Archive for the ‘atv’ Category
The build was straightforward and there are some instructions by Mike G0MJW but only really referenced them for the commissioning stage, checking voltages etc. I was pleasantly surprised to see a large degree of protection on the board, fuses both filament and poly-fuse, reverse protection and zener diodes in the circuit.
The MiniTiouner uses free to download DVB-S receive and analysis software called "Minitioune" written by F6DZP. The Software is hosted on the VivaDATV forum. So I registered and downloaded the software.
V8.0 of the software requires a pull-down resistor adding to the USB module to identify the type of board, so that was added (not pictured).
Power was connected and then plugged the USB lead into the PC (Windows 7 32bit) and it went off and installed drivers. The documentation said I should see two USB controllers, but I was seeing four?
There are several test programs included in the software package to test drivers and board and they were showing errors.
The PC I was using has had no end of serial USB devices plugged in and out over time so suspecting another Microsoft Windows "disappearing up its own backside" driver issue I tried it on another more vanilla machine but had the same problem.
This seemed to point to the USB interface (an FTDI FT2232H Mini Module) perhaps it wasn't programmed? So I downloaded the FTProg utility from FTDI but instead of seeing a FT2232H was showing it as a FT4232H device.
Doing a Google found a reference to the same problem. I downloaded the data-sheet and checking with a meter I could see pins CN2-5 and CN2-11(VIO) on the module didn't have 3.3V for some reason and as the post said if the VIO pin is missing 3.3V it defaults to a FT4232H. In the end I checked my soldering (no fault found) I removed the module from the socket to examine it and after re-seating it the board sprang to life so seems it was just a bad connection.
Eager to test I set up the ADALM-PLUTO SDR running DATVExpress as I'd done previously with the commercial set-top satellite receiver and we had a picture! It was time for a cup of tea!
Now it was working all that was left was to put it in a box.
I have only had a brief play with the software since the weekend but was interested to see if I could receive some RB-TV (Reduced bandwidth) So I set the Pluto and DATVExpress to transmit on 146.500MHz using a low symbol rate (250 Ksymbols/s) and it worked! Bertie was wriggling a bit too much for a clear picture but I had now actually used my 146-147MHz NoV. Now just got to learn and understand the various modulations and settings.
I was able to try out another piece of software, the Spectrum Analyser from Steve Andrew for the SDRPlay. It turns the SDR receiver into a handy spectrum analyser with 10MHz bandwidth from 1kHz upto 2GHz and was able to check the output of the Pluto.
This wasn't a proper test setup by any means, the SDRPlay was still connected to the dual-band collinear outside the shack so the noise is the usual hash I see, but the Pluto was putting out a decent waveform, it did help putting on a proper resonant antenna (a spare mobile magmount) rather than the tiny one supplied.
I plan to do a bit more with the 5.6GHz FPV stuff before the weekend having took delivery of some nice grid antennas and hope to get out to try a contact or some tests with members of SKARS 73
They say "a picture paints a thousand words"and I've always liked the idea of sending pictures via radio having dabbled with sending and receiving SSTV and SSDV, including pictures from High Altitude Balloons (HABs) like the Hamfest HAB flight I did back in 2015
But I've also been intrigued by "Fast scan TV" to transmit moving images. I've seen demonstrations at conferences and in online videos and joined the British Amateur Television Club BATC a few years ago but apart from reading the CQ-TV magazine I had not done anything mainly due to expense and investment I mistakenly thought I would need to make.
Recently I have seen mention of using easy and low cost equipment to get on the air on 5.6GHz (the 6 cm amateur band) using cheap modules intended to transmit “First Person Video” (FPV) back from drones.
