Click here for the Ban PLT website.

Tuesday 16 October 2018

M7 callsigns now being issued by Ofcom to newly qualified foundation licence holders

I decided after seeing this information on another of Lewis M3HHY's videos to wait for RSGB and Ofcom to announce it before posting this, however it appears the M6 callsigns have finally run out (I still hold M6RSQ though do not use it on air at present given that I have an Intermediate (2#0EIJ) but still have the freedom to use it if I so desire as it is still valid) and Ofcom are now starting to issue M7 callsigns to Foundation licencees who have recently qualified.

This does bring the question of how many M0 calls are left for full licence holders, as I hope to qualify before the syllabus changes in August, and obviously M3, M6 and M7 are all used for Foundation, and M1 has already been used for full licences, leaving 2, 4 and 8, 9 is not used for Amateur radio callsigns in the UK, at least in the G series anyway, except in some contest callsigns. though Ofcom may change this as they have that power

RSGB's official announcement was on Twitter in the last 48 hours, however not put out by the fiasco surrounding Activate All Counties that went against him, Delboy gloated in reply with a link to a post from his blog saying he had "beat them to it" when in actual fact he had heard a new M7 call on air local to him on 2-meters after I read the post, which predated RSGB's announcement.

I have always encouraged people in the hobby to go out and get their M6 call, now I simply encourage them to get the M7 call and find there is more than 80 channels at 27MHz and 16 channels at 446MHz to play with.

and I look forward to working an M7 station real soon

73 de 2E0EIJ

Thursday 11 October 2018

Amateur television - a new adventure in radio for me

As you know I went to the National Hamfest this year for both days, giving me an opportunity to speak to more organisations than normal, one of which was the BATC, who were there with examples of their Portsdown transmitter used for DATV (which uses DVB-S and therefore can be received on a domestic satellite receiver but not Sky branded equipment as that is locked down in firmware and cannot be unlocked to tune to DATV) and a couple of other bits and pieces and an opportunity to join, after giving it some thought I plan to do so but lacking a suitable Raspberry Pi I cannot begin to construct the Portsdown myself so I looked at a cheaper and more challenging alternative that the BATC have on their website as a means to transmit ATV.

The alternative are the transmitter and receiver pairs used for FPV from drones, these operate in the 5.8GHz region, part of which falls within the 6cm band, since I gained my intermediate I also have privileges to operate on that band, something I did not have with my foundation, the agreed on frequency is 5665MHz, or 5.665GHz, which most of the units, though not all, can tune to, though I'd want to mount these in a diecast enclosure for two reasons, one so the enclosure acts as a heatsink for the device and two to keep RFI down if any, these units take a standard CVBS (composite) video feed though may need the appropriate sockets fitting to connect the camera to the TX and the monitor to the RX, the TX unit also needs a means to insert a callsign and send out a test card, the BATC suggest a memory card media player unit for this purpose, my idea is to add a video splitter to allow me to see what is being sent to the TX as well.

Camera wise I am sorted, I have a long redundant Samsung camcorder that, since I bought my JVC Everio camcorder, has been seldom used and been allowed to remain in a state of discharge, it had fitted a coin cell battery to back up the time and date, though not a feature I'd need and this battery has not leaked and the camera works fine and tested into a video source the picture is clean enough for transmission.

Antenna wise I need to look at, a single antenna requires a changeover relay, these can be had at rallies for a small amount, the antenna itself needs to be directional, horizontal polarisation, and equipped with an N type connector, 5.8GHz WiFi antennas would work here though these are expensive, a cheaper solution is to build an antenna, as I like building antennas I see no reason why not, a design I have seen involves copper wire and double-sided PCB and a chassis mount N type connector, as I lack any coax at this time I could simply build 2 antennas so I have one for TX and one for RX and the units connect directly, however these use RP-SMA and as such require an adaptor or an appointment with a soldering iron to swap the connector to standard SMA and again an adaptor, the former is quicker and easier.

Before I begin I plan to join the BATC as their annual fee is low, around £8 or so if my memory serves right and they send out a quarterly publication called CQ-TV, which sounds like a good read.

I watched a video from BATC's CAT17 conference in which the very person I spoke to at Newark discusses the 5.8 GHz FPV system being used for ATV, and a demo as well, including antenna information which include modifying a Sky Minidish (which are very common now and there are a few surplus ones doing the rounds) with a PCB log periodic antenna at the feed point, the BATC wiki details a homebrew antenna that I alluded to above.

