Kenwood IF-232C

Four hundred and eighty grams of black box that let a 1980s transceiver talk to a PC - and the ham radio accessory most often mislabeled on the used market.

Overview

At 480 grams and 132 mm wide by 39 mm tall by 114 mm deep, the IF-232C is small enough to disappear behind a transceiver, which is roughly where it belongs. It is not a radio, an amplifier, or a tuner. It is a translator - a communication interface unit Kenwood built to connect its amateur transceivers to personal computers. The manual, printed under the name "Kenwood. Corporation.," describes it as "the interface adapter for connection between the RS-232C terminal of a personal computer and the interface terminals of transceivers capable of computer control." That sentence is the whole product.

The job is a voltage conversion, nothing more. A computer's RS-232C port swings between roughly −12 and +12 volts. The transceiver's control interface expects TTL logic levels between 0 and +5 volts. The IF-232C sits between the two and translates. Universal-radio.com calls it "essentially a voltage converter between RS232 level (−12 to +12V) signals of the computer and the TTL levels (0 to +5V) of the radio." There is no buffering, no protocol translation, and no firmware to update. It is just an electrical handshake between two devices that were never designed to speak directly to each other.

Power comes from a 13.8 VDC supply with a ±15 percent tolerance, and the unit draws 150 mA. It operates from −10°C to +60°C. Inside are five ICs, two transistors, and seven diodes. It is a purpose-built converter, not a computer. The IF-232C is discontinued, and Universal Radio lists it with the blunt status "Discontinued! Please check our Used List."

Key Features

RS-232 to TTL Level Conversion

The core of the IF-232C is level shifting, and the manual is candid about the limits of that function. Signals arriving from the computer at RS-232 levels leave the box at TTL levels for the radio, and vice versa. Nothing is interpreted along the way. The IF-232C does one electrical job, with no firmware or drivers in the middle.

Photocoupler Isolation

The manual singles out the photocoupler circuit as a noise-suppression measure: "For noise prevention the IF-232C incorporates a photocoupler circuit which provides electrical isolation between the transceiver and the computer." Ground loops and stray signals can turn a clean data link into a mess of interference, and the photocoupler interrupts the electrical path between the two devices. The manual also advises that the RS-232C cable "must be shielded and kept as short as possible to further reduce RF interference," and notes that while the RS-232C standard specifies cable lengths under 50 feet, "this length is impractical for RF applications." It also recommends a separate power supply for the IF-232C and for the computer.

DB25 Computer Connection and ACC 1 Radio Connection

On the computer side, the IF-232C connects to a DB25 RS-232C serial port. On the radio side, it connects to the ACC 1 connector on a compatible transceiver. The manual notes that only pins 1, 2, 3, 4, 5, and 7 are used in the RS-232C connection, and it cautions users to pay attention to the wiring of pin number 2. That detail has tripped up more than a few owners over the years. Six-pin DIN plugs (part number E07-0654-XX) were available as options for the radio-side connection.

Supplied Cables and Accessories

The unit ships with a connecting cable with DIN connectors (part number E30-2046-05) and a power cable (E30-1799-05), along with the instruction manual and a warranty card for U.S. customers. The RS-232C cable itself is not included. It must be bought separately from a computer dealer with the correct configuration, which is a recurring problem on the used market, where bare boxes without the original leads are common.

FCC Class B Certification

The IF-232C carries Class B computing device certification under Sub-part J of Part 15 of FCC Rules. The manual's warning section notes that only peripherals certified to comply with Class B limits may be attached, and that operation with non-certified peripherals is likely to result in interference to radio and TV reception. For a device meant to sit between a computer and a radio in a residential setting, that certification was a practical necessity.

Historical Context

The IF-232C dates from the point when personal computers became common enough that hams wanted to control their rigs from a keyboard rather than a dial. Kenwood's documentation describes the unit as "designed for connecting Kenwood amateur radio transceivers to personal computers," and the manual positions it as the bridge between a PC's RS-232C terminal and the interface terminals of computer-controllable transceivers. The TS-940S and the TS-811/711 series are named in the manual as compatible examples. Third-party documentation ties the unit to the TS-850S and the TS-440S, and Universal Radio notes it "faciliates the connection of a personal computer to the TS-450S." The TS-2000 manual references the IF-232C as the optional interface needed "when transferring data to other KENWOOD transceivers."

The instruction manual ran to five pages and covered features, installation, operation, specifications, and troubleshooting. Kenwood's naming has not made things easier. The unit appears in the wild as "Kenwood IF232C," "KENWOOD 232CIF," and even "F-232C" in manual scans, the latter almost certainly a transcription artifact. Marketplace listings have muddied the waters further. Some sellers describe the IF-232C as a "CI-V" interface, but CI-V is Icom's protocol, not Kenwood's. Others attach specifications like "24-bit/96kHz" and "balanced XLR inputs and outputs" that belong to entirely different products. The IF-232C is none of those things. It converts voltage levels.

Collectibility & Value

Prices for the IF-232C range from $39.95 to $120.00 according to available listings (other sources list $79.99-$150.00), though a second-hand example without connecting leads has been offered at £109.00. The unit is discontinued, and Universal Radio directs buyers to its used list rather than new stock. Manual copies circulate separately. One seller lists a "Kenwood IF-232C Manual Copy" alongside a Kenwood AT-200 manual copy priced at $4.99.

Buyer feedback is sparse but generally positive. One eBay purchaser described a unit as a "good used rig" that "came up easily" once a power supply was sourced, noting the condition as pre-owned. Another listing describes the IF-232C as being in "excellent condition," and a third offers it as a "Ham Radio Computer Interface w/ Cables" in good condition. The recurring caveat is the cable situation. The manual is clear that the RS-232C cable is not included and must be purchased separately, with the correct configuration. Units that include the original DIN connecting cable and power cable are more useful than bare boxes, so confirm the E30-2046-05 DIN cable and the E30-1799-05 power cable before purchase.

No common failure modes or repair procedures are documented, and no spare parts availability information has surfaced. The low parts count suggests repairs would be straightforward for anyone comfortable with a soldering iron, but that is an inference, not a documented fact. The manual is the primary reference for the IF-232C, and much of what circulates online about it is either incomplete or actively wrong. The "compatible model: Many" designation that appears in some listings gives no usable compatibility information. Buyers should verify that their specific transceiver has an ACC 1 connector and remote control capability before committing.