I'm IZ1OQU and my name is Stefano, from Italy, and I'm writing you to thank you for the attenuators that you have so simply and clearly explained on your website.
I built one, 10 dB, for my ssb dxing activity. It's really fantastic and I wonder how people can receive me with 50mW SSB!
I tryed on 20, 12, and 10 m bands with same good results, with three top-qrb of 2300 kms (Russia, Finland and Georgia).
Everything under 2000 kms it seems easy to reach. I use vertical dipoles, so not that big antennas even though they are full-sized for their bands.
I'm gonna build a 20dB attenuator to reduce more!
Thank again for your job.
All the best '73
|10 dB Attenuator for 5 watts built by Stefano IZ1OQU|
I designed the 10dB attenuator for 5 W of max input power.
5 W is the output of Yaesu FT817.
You know: it has 4 switchable fixed power outputs: 0,5 W - 1 W - 2.5 W and 5 W.
With 0,5 W and 10dB attenuation, I can have 50mw. On 5 W, it falls to 500mW which is the standard low power - usually enough for many European QSO's.
The 5 W design let me switch on all the 4 power output even though it needs more resistors to handle the power. I could use bigger resistors of 2 W, but the only shop around here is not well supplied for values over 1/2 W.
Stefano used the Power Attenuator Calculator from the PA1B QRPp page to design his attenuator.
This Calculator is developed to design Power Attenuators for 5 watts or more, built with resistors of a modest power, such as 1/4 W or 1/2 W.
I am very pleased to answer the questions that Stefano had.
Thanks Stefano for the questons.