Lastly at this frequency your normal coax is useless, so in the case of 2 antennas and no changeover relay the TX and RX are directly connected to them, 0dB loss, or if you're using a changeover relay, one antenna and possibly also a power amplifier (to get the TX up to 2 watts) then you'd need short coax links that are not lossy at these frequencies and fitted with SMA connectors for changeover relays and adaptors to convert the RP-SMA to standard, at my next rally attendance I of course will be keeping an eye out for microwave changeover relays as these frequencies are classed as microwave.

So in summary I have a camera, I have a mic to connect to the camera, I have a cable to connect the camera to a monitor/TV (which will go to a TX instead), all I need now is the parts to build the system, and because this station will be operated /p 99% of the time it will be created with this in mind, I also intend to build a self-contained receiver standalone to the main station to ensure the TX is actually working with help of an assistant.

I may, once I've got this up and running and had a couple of QSOs over it, demonstrate it to the local club, perhaps keeping the RX at the club and they talking back on 2-meters on the agreed talkback channel.

The best part about all of this is that everything can run off 12 volts so all I need is a battery, and while doing this I can still work on the Portsdown which will take a little while but I enjoy building things, part of the appeal of Amateur radio, the technical side of things too also is of interest hence this interest in Amateur television.

Time for further research and I hope to get something working real soon and I'll keep you updated on progress as it goes on.

73 de 2E0EIJ

Monday 8 October 2018

The fatal flaw of cheap Chinese radios for 2m and 70cm

YouTuber 'Ringway Manchester', Lewis M3HHY, posted a video of himself and another amateur attempting to make contacts on 2-meters simplex from Blackpool Tower, something I myself wanted to do but decided against and, as Lewis revealed, I too would have failed as on the day I had only a Baofeng with me.

Radios made by Icom, Kenwood and Yaesu all have good front end filtering on them and a superheterodyne receiver, with a couple of the really cheap Yaesu radios being an exception on the latter, cheap Chinese radios tend to have a direct conversion receiver and poor filtering, as I demonstrated with my Leixen VV-898 this leads to interference from out of band signals.

Lewis had this problem from Blackpool Tower on a Baofeng UV-5R and another Baofeng which I believe was a UV-82, 10 stations came back to Lewis' calls but he was not able to hear them on either radio.

the other part of the problem is that there are antennas on Blackpool tower, to higher powered transmitters, though these are higher up than what the public are allowed and should have not caused a problem in theory, as I plan to get hold of a Yaesu HT (or an analogue Icom or Kenwood) hopefully before next year's Blackpool rally I hope to be able to give this a go myself and see if a Japanese made radio will be able to do what the Baofeng cannot do, work contacts from Blackpool Tower, also I really hope Lewis gives this another go with another radio, as that is a video I would very much enjoy seeing.

Chinese radios, you do get what you pay for, though don't get me wrong, I do advocate the Baofeng radios as they are very good starter radios for the newly licensed that cannot afford a radio by one of the big three.

Search YouTube for 'Ringway Manchester' for Lewis' video from Blackpool Tower and you'll see the difficulties he was having, after all the tower should make a very ideal place to get into the repeater on the Isle of Man, just Baofeng skimp on the filtering and use an SDR chip in the radios though all radios are prone to front end overload and desense from strong transmissions.

73 de 2E0EIJ

Monday 1 October 2018

National Hamfest 2019 planning already underway

With the success of the camping at this year's National Hamfest plans are already underway to prepare for next year, with a few changes to what I had this year, these are:

  • A better tent, namely the £99 tent from Go Outdoors that I could not afford this time round
  • Solar power aside the generator to run electrical appliances with a heavy duty inverter
  • Running of a station on site, hopefully HF as well as 2 and 70, and possibly an amateur TV setup as I look into that aspect of the hobby
  • Better Internet access arrangement rather than tethering to my phone as I had to do, the mobile data service on my tablet never worked at Newark so everything was through my phone
  • A heater for outdoor use as nights were cooler than expected
  • Reworked cooking facilities though I will still keep the existing stove
I may add to that list as time progresses, I also hope to have either filtering on the QYT and Leixen by then to get rid of the pager interference both sets are terribly prone to or a better mobile set for portable ops that is designed properly.

There are still rallies left in 2018 and I hope my next one will be the Spennymoor rally run by BARAC, and if I am there please do say hi.

73 de 2E0EIJ