Hi George,

The Icom 7300 doesn’t have as good a front end as say your 7610.  It requires more gain management from the RF gain control or the ATT. 

If you ever see the Overload Icon flashing on the main screen, you need to back the gain down. 

That is my take on it.  At times and SDR can take hundreds of super strong signals right up to the point of the ADC’s dynamic range sweet spot.  Once you go over that, well it falls apart very quicky.  Make sure if you see the above the Pre amp is in the off position.  Then adjust from there.

73 jay/w5jay..

From: [email protected] <[email protected]> On Behalf Of WB5JJJ
Sent: Tuesday, February 7, 2023 1:54 PM
To: ADXA Mailing List <[email protected]>
Subject: [ADXA] OK brain trust - A question

I have about 60' of RG-8x lying on the floor going from my shack antenna switcher (2x6) to the recliner in the living room where I'm playing with my new-to-me IC-7300 getting it ready for RTTY (FSK) this weekend and other things.  All was A-OK when I turned everything off last night and went to bed.  

I'm using a 40m EFHW to feed the 7300.  This morning, I fired up my station and the 40m EFHW was still assigned to the 7300.  When I turned the 7300 on, I had a rollercoaster scope display on my waterfall on 160m, 80m, 40m and KARV-AM (610Khz), at 5,000w and less than 2 miles away, is typically an S9+50 was only S3.  I changed to the 160m EFHW and all was good.  Went back to the 40m and still abby-normal operation.  I checked the coax to switch to the 40m antenna with my RigExpert where the SWR was 1.74:1, so the antenna had not failed or fallen (I checked the latter).  During all of this, I reset the 7300 to factory and tried 40m and the EFHW with the same unusual results.  

Now here's the kicker.  When I changed my IC-7610 to the 40m EFHW, all was normal on it -- no broadband wipeout.  So, I put everything back to normal, left everything on and went to the PO and a couple of other stops.  When I got home about an hour later, the 7300 was back to normal for everything.  Could there be a problem with the 7300 or was my 40m EFHW specifically being attacked by a Solar Flair or whatever that did not affect the other antennae or the 7610? 

Everything is back to normal for now.  40m SSB QSO's are sounding like normal, and KARV is "bending" my digital S-Meter peg once again.  

73's

George - WB5JJJ
HoIP - 100105