Transmitter Software Capabilities and Issues (Jessie)

[M0YDH]

Hello Dave
Signal generator question.
I shall re-read the Wiki entry but, in case it doesn't do so already, can the signal generator be switched through to the 4m signal port? It might be the least used and therefore best suited to test instrument applications.

Are you considering relay sequencing in software? It's a question that I've asked in my sequencer circuit build thread.

Great job chief. Chapeau.
David M0YDH

[G8GKQ]

Hi David

The signal generator needs the VCO filter to be out of circuit to cover above 100 MHz (approx limit on 4m), 200 MHz (approx limit on 2m) or 600 MHz (approx limit on 70cm), and the VCO filter is switched by the same lines as the RF output switch. So that is why it uses the 1255 MHz output, so that there is no VCO filtering. Also the 1255 MHz output has the lowest loss of the 4 outputs. So, it Is not really possible to use any other output.

I do not plan to put TX/RX sequencing in the software. Primarily because I mistrust complex systems such as the RPi for controlling destruction-critical functions. Secondly, there are not really enough GPIO pins. Thirdly, everyone has different requirements, and some of my systems have different requirements for each band. Fourthly, it is very easy to do this sequencing reliably in a PIC.

Perhaps I should publish the circuit and code that I use for sequencing my 70 cm setup. I'll need to trawl through my archives to find it, so it may be a day or 2.

Dave

[G8GKQ]

New Software Release

I've just issued a new release 201712181. It includes a total rewrite of the way that the touchscreen is set up and how it responds to touch commands. Not only should it stop the recently reported crashes, it will also allow me to tidy the menus into a much more logical and intuitive structure over the next few releases. Additionally each touchscreen menu now has a title banner.

The only significant new feature is for our North American users. From the console "Output" menu, the Portsdown can be configured to transmit in 480p (rather than the default 576p) in MPEG-2 Camera Mode and also (as long as the EasyCap is configured for NTSC) in MPEG-2 Video In mode. Thanks to Ron N6GKJ for his suggestions on this one.

Please upgrade (instructions here: https://wiki.batc.tv/Updating_your_Portsdown_Software) as soon as possible and report any problems here so that I can get them fixed before the next release.

Dave, G8GKQ

[g0mjw]

Hi Dave,

In process of trying to update I discovered a problem. I am visiting my other QTH, so I need to set the WiFi password. How can I do this when there is no Ethernet? Well never mind, it involves editing the configuration files, but in the process of this I found my original WiFi setup had been over written by the WiFi setup menu, so I can expect the same difficulty when I get home. The solution I used was to bridge the WiFi to ethernet with my laptop, but most new laptops don't have ethernet ports, including my newest one.

Two solutions - don't overwrite existing ssids in the wpa_supplicnt.conf file and develop a means to enter WiFi passwords from the config screen.

Now I have my connection sorted, I will have a go at the update.

Mike


postscript.

Update went OK. All seems well. Will explore.

Trying to get into GB3UD earlier. It has some very strange requirements and needs an option to set PIDs. Can that be done from a button? Maybe this would be realised with a set of presets, memory buttons that can store all the necessary setups pre-programmed?

[G8GKQ]

New Software Release

I've just issued a new release 201801012. It includes the FreqShow spectrum viewer (using an RTL-SDR) which can be selected from Menu 3. More details here https://wiki.batc.org.uk/FreqShow; example display below. It also introduces basic support for the Element 14 7 inch touchscreen, which can be selected in the Display menu of the Console. Note that FreqShow and Video View modes do not yet work with the Element 14 7 inch display.

The release cures the occasional crashes that happened after multiple selections of the signal generator and also enables IPTS streaming in all (H264 and MPEG-2) modes. It also correctly highlights input selections made on Menu 2.

Please upgrade (instructions here: https://wiki.batc.tv/Updating_your_Portsdown_Software) as soon as possible and report any problems here so that I can get them fixed before the next release.

There were some server problems late on Friday 5 Jan, which may have caused some update issues, however, all seems good now and behaviour after the update is as described above.

Dave, G8GKQ

[F4DVK]

Hi Dave,


Edit: It works with the waveshare 3.5, but no touch with HDMI waveshare 7.

Thanks,
Stephane.

[G8GKQ]

Hi Stephane

Yes - that's what I meant by not working with the 7 inch screen. FreqShow does not respond to touch commands from the 7 inch screen. The package used for the touch handling is tstools, so if anyone knows how to get tstools to respond to touch on the Element 14 7 inch screen, I'd be very interested to try to fix the bug. There is also a minor problem with event labelling, but this is not the root cause of the problem.

Dave

[G8PEF]

Dave's response to David's query about the signal generator o/p got me thinking (late at night when I should really have been stacking some Z's, so bear with me) …

The signal generator needs the VCO filter to be out of circuit to cover above 100 MHz (approx limit on 4m), 200 MHz (approx limit on 2m) or 600 MHz (approx limit on 70cm), and the VCO filter is switched by the same lines as the RF output switch. So that is why it uses the 1255 MHz output, so that there is no VCO filtering. Also the 1255 MHz output has the lowest loss of the 4 outputs. So, it Is not really possible to use any other output.

…
Dave

Since the VCO has a second output, is it not easier to just bring this out to a socket on the panel and use that as the signal gen output? It might need a bit of a buffer, but it avoids the issue with the VCO filter. Or am I missing something (and it wouldn't be the first time).

John

[G8GKQ]

Hi John

You are exactly right. If you select the ADF4351 button on the sig Gen, the indicated output is calibrated for the 2nd output from the ADF4351 (which is routed to the back panel on my Portsdown).

The reason that the filter-modulator output can be selected (Portsdown button) is that the output is at a higher level, and in a future version will be able to be modulated with DVB-S (not possible on the ADF4351 output) and have the level varied with a digital attenuator to set the optimum drive level for a PA.

A future version of the transmitting software will be able to control the attenuator and be programmed to set the correct drive level for each band.

Dave

[G8PEF]

Ah, right - thanks for that, Dave. Having not yet upgraded my software from a version before sig gen made it into the menus (been 'concentrating' on the getting the RX working), I wasn't aware that there were 2 output modes.
I guess that I should update and have a shufti

John