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New 6500 user experience

k3Timk3Tim Member ✭✭

Took possession of a new 6500 this weekend.  Thanks to the folks @ Flex for answering pre-sales questions and helping with special shipping arrangement.

I did study this community information for several weeks and spent a 12 hour return flight reading the Flex manuals.  That helps but actually hands on is a bit different.  The setup went smoothly except the Flex Control was a bit of a puzzle as it wasn't found.  Finally found one has to enable it on the startup page - thanks for the community post on that one.

The radio performance is nothing short of spectacular!

A long time (25 years) Ten Tec user and appreciate their QSK capability.  The Flex QSK is actually better.  A bug sounds great and the 'scratchy' characteristic is not present with the Flex.  QSK is super smooth.  The ATU works beyond my wildest expectation.  A random length end fired antenna tunes on 160 to 6 meters.  An external tuner could not tune 160 - so this is a bonus.

AM sync is also very good.  This box was expected to perform SWL listening duties and it sure does.
Speaking of box, I am a bit surprised the size, a bit smaller than expected.  Build quality is top class.  I popped the covers to make sure no shipping damage occurred.  The SMT work / PWB is world class.  (this is my profession BTW).

The AF amp is a WE-300B (tube) based monoblock running 8 watts linear (SE).  Speaker is a large HiFi unit (JMI Labs).  Sound quality is very good to put it mildy.  More like room filling...  CW sounds really good.  Radio Havana was always a problem to receive here but this puppy is doing best job ever.  Other stations are really good, especially the wide ones.  Commercial AM is really great sounding.

A ton of RF noise here (SoCal) but this box seems to brush it aside better than the IF based units.  Not so annoying RFI sound as other radios.

CW QSK is super smooth / best in class.  A bug works very well with this box, something modern DSP rigs seem to have problems with.  SSB setup was simple thanks to tips on this site.

Only problem was RF getting into the PC keyboard and starting MS word / Outlook and other crazy things.  Ferrites settled that down.

Obviously running Smart-SDR 1.38.  It presents the user a nice interface and is fairly intuitive.  Setting mode / XIT / power / audio setups etc etc is straightforward.

Realizing 1.4 is much anticipated the current s/w has a lot going for it.  Being a C coder for several decades one has to realize any estimate of s/w release time should be multiplied by Pi.  That really seems to be more realistic.

Very happy to make the jump from knobs to mouse (well trackball) and FlexControl.
Hope to work you on the bands....



  • Duane_AC5AADuane_AC5AA Member ✭✭
    edited May 2018
    I moved from a TenTec Orion (which followed an Omni VI+), and I'm also impressed with the 6500, Tim. 
  • k3Timk3Tim Member ✭✭
    edited May 23
    Hi Duane,

    The TT Orion seems a very nice rig.  Is your impression the Rcv performance of the Flex is better?

    I moved from the Omni 6 opt 3.  Have an Argo 6 which is the SOTA rig.

    Best Regards,

  • edited January 2015
    Adding to the list of goodies, for phone, the compressor on the Flex is superb and so is the DEXP (downward expander.)  The compressor uses a completely different approach than conventional compressors and was invented by my David Hershberger, W9GR.  It seems to eliminate the need for complex adjustments in multiband compressors, fiddling with attacks and decays and thresholds.  The compression is built into the SSB generation as Controlled Envelope SSB.  There is an article on this technology in QEX and is available online in pdf form at http://www.arrl.org/files/file/QEX_Next_Issue/2014/Nov-Dec_2014/Hershberger_QEX_11_14.pdf

    One thing I would like to see added is more flexibility to arrange panadapters side-by-side, especially when you want to display three or more bands.  You can force this to happen by shrinking the window vertically, but it would be better if it could be done full screen.  This has been discussed elsewhere on the forum. 73, Jim
  • k3Timk3Tim Member ✭✭
    edited May 23
    Hi Jim,

    Thanks for the link to the article!  Basically, we get almost 3dB in power increase in SSB for free.  
    In looking at SDR versus traditional radio I was struck by the s/w add ons one can do versus buying a separate box for old school radio.  One example is audio processing (rcv / xmt) where one can drop a pile of cash on outboard h/w or go the SDR approach for free.  At least that is the way I read how DaX will / does work.  My next steps will be RTTY and other digital modes.

    I have a Elecraft XG2 sig-gen and did some testing of the receiver performance.  The XG2 was checked at work with some very expensive test gear (Bureau of Standards traceable) and the  50 / 1 microvolt signals are very close to spec.  With 50 uv I read -73dB on the scale and S9 on the meter. The 1.0 uv signal showed -107 dB and S3 - all as expected.  To my hearing the MDS was around -124 dB (0.14 uv) which puts it well below the noise level of HF bands.  I am very impressed by this result.  

    BTW the XG2 is an impressive device also.  

    It will be interesting to see what goodies are added to the radio in the future.  I am partial to pre-distortion but this isn't really a requirement but sure nice to have.  A Titan 425 awaits in the wings for eventually when I have better antenna setup.  This AM worked Fuji (40m CW) with a good sig report.  He also was booming in nicely.

