Good news! After a short lull in examination services due to a transition to a new provider, the Riverland Radio Club Inc. is back in the position to provide assessments.
We currently have 2 Club Endorsed Assessors registered with the new provider, Australian Maritime Collage (AMC), with another couple or so in the process.
And if you didn’t know, our Club, through our Endorsed Assessors, offers to successful candidates from one of our assessment activities some Club incentives. This includes:
- Club General Membership for the remainder of the current subscription year. More details HERE.
- Club General Members also get a discount incentive with Berri Betta Home Living JAYCAR Authorised Stockist.
For a bit more info about our assessment services and licensing stuff have a look HERE. If you want you can also have a look at our Club Endorsed Assessors or the Foundation Course & AMC-AR Assessments page.
I was lucky enough to be thought of when a dear friend of mine, who runs an antique and curio business, came across this old piece of medical equipment. This set off her NERD meter and she messaged me asking if I was interested!
I immediately replied yes and she snapped it up for me for next to nothing…the reason being is this thing, the way those knobs are laid out and that big beautiful meter, just screams
But before I consider butchering it and using it for a project I decided to find out a bit more about it…
…and basically ran into a brick wall…
There is very little info on the Internet about the device and definitely no manual!
I actually had to read a couple of scientific papers to work out what the unit actually did, and how it works. This was the only source of information on the unit I could find.
So what is it? – It’s basically a medical radiation detector. specifically it detects radiation from medical isotopes that are injected/ingested/inhaled into the body, that accumulate in a specific area, like the restriction/blockage of blood flow, lymphatic system issues or uptake from tumors/cancer. The patient is probed locally at the site of interest with the large silver hand held scintillation detector that detects the radiation, which shows as a deflection on the meter. It dates from the early mid 70’s when, I guess, it was the early-ish days of nuclear medicine…
So how does it work? It is certainly an interesting device. It is battery powered, by a couple of PP9 9V batteries in series, to give an 18V supply. There is a battery check area on the meter, this is activated by turning the range switch to the “B” position, just up from the “OFF” position. The PP9 battery is still available from a few different places, I’ve ordered a pair to see if this thing still works. It will be interesting to see if the unit is capable of detecting background radiation. I hope it does.
The probes are also very interesting. They employ a Scintillation Crystal and a Photomultiplier Tube to detect radiation from the patient. It’s a 2 stage process. The 1st stage involves the Scintillation Crystal. This is located at the site where the probe contacts the patient, and detects the radio active particles that are emitted from the patient who has been administered a Radio Isotope. This crystal then emits a pulse of light (Scintillation), usually in the visible spectrum. This pulse of light is then detected by the photomultiplier tube and “multiplied” – resulting in a pulse of current for each radiation particle detected, which is then passed to the instrument itself, where the result is processed and displayed.
The Photomultiplier tube is pushed hard up against the Scintillation Crystal via spring pressure. It is encased in an Aluminium tube, most likely for protection.
There are 2 probes with this unit, one marked “Probe type 235N”, which has a moveable shroud with what looks to be a ferrite or powdered iron inner ring touching the probe surface, with a long, curly connecting lead, and another marked “Probe 235”, which has a moveable, plain aluminium shroud. I haven’t been able to establish the difference between the two probes.
OK, so how does it ACTUALLY work? – much simplified, here is how i think it works…
The 18V battery supply is boosted by what looks to be a Cockcroft-Walton voltage multiplier, to a high voltage, most likely variable up to around 3Kv. This is all at very low current, judging by the size of the transformer drive circuit, probably in the uA range. The range switch looks like it selects a number of set voltages. The voltage multiplier board is located in the rear of the unit, seen here. The transformer and drive circuitry are hidden behind the panel with the 3 connectors on it.
This high voltage is fed to the photomultiplier tube via the front panel BNC connector and any detected radiation from the probe results in a current pulse that is measured across an anode load resistor by the metering circuit. This pulse looks to then be fed to an integrator circuit, whose role it is to change the pulses received from the probe to a proportional, steady voltage, (i.e. more pulses more voltage) which is then displayed on the meter. I imagine the fast/slow push buttons would relate to the speed of integration. As an example, if the probe detects little or no radiation, (low or no meter deflection) from an area on the patients body and then more radiation (meter deflection increases) when moved to another part of the body, then that increase for that area would be a concern. A practical example of this (now old!) technology was to use this device after injecting the patient with radio isotope Iodine i-133, to detect blood clots in the legs of patients suspected of suffering with deep vein thrombosis. A meter deflection on a particular area of the leg indicated the clot site.
