What is Passband Tuning?
 

Hello,

I read in a post the new Eton has passband tuning, what does that mean?

Thanks,

Neil

On 21 Jan 2004 02:51:28 GMT, (BCcubed) wrote:

Hello,

I read in a post the new Eton has passband tuning, what does that mean?

Thanks,

Neil
Traditionally filtering is done after the last IF, and just before
detection. The 'Native' IF strip is often relatively broad banded,
6-10Khz. Passband tuning allows you to 'center' the filter anywhere
within that 6-10Khz. So without chaning the tuning, you can move for
example an 2.1Khz SSB filter anywhere within the passband.

the disadvantage of passband tuning is you can get 'blocking'. Signal
levels, which drive AGC are effective measured in front of the filter.
Ergo a strong signal in the passband, but outside the filter can
driver gain down on the signal you want to hear.

Passband Tuning and IF Shift


These two similar techniques allow the operator to manipulate a receiver's
filtering circuitry to favor one of two close-spaced signals without simply
narrowing the passband, which would produce muffling of the audio. Instead,
by shifting the passband, the unwanted signal is rejected and the desired
signal's bandwidth is preserved.



See URL:
http://www.universal-radio.com/catal...r/0175pbt.html
Nice pictorial shows twin passband tuning but single passband tuning is
similar

Also see page 36 of the Kenwood TS-570D Manual at URL:
http://www.kenwood.net/indexKenwood....&FileCatID= 5
Another nice pictorial of the IF Shift control

--
73 From The Wilderness Keyboard
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"BCcubed" wrote in message
...
Hello,

I read in a post the new Eton has passband tuning, what does that mean?

Thanks,

Neil