locked Yaesu FT991A Won't Transmit in FT8 #NewUser #Cat_RigControl #transmit #Yaesu #TechnicalHelpQuestion


Robert44
 

Hi everyone. My Yaesu FT-991A has stopped transmitting using FT8. I have had this problem a few times but it was always cured by doing a full factory reset of the radio. This time that has not helped. The radio/MacBook Pro is otherwise working fine. The radio transmits normal on HF using SSB and AM. Like I said, I did a full factory reset (and correctly reentered all menu items) and restarted the Mac.

I'm not sure but I suspect it may have something to do with RF in the shack. I'm using a TON of ferrite everywhere and a shielded CAT cable between radio and Mac with more ferrite. My antenna is a Chameleon Lightweight End Fed Sloper. I have never had the slightest problem with RF in the shack with normal SSB phone use. Digital stuff is new to me so I'm not sure if the threshold for RF in the shack is lower. I THINK I have noticed the problem of the radio failing to transmit in FT8 with higher power (100 Watts) vs 5 or 10 Watts which leads me to think it could be RF in the shack although my radio and accessories have never been hot with RF to the touch so it's really just a guess.

I reset the radio and computer and dialed the radio down to 5 Watts and still no transmit so I'm stumped. Any suggestions would be greatly appreciated! BTW, I'm an FT8 (and digital) newb but I have made a number of successful DX contacts on FT8 so the radio and setup WAS working fine. Thanks!

Robert KI5TPC


Keith
 

Did you try transmitting into a shielded dummy load?  That can often narrow down the RF-in-the-shack issue.

On 5/5/22 15:30, Robert via groups.io wrote:
Hi everyone. My Yaesu FT-991A has stopped transmitting using FT8. I have had this problem a few times but it was always cured by doing a full factory reset of the radio. This time that has not helped. The radio/MacBook Pro is otherwise working fine. The radio transmits normal on HF using SSB and AM. Like I said, I did a full factory reset (and correctly reentered all menu items) and restarted the Mac.

I'm not sure but I suspect it may have something to do with RF in the shack. I'm using a TON of ferrite everywhere and a shielded CAT cable between radio and Mac with more ferrite. My antenna is a Chameleon Lightweight End Fed Sloper. I have never had the slightest problem with RF in the shack with normal SSB phone use. Digital stuff is new to me so I'm not sure if the threshold for RF in the shack is lower. I THINK I have noticed the problem of the radio failing to transmit in FT8 with higher power (100 Watts) vs 5 or 10 Watts which leads me to think it could be RF in the shack although my radio and accessories have never been hot with RF to the touch so it's really just a guess.

I reset the radio and computer and dialed the radio down to 5 Watts and still no transmit so I'm stumped. Any suggestions would be greatly appreciated! BTW, I'm an FT8 (and digital) newb but I have made a number of successful DX contacts on FT8 so the radio and setup WAS working fine. Thanks!

Robert KI5TPC




Al Rusnak
 

I had the same problem with another Yaseu rig. There was one setting in the radio that I neglected to set after the reset. Found it by going through the menus and checking the manual to make sure the correct setting was chosen.


Al Rusnak,Ke6jac

On May 5, 2022, at 12:34 PM, Keith <geek4096@...> wrote:


Did you try transmitting into a shielded dummy load? That can often narrow down the RF-in-the-shack issue.


On 5/5/22 15:30, Robert via groups.io wrote:
Hi everyone. My Yaesu FT-991A has stopped transmitting using FT8. I have had this problem a few times but it was always cured by doing a full factory reset of the radio. This time that has not helped. The radio/MacBook Pro is otherwise working fine. The radio transmits normal on HF using SSB and AM. Like I said, I did a full factory reset (and correctly reentered all menu items) and restarted the Mac.

I'm not sure but I suspect it may have something to do with RF in the shack. I'm using a TON of ferrite everywhere and a shielded CAT cable between radio and Mac with more ferrite. My antenna is a Chameleon Lightweight End Fed Sloper. I have never had the slightest problem with RF in the shack with normal SSB phone use. Digital stuff is new to me so I'm not sure if the threshold for RF in the shack is lower. I THINK I have noticed the problem of the radio failing to transmit in FT8 with higher power (100 Watts) vs 5 or 10 Watts which leads me to think it could be RF in the shack although my radio and accessories have never been hot with RF to the touch so it's really just a guess.

