AN-93 HF Modem -------------- The AN-93 kit (designed by Johan Forrer, KC7WW) provides any PC user with the capability for operating RTTY, AMTOR, and PCTOR with this simple modem-only design. AN-93 is the equivalent of a BayCom, BayPac, or PMP setup, but for HF digital operations. This very simple kit should be for many that have wanted to play on HF, but didn't want to pay the money for an expensive multi-mode controller. With the AN-93, only three components are required for HF digital communications: a PC-compatible computer, the AN-93 modem, and software that performs the encoding and decoding. The AN-93 comes with a tuning indicator to allow visual tuning and the unit also provides audio output for oscilloscope display. Modem Specification AGC at > 100-mV audio input amplitude Prefilter bandwidth > 1 kHz Discriminator channel filter bandwidth 120 Hz 170-Hz channel separation Data low-pass filter cutoff 200 Hz Automatic threshold corrector Tuning indicator A/D converter for RsoftS error correction The TAPR AN-93 allows for both FSK and AFSK output, allowing operations on all HF radios. Instead of two separate boards as shown in the QEX article, the TAPR AN-93 single board dimension is approximately 4Sx3.5". The AN-93 operates off 12volts DC. The kit allows for self-tuning and calibration. A Digital VOM and a working PC is needed in order to calibrate and test the modem. Connections to the RS-232 serial and parallel ports are made through DB-9 and DB-25 connectors. Interfacing to the radio is through a DB-9 connector. The kit will be shipped with the A/D convertor providing full-memory ARQ capability for PCTOR. Shareware software is included along with Johan's code. If you decide to use the shareware software, TAPR requests that you do submit the necessary registration fee. For a full description of the AN-93 modem and its specification, refer to the May, 1994 issue of QEX and PSR issue #55. --- Reference: Forrer, Johan. (1994). AN-93, an HF Modem for RTTY, AMTOR, and Pactor Software. QEX: The ARRL Experimenter's Exchange. May, #147. pp. 3-11. AN-93. TAPR, PSR Issue #55. Spring 1994. p. 8. *************************************************************************** TAPR 9600bps Modem ------------------ The TAPR 9600bps modem is a full-duplex baseband modem compatible with K9NG and G3RUH standards. The TAPR 9600bps modem, like other 9600bps modems, requires an interface to your radio other than via the microphone and speaker jacks. The modem fits internally into the case of many popular TNCs and supports a 20-pin modem disconnect header which allows for a second external modem (such as the TAPR PSK modem) to optionally be connected. The 9600bps modem uses a 4-layer PC board for minimum noise and utilizes a transmit waveform lookup table in ROM for minimum transmit distortion. The transmit path includes an independent watchdog timer. The modem selection logic correctly routes the PTT command from the TNC to prevent, for example, keying your 1200 baud radio when running 9600bps. The receive filter includes a compensation adjustment to tailor the modem to the radio receiver and AC-coupling to accommodate frequency drift on the channel. An improved state machine is used for clock recovery. The DCD circuit works on both signal quality and the presence of a signal. 9600bps Modem Clock Option The clock option provides the necessary radio port clock for 9600bps operation. When you enable the external 9600bps modem on a TNC 1, TNC 2, or clone, your TNC will automatically be set up for the correct radio port speed. When you switch back to the TNC's internal modem, the TNC will automatically select its normal radio port speed again. Thus, you can switch between 1200bps and 9600bps operation with a single switch. The clock option is necessary if you wish to use your modem as part of a stand-alone full-duplex 9600bps repeater, in conjunction with the bit regenerator option. The clock option is also useful if you wish to operate at a non-standard data rate (say, 8700 bps) for backbone links that you don't want other users on. Note: You will have to replace the crystal in the clock option kit if you wish to use a non- standard rate. 9600bps Modem Bit Regenerator Option This option is intended only for use as part of a full- duplex 9600bps repeater. It is not suitable for use at a home station. The bit regenerator keys the PTT line of the modem whenever it receives an incoming signal (DCD is true). It stores the first 8 bits in a buffer, then starts sending the bits out again, resynchronizing them with its own crystal-controller clock to remove jitter and noise from the received signal. The buffer is 