    Thanks again for the link and your thoughts about the panadapters.  I'm still trying to wrap my brain around one. :-)


  • Duane_AC5AADuane_AC5AA Member ✭✭
    edited December 2016

    Hi Tim - well, had I been active for the last 3-4 years prior to purchasing the 6500 I could give you a better comparison, but I'm still getting antennas back up in the air.  So far, the 6500 is certainly no worse than the Orion, and in many cases is noticeably better (like, 4 high-performance RX's instead of one good and one mediocre RX).  QSK is much faster than the Orion's.  I can't say much more than that yet.  I also have an Argo 6 as a "backup"/QRP radio with a decent RX in it!  Nice little radio.

        73, Duane

  • k3Timk3Tim Member ✭✭
    edited May 23
    Further Updates

    Put several days on the 6500 now and continue to be very impressed / pleased.  It has been running 24/7 without a hiccup,  Power cycled was required a few times to change out a DC supply.  The supply was upgraded to an Astron 70Amp linear with the power cord reduced to 10 inch length so the FLex should be happy about the very stiff DC source.

    SmartSDR is fairly intuitive and easy to learn.  Using the multiple slices is an interestin concept and also easy enough to learn and control with SmartSDR.  Was able to have an RTTY QSO while listening to Radio Havana in the background,  RH drops out when transmitting of course which seems like a good excuse to upgrade to a 6700. :-)

    The FLDIGI setup went w/o a hitch.

    Sync - AM - really excellent.  Was listening to a station that had mass interference on one side band but not the other.  With the sliding filters and display one can observe exactly how to configure the filter to pass the full width of the good side band and a portion of the other SB also.  It seems the sound is slightly better when one passes a small portion of the opposite SB (from 'dc' to about 500 Hz) rather than a single SB.

    MW AM - listening to Chistmas music on local AM stations was really something.  Mind you, the audio amp is a 10 watt Class A tube device and the music from the 50's era was especially mind numbing.  A great room filling sound.  I've heard it said that music was specially Engineered to sound best on AM broadcast (which would make perfect sense).

    CW - Bug interacts well with the Flex and doesn't have the 'scratchy' bug effect.

    RTTY - Can someone kindly inform me as to the max key down time for RTTY and Flex 6500?

    SSB - Can one use a dummy load and a local receiver to set the mic exp/compression rather than asking a remote station for the help.  I don't see a pit fall with this assuming the rcv is not overloaded.

    I did come across a few of the known problems already mentioned out here so won't bother with the details.  No show stoppers more annoying.  

    One thing I would like to see changed is:
    In CW when operating as a straight key (IAMBIC off) the 3C 1/"4 phone jack is still treated as a 3C rather than a 2C.  The sleeve end is still treated as a signal pin rather than a ground.  I have a nice 2C cable for the CW key but can't use it due to the above.


  • k3Timk3Tim Member ✭✭
    edited May 23
    I followed the steps in Smart SDR s/w manual.  The one thing to watch is you turn on the DaX channel for Tx and Rcv that you'll be using,  I did take it in steps making sure RCV made it into the PC (DAX) then into FLIDIGI.  
    Don't run Norton so can't comment on that.  A similar AV program here is showing some one is wanting access to the external web.  Whereas the PC is not on the Web it is of no matter but I shall look into that.

    good luck.
  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited December 2016
    Norton is a virus.  Remove it.  We have so many issue reported via Support that are resolved when Norton is completely removed from the PC and that is very difficult to do, hence the virus comment.  In some cases an operating system reload was required.

    There are much better and cost effective alternatives for virus protection available.  AVG and Avast are just two of many.
  • ChuckChuck Member
    edited July 2017
    My first post to the community so hello to all.

    I am not a 6500 owner yet, but extremely close, in the fox hole leaning forward, hand on the phone.

    I would like to ask about Tim's question; RTTY - Can someone kindly inform me as to the max key down time for RTTY and Flex 6500?

    In my case I sometimes get long winded on Olivia and would like to know the key down times also.
    I think I read somewhere that there is a fan within the 6500.....?

    For the Flex company. Once ordered is there a lead time before shipment or are the units in stock for the most part.



  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited December 2016
    It is all dependent on the ambient temperature in the shack, but I suspect your fingers will become too tired to continue typing before the PA reaches a temperature that exceeds the operating spec for the transistors.  However, if the FPGA in the 6000 does get too warm, the radio has thermal protection logic that will prevent any damage from happening. 

    If the radio is in stock, it will usually ship in 1-2 business days.
  • ChuckChuck Member
    edited July 2017
    Thanks Tim for the quick reply. Questions answered.


  • k3Timk3Tim Member ✭✭
    edited May 23
    I ran some RTTY the past days - with long Xmt the air out of the 6500 wasn't warm so looks like TIm is spot on.  The Astron 70Amp linear supply didn't even get warm to the touch. :-)

  • k3Timk3Tim Member ✭✭
    edited December 2016
    60C 50C. The temps dropped pretty fast with some key-up time.  Voltage stayed within 0.1 volt so I am happy with that!  The 70A supply and 10: pigtail are working as expected. I believe this will result in better SSB Xmt audio.

    A Final User status report to follow.  Expect good news.


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