I reset the radio and computer and dialed the radio down to 5 Watts and still no transmit so I'm stumped. Any suggestions would be greatly appreciated! BTW, I'm an FT8 (and digital) newb but I have made a number of successful DX contacts on FT8 so the radio and setup WAS working fine. Thanks!

Robert KI5TPC








Jamie GOLLY
 

I had a similar issue when WSJT-X was set to USB. I changed to D-USB and TX resumed using Win 10.

JamieK6NGN

On Thursday, May 5, 2022, 12:30:33 PM PDT, Robert via groups.io <robert44henry@...> wrote:

Hi everyone.  My Yaesu FT-991A has stopped transmitting using FT8.  I have had this problem a few times but it was always cured by doing a full factory reset of the radio.  This time that has not helped.  The radio/MacBook Pro is otherwise working fine.  The radio transmits normal on HF using SSB and AM.  Like I said, I did a full factory reset (and correctly reentered all menu items) and restarted the Mac. 

I'm not sure but I suspect it may have something to do with RF in the shack.  I'm using a TON of ferrite everywhere and a shielded CAT cable between radio and Mac with more ferrite.  My antenna is a Chameleon Lightweight End Fed Sloper.  I have never had the slightest problem with RF in the shack with normal SSB phone use.  Digital stuff is new to me so I'm not sure if the threshold for RF in the shack is lower.  I THINK I have noticed the problem of the radio failing to transmit in FT8 with higher power (100 Watts) vs 5 or 10 Watts which leads me to think it could be RF in the shack although my radio and accessories have never been hot with RF to the touch so it's really just a guess.

I reset the radio and computer and dialed the radio down to 5 Watts and still no transmit so I'm stumped.  Any suggestions would be greatly appreciated!  BTW, I'm an FT8 (and digital) newb but I have made a number of successful DX contacts on FT8 so the radio and setup WAS working fine.  Thanks!

Robert KI5TPC


Robert44
 

Thanks everyone I will try all your great suggestions and get back.

Jamie, I was using D-USB so I'll do the opposite of you and give USB a try. Did you change any settings in the software after making this change?

Robert KI5TPC


Robert44
 

Hi again. I tried everything suggested with no luck, including transmitting into a dummy load. I'll play with this some more and report back in. Thanks for the help.

Robert KI5TPC


Jamie GOLLY
 

Hi Robert, no other changes were made.

Jamie
K6NGN

On May 5, 2022, at 2:57 PM, Robert via groups.io <robert44henry@...> wrote:

Thanks everyone I will try all your great suggestions and get back.

Jamie, I was using D-USB so I'll do the opposite of you and give USB a try. Did you change any settings in the software after making this change?

Robert KI5TPC





Robert44
 

Hi everyone. I've been active on another thread about my issues but I think this is better asked here. This is a continuation of the problem I asked below. I got my setup (Yaesu FT-991A and MacBook Pro) working well on FT8 but sometimes it would stop transmitting. In this case the setup received and decoded fine. To get the radio working again I restarted the computer and did a full factory reset of the radio. The radio worked fine for a while but now it has stopped transmitting and nothing I do can get it to transmit again. I'm using the same setting on the software and radio menus that I did when the radio was working so nothing has changed. I've gone over it many times and all settings are correct (at least they are the same as before).

POSSIBLY this issue was caused by RF in the shack although if this is the case it had to be not much RF because nothing had an RF bite when you touched things when transmitting. However the problem SEEMED to happen when I cranked the power up to a full 100 Watts for very weak signals.

The software green button lights up and the red PTT button glows red when pushed. The radio makes a clicking sound and the red light on the radio lights up to show it's transmitting but the PO power out meter shows no RF out. I've tried everything and even uninstalled the WSJT-X software and reinstalled it. I'm at wits end, any thoughts?

