[amsat-bb] How to get a cheap handheld broadband RF preamp

andy thomas andythomasmail at yahoo.co.uk
Sun Feb 9 02:37:37 PST 2014

This is primarily for the team getting ready for the Kicksat Sprite project but I am posting it on the amsat -bb as well as there may be a science teacher out there who may be interested.I'm not claiming it's revolutionary, but timely.

The requirement is for an inexpensive antenna-head preamp, lightweight, running on a battery.

I wouldn't claim it is a low noise preamp, but CATV ampifiers are available for under £5 including delivery from China.

I bought one in a car boot sale for a £1. It was supposed to work on mains electricty (220 volts!) and is therefore obviously unsuitable to use outside.

So I have taken out the mains transformer and the diode rectifier matrix and now run it off a 9 volt battery. I've also shown that the input and output sockets can be changed. This is simple soldering as even I can do it.

Obviously the same principle applies to any TV amplifier, broadband, and needing filtering at the antenna head. Just look to see if 435 MHz is included in the bandwidth.

At some point I'll design and construct an input filter.

For those who may be interested, here's a direct link to my page:


or you can get there by going to  http://www.andythomas.eu , choosing "Funcube" from the drop down menu and then get the page from the bottom of the Funcube page.

73 de andy G0SFJ

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