My limited knowledge of nuclear medicine hasn’t helped in deciphering the Isotope control. I’ve learnt that differing Isotopes are used for differing areas on the body, for example, the Isotope Xe133 (Xenon Gas) position is used when checking the lung and brain. How this transpires to readings from a probe that only has 2 connections for +ve and Gnd is a mystery. More research showed that other Isotopes on the dial are used for checking other areas like kidneys and heart. I’m sure there’s a perfectly clear explanation out there somewhere. Maybe the different voltages are used with the different isotopes…i.e. 1000V range for Chromium51? Who knows? If anyone can add any insight as to how these units operate I would be forever greatful.
The unit is beautifully made. It has a number of quality circuit boards and the wiring is super neat, and has been laced up. it has a number of gold plated edge connectors. It’s all analog, it’s full of IC operational amplifiers operating on a split rail +/- 9V supply. There is a very nice precision 50uA meter movement that would be a bit better quality than your average. The case is a work of art, I have a number of ex scientific instrument cases from England and all are wonderful!!! Should I turn it into an Antenna tuner?
We have certainly come a long way from using this type of instrument for medical diagnostics. The clarity and resolution of todays 3D medical imaging machines is mind-boggling!!!
On that note I’d like to take this opportunity to wish all BRL blog readers a happy, healthy and prosperous 2019.
Well what a year it’s been for our modest little Riverland Radio Club.
This year we have seen our Club members engaged in all sorts of cool stuff, WX Balloon chasing, Project HORUS chases, more activity in the Parks’n’Peeks program, project building, and even back into JOTO. There’s been Satellite activity, we’ve run a successful Foundation Course, assisted in the Riverland Paddling Marathon, and of course the staples of the RRC BRL Gathering, BRL Riverland Nets, WIA re-Broadcasts and so on. For such a modest club I think we punch well above our weight, for which I am proud.
All this good stuff must come with acknowledgements to all those that call into the nets, join our members on air when out and about in the parks, jump into chase cars, run tracking stations, etc. So thanks to all those both members and non-members who have been a part of this year for us.
On the administrative front we’ve almost finalised implementing a new Club Constitution, the website saw a rework, we’ve introduced Berri Betta Home Living – Jaycar as a Club Sponsor (where Regular Members can enjoy a 15% discount), we now have a new structure that includes a number of coordinators, we have ran Foundation course and started new HAMs on their own exciting journey, there is now free Club Membership to new HAMs that undertake a RRC facilitated assessment, just to name a few things.
Our website continues to grow in popularity. We have smashed all previous records, and not by just a little bit! These numbers show some awesome growth… take a look:
- 6538 – YTD
- 3180 – 2017
- 1687 – YTD
- 476 – 2017
- 209 – YTD
- 0 – 2017
- 84 – YTD
- 1 – 2017
Gotta be happy with that growth!
All in all a pretty good year for our Club I reckon, which brings me to a heart felt and special thank-you to our members. I recognise that each member has contributed what they could and I ask for no more that that. Well done all of you.
In closing I would like to take this opportunity to wish everyone the happiest possible holiday season, and hope that 2019 brings everyone a very safe and joyful year.
Cheers and 73 from Riverland Radio Club, and
VK5DW Danny, President
Merry Christmas all
Six Meters is a great Amateur Radio band, and there are quite a few active operators, but just about everyone I’ve talked to recently says something along the lines of “ Six Meters sounds great I’d love to be on it”, or “I’d love to get on Six Meters but I don’t have an antenna” It seems it’s seen as more of a “summer only” band in times of slow solar activity. Indeed, ‘ol Sol isn’t going to let you talk to England via the F2 layer with the current number of sunspots.
