs never die. They simply make
more noise.) The IC7300 might be capable of being
tamed with a reference oscillator replacement. But
I bet more bits in the D/A are required for that
design than exist in reasonably priced D/A
converters. Regardless "state of the art" only
appears in hand tweaked radios or VERY expensive
military or scientific equipment where there is a
perceived need. (And codes of conduct are not
worth the bits they fill on an exabyte storage
array. Cats and humans cannot be herded.)
Even if 7300s are not "clean" as you would have it
are they cleaner than their peers on the
commercial market? From your complaints I suspect
they are not. But it is a point worth asking. I
ignored the argument until it got acrimonious.
{^_^}
On 20220225 04:03:42, Conrad,
PA5Y wrote:
Hi, no it is actually 5
different IC7300s tested by 3 different people,
including Rob Sherwood. if you have time you can
see the plots and some other data that I posted
earlier just do a search. I’m in my lunch break
or I would do it for you.
Yes my TX IS that good but it
is easier for me because I use 0dBm transverter
drives at 28Mhz and transverters with high
quality Xtal local oscillators. The 0dBm from
either my K3S or TS-890S is very good indeed.
IMD3 from both is better than -50dBc.
On 144 MHz, PN noise at 1kHz
separation is -144dBc/Hz and close to 156dBc/Hz
at 10kHz. This is with the LO PLL active, free
running it is a little better. Composite noise
is the same as in this case it is PN dominated.
IM3 is -38dBc but more importantly the 7th
and 9th orders are better than
-80dBc. This is achieved by using tetrode finals
on all bands.
432 and 1296 are of course
worse as the LOs are multiplied from Xtals in
the VHF region. However my TX is some 40dB
better than an IC-9700 at 1.3GHz at 10kHz
separation.
Only 50MHz is a little worse
due to my TS-890S PA linearity but with the
noise on 6m being higher it is acceptable. When
I am on FT8 where linearity does not matter it
is superb. But who cares we are all on the same
‘channel’.
73
Conrad PA5Y
I suspect your specification
is still beyond the state of the art. Is your
transmitter that good?
It sounds like the 7300 is cleaner than average
close in but has some issues fairly far out.
That is a little surprising. I wonder if the
"IP+" technology is simply RF feedback to
linearize the transmitter stages such as is seen
in the old Collins kW SSB amplifiers. I can see
that having an issue that depends on the
charteristics of the feedback loop. But those
are strange characteristics.
I take it the noise peaks are broadband, right?
Do they depend on the transmit frequency in any
way? It sounds very much like there is a defect
in a specific radio near you. Is that the case
or are hams measuring this in general? If this
affects all the 7300s then the FPGA code will
probably have to be reworked to fix the bug. I
kinda wish I had one and a nice lab with lots of
pertinent test equipment. I doubt Keysight and
ICOM would set me up to do it. (It'd be better
for them to set up a tiger team of their
engineers with the equipment needed to suppress
this possible bug.)
{^_^}
On 20220225 01:55:45,
Conrad, PA5Y wrote:
By clean I mean - can I
hear anything of sufficient magnitude to
disturb the noise floor anywhere in band, and
hence inhibit my ability to receive signals
close to the noise floor. The noise floor in a
semi-rural location on 28, 50 and 70MHz is not
particularly low so I do not feel that this is
unreasonable. The biggest problem with the
IC7300 is the AM noise bump at 20kHz and
130kHz which is only 60dB down on the carrier
when running at 30W on 28MHz. This power level
is typical when driving an amplifier. When
modulated with an SSB signal this occupies a
considerable amount of bandwidth. The close
in PN -s only -120dBc/Hz at 1kHz and
-130dBc/Hz at 10kHz. The composite noise is
-115kHz at 10kHz, this is not what I would
consider clean, even close in. The K3S( and a
few others) is far better in this respect
although the PA has quite poor linearity,
especially on 6m.
The Hermes will do a much
better job with any decent PA, even without
pure signal. There are some spurs @ -65dBc
which improve with a higher sample rate. I
have not checked these with the V2 firmware
but I will do immediately I receive my Hermes
from Apache.
I do not think that a
transceiver at the IC-7300 price point has
fixed pre-distortion. As you quite correctly
say keeping it under control over temperature
and voltage variation would be difficult. Also
Icom would almost certainly have mentioned it
in their advertising. What the IC7300 does
well is manage audio overshoots by using a
‘look ahead’ algorithm. This is maybe where
the impression of it having a clean TX comes
from.
I think that the problem
here is that so many transceivers are quite
bad, so I can just about accept that the
IC-7300 is less bad.
73
Conrad PA5Y
OK, please refresh my mind
what you mean by "clean". It certainly appears
to be sending something much closer to pure
signal concentrated within its intended
bandwidth than most other transmitters. I also
understand that it is not as good as it can be
with full active predistortion. Both might
generate increased noise at some significant
separation from the intended signal frequency.
I am not sure of the mechanism by which this
would take place.
As an ornery critter there is nothing I would
sit down and declare "clean" without a
definition of "clean". I guess I am asking for
your definition of the term or even of the
term "clean enough".
{O.O}
On 20220225 01:13:11,
Conrad, PA5Y wrote:
I KNOW for a fact that
the IC7300 is not clean. Please provide me
some evidence to the contrary. I have
measurements with a R&S FSWP Signal
analyser out to a 1MHz BW. You guys are
looking in an SSB BW which is fine unless
you happen to be 130kHz away, then you will
hear plenty of splatter from the IC7300. I
tested the IC-7300 as a result of hearing
this on 50MHz. In other words the lab tests
were driven by on air experience.
You are spreading
misleading and incorrect information.
73
Conrad PA5Y
On Wed, Feb 23, 2022 at
12:24 PM, Max wrote:
I just think if we
follow good design and signal chain
management that superb, clean signals can
also be generated without the need for PS,
that's all.
Max,
I disagree. My signal is my signature. Audio
clarity is admittedly important but what
matters most to me is a splatter-free
signal, and in that regard nothing comes
close to what PS can produce. As I stated
earlier, even the best Class A amplifiers
only have -40dB splatter. PS starts at -60db and
often pushes -70dB. That means that PS
reduces splatter to less than 1% (and at
times only 1/10 of 1%) of what even the best
traditional equipment can produce.
