BATC Forum

A year ago, at a rally, I bought an ATV TRX. It sat in my shack doing nothing as I had no antenna for 23cm. I now have an antenna (36 elements), so I thought i'd give this box a play.... Nothing was marked, bit thanks to Google and some wiring chasing, I got it sorted.... Only to find that my local repeater GB3ZZ is purely digital, and my box isn't.

So the Portsdown transmitter.... I guess it's also a receiver. Is this so.
I see the boards for sale, but not the components. Is there a parts list?
For someone whose hands that are not as steady as they once were, are they simple enough to populate?
Do these transmit sound and video, or is sound via talkback?
Will my SG Lab 25W 23cm amplifier be OK for DATV?
Will I need another driver between the Portsdown and the SG Labs amp?
If the amp is OK, will I still need filters, as the amp has it's own?
Am I right in thinking that the Portsdown TX is purely the output of the IO pins on the Pi, so miliwatts at best?
Is any of the kit, other than the LimeSDR, available ready built. Hands and eyes not being what they once were make ready built kit a huge hassle lifted.

Sorry for all the questions, I just want to know what I'd be letting myself in for if I do decide to take the plunge.

Thanks for any answers, advice, info.
Darren
GW7HOC MW5HOC
Cardiff

Hi Darren

I'll answer some of your questions....

So the Portsdown transmitter.... I guess it's also a receiver. Is this so. Yes, you can connect a MiniTiouner to the Portsdown to make it receive the digital signals from GB3ZZ. The MiniTiouner is easy to build; we sell the PCB and 3 of the hard-to-get parts. Full details of the MiniTiouner are here, including the parts list.https://wiki.batc.org.uk/MiniTioune

The Portsdown 4 needs very little assembly. A Raspberry Pi, a decent power supply, the official 7 inch touchscreen and a LimeSDR Mini. No soldering at all. Connect a Raspberry PI Camera and a USB audio dongle and that will get you a few milliwatts to transmit towards GB3ZZ. Full details here: https://wiki.batc.org.uk/Portsdown_4. Most of the PCBs were for older versions.

I'll leave others to comment on Power amplifiers etc.

Dave, G8GKQ

Thanks for this Dave.
So the min Tiouner is a stand alone receiver that connects to the Portsdown, but will also happily act as a separate RX, so If I built two, I could use one on a separate project?
I have decided to split my existing TRX, using the TX connected to a camera in the garden, and the RX connected to the TV in the living room. My wife can watch the hundreds of birds she feeds without having to stand in the rain

Darren

Minitiouner is a USB connected module that you use with a PI or a PC with appropriate software. So to answer your question, no it is not a stand alone receiver.

Putting a PI with a minitiouner and a screen plus a remote control sensor (and remote) will give you what we call the Ryde - a standalone set top box like receiver.

The BATC minitiouner was specifically designed to be easy to build, with through hole components, large spacing, simple PCB, but if you really can't build anything at all any more then the French Radio Society, REF https://boutique.r-e-f.org/ do have a built version, actually two see https://forum.amsat-dl.org/index.php?th ... -receiver/ These appear to be sold out at the moment.

You can order from France - send them an Email - google translate is a good way to navigate the website if you don't speak whatever language it is written in.


Mike

Thanks Mike. I'm OK with building if it's not too small or too close together. It just takes a little longer
My head doesn't work like it used to either. I have moments of clarity.... These are the times when I have to concentrate.
The rest of the times Life is a little foggy. No matter how much I look at or read something, nothing makes sense. Hence my list of questions I needed clarifying

Darren

What we all have to look forward to...

Here is an image of the unpopulated PCB to give you an idea of the work. The hardest part is probably fitting the NIM as it's 2mm pin spacing vs 2.5mm for most parts. I hope still relatively easy.

Mike

I'm not that old either....
Looking at your image, it looks like with a bright light, a fine tip, and a drop in caffein intake, I might be OK. I'm going to write a shopping list and take it from there.... I'll order a few more components than I need, as I'm certain to lose some, or wreck some along the way

Darren

Does the Portsdown require the LimeSDR and the Minitiouner?

Darren

Darren,
I am a member of the GB3ZZ team in Bristol. Before you get too far into this project, if your intention is to work through ZZ, I suggest you establish whether there is a viable path to it from your qth. You can check this with an online calculator such as Radiomobileonline.
Cardiff is a bit marginal but it will depend on your particular qth.
The next step is to try receiving it. You can do this with an inexpensive free to air satellite receiver for about £20. Have a look at the South Bristol ARC Youtube site where you will find a recording of a Zoom talk I recently gave on exactly this subject.
Finally, ZZ users use 144.750MHz FM for talkback. Please give any of us a call for further help and information.
73 Shaun G8VPG.