Visit to Fleet Air Arm Museum Yeovilton

During the summer months I propose a visit to the Fleet Air Arm Museum at Yeovilton.

If you would like to come please let me know your available dates from those listed below.

10th or 11th June
29th or 30th July
12th or 13th August

Online entry is either £12.80 or £11.20 for concessions (Military service personnel with a valid MOD 90 go free).

Closer to the selected date I will press gang for drivers, for which each passenger will need to agree a fare with.



But the TSGARC is not value for money!

It was recently put to me that the club was not value for money and I thought I’d take a few moments to reply.

First and foremost the TSGARC is a club; it is a group of people connected by common interests who pursue those interests together as a social group.  What any member derives from the club tends to be proportional to what they contribute – its a two-way thing; a sharing experience.

Shack-DrawersAlthough its possible for a club to be purely virtual, existing in cyberspace alone, this is not the model for the TSGARC.  We prefer to talk to one another; to share idea’s, concepts and experiences and we choose to do this face to face.   We believe this approach delivers a better all round experience for members.

Meeting face to face though does require somewhere to meet; it requires a clubhouse.  We are very lucky to have the use of a large room on a shared basis and the sole use of another, smaller, room full-time.  These rooms do come at a cost, but we have secured an excellent rate from the Chantry and by only paying for the larger room when we use it we have an agreement that provides the space we need at a fair price.Paul, M0ZMB

Having sole, full-time use of a room allows us to have a radio room; a room in which we can setup radio equipment and leave it setup so any member may come and use the equipment at a time of their choosing and not be constrained by when the club meets.  Having this room allows those who do not have access to their own equipment to experience the world of amateur radio and to further their learning and experience.

TSGARC Radio roomOur accommodation is dry, its warm, its comfortable, the club provides free tea and coffee and we even have free use of the wireless connection to the Internet because we are good tenants and help the Chantry from time to time.  Together these things underpin our evenings at the clubhouse, providing a relaxing, friendly environment in which members feel able to share stories, advice and to learn from each other.

TSGARC Trailer TowerThe club meets many of the costs associated with the activities its members undertake.  It has recently started to upgrade its HF antenna and is in discussion with the Chantry to relocate and upgrade its VHF antenna.  It has plans for the upgrade of our radio equipment.  It has also supported recent activities such as field weekends by rewarding the landowner and supplying toilets without which the field weekends just would not happen.

The TSGARC must also stand on its own.  It needs the stability and long-term survivability that a secure income permits.  That income allows us to plan for the future, to evolve whilst supporting our members doing the things they enjoy.  We have a club which responds to its members wishes;  members are at the core of the club, they choose and drive what the club does.  Its a great local club.

Andrew Gawthrope

Terms of Reference for the Committee

Over the last few months the committee have authored Terms of Reference or ToRs for their roles.  These record the responsibilities of members who undertake committee roles both currently and into the future on behalf of the TSGARC.

A little terminology: A role is a set of responsibilities, a member may choose one or more roles depending on the size of the roles.

The ToRs have now been uploaded to our website and may be found under the About menu option.

Andrew Gawthrope

The HF antenna…

So, most members should be aware by now that the old 40m dipole has been removed and replaced with a new 40m dipole!  The feedpoint 1:1 balun was also changed for good measure and sealed thoroughly for the winter.

But this is not the end of the work on the HF antenna, that was just task 1 😉  Task 2 consists of two activities and is planned for Spring 2017 once it dries and warms a little 🙂

Activity 1 will add elements for 30m and 20m expanding the 40m dipole into three parallel dipoles. This will result in a tri-band antenna that is resonant on 40m, 30m and 20m giving us a very useful antenna.

Activity 2 will replace the coaxial feeder between the radio room and the antenna feedpoint.

TSGARC parallel dipoleToday we have approximately 2.3dB of loss at 7.1MHz between the radio room and the antenna feedpoint.  Assuming the coax is in the very best condition (which its not) and it’s RG-58C (Its an RG58 of some sort) this equates to about 54m of coax.  That’s a 40% power loss on Tx and Rx.  Replacing this with RG-213 reduces the loss to 0.9dB or a 19% power loss.  An improvement of 1.4dB or 20% doesn’t sound much and its not but consider the situation at 14MHz.  With RG-58C there is 3.2dB / 53% loss but using RG213 the loss is 1.3dB or 26%.