I also agree with Simon that the 7300 (and
also the 7610 for that matter) produces an
extremely sharp-edged signal with unarguably
less splatter than is achievable with any
other non-ANAN radio. It was explained to me
by Ray N5LAX that the reason those radios
are so clean splatter-wise is because ICOM
embedded an algorithm into the firmware that
functions very similarly to PS in the sense
that it corrects for non-linearity in the
PA, but it is a fixed-value (i.e., static)
correction only, not a
real-time self-adjusting correction value
such as is employed by PS. NOTE: I have not
been able to verify that info, but that is
what was told to me over-the-air by Ray when
I commented that I had no idea how the 7300
could produce such a clean, sharp-edged
signal. So I'm repeating it here.
IMO it's unwise and short-sighted to
summarily dismiss the game-changing value
that PS brings to the hobby. Its benefits
are so unarguable that I (and Rob Sherwood)
often wonder why the big-name radios don't
offer it as a standard feature. It's free,
so utilize it for goodness sake!
73,
Mark
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Start as clean as you can achieve then use PS if it
is available. Both right. There is no single perfect correct way.
Judiciously combine methods to make it better. (Wash hands,
isolate from others as you can, and so forth. For an extra 10%
maybe consider a mask.)
{^_-}
On 20220225 10:48:28, Conrad, PA5Y
wrote:
toggle quoted message
Show quoted text
Why
so hostile? I am not trying to upset you. I made it
perfectly clear that I was referring to the transverter port
at 0dBm and that I only operate at 50MHz and above. I also
said that the K3S PA was a disaster on 6m, it is and that is
why I use the TS-890S. I also said that I cannot achieve
these numbers on 50MHz but accept it because of the higher
noise floor on 6m. My aim is to be a good radio neighbour
and to try and get others to do the same. You are obviously
one who cares about such things, so I think that we are on
the same side here. You did not bother to read my post
because you have your own preconceptions. You just want
agreement that PS on the ANAN-7000 is the cleanest possible
signal available. I agree FWIW.
My
measurements were on HF, 28MHz to be precise and appropriate
for some potential users.
You
made a statement that Class A amplifiers cannot be better
than -40dBc 3rd orders, that is not correct.
Analogue TV amplifiers are better than -50dBc and have been
for years. They used to operate at 1kW or more. I just
grabbed the first thing that I could find that was not
heavily mathematical to show that class A amplifiers were
not limited to the constraints you mentioned. A mini
circuits datasheet seemed reasonable. It is harder to get
good IMD at 950MHz.
I
am not the only one who is going to use the Hermes with
transverters, the thread was originally about Hermes. Simon
said that it is better to start clean rather than use pure
signal as a crutch. I agree. The Hermes is a clean source.
Regards
Conrad
PA5Y
On Fri, Feb 25, 2022 at 08:16 AM, Conrad,
PA5Y wrote:
Look here at figure 3a, this is a Class A
RF amplifier with no pre-distortion running at 2W per tone.
The IM3 is -51.48dBc, this is at 950 MHz.
Conrad,
Good grief! This entire topic of your claims of wildly
spectacular IMD3 numbers for your K3S and 890S has nothing to
do with tiny amounts of power at 950 MHZ! The radios we're
discussing (and the 7300 and the ANANs) operate at HF, not
gigahertz!
And we've always been talking clearly in terms of final PA
stage IMD3 levels, not some measurements taken at a
transverter jack.
Show me the measured IMD3 from your K3S or 890S at the output of the PA finals
at any power level over 5 watts, at any frequency the
finals are designed to
operate at, and show me it's anywhere near -50dB. Go ahead,
I'll wait...
Mark
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
I was with you until that last snipe. It appears the
7300 MAY have a problem. If it has spurious at -3db from full
output that are only 60 dB down removed 20 kHz and 100 kHz from
the carrier that can wipe out portions of the band. I experienced
this with somebody running PSK31 who had a subtle ground loop
leading to some weak 120 Hz modulation on his (overdriven) PSK31
signal This made a portion of the spectrum within the PSK31 window
at the time unusable for me. He lived in the same town so I got
his signal at a high enough level for his spurious to be a
problem.
{^_^}
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Conrad,
And it's not our fault that we're all talking apples (HF) and
you're talking oranges (950 MHZ!) lol.
It's clear you're a PS hater, you've made that abundantly clear in
numerous posts in this thread, when in reality there's nothing to
hate about PS. It brings a quantum improvement (at least 20 dB) in
signal cleanness to the table, for free! The algorithm is open
source and can be implemented in software and minimal circuitry.
You just can't stomach the fact that your beloved K3S and 890S
will never hold a candle to any ANAN (or even a lowly IC-7300) for
signal purity.
I'm done with this topic.
Mark
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if you can mary an sdr software together with a packet software
via virtual audo cable then it is all you need
an sdr (hardware) like an rtl dngle .. or whatever
an sdr software (be it sdr console v3 ... or hdsdr .. or sdrsharp
... or...)
a packet software (be it direwolf or multipsk or ...)
virtual audio cable (to route the audio from sdr software to
packet software)
hth
greetz sigi dg9bfc
Am 25.02.2022 um 23:41 schrieb Douglas
Pervine:
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I've been using SDR's for a couple years now, but I still consider
myself a beginner.
I would like to use an SDR to transmit/receive AX.25. Ideally, it
would be great advantage to use Direwolf. Is this possible?
Any assistance would be greatly appreciated.
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I've been using SDR's for a couple years now, but I still consider myself a beginner.
I would like to use an SDR to transmit/receive AX.25. Ideally, it would be great advantage to use Direwolf. Is this possible?
Any assistance would be greatly appreciated.
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Re: Open HPSDR Hermes Anan-10 Support
I have the 16bit ANAN-10.