$100,000,000.00 dollars to anyone that can fix this! (Monopoly money)

Thanks! Robert KI5TPC


Reino Talarmo
 

POSSIBLY this issue was caused by RF in the shack although if this is the case it had to be not much RF because nothing had an RF bite when you touched things when transmitting. However the problem SEEMED to happen when I cranked the power up to a full 100 Watts for very weak signals.
The software green button lights up and the red PTT button glows red when pushed. The radio makes a clicking sound and the red light on the radio lights up to show it's transmitting but the PO power out meter shows no RF out. I've tried everything and even uninstalled the WSJT-X software and reinstalled it. I'm at wits end, any thoughts?
Hi Robert,
My experience is limited to Windows, but in those cases with it you may need only force Windows to re-select audio source or wsjt-x to do it. In the RFI sense the most vulnerable interface is the USB connection. It happen well below any physical RF bite. Actually in most case there is a high RF current, not high RF voltage.
Just disconnecting USB cable and reconnecting it may help (in Windows).
You may also try to select in the wsjt-x Audio tab another audio source and then reselect the FT991A codec (USB audio codec).
I don't know how Mac behaves, but looks that it has the same RFI problem. Well, USB hardware may be the same.
What kind antenna you got and how it is fed? Current balun at antenna feedline and/or a multiturn current choke on the USB line could help.
Normally RFI don't affect to the program itself and a reinstallation does not help. Re-starting PC may help. (If there is a problem with the settings, then istead of program uninstallation e.g. deletion/renaming of the wsjt-x.ini file returns settings to defaults.
73, Reino OH3mA


Robert44
 

Hi Reino and thanks for the tips! My antenna is a Chameleon Lightweight End Fed Sloper. It is a multi band end fed with a good SWR from 40 to 10 meter. I have an RFI choke between the coax and the antenna. In addition I have A LOT of ferrite everywhere in my shack.

I think I have tried everything you suggested but I'll go back and retry. Thanks again and stay safe in your part of the world.

Robert KI5TPC


Reino Talarmo
 

Hi Robert,
I try to be polite, but you have bought only "one half" of the antenna. The coaxial feedline and whatever is connected to it functions as the "missing" half of the antenna. For sure the antenna current at the feed point is small, but it exactly as strong what goes into the antenna wire. As the impedance at the feed point is high more than 2500 ohms, then no current mode balun would be effective at that point. The potential integrated RFI choke on the coax only moves resonance point, there is still the same current flowing on the coax outer conductor.
If the coaxial length to the rig, USB cable and so on to the point where there is a low impedance to ground happens to be an odd multiple of the wavelength, then the current intensity at the USB cable can be same order as the output current of the rig. There are many variables in the equation!
When the feed point of an end fed antenna is close to ground, then counter poises connected to the coaxial outer part easily help to lower the coaxial common mode current. That may also be effective with a lifted feed point. A good current mode balun at the rig end may also help depending on the length of the coaxial cable. At HF frequencies "good" current mode balun have multiple turns through a ferrite toroid as in the transformer of the antenna, even more turns may be needed.
You may need to use less output power, sri.
73, Reino OH3mA

-----Original Message-----
From: main@WSJTX.groups.io [mailto:main@WSJTX.groups.io] On Behalf Of Robert44 via groups.io
Sent: 11. toukokuutata 2022 19:02
To: main@WSJTX.groups.io
Subject: Re: [WSJTX] Yaesu FT991A Won't Transmit in FT8 #Cat_RigControl #NewUser #TechnicalHelpQuestion #transmit

Hi Reino and thanks for the tips! My antenna is a Chameleon Lightweight End Fed Sloper. It is a multi band end fed with a good SWR from 40 to 10 meter. I have an RFI choke between the coax and the antenna. In addition I have A LOT of ferrite everywhere in my shack.

I think I have tried everything you suggested but I'll go back and retry. Thanks again and stay safe in your part of the world.

Robert KI5TPC


Robert44
 

On Wed, May 11, 2022 at 02:44 PM, Reino Talarmo wrote:


The potential integrated RFI choke on the coax only moves resonance point,
there is still the same current flowing on the coax outer conductor.
Hi Reino and thanks for the help! I did not know what I quoted above! I have always thought that the ferrite choke reduces or eliminates the current flowing on the outer conductor of the coax. Also, what do you mean by "The potential integrated RFI choke on the coax only moves resonance point?"

