ARDOP w/ Flex 6500

James Del Principe

Anyone with experience using ARDOP with their Flex 6500? I have no problem with Packet Winlink to an FT 847. It works well. However, ARDOP via Flex is frustrating. It will connect to a gateway sometimes. I have tried local and distant ARDOP gateways and they do connect but unreliably at best. When they connect, there is a negotiation (handshaking) but the message never transfers. Lots of traffic back and forth so they do talk. I can see received signals on my Flex panadapter and on the virtual modem display as well. The green bar will travel across the screen indicating a transfer of the message but it remains in my outbox.

My Flex is a 6500 running 3.2.31.2837. The Winlink Express is 1. 5. 36.0

So the Flex/Winlink Express has some level of communications with several gateways but does not transfer the message. Any thoughts? Best 73, Jim KD1I

Ted VE3TRQ

Thanks for bringing this up, Jim.

We are now using VARA because Winmor has gone away. However, we find that we can usually connect with VARA to any NON-Flex machine, but Flex-to-Flex is absolutely impossible. We run communication exercises with VARA P2P on a regular basis, and those of us with Flex radios can only connect to those WITHOUT Flex radios. Flex-to-Flex results in initial recognition of the call, but the connection never completes. This is some kind of timing issue in tx/rx turnaround, it would seem. In fact, the author of VARA even says in his documentation that Flex-to-Flex communication is unlikely to work.

Why is this, and how can we fix it!!! I really don't want to have to use my K3 with Linux Wine to use WinLink and VARA.

James Del Principe

Ted, Thank you for the fast reply. Of course, it leaves me totally confused. Our ARES group did not wish to use VARA. I have not tried that at all. Last night, 3 of us tried using ARDOP both with a gateway and peer to peer. The others were finally successful but really not reliable. (took several tries and several gateways) They could exchange messages via peer to peer but I could not with either of them. One is in my neighborhood and the other is about 12 miles away. We were, for that test, using 10 meters at night so no QRM or QRN to blame. We could see each others signals on the virtual modem. My neighbor was using a Yaesu FT2000 and the other an FT 991..... both nice rigs and they could talk to each other.

If this is a Flex issue, I am really disappointed. I should buy yet another Signalink interface and use my FT 2000??

ARDOP is often used for ARES work around the country. Has anyone noted problems with their Flex and ARDOP?

Thanks again, Jim

Ted VE3TRQ

We usually don’t use ARDOP, but we have the same issue, Flex-to-Flex. Only Winmor was reliable using a Flex.

James Del Principe

Ted, I can't even get it to work Flex to non- Flex. Yaesu to Yaesu worked after a fashion.

Ted VE3TRQ

We have solid WinLink / VARA P2P connections between Flex and non-Flex, Jim. I happen to be using SSDR on Parallels on a Mac, the other 2 Flex guys are using native Windows. We are all running with Digital mode set to lowest latency (less steep filters in the Settings / Radio setup / Filters).

I have been able to use WinLink mode to connect to gateways with Ardop and with VARA.

James Del Principe

Ted, I can't even get it to work Flex to non- Flex. Yaesu to Yaesu worked after a fashion.

James Del Principe

Thanks for the idea on filters. I will try that in a bit. Also have compression to minimum. Will turn off.

James Del Principe

Bob KN4HH

Ted and Jim, I have the same experience. I did connect to two stations and managed to pass one piece of traffic using my Flex 6500 under ideal conditions. I then tried a connection and sending a long message and was not able to complete the transfer. I switched to my IC-7300 and had no trouble connecting and passing traffic with multiple stations. As with Ted, I had no trouble with the Flex when we used to use Winmore. I monitored the Flex behavior and I did notice that the latency (at least on my network) was such that the connecting station was transmitting before the Flex reverted to receive and overlapping occurred throughout the connection attempt.

James Del Principe

Ted, Thank you for the fast reply. Of course, it leaves me totally confused. Our ARES group did not wish to use VARA. I have not tried that at all. Last night, 3 of us tried using ARDOP both with a gateway and peer to peer. The others were finally successful but really not reliable. (took several tries and several gateways) They could exchange messages via peer to peer but I could not with either of them. One is in my neighborhood and the other is about 12 miles away. We were, for that test, using 10 meters at night so no QRM or QRN to blame. We could see each others signals on the virtual modem. My neighbor was using a Yaesu FT2000 and the other an FT 991..... both nice rigs and they could talk to each other.