These simple units can be used without any modifications to get on air. A number of operators have used them with high gain WiFi panel and/or dish antennas with a clear line of sight path to send pictures to stations using the same equipment over paths in excess of 50km, the current record is over 160km. Chris Leviston M0KPW has an excellent website describing his 5.6GHz system http://www.5-6ghz-atv.co.uk/ and there is more information at the BATC Wiki https://wiki.batc.org.uk/5.6_GHz
Inspired I ordered some kit from eBay a few weeks back, a receiver module and transmitter arrived quite quickly (no slow boat from China this time)
The equipment is powered by a 12V supply and input and output is a composite video signal and audio. It can be fed by a standard camera or video source but I dug out an old Raspberry Pi and soon had it generating and transmitting a test card with the required call sign overlay. The modules are channelised, the displayed 33 number is bank 3, channel 3 which is 5.665GHz selected by the BATC since it sits inside the amateur allocation,
Over the week I refined the Pi software, adding the Pi camera and various libraries in python to generate video with informational overlay, adding a GPS allowed calculation of the locator square when out portable. I have put it in a box (sorry no picture of that) and a switch to flip between live video and test card. I also had a bash at making some double biquad antennas. Regularly updating my twitter feed with various milestones (I recommend you follow me)
Pi sending live video via 5.6GHz with text overlay using pi camera and raspivid easy peasy.. pic.twitter.com/Fthfpbw0r0— Andrew Garratt M0NRD (@nerdsville) July 28, 2018
While browsing the BATC website for information I spotted that there was an ATV Academy workshop being organised by the Telford and District ARS, giving people the opportunity of finding out a bit more about ATV and people could bring along their equipment and projects for advice. So at the last minute I decided to go but because of the distance could only really go on the Saturday. But it was well worth it and a great day. I was made to feel welcome by everyone there and was able to show off my modest achievements on 5.6GHz and learned about the BATC Portsdown Transceiver and MiniTioune receiver projects, even buying the parts to build the receiver.Lol, wife looking suitably impressed by the Pi based image generator which flips between live feed and test card using switch pic.twitter.com/M6qnif5V0P— Andrew Garratt M0NRD (@nerdsville) August 3, 2018
The academy coincided with a BATC Activity weekend and they were going up to the summit of the nearby Long Mynd to operate on the Sunday. Since I wasn't there I had planned to go to a local high point to see if I could make contact with some of the other operators and stations and got the kit ready on a cheap lighting tripod. I was going to use an old portable satellite dish with one of my double biquads at the feed point.Having a great time learning all about ATV today, showing off my humble efforts pic.twitter.com/YTwEf7Sjdl— Andrew Garratt M0NRD (@nerdsville) August 4, 2018
here for better description of offset dishes)
fly tipping and very hot conditions. Due to the the fly tipping in the lay-by I didn't want to be seen getting stuff out of car boot! especially as a few cars had slowed down as they passed.
Nevermind I have ordered couple of cheap high-gain mesh dish antennas so when they arrive I will get out again and arrange some skeds, hopefully roping in some of the radio club.
In addition to the 5.6GHz stuff I have also taken possession of an ADALM-PLUTO SDR from Analog Devices. It is inexpensive (£90/$100) and designed to allow educational experimenting in software defined radio. It is a SDR receiver and low-power transmitter. They had been in short supply but availability has improved.
Charles Brain G4GUO has added support for the device into the DATV Express software. I am hoping to use it for some experiments in RB-TV (Reduced bandwidth TV) so I can actually use my NoVs
I took the PLUTO along to the ATV workshop and was able to see it transmitting and being received by other peoples receivers. So last night I got out the two satellite receivers I have and with a little bit of persuasion with settings got some DVB-S DATV transmitted and received.
Anyway, that is enough for now.. but will try to keep the blog updated as I experiment some more, but follow my twitter account @nerdsville for realtime updates 73 AndrewBit of "shaky cam" but shows the ADALM-PLUTO transmitting across the shack using #DATVExpress being received by an old FTA satellite box. pic.twitter.com/souCJA9qBK— Andrew Garratt M0NRD (@nerdsville) August 5, 2018
Have you ever wanted to be in a movie? Or maybe on TV? Well while you can make your own movie and you could be on a TV, you probably won’t be on commercial TV. However you can be on Amateur TV.
In this episode I talk with Tom O’Hara, W6ORG. Tom has been a ham for a while and had a successful ATV business for over 50 years!! He retired and shut his business down at the end of 2014, but that hasn’t stopped him from working with Amateur TV!
Listen to this episode to find out more about Amateur TV and about Tom:
When broadcast television began to get big, back in the ’50s, the pundits predicted that it would kill radio. It didn’t, of course, because radio changed to serve its market in different ways (music, news and talk replaced soaps and serials). But TV did quickly become the 8000 pound gorilla … despite a recent radio industry group’s campaign saying that people spend more time with radio than TV today.
Television (or video) has existed in ham radio for a few decades. But for us, it’s still a very niche mode, practiced by a relative handful of hams. Despite all my television/video experience and all the video equipment I’ve accumulated for HamRadioNow.tv, I’ve never had much interest in ATV. Some local guys have had an ATV repeater on and off for a while, but I didn’t catch their bug. Of course, I spend very little time at home on the air. 90% of my operating time is mobile. But lots of hams do spend time on the air from the shacks, on radio.
So why hasn’t video been embraced by the masses?
Equipment is probably one reason. Until recently, hams have used mostly the same analog AM video mode as broadcast television did BD (Before Digital in 2009). A little off-the-shelf equipment has been available. Not that expensive, but not an impulse-buy, either. Getting it on the air was a little challenging. Broadcast TV runs hundreds of kilowatts with antennas on 1000’+ towers. Hams discover that when you spread ham-style signals out from a couple of kHz of SSB or FM to cover 6 MHz (the bandwidth of an AM TV signal), those signals sputter out pretty fast (but, as my guest on this show will point out, not that fast!). Repeaters help, but there are only a few repeaters around. And there’s certainly no large group of hams on the air to help pull you in. You have to decide that this is an edge you want to sit on.