Even without big sunspot numbers, Six meters is a lot of fun via Summer Sporadic “E” layer propagation. VK wide and VK-ZL paths are often a daily occurrence, and VK-Pacific regions, VK-Hawaii, VK-West Coast NA/SA are all a possibility.
The fact that just about all modern Transceivers now include Six Meters as standard, and the demise of channel 0 and the accompanying TVI issues that went along with that, ( thanks digital TV!) means that “6” is now more useable than ever.
Another plus with 6 metres is that getting a decent antenna up for the band isn’t difficult. For Sporadic E contacts, although a simple vertical or even a dipole will get you on the band, having a bit of gain and direction will often turn what would be a marginal contact on a vertical into a solid contact. This gain and direction is even more important when using weak signal modes like WSPR, FT8 and JT.
i have been on 6 metres off and on over the years with various antenna I’ve put together, from verticals to beams. This year I decided to put up something better than the 40M dipole tuned up on 6.
I’ve always been aware of the Moxon antenna . I have often contemplated constructing one to use portable for the 20 metre band vertically polarised near salt water. It’s smaller size, small footprint 2 element design seemed ideal to sit on top of one my push-up masts at home.
One of the good things about building a Moxon is that at 50 MHz, it’s not a very big antenna at all and, is easily managed by one person. Lightweight construction methods and wire elements will work a treat.
Fortunately, there is a good deal of info on the internet about the antenna. There was a very good page called “ The Moxon Antenna Project” , but unfortunately it appears to be down at the moment. There was good information, and many build examples on that page, I hope it gets put back up soon. If working with aluminium tubing is your thing, then DK7ZB has a dedicated section for the Moxon on his website.
It really is as simple as putting in the frequency you want to build the antenna for, and letting the program do the work. you’ll be presented with a nice table with all the dimensions. Stick to them to the millimetre if you can, and I”ll bet you’ll be rewarded with a working antenna first pop. Pay special attention to the gap between the two sets of folded elements (measurement “C” in the table above), this dimension is critical to the correct operation of this antenna.
Ok, so on paper, we have all the information on the dimensions of the antenna, now we have to translate those lengths into an actual antenna. I found the best place to start was just googling “Moxon Antenna” and looking at a lot of the images and videos available on line. Everything you thought of (or didn’t), will come up and you’ll soon be inspired. Aluminium, wire, wood, steel, nylon, plastic, fiberglass and PVC are just some of the materials people have used in the construction of this antenna.
I decided to go with a Nylon chopping board from BigW for the baseplate. This is only going to be in the air for the summer, so longevity isn’t a priority. I used smaller short squidpole tubing from Haverfords as my spreaders. The spreaders had a 150mm length of wooden dowel inserted for strength, and were clamped to the chopping board with conduit clamps from the local plumbing supply house. The right angle bracket is a pergola fixing from Bunnings, drilled to accomodate the U bolts I used to suit my mounting mast. Simple!
I mounted a BNC socket through the chopping board and bought out the cable and sealed it with liquid electrical tape. I put a balun at this point also (yeah you should use one). I used an FT140-43 Toroid and wrapped 8 turns through it. I ended up hot gluing the balun assy to the nylon surface, seemed to be quite sturdy.
At this stage, I temporarily mounted the antenna after fitting the wire elements. Click on the pictures to enlarge them, you’ll see the pink brickies cord I used as element spacers. the second picture shows the short piece of 16mm PVC water pipe I used to guide the coax to the feed point. I used a two terminal piece of chocolate block electrical connector, hidden inside the far end of the pvc pipe to transition the coax to the elements feed point. I sealed up the ends with bluetack to keep any water or creepy crawlies out. Unfortunately I forgot to get a photo of this arrangement.
The wires were stretched out and attached with cable ties slipped over the end of the squid pole spreaders and secured with PVC electrical tape.
I used a super strong PVC jacketed, 7 strand copper clad steel, kevlar reinforced antenna wire that I had left over spare from a previous project, but you could use just about anything that can take a bit of tension. 1mm enamelled copper wire for the elements would work well and would be more than strong enough. Just tension everything so that its sits nice and taut across the spreaders.
