Local oscillator below the station frequency--why?
On Feb 18, 10:16*pm, Bill M wrote:
Its a real gripe of mine! *The image rejection is so poor on the top
band of many consumer grade radios that its really a moot point and the
only way to guess which side the injection goes is by evaluating which
side suffers the worse dial tracking...and often thats so close a call
its difficult to say which was intended.
I had this exact problem with the Hallicrafters 5R10A.
With my signal generator set to 30 MHz, the image at 30.91 MHz was
maybe 1 dB lower. However, when I set my generator to 15 MHz (the low
end of Band 4), the image at 15.91 MHz was much less noticeable. So,
the set is a reasonably good performer so long as you avoid using the
high end of Band 4.
-Dave Drumheller, K3WQ
|