Field Report: Denon DN-F20R

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Field Report: Denon DN-F20R

Aug 1, 2002 12:00 PM, By J. Kirk Chestnut, CSRE

The DN-F20R portable recorder captures audio digitally using tapeless, solid-state recording media. I have found that this recorder will withstand the demands of radio news gathering or field audio recording.

Performance at a glance

  • Easy-to-see and use buttons
  • Mic/line level input selector
  • Bass roll-off, mic limiter settings
  • XLR, 1/4" and RCA audio connections
  • Linear, MPEG 1 and MPEG 2 recording formats
  • Dual card recording with optional recording redundancy
  • Backlit display
    As many as four hours with a single card installed
  • Protective carry case

Engineering departments on close budgets and tight schedules will appreciate this low-maintenance device. News reporters will find it easy to operate as well as lightweight. Turn it on, set the level and record. It's that simple, and there are no flaky mini-plug adapters. For the budget conscience, this recorder's initial up-front cost will be justified by its long-term viability.

The big transport buttons are the first things to catch the eye. The unit has a solid feel and a simple, orderly layout. The only moving parts on the Denon DN-F20R field recorder are the controls. The biggest feature of this recorder is that it's the smallest of its kind. Program material is captured digitally on a half-dollar-sized memory card called a Compact Flash Card.

The menu-driven controls are easy to understand and navigate. Clearly illustrated instructions are included in the manual, but the operation is so intuitive that I referenced the manual only to determine my recording time.


Serious RF interference is a way of life in our Westwood, KS, studio facility. If a piece of equipment can stand the RF levels here, it will do well in the field. We operate two AM stations on site with a total of 15kW of power. One tower is located directly over our heads on the roof. Aside from the AMs, we have seven STLs and dozens of cell phones running around the news department. In conducting my tests, I used a budget microphone, a 10-foot microphone cord and a pair of headphones. On its first bench-top test, the device performed flawlessly.

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Digital cell phones have become a major source of RF interference. In many cases, our news crews will send in their stories coupling a cell phone to their recorder. The annoying digital chatter from a news reporter's phone can wreak havoc with a feed. In my un-scientific test, I placed my digital phone next to the recorder. While holding the microphone with one hand, I began to move the cell phone in and out within proximity to the recorder. Spaced about four inches away, I could hear a little chatter in the background (around 42dB down from reference level). It wasn't until I placed the phone in direct contact with the unit � an unusual condition � that interference was noticeable.

Time vs. quality

As with any digital recording device, the compromise between recording time, recording quality and equipment cost becomes an issue. The DN-F20R will record CD-quality audio, but at the cost of memory storage space. A typical 64MB card will yield almost six minutes of CD-quality, stereo PCM audio. Using MPEG1 Layer 2 compression, the recorder yields a clean 30 to 68 minutes of music-grade stereo audio. MPEG2 Layer 2 will yield anywhere from one hour to 1.5 hours of acceptable voice-grade AM-quality audio.

Recording made below the 48kb/s rate were tolerable but contained a considerable amount of warble typical of highly compressed audio. I would limit the use of these slower sample rates for recording conferences, meetings or other non-critical/non-production quality applications. Although this recorder will sample stereo at 16kb/s, set the device for mono to maximize the recording time. That same 64MB card would yield an impressive 546 minutes of fair but listenable audio at 16kb/s. (The Denon website offers a recording time chart:

Recordings can be played back through the RCA analog audio connectors or read directly from the compact flash card with an external computer interface. The computer maps the card reader as a drive. Audio files will be located in 10 designated directories. The DN-F20R automatically assigns an eight-character file name to each cut. Once retrieved, the file can be assigned a more recognizable name for storage on a local hard drive. Users cannot, however, use long file names to label cuts on the flash card.

Budget accordingly

A recovering economy may be a sign that companies are poised to invest in equipment. Plan a capital budget that includes about $1,300 per recorder. For typical newsgathering applications, figure in a headset and dynamic microphone with cord. There is no built-in microphone or phantom power on the mic connectors. Plan on purchasing IC cards from Denon or a Denon approved vendor. The manual warns that products from third-party vendors may not perform quickly enough for the faster sample rates.

Overall, I would give a good grade to Denon's development team. They have packaged all the basic features needed for field production with an eye for the future. The initial cost of this unit might make it a stretch for smaller market operations, but it would be a welcome addition to any news or production department looking for a dependable recorder.

Computer, recording and broadcasting equipment are melding together at an ever-increasing rate. This recorder is the next step. Who knows, maybe the next generation of digital recorders will include network connections or a digital cell phone inside.

Chestnut is an engineer with Entercom Kansas City.

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