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#81
Antenna, Coax and Connectors / Re: Coaxial Collinear (CoCo) A...
Last post by VK5MCH - Sep 09, 2024, 09:35 PMTrim off the excess cardboard.
Waterproof the joins. I used Pabco Hydroseal on all my outside joins.
Continuity check for open and short circuits.
Waterproof the joins. I used Pabco Hydroseal on all my outside joins.
Continuity check for open and short circuits.
#82
Antenna, Coax and Connectors / Re: Coaxial Collinear (CoCo) A...
Last post by VK5MCH - Sep 09, 2024, 08:23 PMMy process for making the radiating element. You may not agree with some of the things I have done so far but it worked for me. And it was easy once I worked it out for me.
Every solder join you make check for continuity, short and open circuits. Its easy to undo one join than find a faulty join from the chain.
Make sure every element is soldered as close as possible to 180 degrees opposite each other.
On some construction notes they simply push the tinned centre conductor under the sheath with no mechanical connection. I wasn't a big fan of this from the start. I can see lots of problems with this method. The join can rotate, oxidise, become intermittent with temperature or come apart completely. I figure if this is going up a pole for many years I want it to stay up the pole. It has to be reliable.
Every solder join you make check for continuity, short and open circuits. Its easy to undo one join than find a faulty join from the chain.
Make sure every element is soldered as close as possible to 180 degrees opposite each other.
On some construction notes they simply push the tinned centre conductor under the sheath with no mechanical connection. I wasn't a big fan of this from the start. I can see lots of problems with this method. The join can rotate, oxidise, become intermittent with temperature or come apart completely. I figure if this is going up a pole for many years I want it to stay up the pole. It has to be reliable.
#83
VHF, UHF, SHF / Re: UHF DATV in Adelaide
Last post by VK5MCH - Sep 09, 2024, 05:59 PMSomething I will be venturing into in the not too distant future.
As soon as I'm done learning about coaxial collinear antennas.
As soon as I'm done learning about coaxial collinear antennas.
#84
VHF, UHF, SHF / UHF DATV in Adelaide
Last post by VK5FQ - Sep 09, 2024, 05:51 PMAre there any active DATVers in Adelaide? I'm looking to see what the interest is on 445.5MHz or 1287MHz, if any?
#85
Silent Keys / Re: Passing of Bevan VK5TV
Last post by VK5MCH - Sep 09, 2024, 02:56 PMMy sincere condolences to Bevan's family and friends.
RIP Bevan
RIP Bevan
#86
Antenna, Coax and Connectors / Coaxial Collinear (CoCo) Anten...
Last post by VK5MCH - Sep 09, 2024, 12:29 PMI have been experimenting with CoCo antennas on ADS-B for the last week. After reading many blogs, forums, watching YouTube videos etc, there does not seem to be any consensus as to the correct way to build this type of antenna.
On one of the forums I found 2 antenna experts (both engineers) who couldn't agree as to the best way to construct one and then feed it. So I guess if the experts can't agree what hope do we "HAMS" have?
As usual the way to get around this is to build it, test it, evaluate it and see if what you have built meets your requirements. The requirements for a CoCO ADS-B receiving antenna are completely different to a 2 metre transceiver antenna. At least in my books they are. First of all you will not be transmitting with it. On all of the blogs etc, everyone is possessed by the distance they can pick up a plane from. If it isn't picking up planes 400 mile away the antenna is crap. Really? To be honest I don't care what's in the air 400 mile away.
The start of this are the on-line CoCo calculators.
https://www.steeman.org/Antenna/collinear-coax
https://www.balarad.net/
https://www.electronics-notes.com/articles/antennas-propagation/phased-array-antennas/collinear-coaxial-antenna.php
https://keptenkurk.wordpress.com/2018/03/26/a-lora-868mhz-collinear-antenna/
https://www.lloydm.net/Demos/ads-b.html
https://discussions.flightaware.com/t/coaxial-collinear-coco-antenna-hyps-facts/17274
Already you can see the confusion that presents itself. So who is right and is there a right way and a wrong way or a couple of ways to build these things correctly? The biggest disagreement was how to feed this antenna.
The one thing all of these antennas have in common is the length of the elements to be made from the coax. They are all in agreeance on this point. So my starting point was working out the best way to join and most important is to separate and solder these elements together. Electrical tape, buttons, thick teflon tape? What doesn't melt when you put solder on it, is reasonably strong, you can drill holes in it for the centre conductor to pass through and is electrically non-conductive? The best distance between the elements is 0mm. But we all know that's not possible. Most construction notes say 0-1mm is fine.
I messed around with this for ages and believe it or not, the best thing I could find was?
A cardboard business card. Cardboard does not melt or burn when you apply heat at soldering temperature, its relatively strong. it does not conduct and it also provides a stable working platform when soldering the elements together, it keeps everything aligned when done properly 180 degrees apart and it's thin. I cut the card into 10mm strips, got out the Dremel and drilled 2 holes in the strip on one end 3-4mm apart. I have my insulator and alignment done.
