New Sherwood 6700 and 6300 tests

Lee - N2LEE

That's why I rotate and polish the tubes every month.

Norm - W7CK

Thank you all very much for the explanations and links.  That really helps!

Gopro

Paul,
you're absolutely right!

Gerald-K5SDR

I have good news on my testing of the radio Rob Sherwood was evaluating.  What I thought might be a hardware problem turned out to be sub optimal software settings.  I am glad that Rob noticed the performance difference because it triggered deeper analysis.

Once I optimized the settings, I found that it improved the performance of not only the FLEX-6300 Rob tested but materially improved another randomly selected unit from a different production lot.  After optimization, both performed at roughly the same level (IMD DR3 in the high 90's), which is materially better than even the ARRL Lab measurements.  The hardware was not touched in any way.  

When Rob returns from his vacation, I will send him the unmodified FLEX-6300 he was testing.  We will create a new software test release that has the optimized settings.  He can upgrade/downgrade the software to compare before and after, which will demonstrate that the fix is purely in software.  While I have not had time to test this exhaustively on the 6500/6700, a quick check leads me to believe that the optimized settings will improve IMD performance of all FLEX-6000 Series radios.  

73,
Gerald

Duane_AC5AA

Hi Gerald - was this one of the user settings available on the SSDR panel, or was it an "inside the code" setting that users can't adjust?

Gerald-K5SDR

It's hard coded in the radio code.  There is no reason for the user to adjust because it requires lab equipment to verify the settings.  There are multiple registers that interact so you have to know what you are doing.

K1UO Larry

Does this software fix have a tracking number?
73,

Ken - NM9P

Excellent! My 6500 with even better IMD performance than before!

Al_NN4ZZ

Gerald,
Great news.   Was the firmware change that affected the performance related to a specific enhancement or bug fix in one of the previous releases?  

I suggested that Rob may want to start adding the software version to the footnotes in his table and I think he is going to do that.   Especially with SDRs I think this is a good idea.     

As was noted earlier, the difference is probably not noticeable to the users in most cases but it is nice to get the best performance possible and it's also nice stay at the top of the pile in Rob's table.

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
SSDR / DAX / CAT/ 6700 -  V 1.10.16
Win10

Ria

Or just put it next to the radio name and date. 

Eg. instead of FlexRadio Systems 
6700 
Hardware Updated

Something like 
FlexRadio Systems 
6700 
H/W Updated , S/W v1.10.16

Al_NN4ZZ

Ria,
Good idea, I like that even better....

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
SSDR / DAX / CAT/ 6700 -  V 1.10.16
Win10

Rick

This is good news, I hope, as last night I ran what would be termed by an engineer a crude experiment using the radios in my shack at present - Flex 6300 and 5000A, K3 (with some S model upgrades), KX3, and Icom 9100. I recorded noise floors using the S meters on 80, 40, and 30 meters, ensuring that filters, preamps etc. were set to be comparable on all 5 radios. I found the noise level on my 6300 to be 2-3 S units higher on 40 and 30 than any of the other radios, even the somewhat long in the tooth 9100. The Icom however did not handle the peak static crashes as well as any of the other radios especially on 80 and 40m. I hope this software fix Gerald has mentioned improves this situation. 
Rick, W2JAZ

Walt

And I hope this type of exhaustive testing is added to the alpha testing process so with every future software release, the user has confidence that there has not been any adverse changes in performance.

Cheers

Ria

We do test new versions exhaustively, but not everyone has access to Rob Sherwood's equipment and expertise, and Flex's lab only has so many (human) resources. So we're not going to catch every last little thing but performance tweaks and deficiencies are definitely noticed in real world conditions. So this essentially means that something which doesn't affect real world performance won't be noticed by most Alpha testers. The good news is that it won't be noticed by anyone else, either. 

