BATC Forum

Hi Dave,

As far as I am aware Langstone doesn’t use any of the RTL software. I suspect it may be installed by default as part of the GNU Radio package.

Colin.

Hi Dave
Pictured is a Lime mini FW 1.29 and Portsdown 4 202009010 transmitting a strong across shack signal without a byte of transport stream being received. D24 plus with superb constellation but no picture. Any firmware gives all tests passed on Lime report. Ive updated to Lime DVB which is now transmitting ; wasn't before after last month's blunders. Again 4 reds on TS. Oh dear. Langstone isn't installed.
I'll press on with my homework that you set, restore to FW 1.29 and try the Jetson.

73
David M0YDH

That's usually a sign the RX isn't working. Do you know it does indeed work?

Hello Mike
I've successfully repeated last weekend's tests. Phew- relief. The Portsdown in my rack here is on Stretch 201912100. I have one Lime mini and one V2 Minitiouner. The output is to Lime mini mode. Your upconverter is doing a good job! Lime DVB mode isn't producing output on the Portsdown 2019.
I suggest that the absence of transport stream is a v4 software or Lime firmware problem? As long as the rack portable station works then I'm fine.

Does anyone in the Midlands want to borrow a 71MHz DATV station for the forthcoming only activity on the band BTW? I'm on parent taxi duty for duration of the 4m and 6m activity weekend. Unless I park somewhere between e.g. Mike and Shaun G8VPG it's not going to be used this year.

73
David M0YDH

Hello you clever programmers.
I have just built up a portsdown4 It is working lovely. ** Thank you developers **

I put phonos on side of case ( Yellow Video out ) but cant see if its implimented "yet" in menu.
Unless I missed it ?

Many thanks Ken G8VDP

Hi Ken

That's a nice-looking build. Keep an eye on the internal temperature (Menu 2, info); I had to put a fan in my Portsdown 4 which I had built into a plastic box with a Pluto - I caught it at 70 degrees C. While they will run OK at that temperature, I wasn't sure about the long-term reliability of the other componets in the box.

Video out is not working on the Portsdown 4 at present. Lots of things have changed around the graphics and video architecture from what worked on the Raspberry Pi 3, and when I tried to enable the video out on the Portsdown 4 I lost all the menus. I'm not saying that it will never work, but your yellow phono might stay unused for a while.

Dave

Thanks for the reply Dave. I am OK with your work and your patience. I can have enough respect to be patient myself.
There's lots of room inside that case still. Despite it having a mains switch mode supply at 5v 5a in it. I can use it in the car too with a 12v/240 mains inverter. The 2 black buttons & LED's under the screen turn on the 2 DC outputs on the side of case. 12v & 5v for powering externals , such as small amps Chinese or (G4BAO), and/or a media player.
Its my Portsdown pi4 build 3, the 1st is filter modulator type. 2nd is the same as the above grey one but black case & pi3b+.
No. 1 is in a metal case but I've noticed with these plastic cased Portsdown's they are susceptible to crashing if a handheld 2m or 70cm is used TX within a meter or so. Not ideal if you take them / portable or mobile. Yet from shack I can do 100w from base antenna with no effects on Portsdown.
Its just handheld there's an issue. Nothing new there though. We know why.
I may need to add some internal screening.

Re temperature, thanks for warning. I'll fit a fan asap and drill a few exit holes.

Thanks again , Ken
G8VDP

I've finally got my Q100 station 'working' and have used firstly NB with Langstone and enough power to match the beacon. PTT worked as planned, I have the PTT control line driving a 5 volt relay (via a transistor etc) and that keys the amp, initially a small SKY WiFi board (£12 on ebay) and latterly my Stealth Purple 60W+ (turned down).
Progressing to DATV, my setup will match the beacon strength on 125ks with the amp giving 'full beans'. The first TX works fine, relay closes after 7 seconds, amp switches on, it amplifies. On going back to rx everything looks OK, the Portsdown still all functions and TX can be selected again, although this time it does not switch on the PTT relay. A reboot sorts it, but the same happens again. This is with TESTCARD.
Using the Picam input produces similar 'lock-ups'.
I found that if I changed source between each TX event, it worked as I'd expect, ie amp gets keyed.
Initially I thought maybe some RF was getting into things, but choking the amp power lead or the Portsdown lead made no difference.
Is something not getting reset on rx perhaps?
But super pleased to have my pictures received by Martin G4FKK at 125,250 and 333ks. Dare I stick my head up over the parapet on the Thursday net
Gareth
***Update*** it seems that changing source (e.g Picam to test card and back again) is sufficient to 'reset' the PTT function??

Hi Gareth,

I have the same issue as you regarding not switching into TX although getting the indication on the screen. I also have a different issue which just may be my temporary lash up as the build is commenced, If I go from Portsdown to Langstone, all is OK, back to Portsdown still OK, return to Langstone and Pluto isn't found. I'll keep an eye on this as I box the system up and wire the power supplies finally.

73 Dave.

Gareth and Dave

There are a couple of issues here.

Before I fire off too many answers, please could you both tell me what software version you are using and what you have connected to your Raspberry Pi 4s. Pluto, WebCam, Audio dongle, coffee heater tec...

There is an issue with the Pluto when transmitting from the Test Card (or contest card) that it hangs in transmit for 20 seconds or so after transmit has been deselected. The Portsdown indicates that it is not transmitting, but actually it is. If you reselect transmit during this period, you get the symptoms that you have reported.

Dave - every time you switch from Langstone to Portsdown the Pluto is rebooted. It takes 20 seconds or so to do this, so if you go back to Langstone before the Pluto has rebooted, you get a warning about the Pluto not being found. This is to prevent you having to wait for the Langstone to start up before it realises that the Pluto hasn't rebooted and gives you an error.

I hope that these "features" explain what you are seeing.

Dave, G8GKQ