I’ve recently received a nice birthday gift in the form of a mAT-10 automatic antenna tuner.
This is a very tiny low power (30W max) automatic antenna tuner which can be used with any radios, but it’s specifically designed to work with the Yaesu FT-817. For them to work together as intended, the control cable must be used connecting the ACC mini-DIN connector at the back of the FT-817 and the one on the top of the mAT-10.
After several trials with different antennas and 2 different FT-817 (one ND and the other not) I always find that not always but on most of the tunning requests made, both of the FT-817 (ND and not) get frozen on the FM mode at either of these 2 moments:
1- right after pushing the mAT-10 multifunction key for 1sec, which is the way to request a new tunning process to start.
2- right after the tuning process has been partially or completely done.
When this frozen rig problem arises, there’s nothing I can do with it: I can’t change band, mode, transmit nor even switch the rig off and the only thing I’ve come up with to exit this status is unplugging OFF and plugging back ON the 12V external power supply.
The rigs get frozen on FM mode because the mAT-10, through the control cable connecting the ACC mini-DINs at each device, makes the FT-817 switch into FM mode because it’s the mode where it will be asked to produce a carrier for the mAT-10 to carry out the tunning process.
Some very few times this is what happens, i.e. I push for 1sec the multifunction key on the mAT-10, then the FT-817 switches to FM mode, then it transmits a carrier, the mAT-10 starts making little noises while moving the variable inductances and capacitances inside until the best possible SWR match is found, moment at which the FT-817 returns back to the original mode it was when the tuning process was requested and everything’s ready to start transmitting, asuming that a good SWR match was achieved.
But most of the times this doesn’t go this way and the FT-817 gets frozen, forcing me to do the 12V power supply unplugging/plugging sequence and even having to do it again after the tuning process was not fully completed when the first freeze occurred.
Comenting this findings with a friend, he told me something about some devices not working well through the ACC connector of some old FT-817 rigs because of a too low or too unstable 5V voltage present at the ACC port.
The two FT-817 I have and I’ve been using so far with my new mAT-10 are both quite old and I fear this may well be the reason for this communication problem.
With so many experts in electronics and so many FT-817 owners in this community, I really hope someone can give me some light on this problem and/or on a possible solution.
As a final comment, I must say that the mAT-10 tuner is working perfectly if I use any of the FT-817s I have as they were any other different rig, i.e. not using the control cable and producing an AM carrier for the mAT-10 to carry out the tunning process.
I’ll be looking forward to your possible helpful comments.
Thanks in advance and 73,
I’d put money on RF feedback on the control cable into the 817. Operate it into a dummy load and I bet it works fine.
Ignacio EA2BD has found this video and this same problem happens to the guy. He explains that this only happens when the CW narrow filter is engaged. You can see it towards the last third of the video, minutes 12:30 to 13:30 and 15:15 to 16:50
My CW narrow filter is always engaged on both of my FT-817, so I’ll try it with CW narrow disengaged and I’ll let you know.
Yep but strange it works fine if the 817 starts in SSB mode but not in CW mode, in both cases it switched to FM , Tunes, but returns to SSB ok but locks the rig rather than return to CW mode. I use the KISS (Keep it Simple Stupid) solution and just leave the control line at home
Did you remember that thread ?
Guru, this is a known problem, there is no problem from SSB mode but if you try from CW the radio freezes and only taking away all power and remove battery unfreeze. This problem was reported to mAT a year ago but they don’t believe it exists. I just forget about the control line and in the back of my FT817ND is the Sotabeams Dongle, it works just as well
That’s interesting, I will switch out narrow filter next time and try
Thank you, Éric,
I’ve been rereading that thread and I confess I had completely forgotten about it. Amazing what time and age (plus all the drugs and chemos I’ve been having lately) can do to a brain and its memories…
I had been thinking on trying some ferrite clips at both ends of the control cable and I’ve read on that thread that I already recommended that fix to Declan and also that he tried it and the problem got solved. Well, I know now what to do.
Thank you very much to all contributors.
