6600 Sherwood racking

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Hi 

since is see no one raise the interrogation ,i do it 

if my memory is good ,as continuous performance improvement  the new radio generation was announced whit similar or better performance that previous generation  6500/6700 ,that was a key sale point  

so now that ROB update it listing whit radio that got all the PCN , 12 place result was quite 
deceptive ? , honestly anything more that 4th place was deception for that new generation 
old plain analog radio is better ranked ;-) 

on my side i may tell that yes on EME operation i see a really noticeable difference in operation
whit respect on my old 6700  ,and still evaluated idea to swap back to 6700

please try to keep that tread constructive whit no flex bashing  ,critic is good basing is not 

Marc L. VE2PN/VE2OLM
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Marc Lalonde

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Posted 3 months ago

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Gerald - K5SDR, Employee

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Hi Marc,
With respect, I am not sure I understand your question.  What specifically are you asking? 
73,
Gerald
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Marc Lalonde

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Hi Gerald  , it more a observation that a plain question 
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k0eoo

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Rob just put the 6600M out on his receiver performance page....
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Steve

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I think what Marc is saying is that IF the 6600M  has been touted as a better performing radio then why is it lower than the 6700 on Sherwood's list.      The question is when does a SMALL "measured" difference in dynamic range even become noticeable in day to day operation of a radio??  Also at what level of measurement is dynamic range  as good as it NEEDS to be.  I suspect that anything above a certain point is as good as it needs to be.  Also Rob has stated there are some caveats to his measurements.  
  
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Gerald - K5SDR, Employee

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Rob is mistaken about "3 Hardware Upgrades."  There is one recommended and one optional hardware upgrade.  This information is in the notice sent yesterday.  I will contact Rob to make sure he understands.  I did check and the unit Rob tested came off the line in the first two weeks of production shipments.
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Varistor

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Here's Rob's follow up in the Icom 7610 group:

Hi Jim,

I am on a computer now because answering your Flex question will be rather involved.  Since you asked a pointed question on a public forum, I have to be completely candid about the past few months and the results of my lab testing.
In the third week of February I borrowed a Flex 6600M from a long time friend, and began testing it in my Denver lab.  Initially it had a PLL problem, as this circuit wouldn’t consistently lock up to the internal TCXO clock oscillator, an external 10 MHz source from my Rubidium house standard, or the optional GPSDO oscillator.  After much fiddling, the PLL locked up solid, and I ran tests for the next 6 hours.  I made my normal suite of measurements, dynamic range, RMDR, noise floor, sensitivity, etc.   

The numbers were not as expected, being inferior to a Flex 6700 in respect to dynamic range and RMDR.  The other numbers were reasonable, and as long as the flaky PLL locked up on a given boot, the radio generally worked OK.  I sent a preliminary report to Flex, and obviously with the PLL issue I was issued a return authorization and the rig was sent back to Austin.  At that time only the PLL problem was corrected, and unfortunately the other performance issues were not addressed.


The 6600M came back to Denver a few weeks later with a repaired PLL circuit.  I ran the rig through the lab again, and all my measurements were within 1 dB of my original lab report.  Dynamic range was still lower than expected for receiver A, and really low for receiver B.  At that point I let the rig run the rest of the day and over night for a 20 hour warm-up.  At that point a thermal issue was observed, as the dynamic range of receiver A dropped to 84 dB, and receiver B increased to 84 dB.  RMDR was still about 10 dB below factory specifications. 


In the mean time, I was able to borrow a 6600 non-M to test to determine whether I simply had a bad sample or if there was a consistent problem.  The 6600 tested virtually identically to the 6600M, and I reported this back to Flex. By now it was March 15th, and almost a month had gone by since my initial long form report had been emailed to Flex. 


Some additional time went by before Flex confirmed that they were now seeing the same issues I had reported in February.  The 6600M was sent back to Flex for a second time, and was there for a few weeks while the hardware issues were being addressed.  Around three weeks ago the 6600M was shipped back to me in Denver, after having undergone hardware updates for the thermal issue and the RMDR problem.  The dynamic range problem was software related, and production software has not been released as of today to correct that issue.  The latest release I see today on the Flex website is v. 2.1.33.  I was able to test dynamic range with non-production software, and with that pre-release software, the 6600M is performing similarly to the 6700 I tested March 17, 2017. That data set for the 6700 is listed on my website as a “second sample”. There are now several radios with more than one sample listed: IC-7300, IC-7610, K3 and K3S and the R8600.  There is also data on three IC-781s going way back to 2006. In general the direct sampling radios have more data scatter than legacy superhet radios.  This seems to be due to sample to sample variations in individual ADC chips.  


