LF setup Chris G4SDG

[rw3adb]

Промелькнуло тут в RSGB - решил всё же отдельную тему, а то потеряется в "Сегодня..."

There station here is a GPS locked FT-817 with tone generated from the QRS programme. The 10.136MHz goes into my homebrew transverter/amplifier which was running with 480W DC input producing about 3A of aerial current. The transmit aerial is a squashed "T" with about 100m total horizontal length at an average height of about 15m. For receive I was using a E-Field probe (which isn't great but I don't have any TX/RX switching), a Hermes Lite 2, SparkSDR and Spectran. On this occasion I did watch with the TX antenna, RSP1a, SDRUno and Spectran as well because manual switching isn't too risky with QRSS!     
 
73 Chris G4SDG

Поздравляем нашего коллегу с его достижениями!

[R7LP]

С разрешения Криса публикую чертеж его антенны на данный момент и информацию об аппаратуре. Хотя в целом все осталось также, как уже описано выше.

The rest of the transmit system consists of a GPS referenced FT817 running at 10.136MHz into a homebrew downconverter and amplifier. The local oscillator is a 10MHz TCXO. The amplifier uses 2 * IRFP250N FETs in a Class E configuration. DC input is usually around 10.5A at 45V so perhaps a little over 400 watts RF as nothing gets warm in the amplifier apart from one coil immediately after the transistors. RF current to the antenna is usually about 2.8A. Any higher DC voltage results in dead FETs! The antenna tuning is very twitchy and susceptible to weather changes and wind blowing the antenna which limits my transmission time.
My receive antenna for LF is an e-probe which works much better than my transmit antenna.