AmateurRadio.com

In this very late episode, Linux in the Ham Shack gets back to some basics. For those listeners who haven’t been around ham radio that much, we take a look at some of the basic concepts of radio communication. Then, we get all up in arms about how long our…antennas are. Explore with us some of the concepts of antenna modeling, different types of antenna design and what they’re good for, and some software that might help you make sense of Smith Charts. As if that isn’t enough, we through in some good-natured ribbing, feedback from our listeners and a whole heap of fun. Tune in and let your worries disappear. LHS Top Tip: Don’t fumble your foo dog too hard, it might go off prematurely.

73 de The LHS Guys

The price of copper has risen by 300 percent over the last two years. Other metals have also risen in value. According to GB2RS News, this is making radio amateurs targets for copper thieves. An amateur in Yorkshire had all his cabling stolen including the coax and ladder line for his G5RV antenna.

I presume the action of an irate neighbour fed up with receiving TVI has been ruled out. The RSGB is encouraging amateurs to make sure access to cables is restricted and that their installations are as secure as possible. Looks like another benefit of stealth operation and attic antennas!

The weather forecast wasn’t promising, even though the morning was fine. But I was keen to get out on the fells. Yesterday I spent a couple of hours making an antenna specifically for Wainwrights On The Air operating and I wanted to try it out. So I headed for Broom Fell, LDW-169.

I’d had the idea for this antenna for a couple of years but hadn’t got around to making it. I was going to call it the WOTA Pole. As, for reasons I will come to, I’m unlikely to be publishing a detailed description of it, I’ll give you the outline of it now. It’s a Slim Jim made from 300 ohm flat ribbon cable, housed in a tube made of white UPVC electrical conduit. The tube breaks down into four sections for easy carrying using UPVC jointing pieces. It’s a similar idea to the SOTA Beams MFD except that is a half wave dipole and has a T piece with a coaxial balun and can be used vertically or horizontally. The Slim Jim should theoretically have some gain over the dipole but it can’t be used horizontally, which is no disadvantage as 99% of WOTA activating is done on FM.

One reason I haven’t used the MFD very much is the difficulty in deploying it. The antenna is provided with two velcro straps so it can be attached to a convenient fence post. Unfortunately our hilltops don’t often have convenient fence posts on the summit. My intention with the WOTA Pole had been to stuff the antenna in my rucksack for support so the radiating element would be above head height. Unfortunately UPVC jointing pieces aren’t very strong and it’s impossible to lift a rucksack onto your back whilst keeping a 2 metre long antenna perfectly vertical to minimize the strain on the joins. As I lifted it up I heard a crack and the antenna fell to pieces!

I didn’t see any damage. It was quite windy up there and I thought the culprit was the wind, plus perhaps I hadn’t pushed the jointing pieces tightly enough together. So instead I decided to strap the antenna to a convenient fence post which fortunately Broom Fell just happened to be equipped with right by the summit cairn. You can see the result in the photo. Lords Seat is the fell on the right in middle distance, with the Skiddaw range further away on the left.

Sunday lunchtime is not the best time to go WOTA activating. I think many chasers are busy filling themselves with roast beef and yorkshire pudding and nowhere near their radios. However Colin 2E0XSD was on frequency having been following my progress via APRS. He gave me a 59 plus report on the new antenna. After a couple of fruitless CQs I started to think that was going to be the lot, then Geoff GM4WHA came up, followed by Malcolm M0XAT. Then no-one. As the wind was bending the WOTA Pole rather a lot I took it down. I then tried a couple more calls using a helical antenna and got Mark MM1MPB and Tony G1OAE. Finally Colin 2E0XSD came up again to say I was only 4 by 3 on the helical antenna. The WOTA Pole had made a huge difference. It’s just a pity there hadn’t been anyone further afield listening at the time.

I walked down the hill a short way to get out of the wind and have the sandwiches and coffee that Olga had made for me. While I was down there I thought I would have another try at hoisting the antenna on to my back in the rucksack. Then I noticed that one of the UPVC jointing pieces – the one at the top of the lowest tube that takes most of the strain – had cracked. When I tried to get it aloft a piece broke away completely and the antenna fell to the ground. Another idea bites the dust. Literally!

On the way down I was pondering what I could do to make this idea work. Clearly the Slim Jim itself performed very well. In fact if anything it worked a bit too well on receive. The VX-8GR receiver exhibited clear signs of overload. I’d noticed this before when I’d used that radio with the MFD. I should really use the Motorola GP-300. Ironic that a radio that cost me £1 at a rally works better than a fancy Yaesu costing more than £300!

The problem with my WOTA Pole idea is the mechanical design. If I’d made the tube two one metre pieces instead of four 50cm lengths it would be stronger. But having something sticking 50cm above the top of my rucksack would be a nuisance when walking under low branches or ducking under fallen trees as I actually had to do on this walk.