Just as the League does, I give any OEM time to correct issues that come up when I review a transceiver or receiver.  It has been just short of three months since I found the problems I have explained above.  It is my understanding that the hardware upgrades have been in production for several weeks.  I will touch on the original data and the improved results in my Contest University presentation on Thursday before Dayton/Xenia.  I’ll add the 6600M to my website before I leave for the Dayton Hamvention.


Hams have been asking me for months about the new Flex products, and now less than a week before Dayton I felt it was time to respond to the question you posted today. 


73, Rob Sherwood, NC0B
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Matt NQ6N

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This is very interesting, particularly Rob's speculation that there may be a bit of variation in ADC chips. It will be fascinating to see how this unfolds. I'll have to check out Rob's talk at Dayton. 
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Rich McCabe

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I just read this again. "The 6600M is performing similarly to the 6700 I tested March 17, 2017."
This was the first review of the 6700 and puts the 6600 even further down the list.
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Pat N6PAT

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I don't understand why people get so hung up on someone else's lists. It's like how people react to a movie critic. Almost like they need some one else to tell them if they should like it or not.
Does your radio work? Do you get good signal reports? Does it do what you bought it to do? If so then be happy with it
(Edited)
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Robert Lonn

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I have the 2nd ranked Icom IC-R8600, I also have the 6600M.. The Icom is a true SDR below 30 MHz, above that it is triple conversion,, so in comparison I stayed below 30 MHz.. I also have a JRC NRD-545, Drake R8B, Routers RDR50  $3K SDR receiver to compare them to.. 

The 6600M can hear what the others can not.. The RDR50 was the best receiver till I got the 6600M. The audio just sounds better, more intelligible audio on weak signals,, and I never could imagine that regular SSB reception could sound almost like I was listening to Wideband AM audio.. SSB is one of those things that you can never get the station tuned in perfectly, but the Flex does that with ease,, basically is can recover the audio with clarity and fidelity..

My RDR50 receiver will beat out the Icom R8600 receiver and the 6600M beats both of them on recovered audio.. Not sure how it got so high on the list, but Bob does a good job with his measurements,, but my ears dont fool me to often..  I hope to do some comparison videos in the future showing the RDR50, R8600 and 6600M in a comparison test..

Robert
WA6PHN
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Gerald - K5SDR, Employee

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Marc,

Are you using the same transverter on the 6600 and 6700 when on EME? 

How much RX gain is in the transverter? 

What is the signal spacing between your receiver and the interfering TX signal? 

How far is your EME antenna from the pager tower?  Is it pointing toward the tower?

Gerald
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Ken - NM9P, Elmer

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Listening to the Flex with a pair quality speakers is a pure pleasure.  Full, rich, articulate, and much less background noise than most other rigs.  Indeed, the reduced "fatigue factor" is huge!
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Marc Lalonde

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same setup as whit 6700 

kuhne MKU 144 G2 whit 25db conversion gain 
WA2ODO "ultra narrow" preamp  whit 0.122db noise figure @27db gain
whit 2MHZ wide DCI bandpass filter in front on LNA

i have make lot of bench test whit the 6700 and find that 144 XVTR VS the kuhne transverter have 1-2 db loss of signal  , both permit to got good echo back 

for avoid urban noise i limit my operation only when moon is above 10-15 deg elevation  

Best regard 
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Gerald - K5SDR, Employee

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Marc, 
  1. What is your total system gain?
  2. What is the signal strength of the interfering signal?
  3. What is the frequency spacing from the interfering signal to your passband?
Gerald
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Robert Lonn

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I probably listen more than I TX... That is because I am on my desk computer doing work related stuff with the radios on in the background... So I dont like to get listening fatigue. The Flex recovers audio better then even my Drake R8B, and that was a radio known for great audio fidelity... I have the Flex hooked up to a Sony Classic- Vintage amplifier driving a Hallicrafters Speaker.. Amazing Audio Quality!!! Two Speakers for Stereo MONO Audio! LOL

(Edited)
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Matt NQ6N

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My interpretation of the PEN announcement and the comments I read yesterday is that perhaps the biggest factor in the Sherwood ranking difference between the 6600 and 6700 is that the 6600 does not yet have a firmware update (which has already been released for the 6700) that will provide a bit of additional dynamic range in strong signal conditions (such as Sherwood's test setup). 

