DV hotspot update 1

I have received notification that The Pi Hut have shipped the Raspberry Pi Zero W I ordered, this should be with me tomorrow or Thursday, I have found a micro SD card from an Internet radio receiver that I build out of an old DAB radio and a Raspberry Pi B V1 until the regulator failed, this card still works and is being flashed with the image, when the Pi Zero W arrives I should be able to insert this pre prepared card and boot it without the HAT to ensure connection to my WiFi network and, in the event of being out and about, connection to the WiFi hotspot in my phone, the HAT config can only be done once the HAT arrives.

The HAT is yet to be ordered, this should happen later this week if all goes according to plan, and though the Colburn and Richmondshire District Amateur Radio Society is doing a talk on System Fusion (of which myself will take part in) that may cover DMR and hotspots as well my own cheap hotspot may not be ready in time as it takes a while for items from China to reach the UK, though I still have my FTM-400 in the car for the talk.

I have also sourced a power cable for the Pi Zero W as I have a few cables lying around, where in the shack it will go I am not sure as yet though I can easily put the hotspot in the living room I'd rather it be in the shack.

I know the Pi Zero I use as an IRC bouncer draws very little even with a USB hub with onboard Ethernet plugged into it, switching out the LED status doesn't make a lot of difference and it is powered with a 700mA charger, as the Zero W has WiFi onboard it will draw more power, how much more shouldn't be too great as long as the signal to the WiFi is good.

more to come

73 de 2E0EIJ

DV hotspot on the cheap

As you know I've got an AnyTone AT-D868UV which I purchased at the Bowburn rally a few weeks ago, and unfortunately due to the primary spectrum user not allowing it there is no 70cm DMR repeater here and thus no access to the DMR network for me but that is set to change and the primary spectrum user need not worry because this should not have any effect due to exceptionally low power on the access side.

The device in question is of course a DV hotspot, now there are loads out there, however until now none of these are cheap... until now that is.

China, a country well known for cheap products, has produced boards that essentially are Raspberry Pi HATs that work as DV hotspots that support modes such as DMR, Yaesu System Fusion, D-STAR, P25 and NXDN (though the latter 2 aren't used in the UK that I know), you can get these assembled in a case with a Pi (or Pi Zero) or for a little cheaper get the parts and assemble them together, the software side is in the form of an SD card image for the Pi called Pi-star, which must be configured to work with the Raspberry Pi and the MMDVM HAT you have on the Pi.

There are instruction videos already on YouTube on how to set these up so I won't be covering that aspect here, as I am going to buy the HAT and the Pi as separate items and assembling them together which will be filmed and uploaded to my YouTube channel.

Powering this unit simply requires a micro USB cable and a mobile phone charger, even one of the widely available power banks can work for this use, I have a Goodmans 8000mAh power bank that could run this sort of setup for a few hours in the event of being away or without mains power, though it still needs the Internet which my mobile phone and tablet can provide as I suspect data use is small, at home I simply just plug it in somewhere in the shack, sit in the living room and have QSOs on DMR, in the car I can use Fusion (I may get a second unit for the car for exclusively this and add the frequency manually to the FTM-400 with TX at low power of course.

I have ordered the Pi Zero W I need for this already (it's like building a house, you have to start with the foundations on which to build), the next order should be for the module, some of the ones from China come with a case and OLED screen so I need not have a display attached to the Pi Zero at all, I am also in the process of getting the Pi-Star image ready, that needs to go onto an SD card which I will purchase locally.

Knowing a Pi Zero can hold a decent uptime I may leave this thing powered up and connected so all I have to do is run the radio.

A bit of programming of the radio will also be involved of course but that's no problem as the codeplug software is on the computer already.

73 de 2E0EIJ

μBITX QRP transceiver kit

on my search for the cheapest way to get onto 40 and 80 meters (top band is optional but I'll stick with 40 and 80 for now) I happened across a kit from India called the μBITX, a small 10-watt HF kit capable of CW and SSB operation from around 3 to 30MHz, for around US$129 (price in GB£ will vary depending on the exchange rate), all it needs is dropping in an enclosure, wiring up, connecting to power, a little calibration and it's good to go.

A kit like this is just what is needed to bring the true meaning of the hobby back, in the earliest days of radio all transmitters and receivers were built from the ground up, though this has near enough all the PCB components soldered onto the board there is a little bit of work to get it working, it also requires an enclosure (metal of course) and a speaker, ventilation should be provided near the finals to help with the cooling.

This kit proves you don't need an Icom, Kenwood or Yaesu radio to get on air on HF, you don't even need an Elecraft for those SOTA activations, just one of these kits fully assembled, a suitable antenna and tuner and you're good to go, and of course batteries, even AA batteries, and you can get on HF from a hilltop, away from that wretched QRM that all today's modern consumer electronics generate, and if you do accidentally cook the PA transistors, they're of a common type and you can replace them for pennies.

