Amateur Radio

ACOM 2000 Flight Case

Thanks to Nigel at Castle Cases, I now have a first-class flight case for my beloved Acom 2000 amplifier, all for less than £250.

ACOM 2000 Flight Case

Built up from a 9mm touring-quality plywood with aluminium fittings and steel corners, clasps and handles, I’m hoping this will last me a lifetime. I particularly love the hex-effect ply finish which is Nigel’s standard offering. Nigel came up with the idea of building a platform for the amplifier so that I can still get to all the connectors on the reverse and the on-off rocker switch on the front panel. This has a dual effect of allowing a neat storage space for the three-pin plug and RS232 linked remote control panel.

I had a case built for a couple of reasons; a cross between safety and convenience: To transport the Acom reliably in its carboard box, one needs to split the transformer from the amplifier because of the weight. If you try and lift an Acom 2000 on your own, you could easily end up with an accident. Removing the transformer effectively takes about 15 kilos out the amplifier, making it a lot easier to shoe-horn it into its box but it takes forever. Of course, the cardboard will only last a few years too and will gradually become worthless. Who needs a box now..? I drove off today and left Nigel with my cardboard (sorry Nigel, I was going to take it away but forgot!).

Going through the trouble of removing the transformer means that I was loathe to pack it into the boot for field days and Scouting events. But having it sit permanently on it’s flight-case tray means that it can come out to play more regularly which means more QRO fun :)

Custom made flight cases from Castle Cases here:

Cheers all (thanks lads for the coffee too!)

Callum.

 

Kenwood RC-2000 Remote Control system for TS-2000

Kenwood RC-2000I’m pleased to report that after soldering hundred of connectors last Friday afternoon, the remote head for my marine-style TS-2000 installation worked perfectly, even though we had extended the head by 70 feet (21 meters).

How did we do this: The remote head requires extensions for a) 8 pin Microphone b) 2 core loud speaker and c) 4 core data. I had heard of a number of people complaining about RF feedback and other such “funnies” so I reduced the problems by over-specifying on the coax run (Ecoflex 10) and going completely over the top for the 8-pin mic and data cables.

The 8-pin microphone connector was a heavy-duty 8mm screened 25m reel from Farnell components at £90, expensive – but I felt worth it. The data was shoved down a neoprene style 4-core professional OFC microphone cable, as was the loud speaker.

The reason for the OFC microphone cable was an alert I had from a user on one of my Yahoo Groups suggesting that unless I used top-quality cable, the high frequencies might roll off on TX. Not being able to change the installation once the boat was built, I had no option but to buy the best cable I could find. As it happens, the audio is currently routed through the 8-core Mic lead, however I do have the option of running the mic audio through a spare pair from the professional microphone cable.

Tests demonstrated that nobody was wise to our remote head. No interference was discovered whether on our outgoing signal, nor on our data lines or speaker and control lines. Not one ferrite clip was used. Remarkable.

A first class effort. Thanks to james (M3YOM) for doing the soldering!

VHF NFD Report 2008 – Double X-Ray Firm

M0XXT/PCollectively, we have extremely limited experience with VHF. It came as quite a shock to the system to score so few QSOs relative to HF contests that we enter; we are used to scoring 1,500 contacts in a weekend. I must say that the turn-out felt positively low. Is this really the state of VHF contesting in the UK..?

Our location couldn’t get better for a Midland club; 1,000 feet high with easy access on private land (IO91bx [edited, did say IO92bx..!]). The weather was a different story with both the consistent rain and very high winds contributing to some scary moments. Why all three antennas were still standing on Sunday morning, I can’t understand however the guys, stakes or poles didn’t move an inch. Perhaps a testimony to all my recent knot learnings at the Scout Hut!