Robert KI5TPC


Reino Talarmo
 

I have always thought that the ferrite choke reduces or eliminates the current flowing on the outer conductor of the coax. Also, what do you mean by "The potential integrated RFI choke on the coax only moves resonance point?"
Hi Robert,
Your assumption is correct, but how much?
How much current is reduced depends on two issues:
The impedance of the ferrite choke and the impedance the choke sees to the both directions of the insertion point. A clamp on ferrite choke at HF is order of tens of ohms and a multi turn ferrite choke could be few thousand ohms. That is the simple part. In addition the impedance of the choke can be quite reactive, but usually ferrite is selected so that the impedance is heavily resistive.
What impedance the choke sees depends on many issues, but in the case of an end fed half wave antenna the impedance is at the antenna side is order of thousand ohms. Towards coaxial cable it depends strongly on the length of coax (as wave lengths) and how the coax or more often how the rig (or PC) is connected to ground. If that connection to ground is made via house mains wires, then also that length needs to be added to the coax length. That impedance could be from tens of ohms to hundreds or even thousands of ohms.
So without a choke we could be 100 mA RF current on the outer conductor of the coax. If we clamp one typical ferrite choke 100 ohms and the antenna impedance is 2000 ohms, then the current will be 95 mA i.e. no real attenuation. Let's take a typical choke, say 1500 ohms, then the current will be 57 mA, still not a huge improvement, but could just move to the safe side, hi! (I assumed that the choke impedance is mainly resistive. If reactive part is large compared to the resistive part, then reactive parts may cancel more or less each other. I have seen in some simulations how an addition of a "good" ferrite choke actually doubled the common mode current in a low impedance case.)
I want to "correct" my statement about the resonance point change due to a RFI choke in this specific case, where the choke will be in a high impedance point, the effect is minimal.
73, Reino OH3mA

PS. this discussion may be quite off the main purpose of this mailing list, but some WSJT-X users have problems in this field although as such RFI cannot solved by programming.


Jim Brown
 

On 5/12/2022 8:57 AM, Robert44 via groups.io wrote:
On Wed, May 11, 2022 at 02:44 PM, Reino Talarmo wrote:

The potential integrated RFI choke on the coax only moves resonance point,
there is still the same current flowing on the coax outer conductor.
Hi Reino and thanks for the help! I did not know what I quoted above! I have always thought that the ferrite choke reduces or eliminates the current flowing on the outer conductor of the coax. Also, what do you mean by "The potential integrated RFI choke on the coax only moves resonance point?"
You are both correct. What Reino is telling you is that the supplied choke is very inadequate to stop current flow, and that multiple turns are required, the number of turns depending on the frequency, to kill that current.

Study k9yc.com/RFI-Ham.pdf and http://k9yc.com/2018Cookbook.pdf

73, Jim K9YC


SteveO
 

Was following this and was confused.

If using an EFHW, you will have an UNUN that transforms the high impedance at the antenna to approximately 50 ohms.

On my mobile and home setups (both EFHW’s) I used to use clamp on ferrites everywhere to no real improvement. I purchased an RF Choke (MFJ) and installed about 12 feet from the UNUN and solved the problem. So I bought a second one for the mobile installation. No more issues for me.

The explanation below “seemed” to omit the UNUN that is part of the EFHW system. I admit I may have skimmed over it quickly and apologies if I didn’t follow.

Best regards,
Steve de KC5NK

Sent from Mail for Windows

From: Reino Talarmo
Sent: Thursday, May 12, 2022 1:52 PM
To: main@WSJTX.groups.io
Subject: Re: [WSJTX] Yaesu FT991A Won't Transmit in FT8 #Cat_RigControl #NewUser #TechnicalHelpQuestion #transmit

