Portsdown pluto PTT -stop- not working

[keng8vdp]

Hello,

I'm currently on version 20220550.
Last 2 days I had a go at QO-100 WB with some success
But also some issues.
1st tests were with lime-mini. Unfortunately the main issue was some interaction with minitiouner running also on a separate Portsdown (same recent software)
Insofar as on receive I get a lock & have more MER than the suggested "MER Needed" yet I get no decode.
Sometimes I do but it struggles.
2nd test was using Pluto. Good quick lock followed by decode. Very happy as Pluto looks like it produces a crisper picture.
The problem I'm having is the pluto won't stop transmission despite tapping TX. Yes the TX button reverts to BLUE indicating it's Off but it's not. The pluto stays on transmit & see signal on the batc spectrum viewer & also on my power meter.
The only way to stop tx is to shut down Portsdown or pull the usb plug from the pluto.
Rebooting Portsdown doesn't fix it.

Next I tried my other Portsdown 4. (Swapped everything over on both systems). Now the pluto takes much longer to transmit 5 times longer on this Portsdown. When I press TX to stop it, it behaves wierd. It might not stop transmit but turns blue indicating off. Sometimes it goes Red but no tx until I tap the RED tx & then it produces RF ( the TX button is now BLUE !) Or it does Nothing until the now Blue TX button is tapped turning it red then after a while I tap it again & it goes Blue , then after around 30 seconds it then stops.


Thanks to anyone for help

Ken G8VDP

[G8GKQ]

Hi Ken

I've just done a basic test here and can't reproduce the problem. To help me, please answer these questions:

What video source are you using for these tests?

What is the Pluto Firmware version? Check from Menu 3, Pluto Config, Check Pluto Firmware.

What Pluto Output power do you have selected?

What hardware version of Pluto?

73

Dave

[keng8vdp]

Hi Ken

I've just done a basic test here and can't reproduce the problem. To help me, please answer these questions:

What video source are you using for these tests?

What is the Pluto Firmware version? Check from Menu 3, Pluto Config, Check Pluto Firmware.

What Pluto Output power do you have selected?

What hardware version of Pluto?

73

Dave

Hi Dave,

Im using built in testcard of Portsdown also tried C920 twice.
Pluto firmware checked : v0.31-4-g9ceb-dirty
Power: I have tried many but the problem remains on all settings
Pluto hardware I believe is V1. I have done some modifications as per internet. Also Swapped TCXO.
Pluto is also re-cased into metal enclosure.
I use Pluto with Langstone without issues. its performs well on 13cm ssb contest nights TX RX changeover relay with a 50w home
made amplifier 50 watts. PTT control is from GPIO and a relay.
Ive also used it on 23cms again with amplifier 150w 2 x coaxial change over. works good.

The same one Portsdown4 ,(I have tried Portsdown mode DATV with Lime-mini and works great terrestrial. (23cms)
Also tried via QO-100 13cms and this works too Lime-mini.
When I try the Pluto through QO100 its better than the lime-mini. crisper image & faster lock and decode.
The problem is as described earlier, Main menu screen TX button Blue ( it goes red when tapped as it should )
However, sometimes there is no RF produced even with a RED tx button. I tap it again and it goes BLUE.
Suddenly I get RF ( Its still Blue ). So I try tapping it again. etc but RF doesnt stop. So I shut Portsdown down via Menu 2.
Reboot it but its the same.
BY the way. This has a new BATC supplied 32gb SD card.

I have another Portsdown 4 that I have been using exclusively for terrestrial on mostly 23cm for around 2 years +
Ive never tried it with the Pluto only Lime-mini. i use it locally with a few other hams and through GB3EY 62KM away.
It performs well into a 2w BAO driving a 45w BAO amplifier.
Trying Pluto in this other Portsdown produces the same problems. Using Lime-mini is fine & PTT button too.

Hope this information clarifies things. Once again your help is appreciated.