Next, cutting the elements and keeping a constant length whilst avoiding shield stray strands also provided a challenge. You may not think so but it did. How hard can it be to quickly measure, cut, measure the trim point, cut 8 pieces of coax all the same length, with no stray shield strands and without damaging the centre conductor? The most annoying thing about coax on a roll is the curl it develops. Best way to fix this is a warm oven. Get them relatively warm and straighten them out in your hand until they cool down straight. Trust me, trying to build these things with pieces of coax shaped like bananas will destroy you in no time.
To be continued
On one of the forums I found 2 antenna experts (both engineers) who couldn't agree as to the best way to construct one and then feed it. So I guess if the experts can't agree what hope do we "HAMS" have?
As usual the way to get around this is to build it, test it, evaluate it and see if what you have built meets your requirements. The requirements for a CoCO ADS-B receiving antenna are completely different to a 2 metre transceiver antenna. At least in my books they are. First of all you will not be transmitting with it. On all of the blogs etc, everyone is possessed by the distance they can pick up a plane from. If it isn't picking up planes 400 mile away the antenna is crap. Really? To be honest I don't care what's in the air 400 mile away.
The start of this are the on-line CoCo calculators.
https://www.steeman.org/Antenna/collinear-coax
https://www.balarad.net/
https://www.electronics-notes.com/articles/antennas-propagation/phased-array-antennas/collinear-coaxial-antenna.php
https://keptenkurk.wordpress.com/2018/03/26/a-lora-868mhz-collinear-antenna/
https://www.lloydm.net/Demos/ads-b.html
https://discussions.flightaware.com/t/coaxial-collinear-coco-antenna-hyps-facts/17274
Already you can see the confusion that presents itself. So who is right and is there a right way and a wrong way or a couple of ways to build these things correctly? The biggest disagreement was how to feed this antenna.
The one thing all of these antennas have in common is the length of the elements to be made from the coax. They are all in agreeance on this point. So my starting point was working out the best way to join and most important is to separate and solder these elements together. Electrical tape, buttons, thick teflon tape? What doesn't melt when you put solder on it, is reasonably strong, you can drill holes in it for the centre conductor to pass through and is electrically non-conductive? The best distance between the elements is 0mm. But we all know that's not possible. Most construction notes say 0-1mm is fine.
I messed around with this for ages and believe it or not, the best thing I could find was?
A cardboard business card. Cardboard does not melt or burn when you apply heat at soldering temperature, its relatively strong. it does not conduct and it also provides a stable working platform when soldering the elements together, it keeps everything aligned when done properly 180 degrees apart and it's thin. I cut the card into 10mm strips, got out the Dremel and drilled 2 holes in the strip on one end 3-4mm apart. I have my insulator and alignment done.Next, cutting the elements and keeping a constant length whilst avoiding shield stray strands also provided a challenge. You may not think so but it did. How hard can it be to quickly measure, cut, measure the trim point, cut 8 pieces of coax all the same length, with no stray shield strands and without damaging the centre conductor? The most annoying thing about coax on a roll is the curl it develops. Best way to fix this is a warm oven. Get them relatively warm and straighten them out in your hand until they cool down straight. Trust me, trying to build these things with pieces of coax shaped like bananas will destroy you in no time.
To be continued
#87
Silent Keys / Passing of Bevan VK5TV
Last post by VK5BE - Sep 09, 2024, 08:03 AMIt is with sadness that I have received the news that Bevan VK5TV suffered a heart attack on Sept 1st, & had passed away on Sept 6th.
Bevan was a huge supporter of the South East Radio Group in Mount Gambier, attending every Annual Convention for over 50 years & participating in the Australian Foxhunting Championships. He will be sorely missed by all that knew him.
Funeral details - Monday Sept 23rd at 1pm at Partridge House chapel, 38 Partridge Street, Glenelg.
For those that are unable to attend & may wish participate, it will be live-streamed.
Here is the link to the live-stream
https://streaming.naoca.com.au/e/cf06fec9-d9b1-461b-ba34-6cd4240bb693
R.I.P. Bevan
Bevan was a huge supporter of the South East Radio Group in Mount Gambier, attending every Annual Convention for over 50 years & participating in the Australian Foxhunting Championships. He will be sorely missed by all that knew him.
Funeral details - Monday Sept 23rd at 1pm at Partridge House chapel, 38 Partridge Street, Glenelg.
For those that are unable to attend & may wish participate, it will be live-streamed.
Here is the link to the live-stream
https://streaming.naoca.com.au/e/cf06fec9-d9b1-461b-ba34-6cd4240bb693
R.I.P. Bevan
#88
Members Items For Sale / [SOLD] FTDX10 for Sale $1700
Last post by VK5GM - Sep 03, 2024, 06:30 PMTHIS ITEM HAS BEEN SOLD. THANKYOU
Hi all,
I didn't get many serious inquiries from VK classifieds.
The radio is now $1,700 (excl. any freight costs).
