January 2021 (Covid19 Lockdown Three)
Early January 2021 during COVID19 Lockdown 3 I decided to invest in a new antenna, Diamond X300N, New Pole, Brackets, Feeder & Connectors just so I could get outdoors and find something to do to pass the time between working from home & the office when necessary. Went for a lighter duty pole than I usually use to make handling the installation easier on my own as unable to call on assistance. Got all the hardware together and then chose the coldest day of the year so far to venture out and erect the new installation. I left the spanner on top of one of the brackets and when I went back up the ladder discovered it had frozen to the bracket. The new aerial is just over 10m from the floor to the ground radials and coupled up with a short run of RG213 cable coupled to a 12m run of LDF450 to the repeaters. Results very encouraging, aerial actually higher than before and now on a different part of the building than before. Noises that seemed to plague the old aerial have disappeared. Reports very welcome.
June 2020 (Covid19 Lockdown one)
Changed aerial & feeder for GB3DC & GB7DC and raised the mast a few meters. Results not as expected and some intermittent crackles now present that are reducing receiver performance on both repeaters. Need to investigate and possible revert back to a new aerial of the type previously in use.
May 2020 (Covid19 Lockdown one)
During Lockdown with increased activity on the radio locally I decided it might be fun to add Analogue FM onto GB7DC as we have no local analogue 70cm UHF repeater in the Derby area anymore and not everyone is into the Digital modes. To facilitate the FM Analogue Mode I had to move frequency as the original channel only permits digital operation.
Output now 430.8750MHz Input 438.475MHz & CTCSS 71.9Hz.
December 2012
Today 27th December 2012 I finally received the NoV License for the GB7DC D-Star repeater. I have been waiting for this for three years. So as soon as it dropped into my Inbox, I had a quick read though it and then connected the aerial to the repeater that was sat ready to go. I think I was on air within 5 minutes. Maybe a UK record for time taken to become operational. I need to rework this website to cater for both GB3DC & GB7DC now as it is a bit of a mess. So expect some updates soon.
February 2012
Just a quick snippet this time. Locally we have a new repeater on 6m that needs a mention. GB3HM went fully operational this weekend 25th February 2012 from Holbrook, an elevated village a few miles North of Derby City. If you are QRV on 6m FM then please do have a listen for it on 50.820 MHz and see if you can make contact. The keeper "Mark G8IQP" is a friend of mine and he would appreciate signal reports from far and wide as to how well it is performing. I hope to persuade him to try Echolink on it in the future to promote even more activity. Check out the website for more information.
Finally I hope to change the aerial on GB3DC later this year for a Dual Band Co-Linear that will serve the 70cm D-Star Gateway MB6IDC as well as the repeater. Plans are to increase the height of this new aerial above the one currently in use hopefully bringing up the coverage. I have only been planning this for 4 years so It is time to get the job done this year.
June 2011
Have had a couple of problems with the repeater during this month. First I noticed an intermittent loss of output power so put the unit on the bench for further investigation but was unable to get it to fail. Did a complete tune up of transmitter and receiver and re soldered some of the critical connections within the PA that are prone to fail and put back into service.
About a week later I noticed some very strange noise on the receiver and possible de-sense. Upon investigation this appeared to be broadband noise coming from the transmitter. I did a few more tweaks and realized that I could of been under driving the PA causing this instability. It turns out that these Nokia base stations that run up to 75w are not happy when running low power. GB3DC is currently only running 5w so that is 70w below full power and could be a bit of a problem.
I am looking into removing the main power transistor from the PA and bypassing it at present because the first stage of the PA will run 15w barefoot ;) and this is more than enough for my requirements.
June 2010
Not much to report. I have added a live audio stream on the website so you can listen to GB3DC with your computer easily. Listen HERE.
No news on the NOV for GB7DC Digital. Seems to be a delay with the Primary User for projects on 70cm. We are all ready to go with the Repeater once the paperwork is in place. And an initial survey of the coverage seems better then expected. I was comparing the UHF to the coverage of GB3DC on VHF and it seems to be hitting some parts of the City with a far stronger signal than GB3DC does!
December 2009
Nothing new to report about GB3DC. I have received a kind donation of a new pole for the aerial and will soon be making an effort to finally move the aerial.
I have been experimenting with Digital D-Star and want to have a go at trying a repeater and gateway for this mode. Please read more HERE
June 2009
I thought I had best make an effort to update the website as not been here for over a year. Not much has happened with the repeater over the last year. I have still not got round to changing the aerial and it is still running on the temporary aerial I installed some time ago to make way for an extension on the side of my house. I am still on the lookout for a good quality clean aluminum 6m scaffold tube so I can get the new aerial installed before I remove the temporary aerial.
I have also recently connected the repeater to the SKYPE network as an experiment. This runs along side the Echolink system already in place and does not effect its operation. Because Skype was never designed to connect to radio I have utilized VOX to enable it to make the repeater transmit when required. This does make it a little clunky in operation but it is surprising how effective it is. The NOV for the repeater does not specify what computer networks I can connect to only that I must ensure to the best of my knowledge that stations connecting are licensed etc. So I am running a Private contact list on Skype that I only add to by request. I think this has got real potential for the future as Skype is becoming really popular and is now also available for free on the Three Mobile Phone service. This enables anyone in the country with a Skype enabled mobile phone to connect to the repeater and make contact on 2m.