Thanks,
Mike N2MS
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On 02/25/2022 3:10 PM Conrad, PA5Y <g0ruz@...> wrote:
Hi Mike if you have a 16bit ANAN-10, not 14bit 10E then you can find it here.
https://apache-labs.com/community/viewtopic.php?f=32&t=3310
73
Conrad PA5Y
-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of N2MS via groups.io
Sent: 25 February 2022 21:05
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Open HPSDR Hermes Anan-10 Support
Simon,
Thanks. Would you know where I can find the protocol2 firmware?
Mike N2MS
On 02/25/2022 2:45 PM Simon Brown <simon@...> wrote:
Hi,
ANAN 10 already supported, not with PS though.
Simon Brown, G4ELI
https://www.sdr-radio.com
-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of N2MS
Sent: 25 February 2022 19:44
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Open HPSDR Hermes Anan-10 Support
I've been following the discussion on support for the EP3C25 Transceiver Card.
Will SDRC support the ANAN-10? I assume I would have to install protocol2.
Mike N2M2
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Re: Open HPSDR Hermes Anan-10 Support
toggle quoted message
Show quoted text
-----Original Message----- From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of N2MS via groups.io Sent: 25 February 2022 21:05 To: main@SDR-Radio.groups.io Subject: Re: [SDR-Radio] Open HPSDR Hermes Anan-10 Support Simon, Thanks. Would you know where I can find the protocol2 firmware? Mike N2MS On 02/25/2022 2:45 PM Simon Brown <simon@...> wrote:
Hi,
ANAN 10 already supported, not with PS though.
Simon Brown, G4ELI
https://www.sdr-radio.com
-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of N2MS
Sent: 25 February 2022 19:44
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Open HPSDR Hermes Anan-10 Support
I've been following the discussion on support for the EP3C25 Transceiver Card.
Will SDRC support the ANAN-10? I assume I would have to install protocol2.
Mike N2M2
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Re: Open HPSDR Hermes Anan-10 Support
Simon,
Thanks. Would you know where I can find the protocol2 firmware?
Mike N2MS
toggle quoted message
Show quoted text
On 02/25/2022 2:45 PM Simon Brown <simon@...> wrote:
Hi,
ANAN 10 already supported, not with PS though.
Simon Brown, G4ELI
https://www.sdr-radio.com
-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of N2MS
Sent: 25 February 2022 19:44
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Open HPSDR Hermes Anan-10 Support
I've been following the discussion on support for the EP3C25 Transceiver Card.
Will SDRC support the ANAN-10? I assume I would have to install protocol2.
Mike N2M2
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Re: IC-7300 composite noise
I thought the same and so indeed I tried batteries with the same result. Also, I tried a variety of lab grade PSUs, prior to trying batteries. Always the same. At this point I gave up and sold my
IC-7300. It is good value for money but not suitable for 10m and above if used with an amplifier.
Regards
Conrad PA5Y
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
On Behalf Of jdow via groups.io
Sent: 25 February 2022 18:52
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] IC-7300 composite noise
On a hunch - run the radio on batteries. That this could be power supply noise modulating one of the stages or (horrors) the D/A converter's reference. (And I sort of wonder what the instrument's own phase noise is. Those numbers look a
little too good. I'll check when I get up. It's bed time on my awfully skewed personal clock. Joanne Standard Time. The time zone changes UTC offset daily by as much as 6 hours. Insomnia is a way of life.)
{^_^}
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Show quoted text
On 20220225 06:59:57, Conrad, PA5Y wrote:
The Keysite picture was showing the spurs from a Hermes at 28.4 MHz with a 192kHz sample rate using the V1 firmware. it has nothing to do with the IC7300.
I have spare time now so I will repost the image of the IC-7300.
IC-7300 is at 30W output on 28.2 MHz with offsets from 10Hz to 1MHz, Blue trace is PN, Black trace is AM noise, Green trace is composite noise. This uses the FSWP which can measure AM noise and PN simultaneously.
Then I will go away for a while.
Looking at the Keysight picture you posted it's hard to tell the characteristics of the peaks that appear beside the (was it?) 28.4 MHz signal. (The screen notation of 390 kHz is confusing. That is the marker's offset?)
It appears like the 7300 is using a digital frequency synthesizer with way too few bits to make a good signal. If I got a rig that bad I think I'd have some stern words with ICOM about it. While it might be marginally legal it is unethical to sell something
that bad. (And at 100W I thought the limit was -70 dB in the US.
{^_^}
On 20220225 04:03:42, Conrad, PA5Y wrote:
Hi, no it is actually 5 different IC7300s tested by 3 different people, including Rob Sherwood. if you have time you can see the plots and some other data that I posted earlier just do a search. I’m in my lunch break or I would do it for
you.
Yes my TX IS that good but it is easier for me because I use 0dBm transverter drives at 28Mhz and transverters with high quality Xtal local oscillators. The 0dBm from either my K3S or TS-890S is very good indeed. IMD3 from both is better
than -50dBc.
On 144 MHz, PN noise at 1kHz separation is -144dBc/Hz and close to 156dBc/Hz at 10kHz. This is with the LO PLL active, free running it is a little better. Composite noise is the same as in this case it is PN dominated. IM3 is -38dBc but
more importantly the 7th and 9th orders are better than -80dBc. This is achieved by using tetrode finals on all bands.
432 and 1296 are of course worse as the LOs are multiplied from Xtals in the VHF region. However my TX is some 40dB better than an IC-9700 at 1.3GHz at 10kHz separation.
Only 50MHz is a little worse due to my TS-890S PA linearity but with the noise on 6m being higher it is acceptable. When I am on FT8 where linearity does not matter it is superb. But who cares we are all on the same ‘channel’.
73
Conrad PA5Y
I suspect your specification is still beyond the state of the art. Is your transmitter that good?
It sounds like the 7300 is cleaner than average close in but has some issues fairly far out. That is a little surprising. I wonder if the "IP+" technology is simply RF feedback to linearize the transmitter stages such as is seen in the old Collins kW SSB amplifiers.
I can see that having an issue that depends on the charteristics of the feedback loop. But those are strange characteristics.