If this is a Flex issue, I am really disappointed. I should buy yet another Signalink interface and use my FT 2000??

ARDOP is often used for ARES work around the country. Has anyone noted problems with their Flex and ARDOP?

Thanks again, Jim

James Del Principe

Bob, thank you for your in-depth research. Our experiences are very similar. I really am disappointed as this is one of several issues that seem to be common with this release - or even previous releases - of SSDR. My panadapter also frequently freezes up and the NR - noise reduction - just muddies up a signal and does not improve intelligibility. WNB does absolutely nothing under any circumstances. Best 73, Jim

Ted VE3TRQ

Maybe it is time to turn this into a Help Desk item in order to get some official Flex input. It is certainly an annoyance, although a bit of timing leniency in the WinLink modem protocols would help things along a lot. And a TNC of some sort would be unlikely to help, as the timing problem appears to be in the RF end.

James Del Principe

Ted, Thank you for the fast reply. Of course, it leaves me totally confused. Our ARES group did not wish to use VARA. I have not tried that at all. Last night, 3 of us tried using ARDOP both with a gateway and peer to peer. The others were finally successful but really not reliable. (took several tries and several gateways) They could exchange messages via peer to peer but I could not with either of them. One is in my neighborhood and the other is about 12 miles away. We were, for that test, using 10 meters at night so no QRM or QRN to blame. We could see each others signals on the virtual modem. My neighbor was using a Yaesu FT2000 and the other an FT 991..... both nice rigs and they could talk to each other.

If this is a Flex issue, I am really disappointed. I should buy yet another Signalink interface and use my FT 2000??

ARDOP is often used for ARES work around the country. Has anyone noted problems with their Flex and ARDOP?

Thanks again, Jim

James Del Principe

Ted, you are correct. I think Bob, KN4HH, is exactly correct.... it is a timing issue and the Flex fails to switch from transmit to receive quickly enough. Will they take this on? I have not heard from anyone else using ARDOP on their Flex except you and Bob. Are we alone in this? Other digital modes work just fine. I also use FLDIGI and MMSSTV without problems. Best 73, Jim

Ted VE3TRQ

The problem here is the nature of the communication - it is essentially packet, with data sent, then an immediate acknowledgement of that sent data. It appears the acknowledgement is never seen if the receiver of that acknowledgement is a Flex radio :-( And of course the various protocols want to make that ACK happen as fast as possible in order to keep the data rate up and message latency at its lowest.

Fldigi and wsjt-x, etc. do not use that quick turnaround ACK in normal operations, although I must say I HAVE had issues with the Fldigi / Flmsg ARQ protocol with the Flex. I never did try to run that one down - just stopped using ARQ.

James Del Principe

This looks like progress.... however, maybe not enough to be successful.

With the latency set to lowest for digital and DIGU selected, with AGC to fast and AGC-T low (around 26) and reduced bandwidth (1.5 K0, I was able to communicate with a gateway (same one as before) but this time it got as far as the green line marching across the screen and I now have packets sent as shown below.

BUT, the messages are still in my out box so they were not really sent.

Here is the result below:

*** Connected to Winlink RMS: AB4NX @ 2021/04/28 23:15:26 USB Dial: 3587.000

*** Station Bearing: 263, Range: 38 km

RMS Trimode 1.3.37.3 Welcme to Georgia ARES Hybrid Gateway

KD1I has 496 minutes remaining with AB4NX

[WL2K-5.0-B2FWIHJM$]

;PQ: 93811875

CMS via AB4NX >

  ;FW: KD1I

  [RMS Express-1.5.36.0-B2FHM$]

  ;PR: 43351758

  ; AB4NX DE KD1I (EM84BM)