With limited resources on VHF, most of the gear had to be procured recently to enter this event including a 17 element Tonna and a three element Moonraker beam for 6m. A couple of months ago, we bought a strange X-Quad affair for 70cms which after completely stripping down and rebuilding last week, appeared to work well but we have no way of comparing it to anything else. [Edit: since found out this is a Jaybeam Multibeam, 48 element 12dbd ATV type antenna circa 30 years old]. At 2m long with zillions of elements, I trust it’s as least as good as the Tonna is on 2m. Time will tell. Again, we had to get equipped with rotators so we bought a TV style rotator for 6m and acquired a Hirschman rotator when we bought the 70cms antenna. The Yaesu G450 is permanently attached to the hydraulic tower for the 2m station (normally running an A3S). Coax was also a stumbling block, particularly for 70cms where we only had 50 watts available to us and potentially lots of loss on our standard cut of Westflex, perhaps too lossy for 70cms? A 30m length of Ecoflex 15 was despatched from Diode with matching connectors last week to compensate.

The line-up ended up with FT-2000 on 6m at 100w with a 50m run of Westflex to a 3 element beam at 10m. For 2m, we ran TS-2000 on 100w via 30m of Westflex to the 17 element Tonna at 10m and a pre-amp at the rig end. For 70cms, we ran a further TS-2000 which is factory throttled to 50w through 30m of Ecoflex 15 to our weird X-Quad type antenna at only 9m. Perhaps a small linear for 70cms next year and a pre-amp? A bigger 6m beam will be discussed for next year too.

Logging was exclusively N1MM on Dell Optiplex machines and 15 inch flat-screen monitors without networking enabled due to running separate serial numbers for each band. One Optiplex blew up on Sunday morning after refusing to boot due to condensation we think. We had shut the station at 2:00am for 4 hours to get some sleep and upon waking up and restarting the generator, James discovered an issue of the PSU. Hilarious at the time because when it was plugged in, it sounded like a crunchy plastic pop bottled being scrunched up and I’m shouting at Tim to take the plug out. But like the boy who always cried “wolf”, Tim’s got wise to my practical jokes and really thought I was scrunching up a plastic pop bottle and refused to cooperate. A final “bang” from the PSU convinced him that perhaps this time, I really was telling the truth! Very funny.

Before the off, Tim’s testing proved useful on 6m scoring a number of interesting DX entities, including 7X2RF from Algeria – which enlightened some passers-by who were amazed at what we were doing. I nearly sold two more Foundation tickets!

M0XXT/P

At 15:00hrs local time we started in anger with myself on 70cms, Terry on 2m and Tim on 6m. Having James and Aidan as rotation operators meant that 70cms didn’t become too onerous (50 QSOs in 24 hours..? Ugh!). Massive thanks to Aidan from the team here; he attracted at least 50% of our score on that band, refusing to give up and logging each contact in a determined and professional manner. This was Aidan’s first time on a contest and he’s just 12 years old. May I take this opportunity to thank those stations that recognised Aidan’s youthful voice and his achievement on this band, you stuck with him to ensure a 100% completion for each QSO. Aidan is currently under guidance as part of his foundation license and to be schooled in contesting so early, we think was marvellous. Thanks to all who helped him. Let’s be clear that he had guidance for each QSO and not left to his own devices.

As a “restricted” entry, we couldn’t use brute force to open any doors and it therefore is a slight embarrassment to only have logged 156 QSOs on 2m, 48 QSOs on 70cms and circa 95 QSOs on 6m.
The “magic” band did prove to house some interesting DX from North Africa through to the deep Mediterranean but 2m and 70cms held back offering us no more than 600 km contacts and then very infrequently. Most QSOs were inside the UK although 21 large squares were worked in the end from Ireland through to Germany.

The weather attempted to dampen our spirits but with such strong characters in the tent, we made our own fun and had a ball all the same. At dinner time, we turned the volume down on all three sets and sat down together for our evening meal. I had cooked a top-line Spag-Boll and Terry had us wash it down with a few bottles of bubbly. Fabulous atmosphere.

