Originally Posted by Nursecosmo
It must be nice to be rich and famous like you Mole. You get all the good stuff.
Hell, I'm not famous and am
the farthest thing from rich! But if you want to help with either, I'm all ears. I've been saving for quite a while for a new rig...so it feels good to finally be able to order it.
I'm a little puzzled by the 2.8 for 2.7 filter swap---would there really be a perceptible difference between the two? I know that when I went from a 2.5 to a 2.1 in my FT-847, I could hardly tell the difference. I figured that I should have gone with the 1.8 to really make a difference.
According to the ARRL test report, the difference in Blocking Gain Compression between the 2.7kHz 5 pole filter and 2.8kHz 8 pole filter is fairly significant when the stations are within a few kHz of you. Here is the key data:
2.7 kHz Filter @ 2kHz above/below - 115/85 db at minimum detected signal
2.8 Khz Filter @ 2kHz above/below - 134/86 db at minimum detected signal
2.7 kHz Filter @ 1kHz above/below - 93/83 db at minimum detected signal
2.8 kHz Filter @ 1kHz above/below - 113/84 at minimum detected signal
IMD is also a bit better with the 8 pole filter. Remember, in the K3, these are true roofing filters and you can still adjust the filter width and shape additionally through DSP.
Funny; I figured you for a Flexradio guy Mole. The filter selection is -of course- digital and customizable/selective with the Flex. With the stove crystal, it holds .5ppm.
See above paragraph. By using both roofing and DSP filtering, you get the best of both worlds without degrading IMD and Blocking Dynamic range. Here's an interesting article that discusses Elecraft's approach: Roofing Filters
Remember the Elecrafts are also Software Defined Radios...they just don't require a PC to run the radio at all times. They're similar to the TenTec in that as new features are introduced (or bugs fixed), you can apply the latest firmware. I also like that this radio will transmit with supply voltage all the way down to 10 volts. That's pretty neat for portable use. There are a few other factors that swayed me this way as well. I hope I'm still convinced after I've used it for a while!