If you would like to give it a try please search for the repeater on Skype. It is using the username gb3dc-r just add this to your Skype list and I will add you to the contact list once I am sure of your status etc & notice your request. You can also email me if you are interested to speed this process up. Email Me
January 2008
Again not much to tell you. The repeater has moved from one part of the house here to another and the cavity filters and isolator have been moved to the loft space above the repeater. This seems like a good move so far as these passive devices did not really serve much purpose in the shack taking up valuable space and never needed maintenance or adjustment. My only concern is if they will handle the extreme temperature changes experienced in the loft space. So far they seem fine with low temperatures but come the summer it could be a problem. We will have to wait and see what happens.
I have also added a weather station to my collection of electronic gadgets brought on a whim. After playing with this for a while and creating a website to show the world the exciting weather we get here in Derby I interfaced it to the repeater to provide voice announcements of the current on site weather conditions. Have a look at the weather website if you have time www.weather.inderby.co.uk
As the weather improves I hope to raise the aerial system on the repeater by about 5 to 6 feet more and put it on the highest wall of the house. This will mean I can finally make use of the LDF450 feeder donated to me. I am on the lookout for a long, thick walled aluminum scaffolding tube to do this. I believe the longest are about 6m which would be really useful. So if anyone can help out with this it would be very much appreciated. I do believe the SGB scaffolding shop in Derby have a few ex hire ones so when the time comes I might have to put my hand in my pocket and get one. At least the place is only a couple of miles away so it will not be to difficult to transport between two willing pedestrians.
August 2007
Not a great deal to report once again. I have reduced the output power of DC as the level and location of users does not warrant the coverage we were getting. There are other local repeaters that serve the long haul work better so a decision was made to reduce power and concentrate on the local area once again.
Myself and a few other people are currently testing a new facility on the repeater. I plan to allow APRS data to be passed to DC and gated upto the internet. Please read more on the APRS page.
I have also once again put one of my spare radios onto the internet. You can now freely tune and listen to an Icom 706MKIIG here by using a web interface please look at Remote RX and have a play.
May 2007
The Remote Receiver project has currently come to an end as the software I was using was far to unstable for my liking. I am yet to find a replacement solution to control my RX via the web. The audio streaming did work very well it was just the control that was a disaster.
April 2007
Happy Birthday GB3DC. The repeater has been on air for a year now. Although it was originally on RV63 and not RV55 that it is now residing on.
I am working on a new project at the moment. My idea is to provide a fully tunable receiver that people can tune online and listen to via an MP3 audio stream. The receiver I am using is an Icom IC-706MKIIG which provides multimode coverage from 30KHz to 200MHz & 400MHz to 470MHz. At the moment the aerial systems in use are very poor but once the concept has been proven I plan to upgrade the aerials to provide a better level of general coverage across the entire tuning range. Why not have a listen and see what you think.
March 2007
Well once again nothing really interesting to report to you about the repeater. The frequency change has been a great success with a complete elimination of all co channel interference that was a regular problem on RV63. I have also increased the output power of GB3DC which is currently running in the region of 15-20w ERP. It is my plan to move the aerial system back to a higher place on the building sometime during the summer which should increase the overall aerial height substantially & allow me to reduce the output power a little. The only other development over the last couple of weeks of February was that the Repeater Management Committee have issued a statement with regard to voice announcements used on amateur repeaters. The statement basically infers that voice announcements are not permitted on repeaters. Now DC used to provide weather and traffic announcements and has done from the first day it became operational. I had originally run the idea by Ofcom and was told that they were happy with what i was doing, Apparently the RMC have brought this up several times and have now taken an official stance on it not been permitted. I have spoken to Ofcom about this and for the time being agreed to remove the weather and traffic announcements until I can get official permission passed to allow them. I will now be looking at ways to get my proposal passed by the RMC and ultimately get a green light from Ofcom to resume. Watch this space!
December 26th 2006
Repeater now switched over to the new frequency on Friday night 22nd. Signal reports are very encouraging with a few S points noticed in most areas. Unfortunately the increase in output power has increased the general noise level on the input. This noise is completely out of my control. I suspected it was initially some de-sense within the duplexer but a few tests have concluded this is not the case. I am still assessing the situation and need to hear a few more stations use the repeater to get an idea if it is causing any problems. I expect to change the aerial position, height and type when the whether improves so may reduce power again until then.
Anyway I will be doing further adjustments over the Christmas Holiday.
December 18th 2006
Some good news today. I received a phone call from Rod Wilkinson at Ofcom to inform me that the application to change channel and increase power / aerial height had been approved and the new NOV is in the post. Once the paperwork arrives I can move channel as soon as I want. So just as soon as I can get a spectrum analyzer home from work and have a few spare minutes to retune the duplexer this will happen. The standby repeater has already been set up to the new frequency and soak tested with the standby logic so fingers crossed it will be a really simple job. Believe me I could do with something going right for a change as the building work mentioned a few months back is still dragging on.
Once this building work is completed and the whether improves I will be moving the antenna back to the original position and increasing the height by a few extra meters which has been approved on this new NOV. I believe this will make a much more noticeable difference to coverage than the increase in power.
May I thank Jon G4TSN from the RSGB Repeater Management Committee for his work in getting this new application processed and the rest of his team plus Rod at Ofcom. Also many thanks for the support of the users since GB3DC has been on air. Seasons Greetings to all of you. Dom.
This site was last updated Friday, 22 January 2021