I take it the noise peaks are broadband, right? Do they depend on the transmit frequency in any way? It sounds very much like there is a defect in a specific radio near you. Is that the case or are hams measuring this in general? If this affects all the 7300s
then the FPGA code will probably have to be reworked to fix the bug. I kinda wish I had one and a nice lab with lots of pertinent test equipment. I doubt Keysight and ICOM would set me up to do it. (It'd be better for them to set up a tiger team of their engineers
with the equipment needed to suppress this possible bug.)
{^_^}
On 20220225 01:55:45, Conrad, PA5Y wrote:
By clean I mean - can I hear anything of sufficient magnitude to disturb the noise floor anywhere in band, and hence inhibit my ability to receive signals close to the noise floor. The noise floor in a semi-rural location on 28, 50 and
70MHz is not particularly low so I do not feel that this is unreasonable. The biggest problem with the IC7300 is the AM noise bump at 20kHz and 130kHz which is only 60dB down on the carrier when running at 30W on 28MHz. This power level is typical when driving
an amplifier. When modulated with an SSB signal this occupies a considerable amount of bandwidth. The close in PN -s only -120dBc/Hz at 1kHz and -130dBc/Hz at 10kHz. The composite noise is -115kHz at 10kHz, this is not what I would consider clean, even
close in. The K3S( and a few others) is far better in this respect although the PA has quite poor linearity, especially on 6m.
The Hermes will do a much better job with any decent PA, even without pure signal. There are some spurs @ -65dBc which improve with a higher sample rate. I have not checked these with the V2 firmware but I will do immediately I receive
my Hermes from Apache.
I do not think that a transceiver at the IC-7300 price point has fixed pre-distortion. As you quite correctly say keeping it under control over temperature and voltage variation would be difficult. Also Icom would almost certainly have
mentioned it in their advertising. What the IC7300 does well is manage audio overshoots by using a ‘look ahead’ algorithm. This is maybe where the impression of it having a clean TX comes from.
I think that the problem here is that so many transceivers are quite bad, so I can just about accept that the IC-7300 is less bad.
73
Conrad PA5Y
OK, please refresh my mind what you mean by "clean". It certainly appears to be sending something much closer to pure signal concentrated within its intended bandwidth than most other transmitters. I also understand that it is not as good
as it can be with full active predistortion. Both might generate increased noise at some significant separation from the intended signal frequency. I am not sure of the mechanism by which this would take place.
As an ornery critter there is nothing I would sit down and declare "clean" without a definition of "clean". I guess I am asking for your definition of the term or even of the term "clean enough".
{O.O}
On 20220225 01:13:11, Conrad, PA5Y wrote:
I KNOW for a fact that the IC7300 is not clean. Please provide me some evidence to the contrary. I have measurements with a R&S FSWP Signal analyser out to a 1MHz BW. You guys are looking in an SSB BW which is fine unless you happen to
be 130kHz away, then you will hear plenty of splatter from the IC7300. I tested the IC-7300 as a result of hearing this on 50MHz. In other words the lab tests were driven by on air experience.
You are spreading misleading and incorrect information.
73
Conrad PA5Y
On Wed, Feb 23, 2022 at 12:24 PM, Max wrote:
I just think if we follow good design and signal chain management that superb, clean signals can also be generated without the need for PS, that's all.
Max,
I disagree. My signal is my signature. Audio clarity is admittedly important but what matters most to me is a splatter-free signal, and in that regard nothing comes close to what PS can produce. As I stated earlier, even the best Class A amplifiers only have
-40dB splatter. PS starts at -60db and often pushes -70dB. That means that PS reduces splatter to less than 1% (and at times only 1/10 of 1%) of what even the best traditional equipment can produce.
I also agree with Simon that the 7300 (and also the 7610 for that matter) produces an extremely sharp-edged signal with unarguably less splatter than is achievable with any other non-ANAN radio. It was explained to me by Ray N5LAX that the reason those radios
are so clean splatter-wise is because ICOM embedded an algorithm into the firmware that functions very similarly to PS in the sense that it corrects for non-linearity in the PA, but it is a fixed-value (i.e., static) correction only, not a real-time self-adjusting
correction value such as is employed by PS. NOTE: I have not been able to verify that info, but that is what was told to me over-the-air by Ray when I commented that I had no idea how the 7300 could produce such a clean, sharp-edged signal. So I'm repeating
it here.
IMO it's unwise and short-sighted to summarily dismiss the game-changing value that PS brings to the hobby. Its benefits are so unarguable that I (and Rob Sherwood) often wonder why the big-name radios don't offer it as a standard feature. It's free, so utilize
it for goodness sake!
73,
Mark
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Re: IC-7300 composite noise
Larry Dodd
Often the clock phase noise is the same whether run on an analog mains power supply or a DC battery. The total noise is inherent in the clock and other circuit design not its necessarily just the source of power. I run my station clock reference through a Silicon Labs Si5323 to clean up and stabilize the clock. Larry K4LED
---------- K4LED Links: https://101science.com https://www.101science.com/radiojove.html https://youtu.be/2-Hoycb65Bc
http://youtube.com/channel/UCtawz3MnMBwjz9ShhSC0ygQ/live
toggle quoted message
Show quoted text
On 2/25/2022 17:52:38, jdow <jdow@...> wrote:
On a hunch - run the radio on batteries. That this
could be power supply noise modulating one of the stages or
(horrors) the D/A converter's reference. (And I sort of wonder
what the instrument's own phase noise is. Those numbers look a
little too good. I'll check when I get up. It's bed time on my
awfully skewed personal clock. Joanne Standard Time. The time zone
changes UTC offset daily by as much as 6 hours. Insomnia is a way
of life.)
{^_^}
On 20220225 06:59:57, Conrad, PA5Y
wrote:
The Keysite picture was showing the spurs
from a Hermes at 28.4 MHz with a 192kHz sample rate using the
V1 firmware. it has nothing to do with the IC7300.
I have spare time now so I will repost the
image of the IC-7300.
IC-7300 is at 30W output on 28.2 MHz with
offsets from 10Hz to 1MHz, Blue trace is PN, Black trace is AM
noise, Green trace is composite noise. This uses the FSWP
which can measure AM noise and PN simultaneously.
Then I will go away for a while.
