Flex 6xxx and digital modes via remote connection

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Hello all,

I've purchased a Flex-6400, though it hasn't shipped yet.  I've been working with a buddy of mine to set it up at a remote location, but recently in speaking with him.  He is unsure if digital modes will be usable since the radio will be remote and no PC at that location.

Is it possible to do digital modes via SmartSDR from a remote location or is a PC required at the remote location with a VPN connection to it?  (or even a Maestro at some point in the future)
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Posted 2 years ago

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Adde Tjernberg

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Unfortunately SmartLink does not support DAX (yet...), but you can solve it by running a through a VPN tunnel.

I'm not sure how it will consume your bandwidth... 
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Mack McCormick, Elmer

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The simplest solution today is to put an inexpensive Raspberry Pi VPN server at the remote location. Log into the VPN from your client and you can then natively connect via DAX, CAT, and SmartSDR if desired. 

I do recommend, if you're not experienced with networking, that you consult with a friend to set-up the Raspberry Pi. It's not difficult if you understand a bit of Linux and networking. 

Most of us use OpenVPN. A google search will yield a lot of tutorials. The software is free and well supported.

The reason Flex has not implemented DAX and CAT remotely is due to bandwidth issues many users would experience. That would lead to a LOT of support calls to Flex which they cannot solve since the only solution is to provide more bandwidth.

You'll love the FlexRadio!


Alpha Team
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RIck - K8GI

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Hi.  Yes, I agree.  Elecraft and FRS are among those at the "top of the pile" performance-wise.  I have used remote-rig and I'd characterize it as a "nicely performing kludge."  It's a great add-on for equipment that was not designed to be network capable and many folks have used it effectively.  Falls way, way short of controlling a complex remote station unless TeamViewer/RDT is used.  I used one of my two RR pairs to control a simple, 100W 6m remote station and it worked splendidly.  But, when one adds a plethora of  "stuff" at the "radio end" well, it's just not well integrated.  I also have a newer RR "twin" that's pretty much still in the box that I'm going to sell regardless.

I've worked some great DX with the K3s and their RX on CW is incredible.  But, comparing my P3s to what FRS has to offer is nonsensical, for a single example.

Rest assured, I'm not too interested in sending $15-20K or more of stuff to the used market and buy all new.  But I'll do what I have to do.  Unfortunately, I know not a single person in my area who uses FRS in a sophisticated way (not talking about just rag-chewing on 80 phone).  Never even seen it "work!"  So, I'm "investigating."  I bought a 6300 and a Maestro and am, shall we say, "learning," albeit far more slowly than I'd like.

I appreciate your comments!  :<)
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You are trying to solve two vastly different use cases. My suggestions for you to consider:

1) Keep the Elecraft + RR for remote radio control
2) Deploy Green Heron Everywhere for full station control- antenna selection, stacking, rotator control, etc.

With GHE your experience running the station will be identical regardless if local or remote.
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RIck - K8GI

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I appreciate your thoughts.  TU.  I played with RR until I gave up.  Never being able to send CW with Winwarbler was one of the barriers -- I don't recall the others.  GH is extremely well thought of; I'll take another look.  In the short time I've been playing with my 6300 I've become "hooked" on SSDR display and that of the Maestro.  The Elecraft P3?  Well, it's a cute add-on to the K3 but pales in functionality to FRS' offering.   

At this point, it appears that whatever I do will be "fiddly" and a kludge.  Likely I will simply give up the thought of remote operations.  Just not enough time to make it work -- trying to adapt old technology to new uses. 

Again -- thanks for your comments!
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Why give up so quickly? You already have the Flex and the VPN setup; why not try SSDR over VPN? You may find out that it works just fine for your needs.

This of course won’t solve the full station control use case, but evaluating GHE is an option that is fully independent of the radio itself.
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KY6LA - Howard, Elmer

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I too played the RR and K3 route for Remote... TOTAL KLUDGE. 

I am a computer nerd from way back and even I found it less than obvious to get working reliably albeit I have always been able to figure it out in each location if I put the effort into it..

I am not a CW guy but I do understand that RR works very well with CW.  I can't comment on Flex. 

RR Works Ok for the use case where you have a fixed remote and a fixed base but if you travel around the world like I do, it requires far too much extra crap to pack in my luggage.  By contrast, for my use cases, all I need to do with Flex is schlep my iPhone or iPad and I am on the air from anywhere in the world... too easy.

