Welcome to PE1RAH

“LE002 - Linear Transponder System”



After the launch of my transponder on the India HAMSAT satellite I got many questions from amateurs all around the world if I have a transponder design for their project to build. These projects were not only satellites but also balloon missions and also for terresterial use in mountain areas.

Unfortunatly it is not easy to build a linear transponder without the proper tools, what makes it the reason that there are more FM transponder experiments than linear transponders. Another problem with linear transponders is that they are relative expensive to make especially when larger bandwidths are wanted. I have tried to find a way to get linear transponders more popular and I think the best way is to make it easy available for amateurs that have not the tools, money and time to develop their own transponder.

The LE002 is a Linear Transponder System that has a technical similair construction as the Dutch transponder on the Indian HAMSAT. The LE002 is constructed in a more professional way and improved to be used for different kinds of experiments.

The transponder is made in a milled aluminium box. The box is milled in such a way that the transponder can be easily mount on any flat surface, without the need to open the box itself. Some more features and pictures below:

The RF input and output have standard SMA connectors.

15-pol SUBD is used for power supply and extra optional features like frequency programming, CW beacon, Telemetry input, IF in/out


Inside view of the transponder.

Block circuit of the linear transponder


Aluminium milled box sizes.


More features:

Power supply : 9Vdc to 14Vdc

Uplink (LE002 version 1)     : 430…440MHz  (Frequency is programmable by PLL in steps of 50kHz)  

Downlink (LE002 version 1) : 144…146MHz (Frequency is programmable by PLL in steps of 25kHz)  C

Bandwidth : 30kHz (Sharp crystal filter) , 15kHz and 3kHz are possible on request.

Output power: +20dBm (100mW) PEP  (output spectrum is inverted from input spectrum)

Weight: 550 grams

Optional: CW beacon, IF in/output (for external beacon, telemetry, or connection with other transponder)



To come:

LE002 version 2 : Uplink 70cm and Downlink 10m


73 de PE1RAH (William Leijenaar).


This page is designed and created by PE1RAH. (William Leijenaar).