Re: IF DSP explanation
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Hi Larry,
If you tune around 20m (band i know the best) connected to a dummy load youll find a spike of noise i think about 336 (well i think thats where it is on mine). This spike is from the radio its self and if you want to work someone under the spike you're going
to have a hard time. The DIF shifts the IF so this spike moves up or down the band (forget which). The general idea as i understand?it is you tune till you find the noise, hit DIF to move it, tune some more until you find the noise again and hit DIF to move
it back so you dont have to hear it.
Not sure if that answers your question.
73
tim w3qp
From: [email protected] <[email protected]> on behalf of Larry Naumann via groups.io <n0sa@...>
Sent: Sunday, January 28, 2024 11:26 AM To: [email protected] <[email protected]> Subject: Re: [Lab599] IF DSP explanation ?
Yes, the bandpass filter was the solution. I just wasn¡¯t sure what the problem was yesterday.
Usually the offending signal is on a lower frequency, this was the other way around and not harmonically related. This was an all qrp activity but the antennas were all rather close. I am sure my bandpass filter will take care of this issue. I still don¡¯t know what difference DIF makes to the receiver other than moving the IF. Although it does state in the manual that with it OFF performance is slightly degraded but no explaination is given. Larry n0sa |
tim W3QP