Bottom Line;  The K3 was NOT PURPOSE BUILT for Remote... when the 6000 line was.  With SmartLink finally working, it totally blows away RR for ease of use and especially lack of additional crap to schlep.

Plus.. while I do like the spots on the display of the P3 with the K3 when you add NAP3, and for a while it was the major reason I liked the K3,  The puny display on the P3 pales in comparison with the SSDR display and especially the spots of the display with SSDR for IOS which again is now the superior product.

BTW.. I am starting to wonder if our anonymous friend, Varistor has ever owned or even operated a Flex rig.  If he had, I seriously doubt he would still be promoting ancient 20th century tech in the 21st century. 

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I don't suppose SmartLink supporting DAX is in t he future road map?
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Tim - W4TME, Customer Experience Manager

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It is a feature we are investigating providing.  The challenge is the high bandwidth utilization of DAX
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Thanks Mack,

I'm knowledgeable in Linux, OpenVPN, and R-Pi.  It will be setting up the Flex to work with it is where I may end up with questions.

Do we know what the bandwidth requirements are for supporting this?
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Tim - W4TME, Customer Experience Manager

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2-20 mbps depending on the type and number of DAX streams.  Which is why DAX is not currently supported and why we are investigating how to best implement that will have the least impact on network bandwidth.
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Bill -VA3WTB

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Yes, it has been stated that DAX with smarlink is planed.
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I don't see “Audio Over IP” being a problem as a LAN has more than enough bandwidth however audio data compression becomes a lot more important with a Wi-Fi or over the internet connection where bandwidth can vary drastically.

The good news is that there are already great audio over IP CODEC’s available today that are made for various audio over IP applications, In fact many of them can process multi channel audio with very low latency. My guess is when the time comes FRS will just incorporate one of these CODEC’s into SSDR in the future. Some have a license fee and others are license free it will just come down to witch one works best.

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Marc Lalonde

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running here trough VPN whit DAX and IQ Strem  whit no issue

usually i run IQ @ 48k  for 2-3 hour for CW skimmer  and remain of the day whit DAX active on 1 slice 

this is my internet usable for last couple of day  18,19 was  very active > 8hour of EME operation 
noting do for reduce bandwidth like slow down refresh rate or else

this  include "causual" home internet usage  of 6 to 10gb per day

so as long you stick to 1 slice  VPN is manageable and have no limitation 

if need low bandwidth for digital mode whit multiple slide put computer remote and access it trough teamviewer  / anydesk  ,this is what i doe for "monitoring"  eg cw-skimmer that send me spot via telnet or WSJT-x trough pskspotter

p.s. make sure that if someday you use audio CODEC to really chose it very carefully ,
most of it destroy digital mode or extreme weak signal  ,try to do digital mode whit RCForb ;-)
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Kyle Krieg

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Easiest Raspberry Pi VPN I've ever setup.  


I can setup a VPN on a Raspberry Pi 3 in less than 30 mins that works the first time. Just forward the correct port on your router and your done.
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Or you can use a Netgear R7000 access point at the remote location, it has a build-in VPN
server that you can then use with a free Open VPN client on your Windows or MAC laptop. 
It all works out of the box.
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Another viable option is Ubiquity Edge Router X. For $50 you get an enterprise grade router, including full blown VPN.
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Wayne, W5XD

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The latest version of WriteLog's FlexRadio driver extends its support to SmartLink (http://writelog.com/category/flexradio-rig-driver.) The driver works with both the full and demo (http://writelog.com/demo) versions of WriteLog and has its own DAX implementation. An installation caveat is that installing SmartLink updates firewall settings appropriately for SmartSDR's use, but WriteLog's DAX additionally requires you to manually open a UDP port on the WriteLog end of the link to receive the RX and IQ channels. WriteLog does no magic with respect to bandwidth, either. The Flex audio channels are currently fixed at 48K samples per second and each sample is 4 bytes. In bits per second, that works out to 1.5M (i.e. 1.5 million bits per second) and there is overhead, too. Digital modes are only going to TX and RX well if you have that kind of bandwidth (which is the same constraint you'll have if you use a VPN instead of SmartLink.)