Using the Ultimate3

I have dusted off the Ultimate3 QRSS beacon kit that I built earlier in the year while a foundation licensee. Having progressed to a intermediate licence I can now operate something I’ve constructed.

Until now it has been attached it to a dummy load with the FUNCube Dongle Pro+ SDR in close proximity as a receiver for experimental purposes.

One unresolved issue was it being consistently off frequency. The DDS modules used are prone to temperature fluctuations and component variances so the Ultimate 3 has the option of using a GPS module to provide both an accurate time source and an accurate 1PPS input which can be used to self calibrate. Except in my case it had proved to be unreliable.

I am using one of the inexpensive GY-GPS6MV2 modules containing the U-Blox chipset I posted about previously with the additional tap off to provide the 1PPS TTL signal.

Initially the GPS module was connected in close proximity to the Ultimate3 but struggled to maintain lock probably due to interference from the DDS module. Even when lock was achieved the calibration never seemed to work. I posted a question on the yahoo support group and from the answers I verified the calibration setting were correct so the only likely culprit was the quality of the 1PPS signal.

The serial NMEA sentences and the 1PPS signal from the GPS are likely to be required in other planned projects, such as an ‘shack clock’ and a GPS disciplined frequency standard. So I decided to put the GPS module  into a waterproof housing that can fitted on the shack roof in clear view of the sky and away from any potential interference. A multi-cored cable supplies power and the TTL RX/1PPS signals being fed back to the bench.

Sourcing an inexpensive weatherproof enclosure (£2) and waterproof cable gland were straightforward enough. I mounted the GPS module on a piece of strip board and replaced the on board LED with one mounted in the enclosure so I easily determine if the GPS had achieved lock, since it only flashes when it has. The LED is sealed with epoxy resin. It should be noted that the outputs of the U-BLOX chip are only rated at 10mA so bear it mind when selecting an LED and calculating the current limiting resistor. The connecting cable is some surplus unscreened alarm cable fitted with a couple of ferrite clamps.

The GPS now has no trouble achieving lock and quickly sets the Ultimate3 clock. Researching the 1PPS problem I hadn’t come up with anything definite, as the signal looked okay on the oscilloscope. But I decided to fit a 10K resistor pull up resistor between the 1PPS output and the 3.3V supply on the GPS module. If this actually made the difference I have no idea but the Ulimate3 now successfully calibrates the DDS using the GPS.

At the moment I have configured the beacon to run WSPR and I have been spotted by other operators. Initially I wasn’t getting much RF out of the device and it turned out to be a combination of poor connection caused by me not removing the enamel properly on a toroid winding and an iffy antenna connector. Both have been corrected and now get a measurable deflection on the SWR/Power meter. With the additional of a second power amplifier FET it is around 200-250mW.

I purchased the Ultimate3 with a low pass filter for the 40M band and while I have had some European spots the results have been a little disappointing. 40M has turned out to be almost unusable at my QTH due to QRN/M so not sure if that is having an effect, also the antenna I have isn’t naturally resonant on 40M so is going through a tuner which will certainly be introducing some losses, without the tuner the FETs get very warm!

With this in mind I have purchased some additional LPFs for the 30M and 20M bands and the LPF relay switching board for the Ultimate 3 so can try/run multiple bands.

144MHz Backpackers Contest

I had a great time today competing in the 2nd RSGB 144MHz Backpackers contest. I entered the 10W Hill Toppers (10H) section since I could operate from the comfort of the car and I could use the FT857 as the Hill Toppers section in the RSGB contest allow operation up to 10W.

The Backpacker (3B) section and the concurrent Practical Wireless 144MHz QRP Contest are limited to just 3W. Normally the FT857 can only be lowered to 5W but by applying a negative voltage to the transceivers ALC line via the accessory socket the transmitters output can be lowered. This method is detailed here it is a simple circuit and I will make one up in due course, I didn’t have the parts to make one in time.

Anyway I digress, firstly I had to find a suitable hill top that wasn’t too far from home. I wanted somewhere quiet and minimised the risk of any confrontation with societies undesirables. A quick look on the local Ordnance Survey map and I spotted a viewpoint symbol.