Looking at the Keysight picture you posted
it's hard to tell the characteristics of the peaks that appear
beside the (was it?) 28.4 MHz signal. (The screen notation of
390 kHz is confusing. That is the marker's offset?)
It appears like the 7300 is using a digital frequency
synthesizer with way too few bits to make a good signal. If I
got a rig that bad I think I'd have some stern words with ICOM
about it. While it might be marginally legal it is unethical
to sell something that bad. (And at 100W I thought the limit
was -70 dB in the US.
{^_^}
On 20220225 04:03:42, Conrad, PA5Y wrote:
Hi, no it is actually 5 different IC7300s
tested by 3 different people, including Rob Sherwood. if you
have time you can see the plots and some other data that I
posted earlier just do a search. I’m in my lunch break or I
would do it for you.
Yes my TX IS that good but it is easier
for me because I use 0dBm transverter drives at 28Mhz and
transverters with high quality Xtal local oscillators. The
0dBm from either my K3S or TS-890S is very good indeed. IMD3
from both is better than -50dBc.
On 144 MHz, PN noise at 1kHz separation
is -144dBc/Hz and close to 156dBc/Hz at 10kHz. This is with
the LO PLL active, free running it is a little better.
Composite noise is the same as in this case it is PN
dominated. IM3 is -38dBc but more importantly the 7th
and 9th orders are better than -80dBc. This is
achieved by using tetrode finals on all bands.
432 and 1296 are of course worse as the
LOs are multiplied from Xtals in the VHF region. However my
TX is some 40dB better than an IC-9700 at 1.3GHz at 10kHz
separation.
Only 50MHz is a little worse due to my
TS-890S PA linearity but with the noise on 6m being higher
it is acceptable. When I am on FT8 where linearity does not
matter it is superb. But who cares we are all on the same
‘channel’.
73
Conrad PA5Y
I suspect your specification is still
beyond the state of the art. Is your transmitter that good?
It sounds like the 7300 is cleaner than average close in but
has some issues fairly far out. That is a little surprising.
I wonder if the "IP+" technology is simply RF feedback to
linearize the transmitter stages such as is seen in the old
Collins kW SSB amplifiers. I can see that having an issue
that depends on the charteristics of the feedback loop. But
those are strange characteristics.
I take it the noise peaks are broadband, right? Do they
depend on the transmit frequency in any way? It sounds very
much like there is a defect in a specific radio near you. Is
that the case or are hams measuring this in general? If this
affects all the 7300s then the FPGA code will probably have
to be reworked to fix the bug. I kinda wish I had one and a
nice lab with lots of pertinent test equipment. I doubt
Keysight and ICOM would set me up to do it. (It'd be better
for them to set up a tiger team of their engineers with the
equipment needed to suppress this possible bug.)
{^_^}
On 20220225 01:55:45, Conrad, PA5Y
wrote:
By clean I mean - can I hear anything
of sufficient magnitude to disturb the noise floor
anywhere in band, and hence inhibit my ability to receive
signals close to the noise floor. The noise floor in a
semi-rural location on 28, 50 and 70MHz is not
particularly low so I do not feel that this is
unreasonable. The biggest problem with the IC7300 is the
AM noise bump at 20kHz and 130kHz which is only 60dB down
on the carrier when running at 30W on 28MHz. This power
level is typical when driving an amplifier. When
modulated with an SSB signal this occupies a considerable
amount of bandwidth. The close in PN -s only -120dBc/Hz
at 1kHz and -130dBc/Hz at 10kHz. The composite noise is
-115kHz at 10kHz, this is not what I would consider clean,
even close in. The K3S( and a few others) is far better in
this respect although the PA has quite poor linearity,
especially on 6m.
The Hermes will do a much better job
with any decent PA, even without pure signal. There are
some spurs @ -65dBc which improve with a higher sample
rate. I have not checked these with the V2 firmware but I
will do immediately I receive my Hermes from Apache.
I do not think that a transceiver at
the IC-7300 price point has fixed pre-distortion. As you
quite correctly say keeping it under control over
temperature and voltage variation would be difficult. Also
Icom would almost certainly have mentioned it in their
advertising. What the IC7300 does well is manage audio
overshoots by using a ‘look ahead’ algorithm. This is
maybe where the impression of it having a clean TX comes
from.
I think that the problem here is that
so many transceivers are quite bad, so I can just about
accept that the IC-7300 is less bad.
73
Conrad PA5Y
OK, please refresh my mind what you
mean by "clean". It certainly appears to be sending
something much closer to pure signal concentrated within
its intended bandwidth than most other transmitters. I
also understand that it is not as good as it can be with
full active predistortion. Both might generate increased
noise at some significant separation from the intended
signal frequency. I am not sure of the mechanism by which
this would take place.
As an ornery critter there is nothing I would sit down and
declare "clean" without a definition of "clean". I guess I
am asking for your definition of the term or even of the
term "clean enough".
{O.O}
On 20220225 01:13:11, Conrad, PA5Y
wrote:
I KNOW for a fact that the IC7300 is
not clean. Please provide me some evidence to the
contrary. I have measurements with a R&S FSWP Signal
analyser out to a 1MHz BW. You guys are looking in an
SSB BW which is fine unless you happen to be 130kHz
away, then you will hear plenty of splatter from the
IC7300. I tested the IC-7300 as a result of hearing this
on 50MHz. In other words the lab tests were driven by on
air experience.
You are spreading misleading and
incorrect information.
73
Conrad PA5Y
On Wed, Feb 23, 2022 at 12:24 PM, Max
wrote:
I just think if we follow good
design and signal chain management that superb, clean
signals can also be generated without the need for PS,
that's all.
Max,
I disagree. My signal is my signature. Audio clarity is
admittedly important but what matters most to me is a
splatter-free signal, and in that regard nothing comes
close to what PS can produce. As I stated earlier, even
the best Class A amplifiers only have -40dB splatter. PS
starts at -60db and often
pushes -70dB. That means that PS reduces splatter to
less than 1% (and at times only 1/10 of 1%) of what even
the best traditional equipment can produce.
