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Messages - OZNRH

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1
Hi Cool  :)..

Yes, but then you also need to live 'alone' in the countryside, even the best transmitter gives a large near field to your neighbors radios, televisions and telephones.

http://benttoft.wix.com/amatoergrej#!product/prd1/3813338041/hf-pa-trin---henry-4k-ultra---4kw

73 Ole ;D..

2
General Radio Discussion / Digital AM modulation test..
« on: March 27, 2015, 0910 UTC »
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  :).

3
General Radio Discussion / Get a christmas E-QSL card :-).
« on: December 03, 2014, 0823 UTC »
Hi here  :)..

48 meters in winter times..:
During the daytime we reach the middle and south of England to Holland and Belgium, around of a circle to north Germany, Poland, Estonia, Latvia, Lithuania, southern part of Finland and the middle of Sweden.
At night moves the ring south on (getting bigger) and now France, Spain, Portugal, Italy, Greece, Ukraine and the southern parts of Russia joins.
We will test whether this still fits with a 'Christmas test'.
Therefore we transmit Saturday and Sunday afternoon (6/7 2014 at 13 to 15 UTC) and again both days from 21 to 23 o'clock UTC on our usual-frequency '6263.5 kHz' in the 48 meter band.
So if you want to acquire a Christmas QSL cards from us, then you must plug the receiver into the high gear and send us a report.

Best 73 from Ole along in Denmark :-).

PS: Read more about us on: http://radiooznrh.webnode.com/

4
General Radio Discussion / Re: Test on 48 Meter..
« on: August 25, 2014, 0724 UTC »
Hello again here  :)..

I can now already say, this test did not go well, because for over an hour (to 21:15 UTC), there was a BIG fat Dutchman only 2.5 kHz. from me with strong sidebands  :-\. He usually does not to be there, so it was not so good for little me.
Therefore I will try again tonight, same frequency and the same time with the hope that he keeps night off or select another frequency.

Best 73 from Ole  :)..

5
General Radio Discussion / Test on 48 Meter..
« on: August 24, 2014, 1141 UTC »
Hi here  :)..

Tonight we will start testing our new 48 meter system and antenna. We see ourselves on Utwente SDR which is a good start.

We start 20:00 UTC (22:00 European Summer Time) and 2 hours until 22:00 UTC. It happens on our test frequency 6263.5 kHz. with somewhat mixed music.

Our output is about 800W PEP on a vertical antenna, 4 meter high with coils on a 'little hill'. Our physical position in Denmark is North Zealand, the Hillerod area (see Google Map).
Reports are very welcome here, or on our Mail 'radiooznrh'a'gmail.com'.

So if you want to get a really DX station, so you have the possibility now :D. We acknowledge with an electronic QSL cards

Best 73 from Ole Piratos OZNRH  :)

6
Equipment / Re: Audio Processing
« on: August 23, 2014, 2018 UTC »
Hi audiokaos  :).

What kind of SSB are we talk about, only for communication or ?

Ole  :)..

7
The RF Workbench / Re: 5 watt crystal oscillator transmitter
« on: July 31, 2014, 1933 UTC »
Hi again here :).

Here is a diagram more after my head :D.. As 'ff' write, the signal from the oscillator is too 'small' to driving the FET. Right now it work nearly as a kind of class C with a 'to small' input, so yes a 'biasing' will probably help. Take a look on my diagram as inspiration.

Ole :)..

8
The RF Workbench / Re: 5 watt crystal oscillator transmitter
« on: July 30, 2014, 1709 UTC »
@makeRF:

You talk about distortion, everything from this construction is distortion, with or without 100K.. You can only talk about the symmetry on the square wave and I'm sure it's not a duty cycle on 50% you see with a scope on the FET-Drain.
I also wondered about the 1000 uF. in the antenna, 0.1uF. should be able to do it with 1 to 2 MHz ..
I would strongly recommend a LP filter in the end, a simple C-L-C filter will do wonders. Just my opinion.

Best 73 Ole :)..

9
The RF Workbench / Re: 5 watt crystal oscillator transmitter
« on: July 30, 2014, 1023 UTC »
Hi makeRF  :).

If I was you, so put a 100K resistor direct from Gate to ground. I do not like the gate hangs and 'float'  :-\..

Best 73 from Ole  :)

10
@Pieritz: When you ask about the sensitivity of used MOSFET, do you talk about as modules or single MOSFET?
The Greek modul use an IRF640 and the German use two types RD06HHF and RD16HHF, here you must 'Google' the datasheets.

If you talk about as modules, the Greek has about 27dB. at 28V. Look here:
http://www.rfsource.gr/files/PM62FDC.pdf

The German has 30 dB Gain at 13.5V, 10mW in, 10W out (P/P):
http://www.qrpproject.de/UK/qrppa2008.html

My setup: 'Home made Exiter --> QRP-PA2008 (inside the exiter) --> PM62FDC' --> SB1000 --> 1 kW P/P (250W AM).

The Spitfire: One of my friends has a Spitfire and I will ask him about he has a diagram, but i think it has a kind of LP filter there adjust to a '3 meter wire', so the output impedance is 'unknown', but if he has a diagram, I will see what there can be done so it works as 50 Ohm.

Best 73 Ole :)..

11
@ ff  :)..

As a princip, I like 'overkill' in my equipment, both on my RF harmonics and the AF spectrum I send out (20 Hz to 6 kHz. with a soft clipper) and with a low distortion as possible. My listeners tells me, my AM sounds is near 'FM quality'.

Okay I know a Diplexer gives not a better harmonic spectrum, but it give my PA transistor in my driver more better work condition and that a good thing for both linearity and intermodulation in the stage.

The cutoff frequencies in a diplexer?

As you can see on my curve pic, its give me possibility to work down from 6 MHz and up to about 7 MHz. with reasonable data. Everything over 12 MHz. go to the load on the HP part.

Ole :).

12
Here you can see the curves for a 49M Diplexer. There was no 'image space' in my first post.

Ole :).

13
Hi here  :)

What happen with your harmonic in a normal LP filter? They are sending back to your PA transistor as 'mismatch and heat'. Therefore send them to a separate 'harmonic load' instead, this is what a Diplexer do.

Best 73 from Ole  :)..

14
A good station setup it's not all, you must also have a good antenna. Look on this site:
http://www.k7mem.com/Electronic_Notebook/antennas/shortant.html

You can learn more about my setup here and look in the 'PhotoGallery':
http://radiooznrh.webnode.com/

Best 73 Ole :)..

15
Hi Pieritz  :).

Here is another option from Germany. Works very fine linear (2.5W AM = 10W PEP). It is kit you have to assemble, I use even 3 of them in 3 different designs.

http://www.qrpproject.de/UK/qrppa2008.html

Remember.. You most have 40W PEP to make 10W AM  ;).
Maybe this one:

http://www.rfsource.gr/pm62fdc-am-pallet.html

One thing more.. You must change your Spitfire output to 50 Ohm..

Best 73 from Ole (Denmark)  :)..

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