M0XXT/P

We were amazed at some of bad signal quality issues being produced on mostly 2m and 70cms; warbley modulation and severe splatter in the main. In one case, we had a couple of polite conversations over a period of a few hours regarding a particular club’s 60Khz splatter until they finally believed us and turned down the wick. I realise that Open class stations might adopt the AKR attitude, “All Knobs to the Right” but for the rest of us, even stations 60 miles away can still be 30db over S9 and this can spoil the fun when the signal isn’t as clean as it should be. Please check your equipment before the contest.

No real issues materialised bar some water in the 70cms feedpoint which was fixed by a wild guess. Dropping the mast and pouring it out and resealing it for another day had us back to full power. The PSU which blew up the 70cms Optiplex didn’t hurt too bad but dropped the 2m station for 10 minutes while James and I recovered the data by swapping out hard drives – just as Terry finally scored a small run into Northern France! The new tent, “Battalion HQ”, held up well to the weather, only developing a couple of extremely minor leaks after continual battering rain for 24 hours. With its huge side-pods, it really became a massive area to work in allowing a full kitchen in one area and an operations room in the other with a dining room for 6 people. We’ll roll this out again for SSB Field Day. Trust you’ll be there?

Results:

6m            95 QSOs           45,847 points       Best DX UT3UA – 2251 Km
2m          156 QSOs           27,819 points       Best DX  F4CQY/P – 640 Km
70cms      48 QSOs             5,066 points        Best DX  PA6NL – 411 Km

Operators:

M0MCX (Callum, Supreme Commander 4th Quadrant)
G4MKP (Terry)
M0URX (Tim)
M3YOM (James)
Aidan (Foundation student)

There is some mild debate in the team if we’ll do this one again. I’m told that VHF can be fun with some lifts into the continent but maybe Silverstone, Wimbledon and perhaps the rain damped that down – as did lift conditions I think.

I’m amazed that with all those FT847s and TS2000s sold, few operators perhaps even knew to turn on their radios for an hour and work a few of us /P stations on 6m, 2m and 70cms. However, we did work a few vertically polarised stations quite easily who were giving away single digit points and I thank those stations for coming on since we worked hard for every QSO. It’s really quite easy to score a few QSOs from home with a V2000 style tri-bander vertical. Someone, somewhere should fly the flag for this since hundreds of private stations could have helped make this a bigger event.

Cheers-n-beers,

Callum (M0MCX)

17 Element Tonna Test for 2008 VHF NFD

17 Element TonnaOur 17 element Tonna is up for a test tonight, to ensure that everything will be working for VHF NFD event this weekend. Initial results are proving that its an extremely capable antenna and at 30 feet high, it’s just sitting over the rooftops, giving me a clear run across Warwickshire to the continent.

Fingers crossed for a bit of a lift tonight since it’s the 2m activity contest and James is popping over for some practice. I’ll write up a small report later.

In case you are wondering, yes that’s a Yaesu rotator bearing that I’m guying to at the 9.5 meter mark. It’s not holding the mast up, just taking the horizontal strain off the rotator.

[Later]

41 QSOs in tonight’s contest and 12 square multipliers. Not a big score but jolly good fun and at least we seemed to be ini the top third in terms of score. Longest DX was GM3UCI for 398 Km.

Callum.

Abuse of power by N1KFC

I seemed to have pressed N1KFC’s eject button when I accused him of being a policeman in Yahoo’s Ameritron Amp group. Funny – I’ve never done that before (cough, ahem!). He’s a very diligent co-moderator! Anyway, the silly oaf then put me on moderated postings, censored my posts and finally deleted my previous ones :) How to change the course of history, eh? There’s certainly some strange folk about :)

Anyway, after much debate, a few of the die-hards suggested we start a new group which we did – and we’ve called it “ameritron” (strange name for an amp group!).

Please feel free to join us there.

Cheers-n-beers,

Callum.

Narrowboat Antenna

IMG_8483Never one to do things by half, I have finally completed the HF installation on my narrowboat. First impressions are excellent, I believe it’s working very well. I now need a solid state 500 watt linear amplifier to make use of the 800w PEP atu at the feedpoint. Can’t wait.

