6400 Receive Antennas

HCampbell WB4IVF

Brad, before you order the 7610, you might want to peruse the user manual.  ICOM makes fine radios (I have 3), but like any radio, it has shortcomings, and you might find that it lacks other features that may be important to you.  That’s why I opted for a Flex instead of the ICOM.   

BTW, my first “radio” was a brand new Hallicrafters S-120, followed by a Heathkit HW-16 rig, so I guess that qualifies me an “expert” in old age too!  (-:

Howard

Ken - NM9P

Gentlemen...please let's dial back the pejorative a bit.  It isn't necessary.

I have been a ham for 44 years, and I was tripped up by this at first.  I ordered my 6500 in January 2013 before any of them were released, after having drooled over the 6700 for a while, but unable to afford it.  (I hope I didn't make the poor 6700 rust out in the process...)

After having read the many of the descriptions of both rigs, and trying to assimilate the technical information, and waiting on pins and needles until August 2013, I received my 6500 and put it into action.

I remember being thrilled, even with the initial pre-release software (some 4 or 5 releases before V.1.0.0 was released to the masses).

But I remember being surprised that I could not receive on both antennas at the same time (HF and 6 Meters)  What I discovered was that I had build my assumptions based upon descriptions of the 6700 and applied them to the 6500 (the only other option at the time, and announced a little bit after the 6700 was announced).

Once Tim explained to me (for the second or third time) the difference between having 2 or 4 slices and the advantage (and expense) of having 2 SCU's, I was satisfied, even if a bit frustrated..

Why the confusion?  

In the final analysis, especially at the time the 6000 series was released, there simply was no frame of reference that easily and adequately explain the new technology and terminology.

The Direct Sampling rig was a whole new ball game?

Multiple VFO's?  Well not exactly....We have 2 or 4 or 8 Slices....but they can tune different bands at the same time....So they act sort of like multiple VFO's but they are much more than that.  They are more like independent receivers all operating off of the same antenna (SCU).

Oh...and you can put different slices on different panadapters and watch them separately....

Multiple receivers?  Well...different slices are LIKE different receivers...but not quite....(see above) If I have an antenna with wide enough coverage, or can combine two antennas into the same RX port with a combiner or duplexer, I can listen to multiple bands from 160 - 6 meters at the same time.  But they all use the same antenna port.  (either ANT1, ANT2, RXA, XVTR, etc.)

We can have one or two SCU's, depending upon the model....Are THEY Different receivers?  Well sort of...If you have 2 SCU's you can use two different antennas at the same time..... 

Do I need two SCU's to do full Duplex?  No...You can do full duplex with only one SCU, but you need to use a different Receive antenna and port than you are using for your transmit antenna.  And you need to have enough port-to-port isolation and filtering so that your transmit signal does not overload your receive port.

Does having 2 SCU's guarantee the ability to do Full Duplex?  Not necessarily, because some manufacturers may not have enough isolation and/or filtering to do full duplex - On the Flex...yes, within the proper parameters....

Full Duplex and 2 SCU's are not one and the same.

The new technology of Direct Sampling SDR's has turned the whole lexicon on its side - introducing a whole new vocabulary, but also incorporating some of the old words, but with new meanings.

It can be very confusing to those making the shift from traditional radios and terminology to understand the new way of doing radio.

And, alas, it can be difficult for fans and marketing to translate the new terminology into language that new buyers will understand without making errors of assumption.

I am certain that FlexRadio is not deliberately misleading people with their ads.  Frankly they don't need the grief that would create.  (By the way, they have a 30 Day return policy if a customer feels they made the wrong purchase.)

But at the same time, no one needs to have their intelligence or operating ability or skills questioned because they may not have fully understood, or have made assumptions about the complex technology involved with the 6000 series.

These are wonderful, but complex pieces of high tech equipment that are redefining the amateur radio lexicon. 

Those of us who have been in the "deep end" of the pool for a long time can sometimes forget what it was like the first time we jumped in to test the waters.

Lets give each other a little grace...and patience.

Ken - NM9P

Roger_W6VZV

It would be a real bummer to "move on to an Icom" and then find out that its "independent receivers" are the same as the 6400M.  For every transceiver I've ever owned, the "second independent receiver" was not really a stand-alone separate receiver -- it was only good for listening using the same antenna and usually on the same band.  My FT-1000MP MarkV, which was near-top of the line when I bought it (back when dinosaurs roamed the earth) was like that.

de Roger W6VZV

Ted VE3TRQ

To be fair to the 7610, it does have two ADCs, albeit I believe they are not quite equivalent to each other. The whole conversation about heat sinks on the 7610 ADCs clearly indicated two of them. And the 6400/6600 are also not free from heat sink issues. Both Flex and Icom make good radios, but none are perfect.

