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.
GB7DC Repeater moved frequency
to facilitate the FM Analogue Mode as the original channel only permits digital
operation. Output now 430.8750MHz Input 438.475MHz & CTCSS 71.9Hz.
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.
Just a quick snippet this
time. Locally we have a new repeater on 6m that needs a mention.
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.
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
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
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!
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
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
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.
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
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.
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
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.
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
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.
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
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Saturday, 11 July 2020