Complete Exciter 50W with stereo generator and audio limiter
Front side of transmitter. In this box is PLL (Phase Locked Loop) control 85-115 MHZ, RF out 50W, power supply, stereo coder and audio limiter. On the left are instruments for VU levels, audio inputs and controls, in the middle frequency counter and at the right power / SWR meter, power control and RF out.
Top view with space for cooling.
Rear view, fan, fuse and current connector.
Inside the exciter, at the left stereo generator and VCO PLL control. (This photo is made before exciter was equipped with limiter). In the middle transformer 350W, 220V filter, at the right power stabilizer and broadband RF out 50 W with BLY87 and BLW60.
VCO + PLL control unit. RF power is less than 1W.
Stereo generator.
This is the last gadget I used for pirate radio broadcasting, and the transmitter works great. Parts used are partly factory constructions and partly custom made. It's fully broadband, and covers the whole band from 87.50 - 108.00 MHz, in increments of 100 KHz, which may be its only shortcoming in comparison with much more expensive highly professional units, although this shortcoming is evident only in conditions of bands dense "population" with strong signals. The broadband power amplifier gives 0 - 50W (variable) of output power with spurious / harmonic suppression better than 60dB. Output connector is N type. Frequency stability is +- 100Hz. Stereo separation is better than 45dB and signal to noise ratio is better than 75 dB.