Spitfire

Hear your old set again

You have just finished restoring your 1930s radio and want to hear some relaxing music or a genuine old-time radio show. Unfortunately your favourite stations have all moved to FM or digital.

Hook a Spitfire up to a CD player, FM radio or MP3 player and it re-transmits your music and shows on medium wave at low power, so your vintage set can tune them in properly, as in the olden days.

A Part 15 station

Running a low-power AM community station needs a 100 mW AM transmitter that complies with FCC rules. The Spitfire gives the full 100 milliwatts allowed for unlicensed Part 15 operation, and its built-in tuning unit matches the 3 metre aerial the rules specify. (US only.)

We redesigned our well-known Gizmo transmitter. We were going to call it the Gizmo II, but it turned out so good that we named it the Spitfire, after another engineering icon of the twentieth century.

Features

• Crystal-controlled frequency synthesiser
• Active stereo mixer
• 16-stage aerial tuning unit
• Audio level and modulation LED
• Dual mono or stereo input
• RCA audio and RF connectors
• Blow-out-proof RF stage
• External ground connection
• Fully regulated power supply
• FCC Part 15 compliant

Inside the Spitfire

A crystal-controlled synthesiser gives accurate, drift-free tuning across the whole AM broadcast band from 500 to 1750 kHz, and also covers the 160 m amateur band.

The updated RF output and modulator stages give very low distortion with modulation right up to 100%, from an almost indestructible output stage. A built-in two-channel mixer converts stereo to mono, or mixes two mono sources.

The 16-stage aerial tuning unit has a variable capacitor to peak the network into the supplied 3 metre aerial. To make setting up as simple as possible, a "magic eye" LED shows when it is tuned. Internal controls set the frequency and the coarse and fine aerial tuning.