I have always thought that the ferrite choke reduces or eliminates the current flowing on the outer conductor of the coax. Also, what do you mean by "The potential integrated RFI choke on the coax only moves resonance point?"
Hi Robert,
Your assumption is correct, but how much?
How much current is reduced depends on two issues:
The impedance of the ferrite choke and the impedance the choke sees to the both directions of the insertion point. A clamp on ferrite choke at HF is order of tens of ohms and a multi turn ferrite choke could be few thousand ohms. That is the simple part. In addition the impedance of the choke can be quite reactive, but usually ferrite is selected so that the impedance is heavily resistive.
What impedance the choke sees depends on many issues, but in the case of an end fed half wave antenna the impedance is at the antenna side is order of thousand ohms. Towards coaxial cable it depends strongly on the length of coax (as wave lengths) and how the coax or more often how the rig (or PC) is connected to ground. If that connection to ground is made via house mains wires, then also that length needs to be added to the coax length. That impedance could be from tens of ohms to hundreds or even thousands of ohms.
So without a choke we could be 100 mA RF current on the outer conductor of the coax. If we clamp one typical ferrite choke 100 ohms and the antenna impedance is 2000 ohms, then the current will be 95 mA i.e. no real attenuation. Let's take a typical choke, say 1500 ohms, then the current will be 57 mA, still not a huge improvement, but could just move to the safe side, hi! (I assumed that the choke impedance is mainly resistive. If reactive part is large compared to the resistive part, then reactive parts may cancel more or less each other. I have seen in some simulations how an addition of a "good" ferrite choke actually doubled the common mode current in a low impedance case.)
I want to "correct" my statement about the resonance point change due to a RFI choke in this specific case, where the choke will be in a high impedance point, the effect is minimal.
73, Reino OH3mA

PS. this discussion may be quite off the main purpose of this mailing list, but some WSJT-X users have problems in this field although as such RFI cannot solved by programming.


Reino Talarmo
 

Hi Steve,

No problem. That mail is a part of a mail chain and in an earlier one the antenna type was mentioned and it was obvious that an UNUN is a part of the installation (it was not a relevant issue in the mail as such, relevant is that the feedpoint impedance is high). It was also mentioned that at the high impedance side the antenna wire is connected to the "upper" end of the transformer and the "lower" end of the transformer it connected to the coaxial outer conductor (transformer is actually an autotransformer, that's fine). So the coaxial outer conductor is assumed to work as a counterpoise or as the missing part of the antenna.

Your addition of the current balun at the coax 15 feet from the feedpoint "cuts" the coax so that those 12 feet behaves as a counterpoise that also radiates. As a result common mode current on the rest of the coax is lower enough and your interfaces behave correctly.

Most probably the common mode impedance of the balun is much higher than those clamp on ferrites offer and the balun is in a more proper position on the coax or did you put the clamp on ferrites at the 12 feet point?

73, Reino OH3mA

If using an EFHW, you will have an UNUN that transforms the high impedance at the antenna to approximately 50 ohms.
The explanation below “seemed” to omit the UNUN that is part of the EFHW system. I admit I may have skimmed over it quickly and apologies if I didn’t follow.


Robert44
 

Hi Reino, Steve and Jim and many thanks for you guys' feedback! Below are the instructions for the Chameleon Lightweight End Fed Sloper antenna I am using (it does have an integrated transformer as part of the antenna):

https://static.dxengineering.com/global/images/instructions/cha-lefs.pdf

Chameleon does say to use their ferrite which is like 6 or so ferrites integrated into a short length of coax which is placed right at the feed point of the antenna. I am not Chameleon's ferrite but rather 6 DXengineering clamp on ferrites (mix 31) at the antenna feed point and 6 more at the radio's (Yaesu FT-991A) coax feed point. This worked well for voice modes even at the full 100 Watts. Also, the antenna with Chameleon's ferrite has good reviews (for voice modes) but I have never seen reviews for digital modes.

Do digital modes and computers tend to be more sensitive than radios using voice modes? I am thinking that is indeed the case. If so a large lack of RF suppression could be the problem here. This is a long thread but the gist of it is my radio receives and decodes perfect but has problems transmitting. It now will not transmit at all, even at 5 Watts. I was thinking that at 5 Watts the RF common mode current would be 1/20 of what it would be at 100 Watts. My wife has an identical MacBook Pro as mine and I downloaded WSJT-X on her computer and still it does not work so I don't think it is a computer problem.

I think I might try moving the ferrite down the coax from the antenna and see how that works. If it does not work I think I will try a different antenna. Also, do you guys think common mode current from using 100 Watts could have damaged my radio??? I THINK the radio stopped transmitting when I tried to transmit with 100 Watts. I have done several full factory resets with no luck and computer restarts. Many thanks!