Ken

[G8GKQ]

Hi Ken

Thanks for that info. No clues there, so three more specific questions:

Is the Pluto connected via USB or Network?

Are you using the Portsdown PTT (from GPIO pin 40) or the Pluto PTT (using a relay driven from the Pluto)?

What Pluto power do you have selected (under Pluto Pwr on Portsdown Main Menu)?

The video encoding is done differently for Lime and Pluto - hence the difference in picture appearance.

Dvae

[g0mjw]

Could it be impatience? Sometimes it takes a while to switch to TX, depending on your encoding. The buffers can be quite long on stopping TX. This might happen with the RTMP method.

Mike

[keng8vdp]

Thanks to you both for the suggestions.
Today I setup another dish & swapped from a single dish. I was suspecting RF as I was only to one side of the dish with the gear. This immediately improved things especially on the receive side whilst transmitting.

Regarding pluto: it's just plugged into Portsdown USB "blue" .. however: both Portsdown have WiFi setup. Regarding my suspicions on RF , I noted my phone next to me loses WiFi connection or struggles when I'm transmitting. The laptop does too. I moved the amplifier outside under the dish. Still WiFi is lost on devices just inside the house on table 8 ft from dish.
Regarding PTT:
One Portsdown has only the touch screen control.
The other Portsdown has been built primarily to use like a radio in Langstone. That has a fist mic. The mic triggers the relative pin on the gpio to go to transmit. I only use that in Langstone mode. It also throws a relay that I fitted in the case. That relay outputs 12v on a phono. The phono connects to an external coaxial relay sitting on top of the METAL Pluto case. That relay switches the antenna from Rx to TX for the 2 SMA sockets on the pluto. The system works perfectly. No issues on any power setting of the pluto. It looks like a transceiver & has a VFO too.
So. For the QO-100 tests I first used that for receive. Of course in Portsdown mode with a miniTiouner .. I used the touch screen controls only.
The other Portsdown (my usual terrestrial one in the shack) has/had never been used in Langstone mode. Never used with a Pluto either. Only used with lime-mini.

So. I decided to try QO-100 using the lime-mini for my 1st ever attempt on the WB transponder. It worked & I got in "just". Settings were 66sr ( 1st attempt baby steps ) taking it slow. Anything higher didn't get in.
Ok so . I thought now I'll try the Pluto. It was set at 0. I changed that to -10. Didn't get in to satellite. BUT tapping TX to off didn't work. I was slightly worried so I tapped it again ..now it's RED again ..tapped again it went Blue. RF still going out waited 30 seconds (lime-mini turned off instantly) the pluto was still on tx ,so in a slight panic I went Menu 2 / shut down.
I booted up again. Changed power to -5 went to tx.
This time I got in. Just over required margin. Much clearer picture. Faster lock, faster decode. Happy me.
Went to stop TX same problem it wouldn't stop.
It has to be understood that on first attempts it's worrying. Main worry being my home made 50w amplifier getting too hot & blowing it up. Popping my pluto ...scared ! Melting my home made helical I can visibly see on the dish. So this not stopping transmit wasn't a nice experience.
So now I thought I would swap over the pluto to the other Portsdown. I did. It produced exactly the same problem.
So again I thought , I'll try lime-mini on this one. It performed as before on the other Portsdown. Tx instant tx-off instant. Got into satellite but struggled on lock then struggle on decode. When I got decode it was a bit fuzzy.