I had two problems with the mAT-10 , the 40m problem when using the SW-3B , ferrites appeared to solve the problem once, but next activation same problem. It’s SW-3B problem on 40m not the mAT-10 in this case.
The FT817ND locking up when using the mAT-10 from CW mode is a separate problem, it remains unsolved (well I have to try switch off CW Nar as suggested) , it is a design problem, and as 99% of CW operators would use the NAR position it’s a serious problem. Obviously proper UAT, User Acceptance Testing was not carried out. It’s a disaster to hike in for two hours, forget for a moment to switch off the narrow filter and lock the radio, unless the proper tools to open the battery compartment with you and face another long walk out with a lost activation.
As mAT sell this tuner specifically for the 817 they really need to acknowledge and solve this problem.
Thanks for that update Dec. It looks to be so much like an RF feedback issue until you see it only happens when in CW narrow. I’m thinking of buying a QRP tuner but as long as the mAT-10 has this issue with an 817 then that pushes it well down the list. It’s currently between the Elecraft tuner or the new N7DDC QRP tuner. I just need to get of my backside and buy one!
OK, Declan, thanks for the clarification.
It’s a major problem indeed because even if the switching off CW NAR solves the problem, having to disengage the CW narrow filter or having to change mode to something different to CW for tunning on a new frequency and then getting back to CW Narrow for normal operation is quite an unpheaval for a mainly or even exclusively CW activator.
In your case, with internal batteries, the upheaval in case of forgetting to switch off CW NAR or changing mode to something different to CW before a new tuning request, can be a big disaster. I don’t have internal batteries in any of my FT-817s, so all I’d have to do is unplugging/plugging the external power supply, but even that is a serious inconvenient when you want to have a normal, comfortable and smooth activation.
Perhaps, the best solution for now will be leaving the control cable at home and doing the tunning with a manually sent carrier, as you are doing now.
I contacted the supplier yesterday to tell them about this issue but they haven’t yet come back to me.
P.D. On the other thread you spoke about a SOTAbeams dongle but I’ve seen a video showing how this gadget works and I don’t fully like it because the carrier is launched by double pushing on the microphone PTT and there are several activations where I don’t even plug the microphone and it remains in its pouch inside the rucksack. Well, I guess I’ll have to decide which is going to be the best work around for me to overcome this issue…
the dongle works very well and if I am bringing the FT817ND with me it usually means I’m planning to also do some 2M FM work so the microphone gets plugged in anyway.
Because I own both ATUs but not an FT817, it’s clear to me that the problem is with the latter, hi.
No, something more serious.
Because it is not the physical presence of the 455 kHz IF filter that causes the symptoms described, but whether it is activated in the operating menu or not, I would rule out RF pickup and bet on a problem at the logical level.
Specifically: I assume that the status information sent by the FT817 to the ATU at the beginning of the tuning cycle is not sent back to the FT817 exactly/unchanged at the end of the cycle and that this effectively “confuses” the control in the FT817 - or the FT817 cannot understand what he said himself before.
Based on the recording of the exchange of information between the two devices, it should be possible to prove this or narrow it down further.
BTW, the interior of the mAT-10 is very clean in terms of HF and well shielded where necessary. I would wait with the ATU-10 version by N7DDC if you read on groups.io how the kit builders are still struggling with it, even with the modification of “factory built” ones from ebay.
Heinz, more useful info, thank you.
I was thinking about CAT problems. Many, many years ago (when a 300MHz Celeron was a fast home CPU!) I was playing with software I wrote that controlled my TS-570 via CAT and then controlling that via a remote internet connection. It worked and later I tried changing the CAT commands for an 817 and I had no end of issues. Basically CAT on a TS-570 “just worked” and there were problems with the 817. I lost interest at that point
I have been testing with my mAT-10 and FT-817ND this morning and I can now confirm that the frozen rig problem when a tunning cycle is requested only happens if the CW NAR is selected and it doesn’t happen if it’s not selected.
The Wimo technical support have got in touch with me to find out what problems I’m having with my tuner. They wrote me in Spanish so I wrote them back in Spanish too.
I explained them the problem of rig freezing when requesting a tunning cycle and I also sent them that video Ignacio EA2BD found and I shared with you here.
