HF Mobile (almost)

Almost there with HF mobile installation. Bit by bit coming together nicely. Final parts of the jigsaw arrive tomorrow with luck and then the fun playing with VSWR, RF, Common Mode RF etc. starts. Hopefully I’ve followed good advice from Andrew and others KOBG.com to name a few. Hoping to use 10, 20, 40 and 80M to start with and then onwards and in between later. Even have a mobile tuner (birthday present) ready to order happy days!!. Home QTH shack is cleared and roofers are due to come next week to quote for replacing the roof and then work can start on garage conversion.

Update on my £2 home brew antenna

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Finally found time to play antenna’s on Monday gone and I can report a successful field test albeit crude and basic on the home brew bought at the recent Kempton Rally.

The test was very arbitrary and with basic equipment (MFJ analyser is on order) so used my old basic SWR meter and handheld (4W) with a lash up push up pole in the garden and undoubtedly load of loss everywhere but….. with reasonable results. I needed to try it somehow and wanted to test as if portable in a field!

It does appear that the antenna works 2M and 70cms and in fact was giving slightly better SWR results on 70.  Crude readings ranged bottom 70cms band 1:3:1 up to top 1:2:1 and on 2M bottom 1:3:1 and top 1:5:1. Receive was clear and easily picking up stations on 2M who were mobile calling in from Devises and beyond.

However…a few problems with the following means a little more work is needed to address; line loss (probably need to replace the old coax used with low loss), weak or bad feeder connection at the bottom of the J pole and the actual antenna joints need sealing but apart from that a good buy for a portable antenna. Also looks as if it was made from good quality aluminium so nice and light.

So I will be bringing the J pole along with a few long wires to the field event so need to get cracking on the repair work before that. Happy days!

73’s

Mark M6KMJ

 

Pneumatic Masts

As some of you will know I’ve been looking at getting a mast for my home which could, if necessary, be removed and used for portable operations.  Some of you will also know that I’ve settled upon a pneumatic mast from Total Mast Solutions (TMS) here in the UK.

The TMS website is not great; the range of masts is huge and information that details the range and available options is either hard to find or non-existent.  After much digging this morning I’ve come to understand that TMS are the UK reseller of masts made by an Italian company – Fireco.  That company has partners worldwide but again its hard to find good informaiton.  However, the Australian partner (EVTA Group) does have a website that provides lots of detailed information and I strongly recommend anyone considering one of the masts to download the Full catalogue, understand the range and options, then download the brouchure specific to the mast range of interest before calling/emailing TMS.

The links I provide here will age, so for up to date information I recommend you always go direct to the TMS and/or EVTA Group Australia website.

Andrew
G0RVM

Calling notice for trailer tower painting

Gentlemen,

The Trailer Tower to be used for the upcoming field weekend and hopefully other events is in dire need of some TLC.

One of the tasks that can be completed by all is the painting of the bodywork. The afternoon of the upcoming Bank Holiday Monday 4th May has been chosen.

Please register your interest below, via email or on the notice board.

Paul
M0ZMB

 

 

 

Digital Modulation talk

Digital Modulation by G0RVMWho would be interested in a 3-part talk about digital modulation principles?  Its aim is to provide a foundation from which digital techniques such as PSK31 can be better understood.

The talk starts with the most basic form of digital communications – on/off keying, progresses through Frequency Shift Keying then onto Pulse, Phase and Amplitude Shift Keying.

The talk will identify some basic formulae to help understand the different modulation techniques and include question and answer sessions.

If you are interested please respond by leaving a reply.

Andrew
G0RVM

Sale or Wanted Corner

At risk of starting a trend on the site……. I’m in the market for an HF mobile rig preferable with a detachable head and ideally if possible either yaesu, ICOM or similar (e.g. yaesu Ft100D or ICOM 706 etc).  happy to look at other models if available. Looked on Lynch line, WS, Navada, Ebay and the usual but a few not many around (couple I’m bidding on). Wasn’t going to do HF mobile but…..decided I might give it a try whilst the shack is WIP.  Open to offers and happy to negotiate a sensible price to pay.

 

Feel free to reply to the post.

Thanks Mark

 

Kempton Park Rally

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A few hours later and reasonable journey with a few roadworks encountered and overcome later we arrived. Cup of coffee to start the motor and off we went. Andrew met his friend so went off exploring as did John and I and vowed to not spend much. Yea right!!  Usual players Moonraker, ML&S, Icom, Yaesu etc etc on show with Waters and Stanton having quite the lions share of space – always good for a browse. John and I found our way to the bits and pieces stalls and bought some minor electrical items (ferrite rings amongst other things) few pence. I was drawn to a mobile antenna system on sale from an independent (can’t remember the name) that on-paper looked impressive but…on closer inspection would probably last 5 mins compared to Hustler or Diamond and the build quality was pants. Resisted that.

Then….went back around again to the smaller stalls and to the small club bring and buys and there it was. An old home brew antenna part built and in need to some TLC. In true car boot fashion asked for a price and couldn’t believe what i got back. £2!!! Yes £2 and we think although needs a close look not done that yet that its a J pole design and according to the club selling it off they seem to think it resonated well somewhere around 145.250-146.000MHz but may have done better elsewhere. So I have my project and with the help of John (M3EQQ) and John (M0HFH) I’m sure we can make it perform with a few mods along the way. Happy bunny!! Especially since we think a few others had seen it and were after it to. Also had an aluminium tripod for £8 but again resisted.

Here she is (folded up of course and currently in the old office/shack);

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I was not alone.. John also bagged a bargain with a Yeasu Ft7800 (I think) for £110 in the rally bring and buy although yet to hear that it performs but seem to be quite tidy. Andrew purchased a mobile mast I think for the field trip and we finished off by looking around once more at the radio’s on offer, new specs and whats coming up.

We finished off talking ourselves into the merits of Total Mast Solutions and Andrew and myself will certainly be investing as it seems an all encompassing and impressive system easy to use and portable in that the system (depending on the model and we were told there are over 100 now) can be broken down and re-assembled to suit the operating conditions, antenna systems etc. Bespoke builds are also possible.

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Then….

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We then found ourselves heading back to Lynch’s and a refreshing cup of tea (and chocolate mini rolls!! excellent marketing tactic well worth the visit!). On a technical note Andrew found his new power supply whilst John and I miandered around the shop and as always I got pulled back to the many antenna systems on offer and in consultation with Andrew have yet again changed my mind on the main system at the new home QTH shack.

A thoroughly good day and well worth the trip. I came away with some ideas/thoughts and perhaps even proposals for future PR events that the club might want to consider and of course my bargain. I’m planning a visit to the Weston rally on May 17th  to see what a smaller scale rally might look like so will be reporting back on that in due course.

Excellent day I believe had by all. Looking forward to the next.

Mark M6KMJ

Kite Antennas

The Thornbury and South Gloucestershire Amateur Radio Kite Club had its inaugural meeting today at Whale Wharf where a number of kites were trialled. The testing was inspired by a recent talk from Roger G4ROJ. We also had a go at aerial bombardment (video on application).

A number of members brought their own kites.

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Rex’s Sled Kite

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Peter’s Box Kite

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John’s Kite

 

Part of the testing was to establish the lifting capabilities of the kites. Rex’s kite was connected to a 5 litre can of water. After emptying a couple of litres out the kite was able to lift it easily.  A second test was carried out with a length of 2.5mm2 wire to form a vertical. It was found that the vertical obviously needs to terminate under the kite.

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