That was all on 1 dish

Today on 2 dishes , 1 on transmit & 1 receive. Next to each other. Both 1.1mtr. No significant de-sensing on receive. Lime-mini on tx set at 92 I got in SR125. ½fec. Then tried 333. No luck. Pushed it a bit "naughty" put power up to 96 & got in . Slow lock slow decode but it got there. Yes I know things go less linear with bad sides. But after all, I am testing & I am learning.
Right next I try Pluto 1st time on 2 dishes. Set at -5. Super Brilliant . Almost Instant lock after 2 seconds of RF out. Decode after about 10 seconds. Come to stop tx & again wait 30 seconds & it's still transmitting ... So this time I don't panic. I press menu 3 button then ( yes it's still showing RF going out on meter ) . Then I press select test card. Power meter now shows a falling needle RF is off, finally (smile)
Looks like I've found a way to stop tx at least.
I've been playing almost all day today. Different settings different power levels, test cards , c920 etc all very good. Even got a couple of good reports via web chatbox.
Managed sr333 ½ fec 30w output too. Amplifier doesn't even get hot, just warm. (It's a 50w device)
I have another amplifier 130w but I still have this pluto problem so I'm not going to go more power yet.
Further tests when in TX. If it doesn't stop then menu 2 tap any button in there & a few seconds it stops transmitting.

Last but not least: the pluto has no internal PTT modification at all. I did earth mod & off the board txco mod + fitted it into a metal case.

Many thanks . Ken

[g0mjw]

Hang on - why do you mention WiFi? The Pluto, the PC all need to be connected by Ethernet. Not Wifi, 2.4 GHz obviously but 5 GHz can be impacted too if the signal is strong. Even with the Pluto on Ethernet, if you connect from a Laptop by WiFi you will be able to turn it on, then there is a good chance the link will fail and it will just sit there.

Please confirm you have nothing connected by Wifi. If you have the PD connected by Ethernet and WiFi it might have issues too, even if you think it is using the cable. Finally, Pluto connected by USB might suffer from under-voltage is the PI PSU isn't providing 5V. All sorts of weird things happen if the voltage drops.

Mike

[keng8vdp]

Hi Mike,

I'm not doing anything with Portsdown that I don't do on terrestrial. I'm not actually using the WiFi when I'm using it. The only time I do is in the shack. I use WiFi to see GB3EY stream as there's no other way to know if I'm getting in.
I don't know how to connect to Portsdown by ethernet or WiFi from anything. Only on first setup I used to connect from a PC
I am NOT pc savvy. I don't know how to use OBS or stream .TS etc. I don't understand that stuff.
Yes the WiFi is active in my Portsdowns.

Must add. The one I use to stream EY in shack is a 3rd Portsdown .. older pi3b+

Again , all 3 Portsdowns have a WiFi connection. I don't actually use it on the 2 Portsdown 4s but technically it is ON I suppose.
Are you saying I should turn it off when I'm using Portsdown for anything whatsoever ?

News to me that.

Regards Ken

[keng8vdp]

More:. Re last post above

Power supply is mains built into the cases 5.1v switch mode 5amps. I never get the lightening indicator on the display. The DC goes direct to gpio pins

I've just turned WiFi off on Portsdowns I'm using for these Tests.
I've gone into QO-100. All's well got in great as before.
Unfortunately the pluto is still the same. Once transmitting it won't stop. Unless I access some other menu and tap a few buttons then it stops.

Hope this helps.

Best regards Ken

[G8GKQ]

Hi Ken

I really do not know what the problem is with your Portsdown and Pluto PTT. I'm sure we'll solve the mystery eventually. Does it do the same when you have no connector on the Pluto output - I am thinking a high current ground loop could be upsetting things?

Please could I suggest a different way of operating your QO-100 station? I use a separate physical switch for the QO-100 PA; I never turn this on until I know that the Portsdown is up and running. During QO-100 QSOs (such as the Thursday evening QO-100 Net) I leave the Portsdown set to transmit all the time (for over 2 hours) and just switch the PA on when I want to transmit. This means that there is no delay when it is your turn to transmit, and you can turn the PA off instantly if there is anything that you are worried about.

Also, I monitor 2409.75 MHz (or whatever uplink frequency is in use) locally in the shack on another receiver to make sure that all is well before switching the PA on.

Lastly, as a luxury, a switched RF attenuator with a hardware control in the transmit line between the Portsdown and the PA would enable you to adjust the power correctly without needing to stop transmission.

Hope that helps.

Dave