The Moxon calculator must have got it right the first time, as I couldn’t measure any VSWR on my FT-817 at the design frequency of 50.110 Mhz . The antenna seemed to be working, a quick test with some local operators, Adrian VK5AW, Rob VK5TRM, and Mal VK5MJ showed it was both getting out and had directivity. Conveniently, I was able to hear a couple of Six metre beacons from QLD as well. Turning the antenna to test the front to back ratio demonstrated a deep null in the pattern with the antenna driven element 180 degrees to the source, exactly as expected.
I decided to mount the antenna above my 8 ele 2/70 Quad, so it is about 13 metres above ground level. I’s rotated with an armstrong rotator, the mast for both antenna is strapped to the palm tree!
The antenna seems to be performing well, It’s only been up for around 10 days and I’ve already had several solid SSB and FT8 Sporadic E contacts so far this summer, exactly the reason I built it in the first place. I leave it on the 6M WSPR frequency all day and have spotted stations as far out as 3D2 Fiji and FK1 Vanuatu. So it hears great as well. It’s also small and light enough to pack it in the car and see if you can get some contacts from a park or summit on Six too.
So if you’re sick of hearing about Six metres and wish you could get on the band, then this simple antenna should be on your to-do list this weekend!
See you on Six
On December 1st the Riverland Radio Club held a Foundation course presented by Rob VK5TRM and Ivan VK5HS.
Robert VK5TRM delivered the Foundation course to the 3 eager potential new Amateur operators. The power point presentation was delivered, as the candidates had all been sent the study material prior the course and had all purchased a copy of the Wireless Institute of Australia ” Entry into Amateur Radio” the course proceeded along in a timely manner. The candidates asked for explanations to clarify anything they had trouble understanding as we progress through the course. The mentoring of the candidates prior the course helps towards running a successful course.
Mid afternoon the time came for the serious part of the day, the exam papers were presented to the candidates, Rob explained the process on how the exam was to be conducted. With the clock set for the 30 minute exam the 3 very nervous candidates proceeded to attempt to answer the 25 multi chose questions (I am never sure who is the most nervous, the candidates or the examiners).
The time was up pens down Ladies and gentlemen, Ivan collected the papers and proceeded the check and mark them. Rob setup the practical component of the course and commenced the session demonstrating the various requirements of operating a foundation station. Once I had completed the marking of the papers we swapped roles and Rob doubled checked the results. I continued on with the practical session.
With the practical session completed we were able to advise the candidates of the outcome of their attempt to join the hobby of amateur radio. We are please to announce all 3 were successful in obtaining a ‘F’ call.
Rob and I then started the paper work, with this all filled out we congratulated them on a job well done.
Rob and I then announced to the successful 3, the RRC offers free membership for the remainder of the member subscription year to persons undertaking a RRC Facilitated Assessment activity. With this membership comes the added advantage of receiving a RRC Membership Card, which when presented at Berri Betta Home Living, a JayCar Authorised Stockist, a discount will apply on non-discounted JayCar product.
It is our job as seasoned hams to mentor the new hams to the hobby, it is easy to get new ‘F’ calls. It is much harder to retain their interest long term and assist their journey through our great hobby.
RRC would like to thank Peter VK5PE whom provided the venue in Renmark & assisted Rob & myself.
RRC would like to introduce Sandy, David and Stephen to our great hobby. Please listen out and welcome them when they get on air with their new call signs.
Regards Ivan VK5HS.
*** NEWS FLASH NEWS FLASH NEWS FLASH ***
Berri Betta Home Living – Member Incentive Program
Regular Members can enjoy a 15% discount on JAYCAR lines, excluding already discounted items.
Head to the “Membership” page and find out more about our membership.
*** NEWS FLASH NEWS FLASH NEWS FLASH ***
Several Hams have asked me what on earth is , and where did I get, the stand supporting my Antenna?
The answer will be revealed in these pages! There’s not much to reveal actually, around every 6-9 months or so, the ALDI supermarket stores sell a 5 legged “Bicycle Repair Stand” for $39.99.
It’s a sturdy stand for elevating your push bike to waist level or better to effect repairs and or maintenance to said bike. However, they also double as a brilliant stand for various Ham Radio activities, as I’ll demonstrate here.