WiFi and Cellphone antennas still not connected. My solution here will probably be a Dlink Router with PCMCIA card running an HSDPA service from Vodafone. The PCMCIA card will take it’s signal from the Cellphone antenna and the Dlink Router will then distribute WiFi throughout the boat via the WiFi antenna on the roof. I have personally cracked WEP and WPA access points so I wonder if there’s any point in securing them? Of course :)

[Edit, July 2008: All antennas connected and working :]

73

Callum.

Tower Update

DSC_3207Last night, we finally fitted the rotator housing and G450 Yaesu Rotator to the tower and tested it out with a small VHF ZL Special which we’ll use for VHF NFD in July (being at 1,000 feet means that we might be able to get away without high-gain antenna arrays, time will tell).

Barry (M0DGQ) is working on designs for a hinged rotator cage which means we will be able to use a 20 foot aluminium pole at ground level. Maybe next year..?

Anyway, we can now claim the record for putting up a 35 foot antenna: 20 seconds with a hydraulic switch :)

Callum

My new vertical(!)

CB AntennaWith a feeling of “if you build it, they will come”, I installed a CB style antenna for the 10m band yesterday evening. I needed to shorten it about half a meter for it to work but I noticed that at 12 feet above the ground, it tunes with a low SWR on both 12m and 10m, although it’s not so good around the 27MHz slot- so it’s not exactly broadband. I was also surprised on the 15m band as it presented less than 2:1 in my shack. Red-herring.. it may present a low SWR, however it’s just a crap aerial on that band. The hobby of designing low SWR antennas goes out the window with the dummy loads.

Anyway, why the hell am I writing this? It’s this; I want to know how to feed a half-wave vertical. Why don’t I need radials? I have a 10m fishing pole and I’ll make one for the 20m band and work it all out myself. I know there’s a coil somewhere..

Oh! .. and in the making of this article, I captured a picture of a fly whilst taking a picture of an antenna. See it here: https://www.m0mcx.co.uk/gallery/picture.php?/692/category/67 

Where’s that Glenlivet?

Ameritron AL811x 800w tuning tips

Ameritron AL-811xDon’t spend your life tuning amps. Do it once with sticky labels and forget!

I’ve recently un-mothballed my Ameritron which has seen good service and delivers 200 watts for 10w drive – ideal for PSK31 and other low-power digital modes. This amp will go further and deliver 400 watts for 30 minutes key-down so it’s ideal for full legal power in the UK.

Anyway, flicking from 80, 40, 30 and 20m during the grey line with the AL811, I’ve discovered that I have never mastered the speedy band switching that some operators appear to have worked out. So I developed my visual system(!) using sticky labels tuned against a 50 ohm dummy load to calculate the fastest (approximate) setting for each band. It works blooming marvelous too!

Since a picture tells a thousand words, I won’t bore you any more. Here’s a close up! https://www.m0mcx.co.uk/pictures/Ameritron_AL-811X.JPG

[Later] – I can’t get 10m to tune. Maybe it’s not an export model? In which case, according to sources on the internet, to convert a non-export model to an export model, one needs to make a mod by cutting a wire. This will enable 12 & 10 meters on the Aux switch. I hate engineering! :)

Cheers, Callum.

 

Ham Radio Realtime Gray Line

Current Gray-Line Position

Courtesy of http://www.fourmilab.ch/, this is the current real-time position of the Gray

Line, as utilised by Ham Radio operators over the world.

For those who don’t know, the”grey line” is a band around the Earth that separates daylight from darkness as the earth rotates.  Propagation along this line can be very efficient.  One reason for this is that the D layer, which absorbs HF signals, disappears rapidly on the sunset side of the grey line, and it has not yet built upon the sunrise side.

Interesting? Well, I’ve spoken to people on the other side of the planet during this 30 minute phenomenon. It certainly gives you a buzz.

[Later: This damned map can takes ages to load.. Grrr]

Cheers.