I also agree with Simon that the 7300 (and also the 7610
for that matter) produces an extremely sharp-edged
signal with unarguably less splatter than is achievable
with any other non-ANAN radio. It was explained to me by
Ray N5LAX that the reason those radios are so clean
splatter-wise is because ICOM embedded an algorithm into
the firmware that functions very similarly to PS in the
sense that it corrects for non-linearity in the PA, but
it is a fixed-value (i.e., static) correction only, not
a real-time self-adjusting correction value such as is
employed by PS. NOTE: I have not been able to verify
that info, but that is what was told to me over-the-air
by Ray when I commented that I had no idea how the 7300
could produce such a clean, sharp-edged signal. So I'm
repeating it here.
IMO it's unwise and short-sighted to summarily dismiss
the game-changing value that PS brings to the hobby. Its
benefits are so unarguable that I (and Rob Sherwood)
often wonder why the big-name radios don't offer it as a
standard feature. It's free, so utilize it for goodness
sake!
73,
Mark
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Re: Open HPSDR Hermes Anan-10 Support
Simon Brown
toggle quoted message
Show quoted text
-----Original Message----- From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of N2MS Sent: 25 February 2022 19:44 To: main@SDR-Radio.groups.io Subject: [SDR-Radio] Open HPSDR Hermes Anan-10 Support I've been following the discussion on support for the EP3C25 Transceiver Card. Will SDRC support the ANAN-10? I assume I would have to install protocol2. Mike N2M2 -- - + - + - Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Open HPSDR Hermes Anan-10 Support
I've been following the discussion on support for the EP3C25 Transceiver Card.
Will SDRC support the ANAN-10? I assume I would have to install protocol2.
Mike N2M2
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Larry Dodd
Right on. Not many amateur radio operators or radio enthusiasts are in a position to pay >$10k for a receiver or transceiver. In reality they don't "need" that level of precision even though its desired. Far surpasses the minimum requirements of the FCC rules. Yes its great to pursue and more power to those that are capable of doing so. Pure Signal is a great achievement. Can't imagine the dollars spent on high end microphones and audio equipment that are far beyond what is necessary for voice communications. The ultimate is that 24k Gold Plated CW key. Larry K4LED
---------- K4LED Links: https://101science.com https://www.101science.com/radiojove.html https://youtu.be/2-Hoycb65Bc
http://youtube.com/channel/UCtawz3MnMBwjz9ShhSC0ygQ/live
toggle quoted message
Show quoted text
On 2/25/2022 18:06:02, jdow <jdow@...> wrote:
There is an economics pressure here. Who is going to
be the first company to give up being price competitive in a small
commodity market and will that company survive the hit to its
bottom line? A LOT of pressure from actual customers will be
required to advance the commodity transceiver state of the art.
(And this thread is about the Hermes with it as a proof of concept
for more general improvements - and their failures. It's been
interesting.)
{o.o}
On 20220225 06:50:24, Conrad, PA5Y
wrote:
Hello I never meant to come across as
acrimonious, just insistent.
The plot is from a Rohde and Swartz FSUP
signal source analyser in this case.
https://scdn.rohde-schwarz.com/ur/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/FSUP_bro_en.pdf
The LO I used is from Kuhne electronics and
is known as the XO1, it was intended as a 116MHz LO for use
with 144 MHz transverters. It is not a custom product. It is
simple Xtal oscillator with a narrow band PLL. The plot shows
its performance when locked to a Leo Bodnar GPSDO at 10MHz.
It is normalised to 1Hz so in an SSB BW you
can add 68dB to this plot assuming 2400Hz BW for SSB. I do not
agree that this performance levels are only obtainable by
special equipment. In fact older equipment like the IC-202
used to fair better. New equipment is making a pigs ear of
this and transmitters are getting worse. A K3S and a
transverter is all you need, or indeed a FDM Duo, Hermes, Flex
or ANAN SDR.
These radios are all capable of meeting the
code of conduct which in practice does have a positive effect.
Not perfect but its existence is useful.
Now that we have such excellent receivers
maybe we should pay attention to the TX chain?
This thread was about the Hermes, I
apologise for hijacking it.
Regards
Conrad
Um, I am not
sure I understand that picture. That is the analyzer's
specification or something very custom you have put together?
I'm answering both emails here.
If that is the noise level you are insisting everybody meet I
suspect you are going to be a very frustrated gentleman for
the rest of your life. (Some old rigs never die. They simply
make more noise.) The IC7300 might be capable of being tamed
with a reference oscillator replacement. But I bet more bits
in the D/A are required for that design than exist in
reasonably priced D/A converters. Regardless "state of the
art" only appears in hand tweaked radios or VERY expensive
military or scientific equipment where there is a perceived
need. (And codes of conduct are not worth the bits they fill
on an exabyte storage array. Cats and humans cannot be
herded.)
Even if 7300s are not "clean" as you would have it are they
cleaner than their peers on the commercial market? From your
complaints I suspect they are not. But it is a point worth
asking. I ignored the argument until it got acrimonious.
{^_^}
On 20220225 04:03:42, Conrad, PA5Y wrote:
Hi, no it is actually 5 different IC7300s
tested by 3 different people, including Rob Sherwood. if you
have time you can see the plots and some other data that I
posted earlier just do a search. I’m in my lunch break or I
would do it for you.
Yes my TX IS that good but it is easier
for me because I use 0dBm transverter drives at 28Mhz and
transverters with high quality Xtal local oscillators. The
0dBm from either my K3S or TS-890S is very good indeed. IMD3
from both is better than -50dBc.
On 144 MHz, PN noise at 1kHz separation
is -144dBc/Hz and close to 156dBc/Hz at 10kHz. This is with
the LO PLL active, free running it is a little better.
Composite noise is the same as in this case it is PN
dominated. IM3 is -38dBc but more importantly the 7th
and 9th orders are better than -80dBc. This is
achieved by using tetrode finals on all bands.
432 and 1296 are of course worse as the
LOs are multiplied from Xtals in the VHF region. However my
TX is some 40dB better than an IC-9700 at 1.3GHz at 10kHz
separation.
