[hpsdr] Hpsdr Digest, Vol 126, Issue 14 - AGC, Digital Modes, and Wide Bandwidths

[Al Pawlowski]

I find turning on the “ANF” function helps a a lot in a situation where there are one, or more, signals in the channel strong enough to reduce the rf gain via agc. If there are too many such signals to leave an untouched area for you to work, the only thing left is to reduce the channel bandwidth you are looking at with the variable filter settings.

Al - K6AVP



> On Aug 20, 2016, at 2:35 PM, hpsdr-request at lists.openhpsdr.org wrote:
> 
> Message: 1
> Date: Sat, 20 Aug 2016 11:02:13 -0700
> From: Mike F <mikecf100 at gmail.com>
> To: hpsdr at lists.openhpsdr.org
> Subject: [hpsdr] AGC, Digital Modes, and Wide Bandwidths.
> Message-ID: <7f60d92c-e626-9444-9c33-4bb351ed60db at gmail.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
> 
> I often do digital modes with my HPSDR system, PowerSDR and either 
> FLDIGI or WSJT-X.
> 
> When using a 3-4KHz bandwidth and WSJT-X, I have noted that if there is 
> one very large signal in the bandwidth, the rest of the bandwidth 
> flatlines.  This is obviously an effect of the AGC on the rest of the 
> signals in the band.  I have played with AGC settings to try to control 
> this effect, but am not really satisfied with any of the results.  I 
> thought "FIXED" might be the best way, but am not sure.
> 
> I assume that FLDIGI does the same thing. Haven't used it much lately.
> 
> Any Thoughts?
> 
> Mike, K7SR