Recorders

Realistic CTR-69

The CTR-69 is a good tape recorder to start out with, as long as you can find one. Radio Shack does not sell this model anymore. It was probably the lowest priced recorder on the market with the ability to manually control the recording levels. Most portable tape recorders have built-in ALC (automatic level control) which does not work out too well when recording lightning sferics. It has a useful LED display for indicating audio levels.

Sony MZ-R37

Thanks to modern technology, an excellent recorder for VLF data was created. The Sony MZ-R37 is a portable digital minidisk recorder. If a person doesn't mind working with the small control buttons, it is an outstanding recorder. It is not much bigger than a cassette tape (4 5/8 x 3/4 x 3 1/2 in) and weighs about 8 ounces with batteries. It has mic, line, optical for inputs and line, headphone for outputs. It includes an ALC which can be disabled for optimum VLF recording levels.

Sony TC-KE500S

This is a stereo cassette deck that was designed for home use only. If the circumstances permit it, an AC inverter is used to power this deck to record VLF emissions. It has three heads which is useful for monitoring the playback levels while recording. It boasts a signal to noise ratio of 59 dB when using high bias tape. It is best used to transfer digital recordings of VLF emissions onto cassette tape, to be submitted to INSPIRE headquarters for data analysis in support of coordinated observations.

Sony MDS-JE320

This unit is a digital minidisk recorder made for home use. It has an optical input to connect with the MZ-R37 portable recorder which is really handy sometimes. The functions of this unit are similar to the portable model. Originally this recorder was part of a combined package consisting of a portable player - to take your tunes with you - and the home recording unit - to record your tunes. This recorder was used with an AC inverter to record VLF emissions during the expedition to Soggy Dry Lake in California.