1:50,000
1:25,000

It isn’t exactly a mountain at just 82m above sea level but is nearby and seemed quiet when I drove out to inspect it. It is the Maplebeck View Point and has a metal plate highlighting hills and structures that can be seen from the ‘summit’ sadly the overgrown hedges did limit the view but it did seem a decent spot with an off road parking area and picnic tables.

The viewpoint
The information plate on the viewpoint

I now needed to sort out the equipment. Operation from a motor vehicle is permitted but all equipment used during the contest must be battery, wind or solar powered. So I made a trip to grab the spare leisure battery from our caravan and the cast iron parasol stand to act as a base for my pole, the antenna would be the Sandpiper 3 element Delta Beam I used in the Lake District.

battery wedged behind drivers seat
Parasol stand and painter’s telescopic pole
Operating from the passenger seat, FT857 on dashboard
Antenna up

I had the FT857 on the dashboard and sat in the front passenger seat, the pole was within easy reach out the window and I had fitted a small pointer on the pole so I knew which way the antenna was pointing, so could turn it by hand.

I was initially quite nervous setting up as it turned out the road was actually quite busy and I was getting a lot of quizzical looks from passersby, but once I got going I just ignored them and enjoyed the contest a lot. A number of walkers asked what I was up to and it seemed the viewpoint was a stop off on a MG owner’s outing this morning.

I made a reasonable amount of contacts, given most people were operating QRP with some decent distances. I did suffer one brain fade and missed another potential locator square when the other station repeated my report back and I blindly wrote it down and then lost them before I was able to correct it.

At one point I thought I would have to pack up as I was getting huge static crackles and pops which were due I think to some nearby high tension electricity pylons and what appeared to be a gathering storm, there was some brief rain but it quickly dissipated.

Next month I am looking forward to the VHF National Field Day and the 3rd Backpackers Contest as a number of members of the South Kestevan ARS are keen to have a serious attempt.

Planning some more /P and /A

All too quickly and the holiday is over

Apart from the UKAC on the Tuesday night I didn’t do anything else with the radio, I did have the HF antenna up but the trapped nerve in my back meant I was in a lot of discomfort after being out and about during the day and so rested and zonked out on painkillers rather than struggling to set up the rig.

I must sort out a proper portable station that I can just open it up and start operating, I am impressed with Charlie’s M0PZT porta-pack frame idea being an excellent solution especially for back packing.

In the past the wife and I used to be keen walkers, tackling many of the peaks in Cumbria, Snowdonia, the Peak District and elsewhere. We completed the Coast-To-Coast Walk back in 1991 and The Cleveland Way the following year.

Dipping my boots at Robin Hood’s Bay in 1991 at end of the Coast-To-Coast

Sadly I am too overweight now to be a serious Summits On The Air (SOTA) operator but I plan on getting back to a reasonable level of fitness. As it happens if I’d been more prepared our walk of Latrigg last week could have been my first Wainwright On The Air (WOTA) activation.

Next month we are off to the Isle of Skye. We are staying in a self-catering cottage with plenty of room so rather than being /P portable I can be /A alternative and will be able to set up the rig in the cottage so can use it as and when I want.

I’ve already mentioned the holiday coincides with the 50MHz/6 Meter UKAC and am currently toying with the antenna choice, one advantage of being so far North is I won’t need to rotate it as pointing it South South East should cover most of the UK. From the photographs of seen the cottage is reasonably elevated with clear views across Loch Bay in that direction. There are mountains ranges to contend with but who knows with propagation? I’ll be in the rare IO67 locator square so might even have to contend with a pile up!

I will almost certainly operate as 2E0NRD rather than M6GTG for that week as using just 10W might be a bit optimistic.

IO67 Locator Square

I got somewhat excited last week when I received an email announcing the RSGB First 50MHz Contest results I was down in 35 place in the SF section but with a rosette next to my callsign? Wow I’d got an award! Pleased with myself I jumped on twitter to spread the news…

Gobsmacked.. pic.twitter.com/sGDI4jDh1W
— Andrew Garratt M6GTG (@nerdsville) June 7, 2014

Perhaps I shouldn’t have been quite as quick to brag as it appears I was the only Foundation Level entrant!

Still I managed 4 verified QSOs on what by all accounts was a very difficult contest, with low activity and poor conditions. In fact I almost missed the contest altogether and was only alerted to the contest by a tweet by Robert @G1ZJP and was late starting as I needed to get the antenna up. I actually made 5 QSOs but one was broken because I mistakenly put 59 in as the serial number.. Doh!

