Icom IC-7851 expanding the TX-RX

The modification of expanding the TX/RX frequency coverage of the IC-7850-IC-7851
post 23 Mar 2024
Icom IC-7851 expanding the TX-RX

Icom-9700 Links


IC-9700 Fan Modification
The fan in the unit does not run while the unit is in receive mode, and this appears to be a cause of significant temperature variations within the transceiver

Icom IC-9700 Modification European
icom IC-9700 the modification only works on european models

ICOM IC-9700 Reference Injection Board
This module allows locking the ICOM IC-9700 radio transceiver internal frequency reference, to an external 49.152MHz signal

IC-9700 GPS-locking mods
As this is not a proper continuous phase-lock system, the internal 49.152 MHz TCXO reference is still subject to drift, especially when the internal fan cycles on and off

Icom 9700 GPS Interface
Icom IC-9700 2m/70cm/23cm rig and want to add GPS capability well then you are in the right place

GPS-9700 Locked Frequency Source
The GPS-9700 is a GPS Locked signal source that was designed for the Icom IC-9700 Transceiver to stabilize frequency when using narrow band weak signal modes

Icom IC-9700 frequency modification
The modification only works on European models and by removing 2 diodes the frequency can be expanded by a few MHz to the USA

Icom IC-9700 operational review
The IC-9700 is a multi modedata), three band transceiver using mostly software defined radio techniques


Linear loaded short dipole 21Mhz For my amateur radio activities on the HF bands I only have a 3.6 m wide balcony available for antennas. After some study I decided to experiment with a shortened dipole for the 15 m band

Rx antennas 4Square Rx Vertical Array

Rx antennas 4Square Rx Vertical Array My frequency design of 1.825 MHz a 90 degrees line would be 33,70 metersinstead of the previously calculated 33,27 m

Atu balanced feeder antenna system

Atu balanced feeder antenna system An ATU has the advantage of bringing the feeder-antenna system to resonance, act as a band pass filter both on receive and transmit and a low SWR