In detail, it features a large footprint so that it’s difficult to tip over, either accidentally or by other means, is made of steel, and boasts a height adjustment and a quick release Antenn…I mean “bike” mount, that allows stuff to be held horizontally…other bells and whistles include a chintzy tool tray and handlebar stay bar.
So what’s in the box?
You get the stand itself, the centre support with the T adapter, the horizontal clamp bar, the chintzy tool tray, and the handle bar stay. The two straps are for use with the handle bar stay, and the plastic bag contains the bolts and allen key for attaching said chintz. The allen key fits all bolts on the stand.
It comes with a set of instructions and a 1 year warranty. For something ALDI, it actually is quite well made!
Assembly is very straightforward
just clamp it up tight or as loose as you like…
But for a park activation with a squid pole, I remove the T head and just use the pole out the top to slip the squid pole over…
For a Satellite pass, I attach the Bike head and use the clamp to hold the X-Yagi. It’s easy to turn the Yagi to adjust the AZ EL to suit the pass…The clamp is plastic and I can’t measure any increase in SWR or pattern distortion in use…
For Microwave Field Day work, the Bike Stand is a cheap way of getting a sturdy stand for Ex Sat. dishes and Gridpacks.
The stand would also do well as a sturdy portable Satellite dish mount for Caravan users and RVers.
A nice touch is the holes in the feet, ready for tent pegs as tie-downs…
So there you have it. These bike stands are a cheap way to get a sturdy stand for Amateur radio related activities, use your imagination! Keep an eye out in your local ALDI catalogue for the next sale date, and grab yourself a bargain!
*Disclaimer* – I have no affiliation with ALDI stores whatsoever!
On Friday, 16/11/18 I planned to activate the Swan Reach Conservation Park VKFF-0832 for the Murray River Parks Award that is administered under the umbrella of the World Wide Flora & Fauna in Amateur Radio (WWFF) Program, so popular with Amateur Radio operators world wide now days.
My Chauffeur (my affable 16yo son Riley) and I left our home location at approximately 8:15 am for the journey to Swan Reach. We followed the conventional route from home via the Sturt Highway, and stopped to stretch our legs at the look-out above the town, just before you ascend into the town itself from the Blanchetown Rd cliffs. It was then the chauffeur’s first go at navigating us across the Ferry, over the mighty River Murray, and onwards to the park,
The Parks is located about 15km from Swan Reach heading west on the Stott Highway towards Sedan and Adelaide. We accessed the park after turning off the the Stott Hwy onto the Old Punyelroo Rd and into the Park entrance itself. It is all clearly signposted. The blue dot on the satellite image was our operating spot, in a nice clearing, a short drive into the Park under some trees.
It was a beautiful day, wall to wall blue sky and a slight, cool southerly breeze, the temperature about 22 deg C. The Chauffeur expertly parked our Millennium Falcon under the nearest shade shrub, and I wasted no time in setting up the portable antenna. For drive-in activations I have settled on my trusty ALDI bike stand tripod, 8M squid pole and 40-30-20 M inked dipole. It goes up in minutes, and radiates my signal very well. I have opted for the tripod instead of tying to a tree or support, as I have usually found that the available centre antenna supports like posts and tress don’t suit where I want to set up. The tripod takes that unknown out of the equation, and allows me to have my squid pole supporting the antenna, right next to the operating position. I have a couple of heavy sandbags to stop the lot tipping in strong winds, but its not often needed. certainly not today in the perfect weather! Coupled with my Icom IC-7300 Transceiver, this setup is a pleasure to use on the air.
I was soon on the air and calling CQ Parks on 7.144Mhz, the 40 Meter band. First in the Log was Gerard, VK2IO with a lovely 55 signal into Swan Reach, followed by numerous stations in VK2 and 3, including Peter VK3TKK/M and Brad VK2BY/M who were both very readable from the mobile, Paul, VK5PAS/3 and his wife Marija VK5FMAZ/3who were enroute to Bendigo, also called in. They were easily worked 56 and It was nice to get them both in the log. After about an hour I decided to change bands by removing the 1st link on either side of the dipole (quick and easy when the antenna is supported by the bike stand) and started calling CQ again, but now on 14.244, the 20 Meter band. This only resulted in 3 contacts, including Geoff, VK3SQ, who had a massive 59++ signal into my location. I was equally strong at Geoff’s end. There weren’t any other takers so I headed back to 7.144 on 40 Meters after about 10 minutes to finish up my activation. This time John, VK4TJ, was obliging along with Marija and Paul, who had found a park to operate from and popped up for a park to park from the Barrett Flora & Fauna Reserve VKFF-2264. Thanks Guys!
