INTRODUCTION:

A half duplex version by PE1JPD with 54 MHz tx/rx shift is working yet in about ten nodes at speeds of 38 kb/s to 76 kb/s in Holland.
The described version, here, is fully revised and improved.
My first concern was to find and stock up specifics components.
A pic micro-controller (16F84) replaces the original Atmel controller (not available easily). First IF frequency has been changed for using standards crystals (48 MHz) .
The vco is replaced by a " plug and play " version with printed coils. The vco runs at the first time after soldering.
The pll loop filter is changed for using G3RUH modulation and Manchester modulation.
The original version could only work with Manchester modulation.
All 23 cm band is covered with 100 kHz steps.
Changing frequency is easy, using two keys and frequency is displayed on LCD display, 1 line of 16 characters.
And the main modification is the separate boxes for TX and RX with their own pll and vco. Shift rx/tx is tunable with the value you want, and all modes are possible (full duplex, half duplex and simplex)

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There are different possibilities :

- RX in one box with its frequency keys tune and the lcd display.
This RX will be built by listeners, swl, for no connect satellites packet at 38 kb/s and more. And for listening to wbfm voice. This RX kit can be built without hams license.

- TRX half duplex kit in one box, like original PE1JPD version.
Using only one pcb, but tx/rx shift is definitively fixed on one value 59 MHz in France, 54 MHz in Holland. You have to cut non standard crystal for 2nd mixer at 48.3 MHz for 59 MHz shift, or 64.7 MHz for 54 MHz shift.

- TRX full duplex in two separates boxes. One box for RX, the other for TX.
Each box has its own pll and vco, frequency tuning is totally independent.
You can choose the shift you want, including no shift for simplex mode.
Only one lcd display and only two tuning keys for controlling both the RX and the TX boxes.
This version can do half duplex and simplex modes, pins diodes are available on the two boxes, the antennas can be switched.
In any case, for every version, the vco are never switched to guaranty minimum TX delays.

TX CHARACTERISTICS:

- Synthesized channels from 1240 MHz to 1300 MHz with 100 kHz steps;
You can reduce step by readjusting reference frequency with the trimmer near the 6.4 MHz crystal;
- TX bandwidth modulation from 40 Hz to 180 kHz;
- Modems modulations possible fsk G3RUH and Manchester;
- Fm deviation from +/-15 kHz to +/-75 kHz;
- Printed coils vco with very reduced phase noise;
- Speed 38 kb/s to 115 kb/s;
- Txdelay (if used in mode half duplex and simplex) = 10 ms;
- Efficient speed =4k characters in 76 kb under tcp/ip protocol, half duplex mode;
- Tx channel width = 250 kHz;
- Tx power 2 Watts;
- Available signals on db9 connector : txdatas, ptt;
- Antenna output on BNC connector (can be changed);
- Metal box, europe format, size 160 mm x 100 mm x 50 mm;
- LCD display and tune keys fixed on the box.

RX CHARACTERISTICS:

- Synthesized channels from 1240 MHz to 1300 MHz with 100 kHz steps.
- Sensitivity around -100 dBm.
- Vco same type than TX vco.
- First IF RX 58.7 MHz, (59 MHz for one-box version) 2nd IF at 10.7 MHz.
- RX band pass width = 280 kHz.
- FM wide band demodulator, 250 kHz max or 500 kb/s.
- Available signals on db9 connector: rxdatas, rssi (s-meter), ptt, dcd
- Antenna input on BNC connector, (can be changed).
- Metal box, europe format, size 160 mm x 100 mm x 30 mm

Due to Lack of Interest from the Packet Community in The UK for High Speed Linking I have now Decided to Discontinue Development and Supply of any Kits

The Above is for Information Purposes Only

Enjoy packet radio!

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