Happy Birthday Severn Bridge

Paul, M0ZMBThe Severn bridge was 50 years old this month.  To commemorate its birthday the Thornbury and South Gloucestershire Amateur Radio Club (TSGARC) ran a special event station with the callsign GB4SBB throughout Thursday 8th September.

The morning arrived, the weather gods smiled upon us, a very nice morning, a little too much wind perhaps.  The first arrivals were on site and unloading by 09:00hrs, put up the tents and started to erect three HF antennas, this took time, a lot of time during which Mike Davis G0JMD arrived popped up his posh toilet tent, a pole complete with a white stick and was operating on air within fifteen minutes. ( Lesson. Keep it simple, practice erecting poles and antennas and to have a plan and to stick to it ).  It became clear that a Special Event Station is not the place for experimenting…..

The day, however, turned out to be a success with 50+ contacts were made and we had visits from passing amateurs, also a member from the Chepstow ARC drove across the Bridge specially.

It was great to see so many of our club members, some stayed a hour or so, the rest were there for the all important break down.

GB4SBB

Special thanks must go to Ron M6EAT for supplying the Generator, Stan G0RYM for the big dome tent, we would have made more use of it had it rained.  And to all the Club members who made it a day to remember.

Click on the images for a larger version 🙂

Richard 2E0RES, Rex G4RAE.

VHF (2m) gets busy…

2m VHF

Strange hot weather but good conditions on 2m 🙂

Monday 5th and Tuesday 6th September very busy on 2m.  At times tonight every 10kHz step and often 5kHz step was busy.  Great to see/hear.  Worked F8IQS in Caen on CW.  His signal was easily 599!

Even bumped into another club member, Steve, M6JJV working contest from Berkeley 🙂

Andrew
G0RVM

Celebration of 50 years of the Severn Crossing GB4SBB special event.

TSGARC members will be setting up a special event station on the east side of the bridge at the  Brightside observation point on Thursday 8th September 2016 at 9.30am  transmitting until 5.30pm. We have set up  a page on Qrz.com for information. Rob and Sue will be handling our qsl cards and John m0hfh will be looking after the qrz log and page. We will be pleased to see members or non members interested in this event at the observation point on Thursday.

gb4sbbfront

The institute of civil engineers is also celebrating this event on the west side of the bridge.

https://www.ice.org.uk/getattachment/events/the-severn-bridge-50-birthday-celebration/The-Severn-Bridge.pdf.aspx

Vintage video evening

Ever heard of Hackaday.com?  Nope I hadn’t either so last night was ‘special’ 😉

Paul, M0ZMB, showed some decidedly old video’s from the website.  The first couple were about Philips A63-11X cathode ray tube manufacture. These were followed by a short video about Bone records and then a fascinating video entitled ‘The craft of the Cooper’.  Although very, very grainy it was delightful to see real craftsmen at work.  The final four videos where about the making of porcelain insulators, electric 100w/120v light bulbs, the joining of cable using lead wiping and transitioning telephone exchanges.   For the enjoyment of members who couldn’t attend or who just have the urge to watch again I’ve placed some of them below.

Others can be found at Hackaday.  Search for ‘retrotectacular’

Coax notch filters by G0GDU

A problem we have experienced on several field days is that transmitted RF from a transmitter overpowers a nearby receiver despite it being on a different HF band or even on a more distant part of the spectrum.

Band pass filters are the usual approach to solving such an issue.  However, another approach is to place a wide notch filter over the entire interfering transmission.  This is the approach described by John Crowder, G0GDU in this article passed to me by Rex G4RAE last Wednesday.

Andrew
G0RVM

Congratulations

Today we had three candidates taking the Foundation and Intermediate tests. All three candidates passed.

Congratulations gentlemen.

Group 2 50percent

The photo above shows Rex (G4RAE), Ron , Mark (Intermediate pass M6KMJ), Peter (Intermediate pass M6KVA), Ron (Foundation pass), Peter (G4OST) and Paul (M0ZMB).

Thanks go to Ron and Rex for invigilating also to the Woodhouse Park Amateur Radio Group for providing the space.

Paul
M0ZMB

 

Hosting migration

I’ve had a busy afternoon migrating this website from a server of my own to a hosting service funded by the club.  Its taken a few hours as there where a few problems but it now seems to be working albeit a little more slowly. 🙂  If you do notice anything strange please drop me an email.

As part of the migration we can now have club email addresses.  I have created role based ones for the committee (e.g. chairman @ tsgarc.uk etc) [remove the spaces] and can do so for any member requiring a club email address.  If you would like one, please let me know.

Andrew
G0RVM

Transmission Lines

Steven Ring M0SVR delivered a technical talk on the theory and practical uses of radio transmission lines. This was followed by a practical session where simple home-made test equipment was used to measure the characteristic impedance (Zo) of several readily available types of cables. The cable test set-up used is illustrated in the picture. This exploits the use of a quarter-wave length of cable to transform the impedance at the right hand end down to 50 Ohms at the left hand end of the cable under test shown in the picture. A 50 Ohm impedance measurement bridge was used to measure the quality of the 50 Ohm match at the left hand end of the cable under test, whilst a 1k-Ohm variable resistive load (R-load) fitted to the right hand end of the cable is adjusted to achieve a good 50 Ohm match as measured on the bridge. The characteristic impedance (Zo) of the cable under test can then be calculated from the formula: Zo = Square-root(50 x R-load).

Graham
G0MGC