Digital to the rescue? Broadcast TV was required to switch from analog to digital over a decade ago. Ham TV wasn’t required to, but some hams discovered and repurposed some relatively inexpensive digital equipment and discovered that digital ATV was better than analog in many ways (better picture, lower bandwidth, high definition, and at least not more expensive… maybe cheaper). They mostly don’t use the same digital that broadcast TV does in the USA. The digital equipment available allows for a variety of modes and schemes, adapted from cable-TV, satellite broadcast, microwave link and European broadcast digital TV. And, btw, in a year or two the USA will change to a totally different digital video system, but that’s another story.
The digital stuff has made ATV repeaters easier, and it’s made operating way more flexible. Analog ATV worked pretty much with a camera pointed at the ham’s face. You could maybe play back a VHS tape into your transmitter, but switching and mixing video required some expensive equipment. The repeaters could repeat the input signal, and that’s all. Well, the the same digital revolution that makes HamRadioNow possible on a shoestring budget (while looking better than broadcast TV did 20 years ago) lets ATV operators become studios. And video over the Internet does the same thing for ATV that it does for D-STAR, DMR, Fusion, etc. on voice: it brings activity from around the world to the local repeater when otherwise the handful of local ops wouldn’t really sustain it.
HamRadioNow has covered many TAPR DCC talks on digital ATV over the past decade. Yes, the first were this talk by Ken Konechy W6HHC (very technical) and this talk by Art Towslee WA8RMC (more operational) back in 2009. Seems like ancient history, but Art says they’d had digital on their ATV repeater in Columbus OH for 5 years . For more, dig out this YouTube Playlist and scroll to Episodes 127, 168, 169, 227, 284!
This year, we talked to digital guru Mel Whitten K0PFX and ATV Quarterly magazine editor Mike Collins WA6SVT in our thunderstorm prone SIB* tucked back in Tent City at the 2017 Dayton Hamvention®. The conversation is mostly aimed at hams who have never (and may never) operated ATV, but wouldn’t mind being informed about the subject. That’s plus or minus (OK, all plus) some ATV jargon that’s hard to avoid when talking to geeks.
Will this ‘new’ digital ATV finally create a mass migration to video? OK, I don’t think so. Maybe for the same reason we still make phone calls instead of ‘video calls’ on Skype, Duo, Facebook and Facetime (etc. etc.). We don’t want to have to look pretty for the camera. Hey, don’t call me on video right now! I’m still in my sweats and I haven’t showered yet. I’m not ready for my close-up, Mr. DeMille.
*Studio In a Booth
With Hamvention already on top of us, I figured I’d throw my two cents worth into the mix with everybody else’s. In this episode of the Everything Ham Radio Podcast, we talk about some of the interesting things that are going to be going on at this years Hamvention at it’s new location in Xenia, OH.
DARA teamed up with The Miami Valley Mesh Alliance (MVMA) to setup a Mesh network on channel -2 at 10 MHz bandwidth. The SSID is AREDN-10-v3.
We talk about all of my fellow podcasters/youtubers that are there and what they have going on and where they are at.
Lastly, we discussed some of the interesting forum topics that are going on during the weekend. To listen to the episode as well as check out all the links and further information on the topic, check out the show notes at:
CQ-DATV is available for free download. I have not tried amateur TV but some remarkable results are being achieved by DATV in the 146-147MHz band. Like all things in our hobby, you can only do so much. I think the use of digital techniques has given amateur TV a new lease of life.
Jumping out of a fully working airplane from 13,000 feet is not exactly my cup of tea. When I stand to high on a ladder I get a little woozy. But this guy jumped from an airplane and using 70cm Amateur Radio Television, shared ti with other Hams. Mark, AF6IM, strapped on a parachute, and a 427 MHz ATV transmitter hooked to a helmet cam and jumped from an airplane to land safely while he transmitted, using a Drake mini-modulator with foldable dualband J-pole, that he released after his chute opened and he floated down to the ground.
As you can see from the video below and the info Mark gave about the jump, the Drake can act as a transmitter when an antenna is hooked to it, but the signal was weaker then expected and only worked when he got to about 2000 feet. He said he may try a linear or use a 5 watt Videolynx ATV transmitter next time he does it.
Mark was transmitting on 421.25MHz or cable tv channel 57, and the recieving station was using a 3-element 70cm UHF antenna connected to a Sansui TV set with built-in VHS deck set to catv channel 57. Improvements are being looked at from what was learned from this jump, and another may be in the future.
If you want to find out more, you can visit the Parachute Mobile website.