  FC EM 6AIO8DEEODK6 146 137 0

  FC EM VH8C64N5M0NP 155 140 0

  F> 60

;PM: KD1I VANYAD5JGXIS 106 K4WQS@winlink.org TEST

;PM: KD1I O4JF5O5C2CV6 155 K4WQS@winlink.org this is a test of the ardop system

;PM: KD1I DFZE4YJGW5B8 301 KM4JDF@winlink.org Last night on 3975

;PM: KD1I LAH5H6NGXHY6 766 KK4EHJ@winlink.org Re:Last night on 3975

FS YY

*** Sending 6AIO8DEEODK6.

*** Sending VH8C64N5M0NP.

*** Disconnected from Winlink RMS: AB4NX @ 2021/04/28 23:18:35

*** Session: 3.1 min; Avg Throughput: 194 Bytes/min; 1 Min Peak Throughput: 194 Bytes/min

So, did any message data actually get sent???  Apparently not. I also tried other gateways and were able to negotiate (handshake) but no message was sent. Many thanks again,  Jim

Ted VE3TRQ

We are switching to using VARA FM for our Club digital net tonight, Jim. A couple of the guys have Flex radios with 2m FM, so we will see how they do. I will be using my K3 because I have not yet connected the 2m transverter to my Flex 6600.

As I have mentioned, we have never had any issues with connecting a Flex to a non-Flex. Only Flex-Flex was a problem. We will see if VARA FM behaves better, given it has the ability to deal with the timing problems that can come up when going through voice repeaters.

James Del Principe

Ted, thanks for the update. I am going to try vara myself on HF in a bit. Let me know how you make out. 73, Jim.

Ted VE3TRQ

We ran VARA FM P2P through 2M simplex last night, Jim. We were successful in running Flex-to-Flex and Flex to a number of other radios. The guys running Flexes did have to use “DFM” for it to work. Our Flex-to-Flex problem seems to be only with HF. Next we are going to try the voice repeaters (and eventually the digipeater capability as well).

James Del Principe

Thanks, Ted. All good to know. I will try vara HF soon and report results. Good luck and 73, Jim.

Kevin WM4J

I'm doing some Winlink Training and one of the exercises requires P2P connections with other class participants, and many of them are using ARDOP. I was having similar issues to others on this thread with ARDOP connections:

• Connections would not reliably establish
• When I could connect the transfer would either not start or it would start and then disconnect before the transfer completed

I started looking at the ARDOP modem settings and help file (Which has tons of useful info) and I found these two settings:

Leader Length: This sets the default initial Leader length for FEC. The initial connection on ARQ will use this value and then automatically adjust to an optimum value after the initial connect request. A good starting point for Leader Length is 240 ms for most SSB radios. Some FM radios or VOX keying may require larger values. For FM operation with slow HT or slow FM radios initial values up to 1000 ms can be used if needed. The leader allows the ARDOP_Win TNC DSP code to detect and quickly tune the radio to match the users frequency. Note: Radio control is far too slow and usually too coarse for this process...all tuning is done internal to ARDOP_Win TNC's DSP code and should track the user frequency up to +/- the tuning range above to an accuracy of about 1 Hz. 

Trailer Length: The trailer or "tail" adds a short (up to 200 ms) tail to the end of each frame transmission to delay the release of the transmitter PTT. This is usually only required in certain SDR radios which have delays in processing the transmitted audio where the normal end of the frame would be truncated. Normally this can be left at its default value of 0. 

I also found some references to trailer length being applicable to VAC (Virtual Audio Cables) / DAX which also add latency to the audio.

My Leader length was about 160ms and my Trailer Length was 0ms by default. Since the docs mentioned that 240ms was a good start for Leader Length I changed mine to 240ms and I set the trailer length to 200ms which is the max.

After adjusting those two settings I was able to connect and complete multiple P2P connections. I was also able to reliably connect to ARDOP RMS gateways that responded to my requests.

To change the settings click "File --> Virtual TNC Setup" on the ARDOP Virtual TNC.

Then you will see the settings screen below where you can adjust the Leader and Trailer Length:

I wasn't very scientific since I was in a hurry and it was 2:00am when I was trying to make the connections, so it's possible there are better values for both those settings. If you use ARDOP you might want to adjust those values and test to see if those are the best values. I don't use ARDOP as a general rule (Vara HF is faster) and the first settings I tried worked well enough for me so I'm sticking with them. If you play around and find better values respond to the thread and let the rest of us know.

arodland

I've done it on a 6600. Works okay. If that bar is moving, then you're communicating, and there's no problem with the Flex or with the DAX setup.