'elastic' so it can accommodate a slightly different '9600bps' data rate from the sending station and its own 9600bps clock. Full-duplex bit-regenerating repeaters for 9600bps are starting to be used in more and more locations. It truly makes 9600bps operation fast and friendly. ************************************************************************** METCON ------ (limited supply - lots of the options!) METCON is a device for remote teleMETry and CONtrol. It is based on an 87C51 microcontroller and provides eight (8) inputs and eight (8) outputs. The inputs can be used for digital monitoring (switch closures, etc.), frequency measurement (up to 10 kHz), and accumulating pulses of longer than 20 mS (number of times a switch opened, drops from a rain gauge, etc.). The basic METCON package includes 4 output relays, although the board can be populated with a total of 8 outputs. METCON outputs are 'dry-contacts' provided by normally open reed relays. These relay contacts are isolated from the rest of the board (i.e. not grounded) and are suitable for controlling a variety of loads, such as energizing larger relays for power control functions. The additional 4 output relays and their connectors are available from TAPR. METCON can be connected to a TNC at a remote site and, via a shared packet-radio channel, may measure and/or control operations at the remote site. Applications might include repeater control and weather observations. METCON includes a serial port with three levels of security access: % None for direct hardwire connection % Password for dialup telephone modem connection % Authentication for non-private party-line packet radio connection Voltage-to-Frequency Module The voltage-to-frequency module converts analog signals (voltage, current, power, etc.) to a frequency in the range that METCON can read via its frequency counter inputs. The VTF converter is useful for measuring signal sources that are a long distance from the METCON board or that must be electrically isolated from METCON. Voltage-to-Temperature Module The VTT module is a voltage-to-frequency module that includes additional components for temperature readings. Output from the temperature circuit drives the standard input of the VTF module, which then feeds into METCON. Kits are available for either Celsius or Fahrenheit readings. 8-input Analog-to-Digital Convertor The 8-input A-D convertor module allows for voltage measurements with METCON. The A-D convertor module does not use any of the original eight METCON inputs, giving an additional 8 inputs. Unlike the voltage-to-frequency module, the A-D convertor shares a common ground with METCON and is therefore unsuitable for measurements where ground must be at different levels or separated from METCON by long cables. Elapsed Time Pulser The elapsed time pulser module is useful for measuring things like how long a transmitter has been keyed up, or how long a cooling system has been running. *************************************************************************** PK-232MBX Installation Kit -------------------------- This kit allows owners of a PK-232MBX with the 'new' motherboard to install the TAPR 9600 bps modem with complete ease. NOTE: Owners of earlier PK232s with the MBX daughtercard may use the installation kit, but the prewired harness for the radio interface, power and control wires will not be compatible. These cables must be fabricated and will involve some minor work on the motherboard itself. The kit consists of two pre-wired harnesses, metal spacers, and screws. The metal spacers and screws are used to mount the TAPR 9600bps modem to the PK-232MBX motherboard by picking up existing mounting studs inside the PK-232MBX. The first pre-wired harness is used to connect the TAPR 9600bps modem to the TAPR PK-232 Modem Disconnect Upgrade. The harness simply plugs into the 9600bps modem at one end and the modem disconnect at the other end. This harness can be used with all styles of the PK-232. The second harness provides connections to all the other points required on the 'new' PK-232MBX which does not have a daughterboard. The second harness is only suitable for the PK-232MBX units of the new style. Installation becomes a simple 'plug and play' operation, with no wiring harnesses to fabricate, no hardware to locate, and no holes to drill! *************************************************************************** PK-232 Modem Disconnect ----------------------- This kit is a simple PC board assembly you can build in an evening and still have time left to operate your radio! Once completed, it simply plugs into an IC socket inside the PK232 and provides you with a 