By this time, my Chauffeur was starting to eye off the Falcon’s upholstery he was that hungry! Likewise, I was also keen for a feed as well. We packed up, left nothing but footprints, and headed straight for the Swan Reach Hotel.
Swan Reach Hotel – a bit of history
The Swan Reach Hotel wasn’t actually purpose built to be a hotel , but morphed from original Swan Reach Station homestead built circa 1865.
Beginning 1861 the original Swan Reach Station was just of a couple of huts, workers’ and shearers’ quarters, some shedding and ramps. You can still see the remnants of some of the buildings located in the beer garden. On the other side of the fence are the remains of the loading ramp, where wool bales from the shearing shed were loaded on to the small tramway that sent the bales down to the river’s edge via wooden slides, and on to the waiting barges that made their way to Goolwa.
In 1896, a Mr Paul Hasse from Lobethal purchased 520 acres of land which included the Homestead. His wife, Emma, applied and was given a licence on the 12th September, 1899. Unfortunately Emma passed away the following year, then Paul continued to run the hotel until 1909.
There have been many major additions to the Swan Reach Hotel over the years of its operation. The stone, single room public front bar was built after 1907, and the second storey added in 1912. Around in 1940s the block form of the hotel evolved with its rendered finish. The grand dining room was added in 1996. The hotel boasts a spectacular view overlooking the Ferry as it completes its never ending to and fro crossing across a lazy river.
Most importantly , the food, drinks, service and view were first class, and my chauffeur pronounced his Chicken Parmy ( we’re from South Australia, so deal with it) one of the better ones he’s had. My rump steak was delightful, and cooked to perfection! We bid Swan Reach farewell, we’ll be back!
* Announcing *
The Riverland Radio Club Inc.
BRL Gathering 2019
To be held at the Overland Corner Hotel Goyder Highway, Overland Corner, South Australia
Saturday, 6th of April, 2019
Ok Folks, come one come all, it’s on again, the BRL Gathering for 2019 is on Saturday, the 6th of April, at the same sensational location, famous for its picturesque setting, Fantastic Hospitality, Great Food and Cold Beer.
ONLINE REGISTRATIONS NOW CLOSED
(Registration isn’t compulsory, but it really helps out with catering, and you’ll go in the draw to win lunch for two on the house courtesy of the Overland Corner Hotel. It also helps us make sure your visit is the best it can be…)
Breakfast – Bacon and egg Sandwich and coffee will be available from 7:30am on Saturday and Sunday mornings.
*Dogs are welcome at the Overland corner Hotel*
* Getting There *
The Gathering is in the Beautiful Riverland in South Australia.We have more sunshine than the Sunshine Coast!
* Accommodation *
Accommodation – The Riverland has many accommodation options catering for all budgets. See here for some ideas. Got an RV, Motor Home or Van? The Overland Corner Hotel has an RV staging area “out back” that is a stones throw close to the Gathering action. There are 4 powered sites. (Bring your power leads) and room for many self sufficient vehicles. Many BRL-ites stay here, and enjoy the added camaraderie!
VK5BRL has planned a fun day of Activities, Awards and guest Speakers. There’s also a
* Home Brew Award *
Have you made something for your shack? Then enter it in the BRL Home Brew competition. There will be two prizes awarded, a “People’s Choice” award, judged by the BRL gathering attendees, and the prestigious BRL “Constructors Award” for the best piece of Ham Radio related gear presented for Judging by our panel. It can be anything radio related, from something simple like a Balun, to a complex microwave transverter!
* Contact us *
If you need any help with any aspect of getting to the venue, accommodation, special dietary requirements or other issues, feel free to Phone the Secretary Andy, VK5LA on 0488778154 or email him.
The 2019 Riverland Radio Club BRL Gathering – The Friendly Gathering!!!