woensdag 3 juni 2015

10 dB attenuators of Stefano IZ1OQU

On my Blog and website I show information, on how I work with QRP and QRPp and the use of attenuators for more than 1000 Miles per Watt QSO's.

Stefano IZ1OQU built a 10 dB attenuator, that I described in an earlier post. (Click to read) With this attenuator Stefano made QSO's with 50 milliwatt in SSB from his home over more than 2000 kilometers, using vertical antenna's.

With a difference of 13 dB between SSB and CW, the 50 mW in SSB can be compared with 2.5 mW in CW.
Congrats to Stefano, for this great achievement.

Stefano has recenly built a light weight attenuator with two sections of 10 dB. He wants to use the attenuator in SOTA and portable operation.
Here is the interesting e-mail from Stefano with photo's of the light weight attenuator.


Dear Bert,
I'm IZ1OQU Stefano. I wrote to you some months ago for the attenuators on your website.
With the 50 mW of the first attenuator that I built, I had my best Miles per Watt SSB QSO's with Finland, Russia and Georgia, over 2200 kms with the top-score of 2700 kms with Georgia: 
54.000 kilometers per watt.

I'm writing again to show to you the new step attenuator that I've made: with switches and 2x 10 dB steps to reach the 5 mW output with my FT-817.
I attached some images of the new toy, made with pcb enclosure. I left one removable side just to shot some photos. You'll see, It's tiny (about 6x3x3 cms size) and low-weight. With that small space it was hard to solder everything but I did it!

I'll look forward to find ways to reduce again the size wile adding more steps but not before some testing: you know, SSB is not the best way to play MxW with such little power but I am still newbie with CW.

I keep following your blog, I shared it to some friends because they also like MxW, QRP and homebrewing things. The MxW comunity in Italy is slowly growing thanks to the WxM (watt per mile, or mile per watt... anyway we call it, it's the same thing) contest.
Go on with your good job

73 from Italy
Stefano IZ1OQU 

Light weight 2 x 10 dB attenuator IZ1OQU 
Stefano will use the attenuator on SOTA and portable operation. FB.
To read more, visit Stefano's interesting QRZ page by clicking on the link.

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