Greg N8GD

As usual, Ken arrives as the voice of reason.  That, along with his technical knowledge, excellent writing skills, and ability to make a complex subject easier to understand, makes him more than worthy of the title "Elmer."

Bill Roberts

As a ham of 54 years (read that "old man") and Flex owner since 2010 (Flex 5000 to 6300 to 6600 in 2018), I experienced no difficulty understanding the difference between 1 and 2 SCU radios or the front end/filtering differences between all models.  Now, I'm all for extending grace but I take minor exception to folks accusing Flex Radio with misrepresenting their products.  The product comparison table states that the 6300 and 6500 radios are single SCU and incapable of full duplex or diversity reception.  The 6600 and 6700 are capable on both counts.  More importantly, if a person is unhappy with his/her purchase decision, they DO have 30 days to return or upgrade the product.  Do I-K-Y do that?  When I consider how patient and kind Flex guys were to newbies like me, whether over the phone or at hamfests, I have difficulty hearing them accused of misrepresentation.

k9bm .

Based on the length of this thread and the number of folks who have weighed in, I think it's fair to say this is NOT a black and white issue.  Ken NM9P had the most sober assessment of the different angles.  To be clear, I never said that Flex had hoodwinked me or misrepresented its product.  What I did say was that Flex used language that was misleading to anyone without an intimate knowledge of the architecture of SD radios.   And I stand by that position, feeling that Flex should share some of the burden of ushering in a new age of radio by helping folks, old and young, understand what they are buying.  If they attach new meanings to old words, this should be clearly explained.

Anyway, I've changed my mind and decided to keep the 6400.  It's not even remotely worth an extra $2k to add 6 meter receive capability.  I have my old Icom 756PRO collecting dust, so I'll interface it with the computer and monitor 6 meters while using the 6400 that way.  I am truly grateful for all the comments, and I guess I'm (slightly) smarter than I was yesterday....

73, Brad K9BM

Ken - NM9P

Brad,  I think you will find, as I did with my 6500, that you have purchased an excellent rig.  Although there is a bit of a learning curve, once you master the panadapter, the settings for AGC-T, and Mic Profiles, you will be amazed at its performance, in spite of the initial letdown of expectations regarding the definition of the receiver(s).

I wouldn't be without my 6500, unless it was to upgrade to the 6600 some day in the not to distant future.

Good luck, and as I can be helpful, please contact me.

Ken - NM9P

Roger_W6VZV

OM I am a new 6400M owner/user and I have been totally loving the rig.  I am pretty sure that you will too.
de Roger W6VZV

Lasse Moell

If you just want to montor 50 MHz, why not get a SDR-receiver like the Elad S2, this will allow you to see whats going on, and if there is someting you can quickly switch over to the Flex.
The S2 covers 0-60 plus FM/Air and 2 meters and then some.
/Lasse SM5GLC

Robert Lonn

Roger,, still have my FT-1000MP MarkV,, 200 watts and 80 watts Class A operation... And a Synchronous Detector,, glad FLEX has one as well!!

Robert 6600M

Robert Lonn

WOW, things are calming down now, and we have another loyal 6400 Flex Customer!!! Before I decided on my 6600M, I spent an hour on the phone with Flex marketing.. I had my list of questions, and they were all answered.. 8 out of 10 questions were answered with a Thumbs Up, I like that, but two questions did not satisfy my radio operating desires, but they were Far Down my list of must have in my radio needs and one of two might be in a future software release.  I also asked a lot about their manufacturing techniques in Texas, and their QC process etc. etc.  One thing I was VERY EXCITED to hear was that Flex charges $200 to upgrade to a new Higher version of Software!!! So when 3.0 is released, It should have some very exciting features.. And we know that development cost time and labor cost.. If Flex could not recoup some of their cost, then where is the incentive to spend the time in development?? If it all plays out, that $200 will get Flex Owners a Next generation Software Package... In the meantime 2.**** will continue to get minor upgrades and changes For Free!! 

Thanks Flex
Robert 6600M

Bill -VA3WTB

It has everything to do with it, the receiver in an SDR radio is much much different then a non SDR radio.  So as I said,,if you understand that an SDR radio uses ADCs and SCUs you would know what they are and what they work.

Bill -VA3WTB

Robert, I remember Gerald saying that the $200.00 does not even cover the cost of development. 

Robert Lonn

Your Correct,, So Flex charges a Modest Amount, they probably could charge $1000, but most people will probably Run Away, so $200 seems like a sweet Spot...

David Pearson

Wish I read this before I purchase my Flex-6400. Feeling dumb for not noticing this. About to put the Flex-5000 back into operations. So, the Flex-6400 is like Flex-5000 without a second receiver.

John KB4DU

If the purchase is within 30 days, flex will take it back and refund.

David Pearson

Past the 30 days already, life got busy, so I miss the window. I will have to sell it then upgrade next year.