Ria, N2RJ
Alpha team

Steve Gw0gei

And I for one certainly appreciate the efforts of. The alpha team in trying to ensure that the end product released to users is as near perfect as possible. For those of us that regularly contest with a flex 6000 radio that's really important and has given me the confidence, after a few cycles , to upgrade within hours of a new release rather than delaying trying it for fear of bugs impacting on one of my series contest results. This reliability helped me gain another hf championship win in rsgb 2016 series and 2017 series is going well too so far. Looking forward to some better close in performances from the next release now. Keep up the good work. 73 Steve gw0gei / gw9j

Walt

I am sorry that I assumed the alpha testing was the factory testing.  I would never expect anyone in the field to have the same test equipment.

So let me re-phrase that to mean factory-testing.  I expect the factory to make sure that every software release does not reduce the performance of the radio.  I purchased the radio based on specifications and third-party performance testing and I would like the radio to maintain that during its life-cycle.

My 2 cents - I am heading to the field tomorrow so no more chatter from me on the topic.

Cheers and two pints, please . .

James Del Principe

Gerald, could this result in a future SW release for all of us to benefit?   I have a 6500 running 1.10.16 non-beta. Is this a candidate?     73, Jim

Tim - W4TME

Yes, it is possible that a future software release will contain logic changes to benefit all FLEX-6000 owners once we have had an opportunity to fully vet the change. 

Ria

Hi Walt,

No need to apologize. But now you know that the Alpha team is made up of real world users. We have power users and regular users so we have a good cross-section. The Flex development team, Tim, Gerald and the rest of the team are very attentive to any issues we may report. We also read the community postings and try to reproduce bugs that are reported here. There is a lot of hard work going on behind the scenes (most of it by the dev team). We are not employees but we are enthusiasts who have a deep interest in the success of the product. 

Gerald taking a close look at the Sherwood results as well our discussions in the thread and communicating directly with all parties involved shows that he also cares about the performance of the radio very much, as I am sure you do. I am confident that the new fixes discussed by him will bring the radio up to the top notch spec that Flex users have grown accustomed to.

Ria, N2RJ
Alpha team

Gerald-K5SDR

I am going to answer several questions on the topic and then go QRT on the subject for now.  Here are the facts in bullet form, which is how I think:

1. This was not a software bug.  The software related to this setting has been the same since we released each radio model.  This is not in code that the software team would normally touch.
2. I would call this a "discovery" because I serendipitously found a setting that increased SFDR headroom that was counter intuitive to what I thought I knew about the hardware.  
3. I made all the adjustments manually so they are not yet in the software.  When we do update the software, it will be in the release notes.  
4. Further testing is needed on the 6500/6700 to see if the same settings apply.  A very quick look indicates that it will apply.
   
5. This is not something that alpha testers can be expected to test.  It would even be complex and expensive to do at the factory.  
6. I agree that independent testing should provide the version number of the software/firmware.  The ARRL does this.
7. @Rick.  This topic has been covered many times over the years but I am sure you missed it.  This is a common minsconception.  First, never trust a superhet S meter.  They are not accurately calibrated at 6 dB per S unit.  They reduce that so that you are fooled into thinking the noise is lower that it actually is.  On 40m the atmospheric noise on your antenna is actually going to be in the range of S3 to S4 in 500 Hz bandwidth - more in a SSB bandwidth.  See the chart below.  Also, when you use the 0 dB gain setting on our radios, that means literally 0 dB gain.  There is no analog gain stage in that setting, which is the most appropriate way to run a radio below 15m and sometimes even on 15m.  Add gain to lower the noise floor on 15m and above.  That's why the control is there.  

73 and QRT,
Gerald

1. 

Gerald-K5SDR

Oops.  I forgot to recommend that everyone read the article by Joel Hallis, W1ZR, in the June 2010 QST titled, "Receiver Sensitivity -- Can You Have Too Much?"  
Gerald

Al_NN4ZZ

Gerald, Thanks for all the details and information. The only thing that remains a mystery to me (and I may have missed something that explains it) is why the numbers would have changed when Rob did his tests. It sounds like the settings you discovered are new. If there are no firmware changes that account for it and no hardware changes then why did the numbers change when Rob teseted the same radio at different times? Regards, Al / NN4ZZ

VE7ATJ_Don