'Standard' TAPR modem disconnect header. This header provides a convenient place to connect the DCD State Machine upgrade kit, the TAPR 9600bps modem, PSK modem, or other items that need this connection. The result is a no-holes enhancement of your PK-232 (or Heath HK-232). *************************************************************************** The TAPR 'DCD MODS' ------------------- Background -- Proper operation of Data Carrier Detect (DCD) is imperative for efficient sharing of a packet channel. Many TNC's don't provide optimum DCD operation, and version 2.0 of the AX.25 Level 2 protocol compounds the problem. However, an inexpensive solution is now available to combat the former case and progress is being made in the latter case with proposed changes to AX.25 Level 2 Version 2.1. The Problem -- Over time, it has become apparent that most modems lack the proper DCD operation. Some work well, some are worse than others, some allow improper operator adjustment, and some have the 'threshold' adjustment set incorrectly. With the release of TNC-2 code 1.1.6 and later, packets that are received without the DCD being active are not passed to the user. This encourages the operator to properly set any DCD threshold control that may be on his TNC. Eric Gustafson, N7CL, has investigated this problem and his findings are available in the 7th ARRL Computer Networking Conference proceedings. It has also been published in TAPR's Packet Status Register. Solution -- If the DCD decision could be made on the basis of 'information coherence' rather than 'is there some sort of signal or noise present?', LAN operation would improve. This premise has been demonstrated in a number of locations where modifications to TNCs have been made. Unfortunately, these early modifications involved wire-wrapping a fair bit of circuitry, thus preventing widespread adoption of the DCD mods. The TAPR DCD kits were designed to make it a trivial matter to upgrade most TNCs to improved DCD operation with the addition of a simple board. These mods are extremely useful for both VHF and HF operation. *************************************************************************** State Machine DCD Upgrade ------------------------- For TNCs with modems such as: KPC-1 PacComm Tiny-2/Micro-2 KPC-4 DRSI PC*PA Type 1 KPC-2400 DRSI PC*PA Type 2 KAM AIWA APX-25 AEA PK-87 AIWA APX-25M AEA PK-88 TASCO TNC-20 AEA PK-232 TASCO TNC-20H PacComm TNC-220 Heath HK-232 Heath Pocket Packet The upgrade adaptor for these TNCs adds an EPROM-based State Machine to derive DCD based on lockup of a digital phase-lock loop. It is a small PC board assembly that mounts easily inside the cabinet of most any TNC (NOT the Heath Pocket Packet/TASCO TNC-521). This upgrade will dramatically improve DCD operation, allowing you to run your radio unsquelched. This alone reduces other stations' TXDelay requirements, improving channel throughput. DCD Clock Option For TNCs with 'software HDLC,' an optional clock generator may be included to provide the necessary clock signal (KPC-1, KPC-2, HF channel of KAM). *************************************************************************** XR-2211 DCD Upgrade ------------------- For TNCs using the XR-2211 demodulator such as: TAPR Beta Board GLB PK-1 TNC-1 GLB TNC-2A TNC-2 PacComm TNC-200 Heath HD-4040 MFJ 1270 AEA PKT-1 MFJ 1274 AEA PK-80 DRSI HF*MODEM The PC board is tiny and shaped to fit into a TNC-1 or TNC-2. After construction (an hour or so), you simply unplug the XR-2211 chip from its socket, insert it into the socket on the upgrade board, then plug the upgrade board into the IC socket vacated by the XR-2211 chip on the TNC. If you are into HF operation, provisions are made to connect a 'Threshold' control onto the demodulator. The result will be fast-attack, slow decay DCD with a hang time to compensate for temporary fades due to multipath. When all stations sharing a channel have proper DCD action, data flows more efficiently. *************************************************************************** TAPR Deviation Meter -------------------- (Discontinued) Until now, setting deviation required using an expensive communications analyzer -- or a friend with an expensive communications analyzer! The TAPR Deviation Meter kit adapts any narrowband FM receiver (2m rig, scanner, weathercube, etc.) to automatically and continuously monitor the deviation of received signals. The Deviation Meter is designed to fit neatly into the Radio Shack Pro- 59 VHF/UHF scanner. The DevMtr takes only a few short hours to assemble. No test equipment is needed for alignment and the unit provides accuracy of better than 5%. Recalibration is