Furthermore, I’ve also written Wimo about other problem I found some days ago, i.e. the first 1sec push of the multifunction key doesn’t trigger the tunning cycle and a second 1sec push is necessary for the tunning cycle to start. After the 1st push, there’s a brief communication between the mAT-10 and the FT-817 and the FT-817 switches to FM mode, but nothing else happens and there it remains. At that point, a second 1sec push triggers the tunning, but the rig remains on FM mode because it’s where it had switched to after the 1st push. However, if, after the 1st push, the mode is manually switched from FM back to CW, then the second push of the multifunction button triggers a complete and perfect tunning cycle, i.e. rig switches to FM, carrier is sent, mAT-10 tuner completes the tunning and finally the FT-817 rig switches back to CW.
This is what it should always happen after a single 1sec push of the multifunction button according to the specification and the user’s manual, but it’s not the case. It looks like there’s a system software bug somewhere and I hope they’ll find it and will offer us a solution.
I’ll keep you informed.
P.D. I think I’m going to share this thread with them.
On the issue of 817 communicating with a compatible tuner. I use an LDG 817H with mine, and it goes to 1:1 on some bands. On others, it sees 1:1 and goes past, then stops on 4:1. I try twice again, and it stops on 3:1. The batteries are fresh in both the 817ND and LDG. What’s going on?
Had a similar problem with a T1 tuner that was not used for a longer time. Was told that if one of the latches/switches gets stuck it can generate a similar effect. After triggering the tuning process a couple of times it worked again in my case.
I can confirm that. Latching relays are used to keep the power requirement as low as possible.
By the way, the latest firmware update is supposed to fix similar issues on the KX2.
What’s a latching relay?
It is a relay that is set (ON) or reset (OFF) by the input of a pulse voltage. Even after the input voltage is interrupted, this relay maintains its set or reset condition until it receives the next inverting input. It is also called a keep relay
LDG is usualy using this type of relay. It might as well be a faulty relay.
The Funkamateur in Germany were selling at some point these latchig relays.
finally got a chance to check my 817/mAT-10 connection with the NAR CW filter out. As you found all works as it should so it’s an issue for mAT people to think about. I don’t think I would use the cable anyway as I can see lots of bent pins when struggling on a summit to connect it up HI. For me the Sotabeams dongle is a far better solution as it is always plugged in and a couple of fast clicks on the mic and away we go
OK, Declan, thanks for the feedback. Yes, it’s now confirmed from multiple users that there’s a problem when CW NAR is engaged.
I’ve got an email from the supplier WiMo to thank me for all the information provided and the video. They said they have forwarded all that info to the manufacturer MAT-TUNER BG3MZU and they have also offered me a money return, although they don’t make it clear if they need the mAT-10 tuner back.
In any case, I think I’ll keep the tuner and I’ll use it for SOTA, as, from all the possible ways to do it, I think I have identified an easy way to do the tuning which is not as it was originally intended, but it shouldn’t be so much of a problem, I hope, and the FT-817 won’t enter in conflict with the CW NAR mode selected.
Since I customized several years ago a red wine bottles wooden box to accomodate my FT-817ND and my manual tuner MFJ-941B perfectly fitted inside with all coax and other necessary wires preconnected, that’s been for several years my SOTA-kit:
Now, with the arrival of the mAT-10, I had to think about a possible modification or a completely new SOTA-kit. Well, I’ve been very lucky and all I’ve had to do is taking the MFJ-941B tuner out of the box and placing the mAT-10 in its place the way you’ll see here:
Now I only needed to drill a through hole at the side of the wooden box to be able to plug the mAT-10 battery charger without needing to take the tuner out of the box. Job done this afternoon:
Finally, I wanted to seal perfectly the front, particularly the right hand side where the antenna and control cables connect to the mAT-10 in order to prevent the ingress of debris, leaves, insects and all this type of natural “pollution” available at the SOTA summits. Job done this afternoon with a white foam pannel from the mAT-10 packaging and a cutter.
I can’t wait to go out onto some SOTA to try it.