Digital AM modulation test..

[OZNRH]

Hi here ..

On Saturday and Sunday (28/3 - 29/3) at 9 UTC to 11 UTC and again on Sunday 16 UTC to 18 UTC, we will test our new 'digital AM modulation'. This happens on 'our' frequency 6264 kHz.
Reports are very welcome here or to 'radiooznrh(a)gmail.com'. You can read more at: http://radiooznrh.webnode.com/

Best 73 from Ole .

[Thee]

Wat voor type ga je gebruiken?
Wordt anders zo een gezoek wat voor modulatie het nu is.

[OZNRH]

Hi Thee ..

It must be received as normal AM, it is only about the way AM is made internally in the exciter. See more here: http://radiooznrh.webnode.com/photogallery/

Ole .

[Blaupunkt]

Gewoon AM in de voortrappen dus, direct achter de oscillator. Inplaats van de MC1495 wordt een SO42P gebruikt als een dubbel gebalanceerde modulator.

[pepi&cokie]

Gewoon AM in de voortrappen dus, direct achter de oscillator. Inplaats van de MC1495 wordt een SO42P gebruikt als een dubbel gebalanceerde modulator.

De SO42p uit de 70's komt weer eens aan de bak .

C ...........

[OZNRH]

Hi Again ..

Sorry ... I'm not good at Dutch and Google gives me something 'translation nonsense' to Danish. Yes, S042P is an old Siemens circuit, but I use it partly because I have it and partly because it works quite well as a balanced modulator.
As I also write on our website at the diagram, other circuit as (MC1496 NE602 and 612), do it as well, but is not directly pin compatible with S042P.

Never mind, S042P has nothing to do with my digital modulation, it can be seen here:
http://radiooznrh.webnode.com/photogall ... talmod-png

73 from Ole ..

[Thee]

Tak så meget for oplysninger, flot hjemmeside du har.
Men også jeg ser der ingen digital kanal.
Havde håbet at du ville sende i HD.
DAS: fremtiden for AM-bands på C-QUAM efter så.
Binde forløber, se hvis analog form af HD radio.
HD radio kan også dekryptere fine C-QUAM, binde godt af den.

I konvertering engelsk til hollandske Google går fint.
Du er nødt til at vide hvad det handler om, ellers bliver det hurtigt ulæselige.

Venlig hilsen, Theo ___ være dig selv.
Der er allerede så mange andre.

Sendt fra min bærbare computer ved hjælp af Windows

Dank je wel voor de informatie, mooie web site heb je.
Maar ook daar zie ik geen digitale zender.
Had gehoopt dat je in HD zou uitzenden.
Das namelijk de toekomst voor de AM banden, op C-QUAM na dan.
Das de voorloper, zie dat als de analoge vorm van HD radio.
HD radio kan C-QUAM ook prima decoderen, das het goede ervan.

In Google gaat het converteren van Engels naar het Nederlands prima.
Je moet wel weten waar het over gaat, anders wordt het snel onleesbaar.

[OZNRH]

Hi Theo Again and thanks for answer, almost in Danish ..

I can now see that my post was a bit 'misleading' and I should have written that it was about the way to do AM (mostly for nerds ). I have experimented with many types AM modulators to get the best music quality with 'standard AM' (A3E). Here I found, that with PWM I could produce the best and most 'voluminous' modulation and yet maintain a good quality of music.

I know you can obtain a fine quality music on AM bands with 'C-QUAM', but it is not my intention because I love the 'good old AM sound' with fading, noise and max 6 kHz. for the music (pure nostalgia). But despite this, I try to get the optimum out of the 'old AM system'.

Best 73 Ole ..

[Blaupunkt]

Hi Theo Again and thanks for answer, almost in Danish ..

I can now see that my post was a bit 'misleading'

Here I found, that with PWM I could produce the best and most 'voluminous' modulation and yet maintain a good quality of music.
.

The pwm signal generated with the LM311 is converted to normal AM in the following amplifiers.
If you're using really digital amplifiers than it is a different story.
The LM311 is a slow comparator and not suitable for fast rise and fall times.
I use pwm in my modulator, at 125kHz and the LM311 is to slow even at these slow frequency's, use the LT1016 or so.
However in your schematic you can use one single transistor in series with the driver to generated AM, or one of those balanced modulator ic's.

[OZNRH]

Hi Blaupunkt and thanks for answer .

I used a LM311 because such a comparator I had in my collection. Yes, if I measure directly at the output of LM311, so I can see there is something wrong with the rise and fall times, therefore I used a Schmitt trigger (4093) and now I have nice 'PCM modulated squares', which is converted into fine AM in the following top-coupled band pass filter. Maybe not the right way to do it, but it works fine.

