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

ANTENNA TUNER!!!

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 Scintillation Crystal

Fits in the front of the tube

infront of the Photomultiplier tube

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?

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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.

73

Andy, VK5LA

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…

ready for action

squid pole slips over the top

Deployed

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…

plastic clamp holds the yagi firmly

ready for a pass…

For Microwave Field Day work, the Bike Stand is a cheap way of getting a sturdy stand for Ex Sat. dishes and Gridpacks.

From 2.4Ghz Gridpacks…

To Dishes…

strong and sturdy…

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.

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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.

*Please Register online here if you’ll be attending*

(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.

Lunch –  Lunch at the Hotel is a must! Check out the menu and get your taste buds excited for April. The Hotel’s food is renowned for its quality and value!

*Dogs are welcome at the Overland corner Hotel*

Dinner – Will be at the award-winning Mallee Fowl Restaurant for those wishing to catch up with friends old and new! Please let us know if you wish to attend. Check out their Menu here.

* 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!!!

This is a post about my journey in getting a compact portable APRS station going for portable and emergency use…it will be over a few posts as I try a few different methods of implementing my system…enjoy!

APRS stands for “Amateur Packet Reporting System” – APRS has been developed since the late 1980s by Bob Bruninga, (call sign WB4APR), He still maintains the main APRS Web site. The initialism “APRS” was derived from his call sign.

First a brief history of my packet and APRS setups…

I have run packet Radio, off and on since 1995, when I was first licensed as VK5XAW. My first Packet Rig consisted of an Apple Mac Plus, a VK7TM (Sadly, long now a Silent Key) “Pocket Packet” modem I built from a kit, and my first 2m Radio, an Icom IC2GXAT 7watt handheld radio,  plugged into a pole mounted vertical up at about 10m high.

Everyone said it wouldn’t work, but work it did. As far as I knew I was the only one in SA using a Mac for Packet.

The VK7TM kit modem worked
well and the software for the Mac impressed. I had a lot of fun on the VK5TTY bulletin board, and many direct contacts with Stef, VK5HSX.

I went to my first PC, a 486DX100, (!) and then a PK232 – a real proper modem. The 232 soon got relegated to RTTY duties in contests, so I graduated to the PK88 and the MFJ TNC2 clones. I’m sorry to say I can’t even remember the name of the terminal software everyone used to use, written by a French ham? It was a long time ago.

Packet usage began to decline and started to go the way of the Dodo, When it was well and truely elbowed by the newly emerging all singing all dancing APRS.

I believed my first system, from (fuzzy) memory was a MFJ TNC2 clone with a custom ROM, not even a GPS, just  home lat/long entered in to the software as a home station. Quite boring really!

I then moved on to a couple of mobile setups, including a Byonics Tiny Trak3 with a Garmin GPS and Yaesu VX6R 5 Watt handheld, then neat system with an Alnico DR135 Mk111 2M Rig with an Argent Data Systems T2-135 internal modem fitted, with data display and mapping/messaging from a dash mounted Garmin c510 StreetPilot in-car GPS/navigation unit. Luxury!!! The argent data setup used the proprietary Garmin sentences to do the overlays on the Streetpilot.

That system served me well despite its warts. It tended to be erratic with keeping my own path on the GPS map, but did quite a good job of updating other stations. I found the Alnico Radio to be a good performer with bomb proof front end.

I hadn’t run packet for a number of years until recently. My needs with APRS have now changed, and as I’m quite often out doing Park Activations for the WWFF program, so I like the ability to map for two reasons.

A) As proof that I was where I said I was…and

B) Safety. If I’m lost, it should be easy to find me!

After doing a bit of trawling on the ‘net, it seems that there is quite a few options for APRS these days.

Kenwood and Yaesu both seem to have full function units, both high power mobile and Handheld, that are ready to go out of the box – just put your callsign and SSID in and you’re  away. These are a few generations in now, and have matured into 1 box solutions. Both have limitations with the information that can be displayed

As tech has moved on, so has software and by far the best way to display yours and others APRS data is on aprs.fi, a web based app that uses google maps to plot positions and  track stations world wide in a web page.

Tablets have revolutionised mobile computing and this is the way I have chosen to go as a display for my vehicle APRS system that I’m currently putting together.

I have recently acquired a Samsung Galaxy Tab A, as the dash mounted Display for my APRS set up. It is simply Velcro’d to the dash surface, when in use, and removed when not required to reduce the risk of sun/heat damage or theft. It seems to work extremely well. The tablet doesn’t have to be flash, as long as it has an inbuilt GPS, most reasonably recent ones do, it should be suitable. not that you can even use an Android phone at a pinch. 

It is a perfect size for this application, and is a bigger, brighter and clearer display than any currently available out of the box APRS Radio, and can be used as an Android tablet when not pressed in to APRS duty.

