The Afternoon 7.268 Group
The Group on 7.268. Moe N9CCE net control . With a little Qsb coming from 7.265
WX9DX 68 Group net 40 meters 7.268MHz KN8I SCO
January 2012 net. This is a flex 5ka SDT radio listening to the 7.268MHz net 1/17/12, just before the 3:57pm shortwave interference starts. Larry KN8I is the service control op for Tuesdays on this group. Everyone is welcome to join in and it is a great social net. This net is 7 days a week from 2pm to 4pm central time. This is how the 68 group sounds after the shortwave starts up at 3:57pm central time here in the USA. This makes the Ham Radio Nets move off of the part of the band they are normally able to use. The shortwave broadcasts on the Ham Radio band cause such a problem that if Ham Radio is used on the top part of the 40 meter band, it would not be effective for communications in and out of the USA after 3:57pm CT.
Flex 5000 Filters
This is a demonstration of the FLex 5000 filters. I am on 40M with the pre-amp on. I am using a crystal controlled signal generator which has the best spectral purity, but its best output is S9. I tried an Elecraft transmitter which could generate a higher signal strength but had far worse spectral purity so I opted for this. The band width starts at 400hz on CW dropping to 13hz. I re-tune the radio so at each succeeding decrease in band width I am back at S9 and drop the bandwidth. I think this is a better demonstration than constantly retuning since the equations that determine the filters are all the same equations as opposed to discrete crystal filters, so the characteristic of each filter is the same, only the bandwidth is different. MDS with the pre-amp active on 40M is on the order of -150dBm. As you can see the performance of the filters is phenomenal and with NO ringing. You can also hear how quiet the receiver is in this demonstration. I will do a video on the AGC at some point to show why this is such a quiet receiver. The lack of fatigue when listening to this radio is the best of any radio I have ever owned Because of the AGC and the quietness you can really spend hours and hours listening with virtually no fatigue. Hope you enjoyed this one as I think its one of the best aspects of the radio