A little "ham", a little "home audio"

But a lot of coolness. :cool:

Recently managed to lay my hands on an NCS Multi-RX and Multi-Switcher pair. The Multi-RX unit allows you to take audio inputs from up to 6 different sources and route them selectively or spatially to a pair of speakers. It also allows you to use one or more of the audio sources to trigger a tape recorder control relay. A provision is made for the mixer output to be routed to other audio processing equipment (such as a DSP unit) before being routed back into the main amplifier.

A master Mute control for use when the unit is run with a Multi-Switcher and connected transceivers is provided, as is computer control of various functions.

In putting the unit in the lineup, I managed to save the shelf space of 4 separate speakers. At present, two BCT-15X and two BCD-996XT scanners feed channels 1/3 and 2/4 (respectively), while a pair of R-7000s are routed through channels 5 and 6. The right-channel Mixer Out leads to Channel A of a Timewave DSP-599ZX, and its Channel A Line Out goes back into the Multi-RX Amp In. Channel B of the '599ZX gets a separate audio feed from a 3rd R-7000, which is run independently of the first two. I can select either of the '599ZX channels for processing while the other runs in pass-through mode.

The finishing touch is a Denon DN-F450R digital recorder. This is a damn slick little unit. With a 32GB SD card, mono audio, 44.1KHz sampling rate and 64K MP3 quality, I can get almost 4000 hours (half a year!) of continuous audio recording. The Multi-RX can start and stop the unit, and I can route various audio sources through the DSP for pre-processing.

A HUGE tip of the hat to Doug, K4SWJ - former owner of NCS - for providing me with a lot of details about the units and for (indirectly) assisting with getting the faulty -3230 into operable shape. Sadly, these units are no longer made - but they're highly sought after among the communications community. This equipment has definitely made my listening more fun, and incorporation of the -3240 into the lineup is next on the list.

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Way cool! We have a similar model one of these in one of our locations but it's not in use. Maybe we need to go back and take a second look. Could have applications for monitoring multiple radio audio.

Spent several hours building cables for the NCS-3240 and finally got it wired into the shack this week.

This unit allows the selection of four transmit audio sources (such as microphones, SSTV gear, TNCs, what have you) and four radios. It also routes keyer output to the selected radio, and RX audio (if used) from each main (and sub) receiver to a left and right speaker. My operating position where the -3240 is used features an FT-980, FT-102 and two FT-726Rs. A DTMF hand mic, MD-1 desk mic and a Kantronics KAM are the audio sources. The -3240's rear-panel Aux1 and Aux2 audio connectors were used to interface the TNC to the rigs. Speaker or Line-level Receive Audio can be routed by cable construction and input device selection...but in a nutshell, my setup has either of the two HF rig's Line Out signals connected to the KAM's HF Radio port when they're selected. Likewise, the FT-726Rs are connected to the VHF Radio port upon selection of either radio.

A couple of gotchas for future reference in case anyone else happening across this thread has the units and is puzzled about the way they operate:

• ALL PTT lines are active at any one time, not just the selected source. Careful about bumping the mics or leaving the unit unattended if the selected transceiver is in a carrier generating mode as the rig will be keyed inadvertently.
• If using the rear-panel PTT connection to mute a companion NCS-3230, a couple of 1N4148s or similar may (or may not) be needed in the line to prevent the -3240 from muting the -3230 when the unit isn't in TX mode. These are wired in series with the cathode end of the string to the -3240's PTT connector center pin, and the anode to the -3230's Mute All connector: 3240 (PTT) ---|<|---|<|--- 3230 (MUTE)
• When using the -3240 with a TNC or other device which momentarily activates its PTT line upon power-up, make sure the -3240 is off -or- no radios are selected when you turn the TNC or other device on. If not, you'll briefly place the selected radio into Transmit.

All in all, a great combo. I wish they were still manufactured.

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