Robert KI5TPC


Reino Talarmo
 

Hi Ropert,

The sensitive part of your installation is the connection between your radio and MacBook. I think you mentioned it to be a USB cable. A quite low common mode current on the cable do enter into your rig and MacBook sensitive digital circuits disturbing USB communication. How the RF current enters through USB connections depends on how the circuitry and cable screens are wired. Further information is e.g. in Jim's papers: k9yc.com/RFI-Ham.pdf presents the concepts; k9yc.com/2018Cookbook.pdf presents designs of effective transmitting chokes for the HF bands. Note that a common mode choke works correctly, when there is a low RF impedance to ground on the both side of the choke. A short wire to "real" ground would be best.

SSB does not normally use at all the rig - MacBook communication unless you have some logging program in use. You could get RF burns, if you rig and microphone happens to be in high impedance point of your "antenna system". In any case radio - computer interfaces can be much more sensitive than human can sense, or should I say "is".

It could be possible that something is damaged in the radio as well due to high RF current/voltage 100 W transmission can generate. Does SSB or CW still works or have you lost all transmission capability?

The antenna manufacturer does not tell the whole story how an end fed antenna actually works by the laws of physics (any current needs a return bath). By the way in the recommendations of the European radio amateur training discourages use of EFHW antennas due to the fact that the user needs to deal with the "missing half of the antenna". Please note that know how well EFHW can work, when a suitable "grounding" arrangements are used and power level is not too high, say 10 W. In most cases the antenna feed point in those cases is close to ground, not elevated as in the installation instructions you referred.

You could try a counterpoise from the outer cell of the antenna connector and a current balun on the feedline. Even better could be to insert the current balun where the feedline goes close to ground and connect the feedline outer conductor to ground at that point. Unfortunately that may affect to the SWR values. I could not deduct how they simulated radiation patterns in Figure 4. Well at least they had a perfect ground.

73, Reino OH3mA


Robert44
 

Many thanks Reino for all your information! Today I improved my station grounding in the shack. My grounding outside is good, three 2.4 meter ground rods that are 2.4 meter apart and close to the shack. I just increased the size of my copper buss bar pipe behind the radio and equipment to 25 mm diameter and the copper strap to the ground rods is also 25 mm wide. I even built a simple conducting pad for the computer to sit on. I wish I could think of a better ground connection for the computer but there is just nothing to screw to!

The connection between my computer and the radio is a high quality shielded Tripp Lite cable with built in ferrite at both ends and I have the 2 meter long cable passing through a ferrite (#31) torrid with 9 turns. I think everything is pretty will grounded but I think you are right and my end fed antenna is to blame. I think I remember that things worked ok at low power but quit working at 100 Watts. After a computer and radio reset things started working a couple of times but now I'm thinking the radio might be damaged.

The radio works fine on HF for SSB and AM modes and VHF/UHF for all modes. It just won't transmit on FT8. It receives and decodes fine on FT8 though. I don't think the computer is damaged because it seems to work fine (I'm on it now) and I downloaded WSJT-X on my wife's computer (identical to mine) and the radio still won't transmit.

Today I added a 4.3 meter (10% of 40 the meter band) counterpoise with a hose clamp to the SO-239 connector at the antenna and still the radio did not work even at 5 Watts so I'm thinking the radio is damaged. I might try another antenna but I doubt I'll get it to work. I think I'll need to send it back to Yaesu but at least it's under warranty still. I live in the middle of a large city (Houston, Texas, USA) in a single family house on a fairly small lot so the end fed antennas are really easy to work with and very stealthy but I'm not so sure about them anymore. I have had no problems at 100 Watts with any phone mode (I don't do CW) but I have never done anything digital before now.

I quickly looked at the two papers above and they look really good, I'll read them! Many thanks for all your help, I've really learned a lot here. I am an 'Extra' class ham here in the US but I took all three level ham tests quickly one after the other so I'm actually a very new ham and still learning the basics. Many thanks for all your help!

Robert KI5TPC


Reino Talarmo
 

Ropert,
You may have done this multiple times, but before sending your radio for repair, check again whether CAT control is working. The Test CAT in the Radio tab and e.g. that radio changes band. Also a check on the transmit audio path and settings both in rig and computer should not harm.
Good Luck!
73, Reino OH3mA