Proposed Field Day Location

VHF NFD Location

I’m very excited that we appear to have found a new Field Day location in the Cotswold Hills, particularly useful for VHF NFD since it is only a whisker short of 1,000 feet. Of course, this will be spectacular for SSB Field Day as well since we might even make use of the height to secure a few more 10m SSB contacts around the UK and into the continent if we’re lucky.

Tim, James, Terry and I visited the site today to ensure that it is suitable – and at only 40 miles from Solihull it’s not as if we’re stretching the fuel tanks to get there either.

I’ve never operated seriously at such a height so I will be fascinated to know how our performance compares with other years when we used to operate at a local club that sported 450 feet ASL plus a 100 foot mast. I have a feeling the extra 500 feet might prove to be exceptionally useful!

May I thank Tim who drove around one evening for hours with a friend of his, door knocking land owners that happened to live very high up. This land owner shall remain anonymous for the time being. Thank you Sir for assisting our group.

VHF Field Day 2008 M0XXT

VHF Field Day 2008 M0XXT

We’re looking for 1st-class contest operators which a good sense of humour who want a couple of interesting weekends away with our club call; M0XXT. If you are interested in joining our group, please email me your phone number.

Callum, M0MCX.

Construction of the 80m Vertical

I’ve had a few emails requesting a deeper understanding of the 80m vertical we put up in January. Andy (M0CTR) kindly emailed me today and I have published my email so that others might benefit.

Andy, The 80m vertical was an interesting project. Firstly, let me explain that the 80m vertical was a carbon copy of a 40m vertical I made a few months before. I multiplied most of the dimensions by a factor of 2 – bar the vertical radiator. I needed to make a coil for the middle. Have you seen this: https://www.m0mcx.co.uk/?p=68 – and read the PDF article. It was this that gave us the inspiration for the 80m version.

To business: The whole thing has an elevated radial system – this is very important because a grounded system would need loads more radials and the match would not be near the 50 ohms we achieved. Building a quarter wave though is relatively easy if you just build everything in quarter wavelength dimensions – hence the 20m long radials. Theory suggests that you only need 2 x elevated radials for an elevated vertical, however practice is demonstrating that you do get a slightly better radiation pattern for 4 x radials since nothing is actually accurately cut (even if you think it is). Don’t despair though – we have built this with 2 radials and it’s very compact like this. A wire cross 40m x 40m is a huge beast.

The height: We used a 6m scaffold pole to raise my 12m spiderbeam pole up. The photos don’t do it justice.. It’s quite high! You need the height though to make it all work. Don’t get me wrong.. It will work at say 12 feet above ground, but the higher the better. Theory tells you to build the radials at a 30 degree angle from the horizontal, but you would need to go higher again. However, it all becomes big – even the weight of the wire starts to make stuff sag – and the coax gets tangled, you trip over guy wires, etc, etc.

Dipole CentreAssuming you have built everything so far to this large scale, you only need to worry about the vertical radiator and then this is just a matter of making a coil. I forget the actual dimensions, I think it ended up at 33 turns on a 2 inch former, using 2.5mm ring mains insulated copper wire (we used the Red portion!) and we put the coil right in the middle of the vertical. It’s an easy matter of raising it, measuring SWR then lowering it again to make adjustments to the coil to finally get a match. I seem to remember that one turn was worth about 40kHz (this moved the SWR from 3.700 to 3.740) but I don’t remember exactly.

I guess you must have seen this: https://www.m0mcx.co.uk/?p=100 – well you will also note in the photos that we started life with about a meter of spare wire sticking out the top of the SpiderBeam pole. We didn’t need this, we had to chop it off and reduce the turns to get the frequency up to about 3.700. I recall that in the end, we agreed to remove another turn but by then, we just wanted to operate!

The feed point was a dipole centre from Lynch / Westlake or somewhere, however a home-brew one would have done just as well. Ensure that everything is watertight and that the centre conductor does end up feeding the vertical – not the radials! You may laugh, but I really did make some contacts on 20m on a narrowboat once by feeding the hull instead of the vertical (yes, the vertical became the ground for the boat antenna!) see here: https://www.m0mcx.co.uk/gallery/picture.php?/501/category/44.

