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Sunday, 7 December 2014

How can something so Simple be so Tricky?

Well,

What a couple of days! I dropped the antennas down yesterday, the idea being to fit a Masthead preamp for the 2M antenna.

The preamp has been homebrewed, but I am sworn to secrecy as to it's design and origin. Needless to say, keeping an eye out here:

http://g4ddk.com/

May prove to be a most excellent idea if you happened to want one of these.

This is the basic board populated but still under test inside the house:


The board  gave me about 17.5dB of gain right across the 144-147 MHz range. This is a close up of the top of the amplification peak on the Spectrum analyser:


So I took the antennas down (which involves taking the closest element to the ground off the HF beam):


and I fitted the pre-amp. Now, this involved replacing the direct feeder to the beam and introducing a joint in the coax (so I can remove the amp if needed in the future).


So the preamp in in the waterproof box you see above, after many iterations I have the set-up working perfectly. I have, during the process, proved how completely incompetent I am at fitting N-Type connectors!  I've got there in the end though - only about a day and a half elapsed time!

All told though, a most excellent result.

Freddie has become exceptionally clingy to me since I returned from the Middle East earlier this week, hasn't helped much today though:



Local conditions.

Good, egh?

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