Only 50MHz is a little worse due to my
TS-890S PA linearity but with the noise on 6m being higher
it is acceptable. When I am on FT8 where linearity does not
matter it is superb. But who cares we are all on the same
‘channel’.
73
Conrad PA5Y
I suspect your specification is still
beyond the state of the art. Is your transmitter that good?
It sounds like the 7300 is cleaner than average close in but
has some issues fairly far out. That is a little surprising.
I wonder if the "IP+" technology is simply RF feedback to
linearize the transmitter stages such as is seen in the old
Collins kW SSB amplifiers. I can see that having an issue
that depends on the charteristics of the feedback loop. But
those are strange characteristics.
I take it the noise peaks are broadband, right? Do they
depend on the transmit frequency in any way? It sounds very
much like there is a defect in a specific radio near you. Is
that the case or are hams measuring this in general? If this
affects all the 7300s then the FPGA code will probably have
to be reworked to fix the bug. I kinda wish I had one and a
nice lab with lots of pertinent test equipment. I doubt
Keysight and ICOM would set me up to do it. (It'd be better
for them to set up a tiger team of their engineers with the
equipment needed to suppress this possible bug.)
{^_^}
On 20220225 01:55:45, Conrad, PA5Y
wrote:
By clean I mean - can I hear anything
of sufficient magnitude to disturb the noise floor
anywhere in band, and hence inhibit my ability to receive
signals close to the noise floor. The noise floor in a
semi-rural location on 28, 50 and 70MHz is not
particularly low so I do not feel that this is
unreasonable. The biggest problem with the IC7300 is the
AM noise bump at 20kHz and 130kHz which is only 60dB down
on the carrier when running at 30W on 28MHz. This power
level is typical when driving an amplifier. When
modulated with an SSB signal this occupies a considerable
amount of bandwidth. The close in PN -s only -120dBc/Hz
at 1kHz and -130dBc/Hz at 10kHz. The composite noise is
-115kHz at 10kHz, this is not what I would consider clean,
even close in. The K3S( and a few others) is far better in
this respect although the PA has quite poor linearity,
especially on 6m.
The Hermes will do a much better job
with any decent PA, even without pure signal. There are
some spurs @ -65dBc which improve with a higher sample
rate. I have not checked these with the V2 firmware but I
will do immediately I receive my Hermes from Apache.
I do not think that a transceiver at
the IC-7300 price point has fixed pre-distortion. As you
quite correctly say keeping it under control over
temperature and voltage variation would be difficult. Also
Icom would almost certainly have mentioned it in their
advertising. What the IC7300 does well is manage audio
overshoots by using a ‘look ahead’ algorithm. This is
maybe where the impression of it having a clean TX comes
from.
I think that the problem here is that
so many transceivers are quite bad, so I can just about
accept that the IC-7300 is less bad.
73
Conrad PA5Y
OK, please refresh my mind what you
mean by "clean". It certainly appears to be sending
something much closer to pure signal concentrated within
its intended bandwidth than most other transmitters. I
also understand that it is not as good as it can be with
full active predistortion. Both might generate increased
noise at some significant separation from the intended
signal frequency. I am not sure of the mechanism by which
this would take place.
As an ornery critter there is nothing I would sit down and
declare "clean" without a definition of "clean". I guess I
am asking for your definition of the term or even of the
term "clean enough".
{O.O}
On 20220225 01:13:11, Conrad, PA5Y
wrote:
I KNOW for a fact that the IC7300 is
not clean. Please provide me some evidence to the
contrary. I have measurements with a R&S FSWP Signal
analyser out to a 1MHz BW. You guys are looking in an
SSB BW which is fine unless you happen to be 130kHz
away, then you will hear plenty of splatter from the
IC7300. I tested the IC-7300 as a result of hearing this
on 50MHz. In other words the lab tests were driven by on
air experience.
You are spreading misleading and
incorrect information.
73
Conrad PA5Y
On Wed, Feb 23, 2022 at 12:24 PM, Max
wrote:
I just think if we follow good
design and signal chain management that superb, clean
signals can also be generated without the need for PS,
that's all.
Max,
I disagree. My signal is my signature. Audio clarity is
admittedly important but what matters most to me is a
splatter-free signal, and in that regard nothing comes
close to what PS can produce. As I stated earlier, even
the best Class A amplifiers only have -40dB splatter. PS
starts at -60db and often
pushes -70dB. That means that PS reduces splatter to
less than 1% (and at times only 1/10 of 1%) of what even
the best traditional equipment can produce.
I also agree with Simon that the 7300 (and also the 7610
for that matter) produces an extremely sharp-edged
signal with unarguably less splatter than is achievable
with any other non-ANAN radio. It was explained to me by
Ray N5LAX that the reason those radios are so clean
splatter-wise is because ICOM embedded an algorithm into
the firmware that functions very similarly to PS in the
sense that it corrects for non-linearity in the PA, but
it is a fixed-value (i.e., static) correction only, not
a real-time self-adjusting correction value such as is
employed by PS. NOTE: I have not been able to verify
that info, but that is what was told to me over-the-air
by Ray when I commented that I had no idea how the 7300
could produce such a clean, sharp-edged signal. So I'm
repeating it here.
IMO it's unwise and short-sighted to summarily dismiss
the game-changing value that PS brings to the hobby. Its
benefits are so unarguable that I (and Rob Sherwood)
often wonder why the big-name radios don't offer it as a
standard feature. It's free, so utilize it for goodness
sake!
73,
Mark
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Simon Brown
Getting PS working is a major goal for Q2. I actually have a lot of code in place…
toggle quoted message
Show quoted text
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 25 February 2022 19:35
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card No problem Mark. Really! I also got uppity about the IC7300 😊 I think that we would both like PS to be available on SDRC, but that is far from trivial and a lot to ask of Simon. 73 Conrad Conrad,
My apologies for my untoward attitude, you're a good man. This whole discussion has just got me really worked up for some reason so I need to back away from the thread.
Best regards,
Mark K1LSB -- - + - + -
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
No problem Mark. Really!
I also got uppity about the IC7300
😊
I think that we would both like PS to be available on SDRC, but that is far from trivial and a lot to ask of Simon.