Frequency RG-58C RG-213/U Ultraflex-10
7.1MHz 2.2dB 0.9dB 0.5dB
10MHz 2.7dB 1.1dB 0.6dB
14.2MHz 3.2dB 1.3dB 0.8dB

Coax loss per 54m 

To put this differently.  The transmitter places 100W max into the feeder at 7MHz, 10MHz and 14MHz.  With RG-58 the antenna receives: 60W, 54W & 47W respectively.  Replacing with RG-213 results in: 81W, 77W & 74W.  Using a better coax and one that does not cost  much more than RG-213 the situation can be improved further.  The overall difference of using something like Ultraflex-10 over RG-58 is definitely worth having and that is why activity 2 is so important.

The completed parallel dipole antenna will remain in its current location supported by the trees at either end.  But supporting the end of the antenna elements will require two attachment points instead of the one we have today.  Investigation has showed this is not a significant obstacle.

Thanks to Peter, G3LDO for the above diagram taken from his excellent book Backyard Antennas.

JOTA 2016 Announcement

This weekend the club is excited to be hosting another Jamboree On The Air (JOTA) event. We will be based at the 1st Olveston Scout hall from Friday through to Sunday. We plan to set up stations covering VHF, HF, SDR, Morse, 3D Printing and more. Over the weekend we are expecting to receive visits from groups of scouts so that we can share our knowledge and experience with them.

We will be operating under the special even callsign GB1OSG for the weekend.

We hope to see plenty of scouts and a club members over the weekend, and i’m sure as usual a lot of experiments (successful or otherwise) will take place during our free time!



RSGB Convention 2016 update

Camb-hams FlossieMyself G0RVM and Peter 2E0UAR attended the RSGB Convention in Milton Keynes this year.  We left Bristol around 15:30hrs but got stuck in jam after jam.  Towards the end of the journey ‘here comes another set of blue lights’ was becoming a bit of a joke!  Fortunately we did arrive before the buffet dinner finished.  It was a close thing tho as there where only a few slices of pudding pie left 😉

This was my first Convention and I must congratulate the RSGB for such a great event.  The accommodation was good, the food and conference facilities excellent.  It was educational to hear talks on a variety of subjects from speakers deeply knowledgeable in their subject.  Access was free to those under 21yrs too – a great way of incentivising attendance by younger radio amateurs.  Thank you RSGB.

In addition to the rooms hosting five parallel lecture streams there was a room with stands by Icom, Kenwood, the RSGB and of course, Martin Lynch who were the prime sponsor.    Outside this room was a rather large trailer tower with HF antennas providing live signals for the exhibitors.

Kenwood TS-990Proudly parked outside the front of the conference centre was Flossie, the mobile radio van of Camb-hams.  Protruding through its roof was a Clark pneumatic mast with rotary HF dipole.  The van looked excellent and a great way to get a portable setup to a distant location, setup and on-air with minimum fuss.  As I have a pneumatic mast also it was good to swap experiences, finding we shared some of the challenges associated to these masts.

Some of my favourite talks over the weekend were:

    • The new world of amateur satellites, Graham Shirville, G3VZV
    • The Story of SDR and FlexRadio, Gerald Youngblood, K5SDR
    • The VP8SGI & VP8STI DXpeditions, Mike McGirr K9AJ
    • Space Weather, Prof. Cathryn Mitchell, M0IBG.

I was really looking forward to “Best practice for VHF UHF DX” by Ian White GM3SEK but unfortunately Ian had to cancel.  Maybe next year.

Camb-hams FlossieFrom the first talk identified above I learnt that we as radio amateurs are soon to have a ‘bend-pipe’ transponder in geostationary Earth orbit.  Wow that is an amazing feat and I can’t wait till its operational.  Amazing.  The talk by Prof. Cathryn Mitchell was excellent being delivered superbly and hugely informative.  It was interesting to hear how in 2015 space weather was identified in the UK National Risk Register with an impact of the same scoring as emerging infectious diseases, inland flooding, effusive volcanic eruptions, major industrial accidents etc.  In fact, in 2015 the likelihood of a major space weather event occurring in the next five years was in the second from highest category.

I can thoroughly recommend attending the Convention and I know I will be booking my 2017 ticket as soon as they become available next year.