Your idea of using a 'LT1016' as comparator sounds exciting, maybe I can have nice PCM without my 4093, I will see if I can get hold of such a 1016.

Regards Ole .

[Thee]

dag Ole,

Jeg forstår dig "digital" men tror du vildlede lytteren med det.
Der antager, at der er et digitalt signal kan høres.
Ikke at det er AM-signalet via et vanskeligt kredsløb er lavet.

C-QUAM er helt analog og er bagudkompatibel til AM.
Men kravene til senderen, er helt forskellig fra hvad du forsøger at oprette.
Læse, er det meget sværere at gøre.

Hvorfor har du den nyeste LPF ikke lavet i din tidsplan?
Jeg ville gøre dette korrekt

dag Ole,

Ik begrijp je "digitaal" maar denk dat je de luisteraar er mee op het verkeerde been zet.
Die gaat er van uit dat er een digitaal signaal is te horen.
Niet dat het het AM signaal via een moeilijke schakeling is gemaakt.

C-QUAM is volledig analoog, en is backwards compatible to AM.
Maar de eisen aan je zender, is totaal anders van wat je nu maakt.
Lees, het is veel moeilijker om te maken.

Waarom heb je de laatste LPF niet gemaakt in je schema?
Ik zou dit juist doen

[OZNRH]

Hi Again Theo

As I write earlier:
** I can now see that my post was a bit 'misleading' and I should have written that it was about the way to do AM (mostly for nerds ). **

C-QUAM is not my mission, I love the 'good old' AM sound with all its problems, but C-QUAM could be a technical exciting challenge, but again, I do not know much about it. How does it sound in an ordinary AM receiver? Only as data noise?
How is the signal processed internally in the transmitter? In linear stage, or can I use class C stage, or ?? Have you any link with schematic examples to bring me further in the case.

Has it something to do with 'DRM' ?

Best 73 from Ole

[HendrikJan]

Signal is not very strong, but audiable. Modulation looks good. SINPO: 1-2/5/3/3/2-3
Conditions seems to be bad?

[OZNRH]

Hi HendrikJan ..

Thanks for rapport. It was just what I am pleased to hear, good modulation at weak signals.

Remember I'm on the air Again 16 UTC to 18 UTC same frequency for the next test.

Ole ..

[HendrikJan]

At this moment stronger as this morning.
Sometimes interference from an Utility station on 6261.

[pepi&cokie]

Signal is not very strong, but audiable. Modulation looks good. SINPO: 1-2/5/3/3/2-3
Conditions seems to be bad?

Wie kan zeggen wat die SINPO of SUPO code is ? Enigma code of zo ?

Althans kan de ENIGMA machine uit 1942 dit niet aan .
De 4-rotor versie met triton kan het dan ook niet decoderen ?

C ..............

[HendrikJan]

SINPO: internationaal gebruikte indicatie voor ontvangst:

S = Signal (signaalsterkte)
I = Interference (storing van andere stations)
N = Noise (atmosferische storing)
P = Phading (fading)
O = Over all (totale ontvangst, samenvatting voorgaande)

1 = slecht, 5 = zeer goed.

[Bootsman]

At this moment stronger as tomorrow.
Sometimes interference from an Utility station on 6261.

stronger as tomorrow or as yesterday, otherwise this morning??

[pepi&cokie]

Wel, daar had ik nu nog nooit of nooit van gehoord .

C ..........

[HendrikJan]

OK Dokkie, you are right.

[OZNRH]

Hi again HendrikJan ..

Thanks for rapport, very fine.
The station you heard on 6260 kHz. was 'The Voice of Asia' from Tashkent .

73 from Ole ..

[jan W]

Signal is not very strong, but audiable. Modulation looks good. SINPO: 1-2/5/3/3/2-3
Conditions seems to be bad?

Wie kan zeggen wat die SINPO of SUPO code is ? Enigma code of zo ?

Althans kan de ENIGMA machine uit 1942 dit niet aan .
De 4-rotor versie met triton kan het dan ook niet decoderen ?

C ..............

De enigma kan het inderdaad niet doen die is te oud, deze code is nieuwerwets uit 1959 , CCIR recommendation NO 251 (kan ik echter niet vinden)
pagina 422 http://www.itu.int/dms_pub/itu-s/oth/02 ... 02PDFE.pdf

http://nl.wikipedia.org/wiki/SINPO-code

Er is ook nog een uitgebreide versie met codes voor de modulatie: SINPFEMO en een uitgeklede versie SIO

officieel document: http://www.itu.int/dms_pubrec/itu-r/rec ... !PDF-E.pdf

[pepi&cokie]

Heb er dingen van opgestoken die ik nie wist .

Dank

C ..........