Hello Members,
On my 2025 Wish List is a club Repeater, and now it's here... There's still a lot of work to be done.
Note: This is a year long project to learn and have this repeater running for our club.
UPDATE 3RD JAN 2025
Today (Friday, January 3rd, 2025), a group of us went to the Moorabbin Club to pick up our Club Repeater and Cavities.
We are thrilled to implement our own club Repeater, which is a fantastic project for everyone to learn not only how a repeater functions but also how it is assembled.
A few items that are required are:
Power Supply (Done - Sort of)
Power Supply Cable (Done)
Programming Cable (Done)
I believe we have other required components at the club: Coax and Coax Connectors, Antenna.
I will utilize this blog page to showcase the build project.
More fun to come...
Cheers.... Craig vk3ncr
THANK YOU!
On behalf of Famparc and its numerous members, I would like to express gratitude to the Moorabbin & District Radio Club Inc for their generous donation of the aforementioned hardware.
UPDATE 6TH JAN 2025
After collecting the hardware, I dropped it off at the club rooms on Saturday 4th Jan 2025.
Everyone looked to be very impressed by the hardware and are excited in this new club project.
A while back I managed to find and download many PDF for the MX800 Repeater, as well as the Windows Software to program it.
With the amazing knowledge of Rakshit VK3DHR, he managed to get the software running on a PC at the club rooms.
On Saturday I emailed to companies that I understand offer asssitance and parts for the repeater. I sent a request for the Power Cable, as it is quite unique. I will also make enquires for the programming cable.
That's about it at the moment.
Issues we face:
Most of us within the club have either none or little experience in setting up a VHF Repeater, that includes me.
Issues:
Procurer Power Cable (DONE)
Procure or make Comms Cable to communicate with Repeater to setup. (DONE)
Setup Repeater (DONE - SORT OF)
Find a suitable set of frequencies
Re-Tune Cavities once we work out how to setup Repeater
Looking for a clear Duplex Repeater Frequency.
The one I looked at was 147.950/147.350, however I was told by Ken from Moorabbin Club that these frequencies are close to 500 watt Pages which are near by.
The Cavities that we have, have been tuned for the Moorabbin Clubs own local repeater.
The new frequencies I am looking at are:
147.275 147.875
Which is used by Repeater VK3RMP Caveat North Central Vic.
If we find these frequencies perhaps suitable, we then need to setup the Repeater, and also get the Cavity Filters tuned for those frequencies.
Summary:
Find a suitable Frequencies.
UPDATE 7TH JAN 2025
I have received a quote for the Power Cable and Comms Cable and requested a invoice so we can pay for the items. The quote was approved by the Committee.
The supplier is Spectra Engineering WA.
I am researching available and perhaps potential Frequencies for our Repeater.
So far...
146.875 146.275 No go!
146.775 146.175 Possibility
147.025 147.625
147.200 147.800
147.275 147.875
If you would like to suggest a frequency, or check the above, feel free.. Please Post below.
UPDATE 10TH JAN 2025
The Repeater Power and Serial Comms Cable have arrived..
We will begin doing to testing on Saturday 11th Jan.
Look out! there could be blue smoke escaping LOL
UPDATE 11TH JAN 2025
A fun morning at the club rooms with both Colin and myself learning and playing around with the Repeater.
Now that we have the new Power Cable and Serial Comms Cable, we plug it into power and to our surprise it fired up. I then installed the programming software on our old PC near the fridge, and managed to get the software to talk to the repeater.
After a while searching for a password so we could properly log into the repeater, Rakshit turned up and got stuck in to getting the software to adjust frequencies etc.
After lots of fun and learning, we managed to use our radios to test the operation of the repeater and to our relief it looks to be working ok.
Lots more steps to go yet. Colin was also playing around with the cavities. These will need to be changed to another frequency group.
I think the next step is to connect the repeater to the Cavities and continue testing and learning.