accomplished at the push of a button. The DevMtr provides deviation readings by local LED readout, serial port output, and a special pulse output for use with METCON. The METCON output can allow readings from a remote site, such as a repeater, making the DevMtr a community resource. The DevMtr is based on a Motorola 68HC11 microcontroller and is self-calibrating. Configuring it for different receivers is simple. The DevMtr requires 8-16 VDC at 100 mA. The receiver IF must be in the range of 10 to 11.5 MHz. Other IFs may be accommodated with component changes in the calibration VCO. Contact TAPR for details on other IFs before ordering. Stop groping in the dark, ignoring your deviation or hoping it is correct! Get a DevMtr kit and help make your packet station an optimum performer! Proper transmitter deviation helps your packets get through with minimum retries. It is a must for setting up 9600bps links. *************************************************************************** TAPR PSK Modem -------------- (Discontinued) The TAPR PSK modem kit is designed for use with FUJI/OSCAR 12, the Microsats and JAS-1B as well as linear satellite transponder operation through OSCARs 10 and 13. In addition, it is suitable for weak-signal work on terrestrial HF and VHF paths. The PSK modem has been tested with Kenwood, ICOM, and Yaesu radios. The kit consists of three (3) printed circuit boards and all parts to populate them. It also includes cabling, connectors, LEDs, bargraph displays and switches to complete the modem. It does not include a case or power supply (it runs on 11-16 VDC). A case is available separately. Construction requires a fine-tip soldering iron, a steady hand, two or three quiet evenings, and access to a calibrated oscilloscope. A function generator or calibrated audio tone source and a Digital Volt Meter are useful, but not mandatory. A front panel switch bypasses the PSK modem and restores normal operation to the TNC, including radio connections. Front panel indicators include a LOCK LED (indicating lock to an incoming signal), signal strength bargraph and center tuning moving-dot display. Manchester (for satellites), as well as normal PSK transmit modes, are available at the flip of a front panel switch. Doppler correction polarity (and defeat) is also switch selectable. The TAPR PSK modem requires transmit data and a x16 or x32 clock from the TNC; it supplies RX data, RX clock and DCD to the TNC. Any TNC-1/clone (Heathkit HD-4040, AEA PKT-1) or TNC-2/clone (AEA PK-80, GLB TNC-2A, PacComm TNC-200, MFJ 1270/1274/1278) will interface with no problems. The PK-232 will interface easily to the PSK modem with the use of TAPR's modem disconnect kit. Other units may interface but have not been reported to TAPR. Units with software HDLC may not interface (GLB PK-1 series, Kantronics KPC- series and KAM for example). The TAPR PSK modem utilizes a Costas loop demodulator which has a 3 to 8 dB better performance than designs which limit the signal at the input stage. It has been extensively tested and optimized for 1200 bps operation. Other speeds are possible with changes to the input filters, but these changes are untested and undocumented. Note: The PSK modem is not designed for recovery of the 400 bps non-HDLC telemetry transmissions from OSCARs 10 and 13. These transmissions are not compatible with standard packet TNCs. *************************************************************************** TNC-2 Printed Circuit Board --------------------------- (Discontinued) Although TAPR has licensed the TNC-2 design to several commercial manufacturers and is no longer producing complete kits, there have been many requests for the bare printed circuit boards used in the TNC-2 by those who would like to 'build their own'. If operation exclusively with an external modem (such as the TAPR 9600bps modem) is desired, it is not necessary to wire the internal 1200bps modem portion of the board. Additionally, there are hams in many countries who have difficulty in obtaining equipment at affordable prices, but have access to parts and have expressed interest in building inexpensive TNCs. To meet these needs, TAPR is offering the TNC-2 printed circuit boards with a 5.25inch MS-DOS format disk containing assembly and operational information and EPROM code, plus a printed schematic diagram. ========================================================================== Tucson Amateur Packet Radio Corp. 8987-309 E Tanque Verde Rd #337 * Tucson, Az * 85749-9399 Phone: (817) 383-0000 * Fax: (817) 566-2544 TAPR is a Non-Profit R & D Corporation ==========================================================================