The software that makes this all modern day APRS happen is an Android app called APRSDroid. It is a free download from the Google Play store. There is no equivalent iOS app, as iOS lacks support for Bluetooth Serial Port Protocol (SPP). The software supports the following connections…

1.via TCP/IP ( needs an internet connection), 2. via AFSK ( audio in and out using the headphone socket to a Radio, 3. via a Bluetooth to a TNC (like the Mobilinkd TNC) and finally, 4. Kenwood (NMEA waypoint)

At the moment, to get my position on the APRS network, my setup is operational with the Samsung tablet > an ASFK connection via a simple interface> Yaesu FT7800R mobile radio.  APRS RX displays the incoming packets from the 2M Radio, and everything is displayed on the Galaxy tablet in the APRSDroid app. The only disadvantage is that it is not a wireless solution from the Tablet at present, but it’s cheap and it works. The goal is to have say a Pelican style case, with a 2M mobile radio and a Bluetooth capable TNC and all connections ready to go. Just plug it in to some power and an antenna and you’re on APRS, using the Bluetooth connected Tablet as a remote display. A picture tells a thousand words… I have started on the case for the setup, adding an auxilliary USB charging port shown here being tested on the way to help out on a Horus ballon launch with the club…

Until the next instalment on this build, here are a few links to the software and hardware I’m using…

Mobilinkd – http://www.mobilinkd.com/?gclid=CjwKCAjwj4zaBRABEiwA0xwsPwKCAQ68kaig3HeXiN_SCh4bcOryoV-f3G_yN9r2dX8ZgxSLVvXx1RoCXFgQAvD_BwE

APRS.FI – https://aprs.fi/#!lat=-33.86670&lng=151.20000

APRSDroid – https://aprsdroid.org/

Samsung Galaxy Tab A6 – https://www.samsung.com/au/tablets/galaxy-tab-a-7-0-2016-t280/

Andy

VK5LA

On Saturday 5th of May I activated another park for WWFF and VKFF.
Pooginook Conservation Park is a plot of mallee about a 45 minute drive, approximately 50 km west of my home QTH.

From the National Parks website…
“The dense Mallee scrub in the northern part of the park provides shelter to a range of wildlife, including Kangaroos, Echidna, Hairy-Nosed Wombats, Fat-Tailed Dunnarts and the rare Malleefowl. In contrast, the southern section features open Mallee as the area was once largely used for wheat farming.

The park provides good opportunities for bird watching. Keep a look out for Black-Eared Miners, Honeyeaters and many other colourful Mallee birds. During spring the park blossoms, displaying a variety of colourful Mallee plants. The park’s camping ground is accessible to conventional vehicles, however, some sections of the boundary road are only accessible by 4WD.”

I drove in to the park from the Goyder Highway, it’s signposted but the sign is old and faded and is white on a brown background. As I pass this sign regularly for work road trips, I knew it was there but if you’re unfamiliar with the area you might miss it.
The Park sign itself is old and dilapidated, I’ve noticed a lot of the South Australian Park signs have been upgraded to nice clear easy to read Green/white signs but this one hasn’t made the grade yet…

I only had to drive in a short way until I found a nice clear area to park my vehicle and set up the station…

Although the signs have long disappeared I’m fairly sure this is one of the designated camping areas in the park. If you do come here to camp overnight or longer, you will need to bring absolutely everything, as there are no facilities here.

 I wasted no time in setting up the station between my car and a convenient tree. The weather was perfect for a park activation, around 22 degrees with a coolish, light south westerly breeze. Although there were some visible 22Kv power lines running east west about 500 metres away to my north , I hoisted my Link dipole up on its Squidpole so that both legs were at 90 degrees to them to hopefully quench any noise they might generate. I didn’t have to worry however, as the noise floor was non existent, the joys of a quiet park!

This activation was an interesting “first” for me. This was the first time I would be using a logging program on my iPad to log the Park contacts, instead of the usual paper logs. I hate paper logs, and the work involve in getting the contacts into a computer and emailed off to the right people.

I had done a fair bit of research in looking at a log programs that would be suitable for a park activation. My requirements were quick entry capability, support for VKFF/WWFF and generation of the correct ADIF formatted logs for direct emailing off to the coordinator. There didn’t seem a lot out there.

I was at the stage where I was considering buying an Android tablet so I could run the most excellent VK-Port-log (http://vk3zpf.com/vk-port-a-log). After registering and downloading the app from the files section of the yahoo group, I gave it a try on my android phone. It’s very good but the phone format I find is a little small for the eyes and fingers.

It was while I was looking at the parks and peaks web site where I saw a link to the Parks and peaks iPhone app (https://www.vk5ayl.com/). Sue only had the non logging version available via the App Store so I got in contact with her about the newer V2 version that supports logging. To cut a long story short I soon became a beta tester and was now trying the app in the real world for the first time…

The app offers spotting and alerting to the parks and peaks website, along with logging of contacts for an activation…

This is all entered as you log the contact, directly into the phone or iPad. It’s very quick and easy to do. Most fields can/will auto populate, for example when you enter a call sign, if there is a matching name in the database (which is updated at the push of a button under settings) it will magically appear in name field.

After the QSO’s are done you are left with the log for the activation. You can Scroll through and edit any entry with a double click if you need to.

Then export the log…

It’s really that simple.

Just like Port-a-log has revolutionised portable logging for the Android platform, Parks and Peaks will soon be the go to app for the iOS platform.

Ok, there was a few things about the app that I felt that needed attention and Sue, VK5AYL was most receptive to ideas. I’ll be using this app on all my park activations
from now on, it’s fantastic! No more dread of converting paper logs into the computer. (Yes. There will always be a pen and paper in the go kit just in case)

I ended up with 55 contacts in the log in about 2 1/2 hours. You tend to learn something each activation and for this one, it was “Don’t forget the Aerogard”
I did, and the flies were INCREDIBLY annoying!!

Andy, VK5LA