73
Conrad
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
On Behalf Of oldjackbob via groups.io
Sent: 25 February 2022 20:20
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Conrad,
My apologies for my untoward attitude, you're a good man. This whole discussion has just got me really worked up for some reason so I need to back away from the thread.
Best regards,
Mark K1LSB
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Conrad,
My apologies for my untoward attitude, you're a good man. This whole discussion has just got me really worked up for some reason so I need to back away from the thread.
Best regards,
Mark K1LSB
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Wooooaahhh hold on. I most certainly am not a PS hater. Its great! You really have got the wrong end of the stick. The ANAN-7000 is a fine radio and is definitely capable of better performance with
PS than either of my beloved radios. However, for me, driving transverters I have no need for Pure signal.
I have no idea where ANY of that came from.
I do dislike the IC-7300s because I have loads of the bloody things nearby on 6m and it is not clean. No way. However, when things were properly described I accept that it is good enough on the low
bands where the noise floor is MUCH higher.
The ANAN-7000 even without PS knocks spots off it.
So, we agree.
73
Conrad PA5Y
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
On Behalf Of oldjackbob via groups.io
Sent: 25 February 2022 19:42
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Conrad,
And it's not our fault that we're all talking apples (HF) and you're talking oranges (950 MHZ!) lol.
It's clear you're a PS hater, you've made that abundantly clear in numerous posts in this thread, when in reality there's nothing to hate about PS. It brings a quantum improvement (at least 20 dB) in signal cleanness to the table, for free! The algorithm is
open source and can be implemented in software and minimal circuitry. You just can't stomach the fact that your beloved K3S and 890S will never hold a candle to any ANAN (or even a lowly IC-7300) for signal purity.
I'm done with this topic.
Mark
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Why so hostile? I am not trying to upset you. I made it perfectly clear that I was referring to the transverter port at 0dBm and that I only operate at 50MHz and above. I also said that the K3S PA
was a disaster on 6m, it is and that is why I use the TS-890S. I also said that I cannot achieve these numbers on 50MHz but accept it because of the higher noise floor on 6m. My aim is to be a good radio neighbour and to try and get others to do the same.
You are obviously one who cares about such things, so I think that we are on the same side here. You did not bother to read my post because you have your own preconceptions. You just want agreement that PS on the ANAN-7000 is the cleanest possible signal
available. I agree FWIW.
My measurements were on HF, 28MHz to be precise and appropriate for some potential users.
You made a statement that Class A amplifiers cannot be better than -40dBc 3rd orders, that is not correct. Analogue TV amplifiers are better than -50dBc and have been for years. They used
to operate at 1kW or more. I just grabbed the first thing that I could find that was not heavily mathematical to show that class A amplifiers were not limited to the constraints you mentioned. A mini circuits datasheet seemed reasonable. It is harder to get
good IMD at 950MHz.
I am not the only one who is going to use the Hermes with transverters, the thread was originally about Hermes. Simon said that it is better to start clean rather than use pure signal as a crutch.
I agree. The Hermes is a clean source.
Regards
Conrad PA5Y
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
On Behalf Of oldjackbob via groups.io
Sent: 25 February 2022 18:48
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
toggle quoted message
Show quoted text
On Fri, Feb 25, 2022 at 08:16 AM, Conrad, PA5Y wrote:
Look here at figure 3a, this is a Class A RF amplifier with no pre-distortion running at 2W per tone. The IM3 is -51.48dBc, this is at 950 MHz.
Conrad,
Good grief! This entire topic of your claims of wildly spectacular IMD3 numbers for your K3S and 890S has nothing to do with tiny amounts of power at 950 MHZ! The radios we're discussing (and the 7300 and the ANANs) operate at HF, not gigahertz!
And we've always been talking clearly in terms of final PA stage IMD3 levels, not some measurements taken at a transverter jack.
Show me the measured IMD3 from your K3S or 890S at the output of the PA finals at any power level over 5 watts, at any frequency the
finals are designed to operate at, and show me it's anywhere near -50dB. Go ahead, I'll wait...
Mark
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Conrad,
And it's not our fault that we're all talking apples (HF) and you're talking oranges (950 MHZ!) lol.
It's clear you're a PS hater, you've made that abundantly clear in numerous posts in this thread, when in reality there's nothing to hate about PS. It brings a quantum improvement (at least 20 dB) in signal cleanness to the table, for free! The algorithm is open source and can be implemented in software and minimal circuitry. You just can't stomach the fact that your beloved K3S and 890S will never hold a candle to any ANAN (or even a lowly IC-7300) for signal purity.
I'm done with this topic.
Mark
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Re: Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Agreed, But this is off the shelf Ham stuff.
Conrad
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
On Behalf Of jdow via groups.io
Sent: 25 February 2022 19:26
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Open HPSDR Hermes (14 bit ADC, EP3C25) Transceiver Card
Um, 51dB (the fractions are imaginary) is not all that good even at 1 kW. It's better than what you can buy today, for the most part. But. it's not very good when 60 dB to 70 dB is available and achievable.
{^_-}
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Show quoted text
On 20220225 10:15:01, Conrad, PA5Y wrote:
Well I did say at 0dBm! Clearly. It is not my fault that you have PS fan boy eyes.
Copnrad
On Fri, Feb 25, 2022 at 08:16 AM, Conrad, PA5Y wrote:
Look here at figure 3a, this is a Class A RF amplifier with no pre-distortion running at 2W per tone. The IM3 is -51.48dBc, this is at 950 MHz.
Conrad,
Good grief! This entire topic of your claims of wildly spectacular IMD3 numbers for your K3S and 890S has nothing to do with tiny amounts of power at 950 MHZ! The radios we're discussing (and the 7300 and the ANANs) operate at HF, not gigahertz!
And we've always been talking clearly in terms of final PA stage IMD3 levels, not some measurements taken at a transverter jack.
Show me the measured IMD3 from your K3S or 890S at the output of the PA finals at any power level over 5 watts, at any frequency the
finals are designed to operate at, and show me it's anywhere near -50dB. Go ahead, I'll wait...
Mark
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