MOSFET 50MHz amplifier

I've built a couple of amplifiers recently. This one is for Six Metres, I just followed a design from OZ1PIF's website. It uses eight IRF510 MOSFETs. Output should be up to 250 Watts but I've not driven it hard enough to obtain that amount of power but 10 in produces 150 out so I'm happy with that. Seems to tie in nicely with the figures on OZ1PIF'S site. It's QRP to some but I've rarely run more than 20 Watts on Six from anything home-brewed here and I once worked VK with that.

No front panel meter, no high swr protection, no cooling fan but the MOSFETs are very cheap!

Front panel. The case is from a faulty SMPS.

Meteor scatter signal from DB0FAI

This recording of DB0FAI (144.490MHz) was made at 0825 UTC on 6^th May 2013 via meteor scatter during the Eta Aquarids shower.


The spectacular start to the reception of the beacon is caused by a meteor passing into the E-layer of the ionosphere producing a trail of ionisation that last for many seconds before fizzling out.

Two seconds before the main reflection is a minor one of short duration.


Distance between G8TTI IO81WM & DB0FAI JN58IC is 994.47 km (617.966 miles).I made a large number of recordings very similar to this that morning.