So I would guess that a 6600/6600M with the firmware update AND PEM updates will rise in the Sherwood rankings.   Note that the Sherwood rankings for the various tests of the 6700 do not seem to indicate whether the firmware update was installed, so it's not clear what impact it had on the results in the various tests. 

Compared to other high end rigs I've used, the 6600's receiver sounds fantastic and the close-in dynamic range makes a crowded 40m CW segment feel like there's plenty of room for everyone, signals sound clear and pure, and weak ones are copyable without the typical audio artifacts introduced by other rigs' filters.   Also, the Sherwood tests do not really cover one of the most useful aspects of the 6600's receiver design which is contest band bandpass filtering suitable for full duplex operation. 

73,
Matt NQ6N
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Ria - N2RJ, Elmer

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2.2.8 was released today. I believe that contains the software update.
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Marc Lalonde

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Gerald 

measure precise system parameter of remote mountain top  site is not easy 

but before install system i measure on bench signal to noise ratio of the system whit calibrated signal generator (Agilen ESG-D4000A ) and precision mini-circuit attenuator  for make signal to noise testing and and to XVRT port isolation  and notice a small degradation VS the 6700  ,but as i trade it i cannot redo A B test

since snow melt i only have go onsite one ,so more test is planed  and hope PCN will help
but operation LOG since i put 6600 on air clearly show 5-6db signal loss somewhere and more intermod ,i wait to have more bench testing before check for a help-desk ticket or else

the 100khz blocking range may a clue ,no sure yet

p.s. i see only 2 mod on the PCB  , heatshink and ,cap on LDO  not 3 as Sherwood said ?

Best regard 
Marc VE2PN/ VE2OLM




 
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Craig Williams

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I love it when the head man takes time out to educate the average Ham.
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Marc Lalonde

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ho when it not got first Canadian ranking on ARRL  EME constest on 144 band
that the kind of week-end project that average Ham do on it basement ;-)

if you not yet figure it out ,that a Vita-57  DFC radio ,and yes it work 

Marc L. VE2PN

(Edited)
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Bill Roberts

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?
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Marc Lalonde

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Hi  Gerald 

have try to make some test this morning ,but sun to close to moon for my antenna aperture ,so grab lot of noise   ,next good "window" is next Sunday

have make some terrestrial test ,at low elevation human noise dominate so lower gain and increase of dynamic range not hurt ;-) 

for on moon signal previous experience seem to show that increase gain make small advantage ,but i wiling to test it again whit pre-amp set to 0db  and made some signal average   ,also next Sunday degradation is under 1db ,usually on the past whit the 6700 i got easy my echo whit that degradation ,so it will good time to make test ,  will let you knot 

Thank for you time it appreciated ,and have nice Dayton show , i sure new radio will sell like hot cake  ;-)
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Gerald - K5SDR, Employee

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Marc, one thing I meant to point out is that MDS (i.e. sensitivity is exactly the same in both receiver gain examples at -146.9 dBm in 500 Hz bandwidth. That number would have to go down if gain increased sensitivity. I actually think you could reduce the gain in your transverter a bit without loosing sensitivity. You could also super cool your LNA to reduce the “T” in kTB. ;>)
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Ria - N2RJ, Elmer

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My personal opinion:

Sherwood rankings matter, but not the be all and end all. 
Anything >80dB RMDR or narrow spaced DR is very good. Most humans won't notice above that. 99 is amazing.

Flex is always continuously improving the radio. Since this is a software defined radio, software can fix a lot of issues. Sometimes a hardware change has to be made. The PEN is designed to correct an issue with the heat sink during long term operation. The RMDR enhancement is designed to correct some power supply filtering. 

Either way you have a GREAT radio, any 6000 series radio. 

There are so many other things which make the radio amazing - turn key remote, single cable (ethernet), 4 slices, and connections that make sense for a lot of environments. Not to mention a fully open API for third party software.

Gerald, Steve, Eric, Tim and the rest of the FlexRadio engineering staff are very much accessible. You have choices though. My choice is to stay with Flex, because I think overall they are a great solution to a variety of station scenarios. When I set up another remote location I'll likely be getting one of the newer radios. The price point for what you get is pretty good. 
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Marc Lalonde

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yup agree that reason i still whit Flex , for remote operation competitor is far Behind 
the DAX and CAT  flex system is a real must  ,all other rely on virtual cable and serial port splitter , Smartink is also nice feature  ,still not find is best for me is 6700 and 6600