Saturday, 8 May 2010
1.3 GHz GH Engineering PA on test
Finally the missing parts arrived and I was able to do some testing of
the 1.3 GHz power amplifier. The output is only about 1 watt at the moment.
There was a lot of lossy RG58 cable between the USRP2 and the test bench hence
the low power.
One thing I found was that if the SMA connectors are not screwed tight you loose
quite a lot of RF. The two black cables inside the amplifier are scrap semi-rigid
cable covered in heat shrink sleeving that I bought on eBay.
I am not the worlds best metal worker but the case, which was made from
pieces of U channel aluminium and flat plate is enough to maintain the PAs
I also made some changes to the Software. The idea was to reduce the amount
of memory it requires so it would work better on the laptop. A nice by-product
of the change has been a significant reduction in the system latency.