v3.2.34 CW mode issue...

k0eoo

I just installed V3.2.34 on my new 6700 with no issues. But, while testing the new update in each of the different modes I use I noticed large amplitude spurs on either side of the CW carrier frequency. the first spur is +/-6kHz from the carrier. I tested on 15m, 40m and 80m with the same 6kHz offset on each band. My CW settings were Delay=30, speed=30, break-in and iambic selected and pitch 450.

If I did something wrong in the upgrade from V3.2.30 to V3.2.34 please let me know. I followed the install instructions to the letter.

k0eoo

I am posting an update to my spur issue. In further testing I can almost eliminate the spur by increasing the CW delay from 30 to 40 or more... But, at a delay of 40 or more there still exists a very brief spur of the same offset as before, but, at a much reduced amplitude, maybe reduced enough so as not to be transmitted.

If this is the case please delete my post.

K0FLY

I see the same thing that you are on the display (spurs approximately 6 KHz away from the carrier), however, I cannot find them on a second receiver. I'm tramsmitting on a 6500 (dummy load) and listening on a 6600 (antenna is coax to a switch) If I add in the 32 DB preamp on the 6600 I can see the spikes at approximately 75 dB down .

I'm not worried about the spectral purity.

Gayle K0FLY

KD0RC

@k0eoo , you cannot judge the spectral purity of a signal by watching the transmitted signal. You can use a different receiver on your 6700 to see the signal and any transmitted sidebands.

Set your transmitted signal to 1watt. Open a second panadapter and set its slice to a different antenna than the transmitter (you probably won't need an actual antenna on the port). Turn on Full Duplex (FDX). You should be able to see your signal and get a good idea of its quality.

Ken, NM9P has some great videos on YouTube about using this technique for looking at SSB signals. The same approach will work for CW.

k0eoo

Thank you Gayle and Len for your comments! I do understand what you're saying about the spurs not baking it to the antenna, I should have tried that test my self. The reason I made the post was I didn't see those spurs at a Delay of 30 with my 6500 running V2.6 software. The 6700 on V3 is brand new as of about 1 month ago...

Again, thank you Gayle and Len!

Erika - KØDD

Dennis, I tested my 6500 looking for your giant spurs. I dialed all the way back to zero delay and out.... yours is looking like Hoar Zorches. I notice that I run my panafall display differently than you do. I move the transmitted display to show 140 dbm ... and I have selected the arrow at the top so only 10 dbm is showing. At full power the zorches are tiny and slightly over -50 db below the top of the signal. Almost as far down as the on frequency carrier when I'm on ft8. Ok so, when you have the cw delay all the way down I see those guys not looking as ominous. If I crank the delay up they are completely gone or just little bumps.. Ive never been a full break-in user, so setting it at 75 to 100 things are cleaner. What those spikes are? 50-60 db down they are only noise...

I have the software on mine too, and it about alI needed to do is reset all the visual settings.

Erika DD

KD0RC

@Erika - KØDD - Yep same results here. 1 W or 100 W, spurs are way down from the fundamental. I also noticed that a steady state carrier does not show them at all. They only appear briefly when Keying (at least on 30 M where I did my testing). I did get a surprise when I sent VVV DE KD0RC on 10.124 and a DX Cluster spot popped up with my call... I finally figured out that it was from the Reverse Beacon Network. 30 was pretty quiet (except for FT8), yet I had a pretty good sig into AZ. Lack of band activity does not necessarily indicate poor band conditions. Guess I need to send more CQs on "dead" bands!

Erika - KØDD

Oh one more thing that might be of note. Run your same test with the extra bands not up. When you're monitoring multiple bands on the same scu the thing goes into 'wide' which turns off the band filters if I remember that right. Then try it with two bands on separate antennas and that should also be sepatate scu and would not be in wide mode. I've never had one of those 6700 two scu radios I'm too busy just operating 1 band 1 scu 1 antenna and can't handle breakin keying because some body else sending between my dits is a huge distraction. Thats just my limitation I suppose But looking over your screen shot again I noticed it was in wide and you had bands stacked up on there. Bet thats it. I'll get on at 9 and see what you found out.

Erika DD

KD0RC

Hi Erika, I don't think that wide mode has any influence in this case. The bandpass filters are bypassed in wide mode, but since we are looking at in-band signals, it doesn't matter if the filters are engaged or not. The bandpass filters are to keep out of band sigs out, they are not roofing filters.

Mike-VA3MW

@k0eoo

I opened a ticket for this.

Nice write up on how to create the issue. Thanks!