The full details of this kit and how to order it are here, and I am very tempted to order one myself and start getting out there and getting on HF.


73 de 2E0EIJ

possible T2LT shootout

I recently happened across eXtreme Antenna Systems, run by Scott 26DRX111/26CTX3111/2E0XVS, he sells antennas ranging from the humble T2LT (of which I built one myself as per Gary 26CTX101's instructions.

Looking at his pre-made T2LT I thought "why not order one and run it against my own T2LT, on the same day using the same radio and the same mast and see which fares better", and this probably will take place after the celebration of legal AM/SSB on the 11-meter band, and after this purchase one of his antennas that can work both 10 and ll meters, put that in the tree outside and have only one feeder back to the shack with a switch in the shack between the Grant II and the CRT SS9900 which may get me on part of HF from home at the very least and may well eventually be swapped by the CRT SS6900N as that has CW whereas the 9900 does not, to do the shootout I may well need a second SOTApole from SOTABeams, as the current one has proven successful already on tests prior to its first official use.

If the 10/11 1/2 wave antenna proves a success from home I will order a second for portable ops to be able to use 10 and 11-meters in the field, this may well prove beneficial for the National Hamfest 2018 in which I plan to run a station from.

I will of course need an antenna switch for the shootout as well

I'll update in due course

73 de 2E0EIJ/26CT730

Local 11-meter noise tests

Before work today I decided to get the mast out and up at the home QTH on the drive on mast stand, this was to find out what the local noise levels using a T2LT antenna would be around here as I plan to hide one somewhere convenient, barely passing S1 on the meter, for arguements sake I took the reading on my CRT SS9900 (bear in mind this is not a type approved radio for the Citizens' Band service so I did not transmit of course) and the President Grant II, the noise did not exceed S1 on both radios for most channels, some cases it would hit S3 but the noise levels were good, even with the SS9900's RF gain turned up to full, this was, however at around 3pm on a weekday, I suspect when everyone is home and they have electronics running the noise level will go up.

QRM is a major inconvenience for the modern radio operator, the vast majority of electronic devices sold are compliant with the rules that prevent them generating QRM, however there are certain things such as solar charge controllers and, worse, PLT homeplugs for networking over the mains that can potentially wipe out most if not all HF bands, the latter are well known examples of devices not complying with the directives in place and being sold regardless, most solar charge controllers are usually cheap units from China and in most cases quality control leaves a lot to be desired.

So I am going to repeat the tests another day when I know that many people will be on the Internet, this may take place after the celebration night on Wednesday, perhaps the Monday night after the celebration night, this will make this test fair.

The next 11-meter related post should be on the subject of the celebration of legal AM and SSB,

73 de 26CT730

Mast update 2

The mast arrived today around midday, almost with the delivery driver leaving thinking I was not in not having waited long enough for me to answer the door and thus me not getting the mast.

First impressions were that it was a good quality product and I expect it to perform well, the bottom of the mast however keeps coming off and thus risking me losing the mast sections, this can simply be glued back on with a bit of superglue.

I took a drive up to one of my usual local radio testing points later on in the day, about 3pm, got the mast up, and into my drive on mast stand and fastened to the driver's door of the car with the radio on the bonnet rather than a fence post as at this location there weren't any readily available.

The band was open but as I caught it starting to close, I managed to catch a station in the south of France on UK40 channel 40 but could not work him, though he was operating at 15 watts and also I was getting more local transmissions on top of him, I heard a station to the north of me as well on the same frequency but quieter than the French station, by the time I tried again the band had closed so it was at this point, as I had other things to do, I decided to pack up.

SWR as reported by the Grant II (I forgot my good HF SWR meter) was spot on, though a test on a proper SWR meter is always a good idea (I am not a fan of built-in SWR meters) and will take place on the day of the celebrations next week.

Overall I am pleased, the antenna is working and is bringing in stations, and tunes and transmits just fine.

73 de 26CT730

Mast update 1

The telescopic mast is expected to arrive tomorrow, a week ahead of its first official outing, this will be helpful as the existing mast I have is damaged as you know, this will hopefully give me an opportunity to go out and test out the T2LT antenna on the President Grant II from my usual places, as not having the antenna on air in some time has led to concern that it may not be working as it ought to be, I was primarily concerned that it had been damaged during the move, though this is not as much of an issue as I simply can build a new one as I have sufficient parts to do so.

Should the mast arrive tomorrow in good time this will allow me to get it up to a high point locally and get it out on the air with the Grant II, which will run off the battery power supplied from the jump starter, I don't expect there to be many stations on 11-meters during the day tomorrow as it is a weekday.

I hope to film this for YouTube as I would like to show a bit of success with the antenna, the Big Multimode Nets/Activate All Counties next week will definitely make it to YouTube, and SSB contacts as part of this would be great.

I hope band conditions on the day of testing are desireable

73 de 26CT730