The receipt from Strictly Ham last August shows the radio purchase. Yaesu warranty, I am assured by Ross at Strictly Ham, is 3 YEARS, so there are almost 2 years remaining.
This is a saving of hundreds off new price, and you get a like-new radio with 12V power cable, manual, original hand-mic, included. And in the original box :-)
I assure you NOTHING is wrong with this kit.
I value integrity and honesty very highly, so it's in my interests as well as yours that you get exactly what is described in perfect condition. Please contact me via email. don.brown.work@gmail.com
cheers,
Don
VK5KT
PS - I would also swap the radio for a very good 1kW HF linear, plus cash adjustment up to $1200
Hi all,
I didn't get many serious inquiries from VK classifieds.
The radio is now $1,700 (excl. any freight costs).
The receipt from Strictly Ham last August shows the radio purchase. Yaesu warranty, I am assured by Ross at Strictly Ham, is 3 YEARS, so there are almost 2 years remaining.
This is a saving of hundreds off new price, and you get a like-new radio with 12V power cable, manual, original hand-mic, included. And in the original box :-)
I assure you NOTHING is wrong with this kit.
I value integrity and honesty very highly, so it's in my interests as well as yours that you get exactly what is described in perfect condition. Please contact me via email. don.brown.work@gmail.com
cheers,
Don
VK5KT
PS - I would also swap the radio for a very good 1kW HF linear, plus cash adjustment up to $1200
#89
Members Items For Sale / [SOLD] FTDX10 for Sale $1700
Last post by VK5GM - Sep 03, 2024, 06:19 PMSOLD
Hi all,
I didn't get many serious inquiries from VK classifieds.
The radio is now $1,700 (excl. any freight costs).
The receipt from Strictly Ham last August shows the radio purchase. Yaesu warranty, I am assured by Ross at Strictly Ham, is 3 YEARS, so there are almost 2 years remaining.
This is a saving of hundreds off new price, and you get a like-new radio with 12V power cable, manual, original hand-mic, included. And in the original box :-)
I assure you NOTHING is wrong with this kit.
I value integrity and honesty very highly, so it's in my interests as well as yours that you get exactly what is described in perfect condition. Please contact me via email. don.brown.work@gmail.com
cheers,
Don
VK5KT
PS - I would also swap the radio for a very good 1kW HF linear, plus cash adjustment up to $1200
Hi all,
I didn't get many serious inquiries from VK classifieds.
The radio is now $1,700 (excl. any freight costs).
The receipt from Strictly Ham last August shows the radio purchase. Yaesu warranty, I am assured by Ross at Strictly Ham, is 3 YEARS, so there are almost 2 years remaining.
This is a saving of hundreds off new price, and you get a like-new radio with 12V power cable, manual, original hand-mic, included. And in the original box :-)
I assure you NOTHING is wrong with this kit.
I value integrity and honesty very highly, so it's in my interests as well as yours that you get exactly what is described in perfect condition. Please contact me via email. don.brown.work@gmail.com
cheers,
Don
VK5KT
PS - I would also swap the radio for a very good 1kW HF linear, plus cash adjustment up to $1200
#90
WICEN South Australia / WICEN S.A. Newsletter – Septem...
Last post by VK5ZAR - Aug 31, 2024, 09:57 PMWICEN S.A. Newsletter – September 2024
Inside this issue:
• WICEN S.A. Committee Update
• Social Get Together / Guest Speaker
• WICEN Poem
• Saturday Field / Technical Days
• Rally Working Group
• MSS Barossa Rally
• WICEN Sunday Night Net
• Shannons Adelaide Rally
• FM VK5 2m/70cm Repeater List
• VK5 Digital Voice Repeater List
Special Points Of Interest:
• WICEN Radio Net Sunday 1st September 2024
• Shannons Adelaide Rally 8th to 10th November 2024
• WICEN S.A. Social Get Together Saturday 23rd November 2024
Put these dates in your diaries now so that you don't miss out on participating on these amazing events.
@everyone
For access and to download an electronic PDF copy of the WICEN Newsletter go to the WICEN SA FaceBook page at https://www.facebook.com/groups/170093383089448
Arno.
Inside this issue:
• WICEN S.A. Committee Update
• Social Get Together / Guest Speaker
• WICEN Poem
• Saturday Field / Technical Days
• Rally Working Group
• MSS Barossa Rally
• WICEN Sunday Night Net
• Shannons Adelaide Rally
• FM VK5 2m/70cm Repeater List
• VK5 Digital Voice Repeater List
Special Points Of Interest:
• WICEN Radio Net Sunday 1st September 2024
• Shannons Adelaide Rally 8th to 10th November 2024
• WICEN S.A. Social Get Together Saturday 23rd November 2024
Put these dates in your diaries now so that you don't miss out on participating on these amazing events.
@everyone
For access and to download an electronic PDF copy of the WICEN Newsletter go to the WICEN SA FaceBook page at https://www.facebook.com/groups/170093383089448
Arno.