So that’s it really. Use any wire for this. It won’t matter at all. The coil needs to be insulated wire because otherwise it will short out and become a straight vertical. Oh! And you might like to put half a dozen ferrite cores on the coax near the feedpoint as a kind of RF choke so that your RF doesn’t come back down the braid and cause you RF feedback. We never did though.

Results? In the end, I personally concluded that the only band I don’t like verticals for is the 80m band(!). I have compared this antenna with high dipoles (60 feet) with both USA, ZL and VK switching between this vertical and the dipole – none of them gave me a better sig report on either antenna. “No difference” was the reply. However, a 60 foot high dipole is a pretty big monster in its own right unless you have some serious kit. We are endlessly operating of the fringe of physics – yes we have snapped a 12m Moonraker mast last year pushing the limits!

Tip: Next time we’re going to try an inverted L without the coil. Modelling suggests better inter-G and almost as good far field plots at lower angles for DX. Watch this space (as they say!)

Good luck,

Callum.

Shakespeare Marine HF SSB 5300 Fails Again!

Shakespeare’s top-of-the-range HF antenna continues to defeat me. In response to my original failure, they sent me another one which they told me had been tested at their UK headquarters for structural integrity. It arrived promptly enough and I left it in the box for a few weeks until I got it out last Sunday for a quick test.

I discovered that the stainless ring that feeds three buried verticals inside the glass fibre (which I assume is to increase bandwidth) had come away from the main pole and splintered the top coat of resin. Clearly unnaceptable. Freezing water for a start would make mince-meat of this. I took some pictures and sent them off for comment.

It turns out that the US factory think that this is normal and quite safe. Let me get this right, a $600 antenna that is supposedly designed to save your life in the event of you needing to get help as a last resort via HF first breaks in half on a sunny lawn(!) then its spare develops a major crack sequence just where the feeder enters the mast(!) on the replacement.

Now I don’t want to be alarmist but the last time I put the following words: “shakespeare marine 5300″ into my favorite search box, this page came first. A great advert if you want to buy a Shakespeare Marine HF Antenna (another search term which this site enjoys first place at google). I’m starting to get bloody pissed off since the boat show is in 6 weeks time.

Have no fear though! I have found a different supplier that apparently takes quality a lot more seriously than Shakespeare Marine. Courtesy of my mate Stewart (F/GM0GTU/MM), who is currently sunbathing on a large boat off the coast of Angola, he has introduced me to Conmod and their fabulous range of professional range of HF antennas:

They even do a hinged version which would be great! If you have very large pockets, they even do a motorised elevation hinge! Woah. Stewart is currently using their AT82M (8 meter vertical) and has worked 76 DXCC entities in three weeks.

Anyway, Shakespeare, if you can’t get your finger out and ship me a perfect 5300, I’ll be hogging the limelight for Shakespeare Marine search terms for many, many moons to come. Get your arse in gear and ship me a spanking new 5300 please.

<later> I’m pleased to report that the 2008 model is spankingly fabulous. They shipped me one directly from the US to replace all this mess I had and I love it. It’s very white and nice and shiny and smooth. It also polishes up well which got all the winter dirt off a few weeks ago. Thanks Shakespeare.

IMG_8483

Cheers,

Callum.

New Yahoo group: uk.amateur.radio

Competing directly with the jumped up bunnys who post anonymously on uk.amateur.radio, I honestly and openly welcome you (and hereby invite you!) to join the Yahoo Group uk_amateur_radio, regardless of any brushes with the law you may have had or anyone else in the UK hobby (or with me for that matter!).

Subscribe to uk.amateur.radio

I really like the idea of uk.amateur.radio but the anonymous postings concern me. At least an open warranted forum will encourage genuine debate.

We’re looking for at least three independant moderators who can approve / deny access to the list. Just drop me a line if you would do this job.

Here’s the direct link: http://groups.yahoo.com/group/uk_amateur_radio/join

Thanks.

Callum, M0MCX