[hpsdr] Angelia-Alex-Munin Transceiver.

Helmut, DC6NY dc6ny at gmx.de
Tue Jan 29 14:18:09 PST 2013

Hi Kjell,

we discussed the IMD3 issue of power amps in 10/2011. You know the limitations due to low supply voltage and multi-stage design. I'm sorry, but you are wasting more than 35 dB of IM dynamic range between Penny/Hermes/Angelia and an 100W-amplifier. This is not necessary. I recommend e.g. the 300 W-amp, published  in the Funkamateur 8/12: 100W: -43 dBc (-49 dB PEP!) or 300W: -35 dBc (-41 dB PEP).

I achieved similar performance with a 300 W LDMOS from freescale. As Frank, WA1GFZ, mentioned the benchmark shouldn't be these 'rice boxes' and please, really forget this silly PEP bonus. Not only the 'amp-pope' Helge O. Granberg and his whole Motorola staff only used the Mil definition for IMD in all of their publications.

73, Helmut, DC6NY

-----Ursprüngliche Nachricht-----
Von: hpsdr-bounces at lists.openhpsdr.org [mailto:hpsdr-bounces at lists.openhpsdr.org] Im Auftrag von Kjell Karlsen
Gesendet: Dienstag, 29. Januar 2013 19:34
An: hpsdr at lists.openhpsdr.org
Betreff: Re: [hpsdr] Angelia-Alex-Munin Transceiver.

***** High Performance Software Defined Radio Discussion List *****

Hi all.

I have done some IMD measurements and the improvement when using 24V is  
near 10 dB in both IM3 and IM5. BUT with 1A bias current in each  
transistor the power dissipation is high so the bias voltage must be  
temperature controlled to prevent thermal runaway. This is not done in  
Munin so I have to do more experiments. Until this is done, I´ll use  
maximum 16V.

73, Kjell

På Tue, 29 Jan 2013 13:29:01 +0100, skrev Kjell Karlsen <la2ni at online.no>:

> ***** High Performance Software Defined Radio Discussion List *****
> Hi all.
> I have built a new OpenHPSDR Transceiver using Angelia, Munin and the  
> Alex filters installed in a small rack. The size is (W X H X D) 280 X 90  
> X 240 mm. The rack is more or less home made but you can find similar  
> enclosures that can easily be modified for this use.
> The rack is divided into two horizontal rooms and Angelia is installed  
> in the upper compartment together with the power input filter and the  
> fan. Munin+ Heat Sink and the Alex filters are in the lower compartment.  
> The cooling air is blown down through the heat sink and out on the back.
> I have uploaded 7 pictures to  
> http://www.hamsdr.com/profile1.aspx?id=6498.
> **185.jpg: The top compartment seen from the front.
> **188.jpg: The top compartment seen from the back.
> **189.jpg: The bottom compartment seen from the back.
> **190.jpg: The bottom compartment seen from the front.
> **192.jpg: The unit with cover installed.
> **193.jpg: Both Angelia and Hermes/Apollo from back side.
> **195.jpg: Both seen from front.
> This is NOT how ANAN-100D is going to look like! It is my solution and  
> Hermes can of course be used instead of Angelia.
> As you might see on **188.jpg, I am using a 10-30V 90W PicoPSU directly  
> plugged into Angelia. There are no detectable spurs generated by this  
> PSU.
> Munin can safely run on 24V. I have not done any exact IMD measures so  
> far but what I see is that the IM3 and IM5 are at least 6-10 dB better  
> at 24V than at 13,8V with 100W PEP out. Even at 150W PEP, the IM3 and  
> IM5 are > -32 dbc (PEP) at 13,8V on all bands except on 12, 10 and 6  
> meter.
> You will also see that I have glued a large heat sink removed from an  
> old VGA card on the FPGA. It is not absolutely necessary but I feel  
> better using it! On the two AD Converters I have placed heat sinks made  
> for RAM chips. You can find them on e-bay.
> The fan is 80X80 mm salvaged from an old PC PSU. It is temperature  
> controlled so it normally runs very quiet.
> The DC input filter is installed just to be safe. As you see, I am using  
> 4 Power Pool connectors, 2 for each wire.
> The 9 pin D-connector is going to be replaced by a 15 pin and used to  
> control an external PA or antenna switch.
> This is what I have used the darkest time of the year for! Now we have  
> got the sun back after nearly 2 months darkness. Still the day is short  
> and cold but with half a meter of snow, the skiing conditions are good.
> 73, Kjell

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