UPDATE 15TH JAN 2025
During the Wednesday at the club rooms, I managed to find some cables and connectors to be able to connect the Cavities to the Repeater unit, After some frustration trying to find the parts, I connected the Cavities to the Repeater and Cavities to the Diamond X200 Antenna above the front door of the club.
Did some testing using my hand held.. So far looks to be working fine. Rakshit did do an amazing job of programming the repeater last Saturday which not only included setting frequencies of the Repeater for the Cavities frequencies, but also setting the power output, 91.5 Hz CTCSS, and to my surprise the Repeater Ident.
The next step is to make or procure some better coax patch leads between the Repeater, Cavities and Antenna.
I believe based on the sockets on both the Repeater and Cavities, this is what leads we require.
After further research concerning Coax, I received this reply from a fellow Repeater Builders.
Update Concerning what Coax to use:
"As the author of the Repeater Builder website - please don't use RG213, RG58 or LMR type cables in duplex service. Use double-shielded - silver plated cables everywhere possible. RG214, RG400, and RG142 are excellent choices. Please don't be tempted to use LMR400 or similar tinned braid over aluminum foil construction cable. These make noise in duplex service - as in a repeater."
Update Concerning Connectors:
Rg214 crimp N connectors, be careful with modern T connectors, some of the cheap units have a spring that makes the connection from the leg inner conductor to the cross (top of the T) inner conductor. At 2m and 70cm this spring can act as an inductor, this has been known to cause issues with the tuning of the system. The old T connectors have a straight soldered connection inside! Cheers Stu VK4SDD.
Update Concerning Antenna's:
Also don't use a dual band antenna, I tried using a diamond as a test antenna for a 2m repeater and the desense was huge, swapping to a 2m only antenna, the desense disappeared. Don't know why there was a problem, did not really want to waste time on it.
I found the Diamond F23H Monoband antenna for 2M could be a solution for this.
Strictly ham show them on his website.
Small update..
After some basic testing and reviewing the many Repeater Frequencies, I think setting the Repeater and Cavities to :
146.775 146.175
As the closest repeater at these freq.s is as above. A good distance away.
Of course this all depends on the ACMA.
UPDATE 17TH JAN 2025
After much research and help from fellow Famaprc Members, the 3 Repeater to Cavitiy Cables have been ordered from https://www.eyou.com.au
These cables are built using RG400 Coax which was suggested as above.
I could not get a cable made with N Type to SO239, so we need a Gender Changer which will be for the cable that connects the Cavity to Antenna.
RF Line-of-Sight
The RF Line-of-Sight tool allows users to easily drag-and-drop locations and obtain point-to-point line-of-sight information anywhere using Google Maps. This map is useful in planning and troubleshooting cellular networks for IIoT / SCADA monitoring applications. SCADACore’s Industry 4.0 solutions include true 3D HMI / Digital Twin and Web HMI that works over the web.
This free online tool takes antenna height and the topographical formations of the earth to calculate the line-of-sight of a radio path. Note that buildings and other obstructions is not taken into consideration when calculating line-of-sight using this tool.
UPDATE 20TH JAN 2025
Our ordered Patch leads have arrived as of Monday Morning.. With amazing service from https://www.eyou.com.au
I found a brilliant video from W6NBC on Youtube concerning Cavity / Duplex devices for repeaters.
John talks about an article that he has produced which I have also created a link below.
Anyone interested in our clubs 2M Repeater Project Build, I suggest you watch this excellent vidoe by John W6NBC.. Our thanks to John Portune W6NBC for both the article and video.
Cheers..
Craig. vk3ncr
Any suggestions please make comment below.
Good work Craig
Good articles by John Portune
Hi Craig
ran the RF-line-in-sight programme. Brilliant, and very interesting results. Looks like planned placement will work well.
Was Googling "tuning cavities" and there is quite a few good videos on Utube including this one from Australia. Thought it might be an interesting reference
https://www.youtube.com/watch?v=NKw6-x4gFJI
Keep up the good work guys.
Be great to have a club repeater
Nice. this is going to be a great project for this year. I am excited to learn.