The minimalist QRP blook V7

 Here is the new version of the minimalist QRP Book V7

Link: 

The Minimalist QRP Book V7

73 and 72 de IZ3AYQ 

AMNVOLT - ATS mini receiver

 During the holidays i tested an Amnvolt receiver, "Ats mini receiver, F/W v 1.01
It is based on the si4732 integrated circuit.
It is not very sensibile, but with its 50 cm telescopic antenna i could reveive many OM stations from Europe and also from USA and Asia. Also i coud receive broadcast stations with strong signals, and the RAF Volmet on 5450 kHz USB.
RX bands: from 150 to 30.000 kHz  HF
and from 64 MHz to 108 MHz VHF.
73 de IZ3AYQ 

 

Testing the Rooster on the air

 Testing the Rooster for 20 meters. I used this small CW Rig with a vertical end fed of 10 m, on a fishing rod, balun 64:1, and a manual antenna tuner. The power is 1 watt or less; the frequency is almost fixed, going from about 14059.5 to 14059.9 kHz.
I three days, i had QSO with:  EB5F (1322 km), EA2BJ (1195 km), OH2EUZ (1859 km), G3YPZ (1181 km).
73 de IZ3AYQ Fabio

 

 

 

The Rooster, a very small RTX

 My Rooster has about 1 watt of power, and the frequency goes from 14060,1 to 14060,9; it is near the QRP frequency, but not exactly on it, as I want to operate on 14060.5 kHz.

 It is possible to change the frequency with a trimmer on the board.

Most of the components are SMD; they are already soldered; only about 20 traditional components must be soldered in the kit. So, it is an easy kit.

73 e 72 de IZ3AYQ Fabio 

The Rooster 20 m

Testing the kit Rooster for 20 m; 1 watt or less, frequency 14060.5 +/- 0.5 kHz; CW. 73 and 72 de IZ3AYQ Fabio

QRP IS A REAL POSSIBILITY

Many Thanks to Bert, PA1B, who made the figure more readable! Bert is a QRP and QRPp enthusiast, experimenting with very low power transmissions, even with 3.6 milliwatts.

This is the link to his interesting blog: Blog

(you can find QRP and QRPp activity, attenuators, his Monster Can antennas, and more).

Use of the figure.

In this figure you can see that if you use 1.000 W and your signal is 9+40 dB, if you use (under the same conditions) 1 watt, then your signal is 9+10 dB; so, if the QRM is under 9+20 dB, the QSO is possible.

If you use 100 watt, and your signal is 9+20dB, then, with 1 watt the signal is 9, with 5 watt the signal is 9+7dB, and with 100 mW the signal is 7+2dB.

If you use 100 watt, and your signal is 9, with 1 watt the signal is 5+4dB. Again, if the QRM is under 5+5dB, you can make QSO also with only 1 watt.

73 de IZ3AYQ

Why QRP is a real possibility

 QRP is a real possibility. In this picture you can see that if you use 1.000 W and your signal is 9+40 dB, if you use (under the same conditions) 1 watt, then your signal is 9+10 dB; so, if the QRM is under 9+20 dB, the QSO is possible.

If you use 100 watt, and your signal is 9+20dB, then, with 1 watt the signal is 9, with 5 watt the signal is 9+7dB, and with 100 mW the signal is 7+2dB.

If you use 100 watt, and your signal is 9, with 1 watt the signal is 5+4dB. Again, if the QRM is under 5+5dB, you can make QSO also with only 1 watt.

73 de IZ3AYQ