This weekend is the 2nd RSGB 144MHz Backpackers contest and the Practical Wireless 144MHz QRP Contest Unfortunately the FT857 is too powerful for the QRP contests as the limit is 3W but I could have a go at the Hill Toppers section in the RSGB contest which is limited to 10W and as luck would have it I am left to my own devices this weekend so might take a drive in the car..

Ultimate3 QRSS Beacon kit built!

At the start of the year I did some experimentation with cheap DDS modules based on the Analog Devices AD9850 connected to the Arduino board, making a rudimentary WSPR transmitter prototype.

My current licence restrictions prevent me using anything home-brew for transmitting except for commercial kits. So I ordered an Ultimate3 QRSS beacon kit from Hans Summers (G0UPL) thinking that it would be okay. I subsequently learned that any commercially available kit must satisfy IR 2028 which is all a bit vague and unclear but sadly I don’t believe this particular kit does.

All was not lost, building this kit should more than satisfy one of the practical assessments of the intermediate examination, which will get me around this problem.

The Ultimate3 kit is extremely popular and so I had to wait a little for delivery and it arrived on Friday. After the last few weekends of non-radio activities I had planned to get my antennas backup and do some proper operating. Like many people I had been forced to take everything down due to the barrage of storms and high winds the UK has been experiencing recently.

A tidy workbench

Saturday saw no let up in the wind, so I decided to spend a few hours building the kit instead.

The instructions were extremely clear and straight forward and soon had it built up, though it is high time I invested in new soldering station. I have a basic Antex 25W iron. I cannot remember exactly when I brought it but it is well over 10 years ago.  It was more than adequate to build this kit and for soldering connectors but I could do with something adjustable and more comfortable.

Taking shape

The only issue I had was winding the first toroid, 25 turns later I realised I had wound it the wrong way round so the leads didn’t line up with the holes in the PCB. I could have made it fit but nope I will do it properly so I unwound it and did it again.

I also made the mistake of not scraping the enamel off the toroid wire and tried the heat it and bubble it off method, except I think my iron just isn’t hot enough so ended up using a piece of wire wool to remove the enamel.

Lessons learned I soon had the other three toroids correctly wound and wire prepared for the low-pass filter board.

Close up of the LPF

   A final visual check and powered it up and it worked first time!

All built
It works!

Setting it up

Full of confidence I grabbed my trusty GPS module which has been pressed into service on a few Arduino projects including the HAB project. Quickly soldered some connecting wires and powered everything up.. all was well or so it seemed when the display suddenly went blank, backlight was on, just no characters.

Pressing the button I occasionally got some random characters and a flashing cursor! I de-soldered the GPS and still nothing. I suspected the display was faulty but trying it on the HAB prototype board confirmed it was okay. I checked the display connector continuity and everything appeared okay.

Out with the oscilloscope I started probing, everything checked out. Crystal was oscillating and data pulses on the display control lines. Then I checked the supply pin on the display and it was only reading 4.1V, this under-voltage would explain the odd display behaviour.

PSU output was 5V, micro-controller was 5V, DDS module had 5V. All very puzzling till I removed the DDS module and spotted a discoloured track on the PCB, touching it with a screwdriver and the lacquer fell away revealing a tell tale scorch mark, somehow I had made a nice resistor!

Burnt track to right of micro-controller

A quick wire link soldered in place and everything was back to normal.

What caused it? Checking the de-soldered GPS connecting wire I spotted a stray single strand of wire on the ground wire. I suspect this must have shorted to the adjacent 5V line and since I was using a nice beefy ex-PC PSU as a bench supply it had popped the track without the hint of a flicker. The GPS has been rewired properly and is working nicely, now to connect a dummy load and experiment some more.

Sunday was a lovely day, wind dropped so antennas have been put back up and I took the opportunity to tidy up the installation a bit. I also dug out an old fibreglass pole to put the M0CVO HW-20HP back up. I didn’t get to do any operating in the end as by the time I had done this and made up a couple of decent patch leads it was time for roast beef and all the trimmings and an evening in front of the TV.

The HW-20HP back up

Putting PL259 and N-Type connectors on coax is also part of the intermediate assessment, so perhaps I should have videoed making up the patch-leads as proof 😉