Perhaps I should give up the idea entirely and try to make a rucksack mount for BNC fitting antennas. Then I could use the telescopic 5/8 wave that I usually use on less windy days fitted directly to the radio. What do you think?

A few readers of this blog may have been surprised to contact me on a new mode last night…RTTY.  I’ve tried radioteletype once before in the past (also in the NAQP contest) but rather unsuccessfully the first time.  The second outing was a bit better.  I suppose with practice it becomes fun, but the primary motivation here is ARRL’s Triple Play award for contacting all 50 states each three times, using CW, SSB, and digital.  CW was, of course, easy.  And, I’m making good progress on the SSB totals.  So, I figured I would stop putting RTTY off and give it a shot.

As you are probably well familiar, I normally contest with two TS-930s.  Their prior owners (who were CW contest/DX types like myself) made various “improvements” to them, most of which I appreciate, but I have no idea how they affect FSK. One radio simply does not work on FSK (need to look into this) and the other has the passband shifted about 50-100 Hz off-center of the normal RTTY frequencies. So, when I was running AFC in MMTTY, it would “walk” to the point that having a lock on the other station would put me at the edge of their passband. I had a terrible time making QSOs for the first hour until K0TI told me I was off-frequency (thanks, Dan!!!) and then I started paying attention to all of the numbers in MMTTY and turned off the AFC, which had some deleterious effects that I overcame thanks to the occasional repeat. Typical analog op becomes digital lid op.

I sent the MacBook (our “home” computer) with Sarah to a conference yesterday.  Since that’s the only place I have LoTW’s Trusted QSL installed and I failed to export a .p12 file, I’ll have to hold tight for a couple of days until they return.  (This is not entirely true, I have an old .p12 file, but I haven’t backed it up again since I renewed the certificate a few weeks ago.  Bad backup practices…although I just got a new external drive so the old drive can be used to do a Time Machine back up…finally.  Another day, another project.)

This post mostly mirrors my 3830 post, but here are the numbers for the curious.  My grepping missed one QSO on 80 meters when I did the totals (N1MM rounded the frequency up to 3600 kHz) for 3830.  So, these numbers are right, aside from log-checking discounts:

Call: K8GU
Operator(s): K8GU
Station: K8GU

Class: Single Op LP
QTH: MD
Operating Time (hrs): ~3

Summary:
 Band  QSOs  Mults
-------------------
   80:   37    21
   40:   58    27
   20:   35    18
   15:
   10:
-------------------
Total:  130    66  Total Score = 8,580

Club: Potomac Valley Radio Club

Team: PVRC #1

Series Four Episode Five of the ICQ Amateur / Ham Radio Podcast. News Stories include:

• NZ proposes changes to 27 MHz band 
• Ham Radio promoted on TV in New Zealand 
• New country added to CEPT reciprocal agreement
• New SA amateur radio regulations 
• 1st Portuguese DStar reflector 
• RSGB looking for EMC volunteer 
• RSGB AGM to be held in Derby 
• Revalidating UK Amateur Radio Licence 
• Radio-active solar flare 
• UK Six Metre Group launch newsletter
• Data across the Atlantic on 502kHz  

Your feedback, upcoming events, Ed Durrant's (VK2ARE) VK report and Martin (M1MRB) features portable power.

Series Four Episode Five of the ICQ Amateur / Ham Radio Podcast. News Stories include:

• NZ proposes changes to 27 MHz band 
• Ham Radio promoted on TV in New Zealand 
• New country added to CEPT reciprocal agreement
• New SA amateur radio regulations 
• 1st Portuguese DStar reflector 
• RSGB looking for EMC volunteer 
• RSGB AGM to be held in Derby 
• Revalidating UK Amateur Radio Licence 
• Radio-active solar flare 
• UK Six Metre Group launch newsletter
• Data across the Atlantic on 502kHz  

Your feedback, upcoming events, Ed Durrant's (VK2ARE) VK report and Martin (M1MRB) features portable power.

New Zealand flag (from Wikimedia Commons)

Tonight, before heading home I dropped by the VA3CUA station at the University where I work.  I used the Icom ID-1 to link the 1.2GHz module of VA3ODG to reflector REF003C, an Australian reflector.  Linked also to the reflector was the repeater ZL1VHD in Auckland, New Zealand. After making a call out on the reflector I had a reply from Marlene, ZL1MYL. We had a nice but brief chat and she told me that there had been messages passed through the Auckland D-STAR repeater for people in the earthquake damaged city of  Christchurch. Messages received were being relayed on via other modes on VHF to Christchurch, as that city does not have a D-STAR repeater.  The chat with Marlene was short as she had to take a phone call, but I did then talk to her husband Laurence, ZL1ICU.

Later tonight I saw the message from the ARRL that confirms that 2m is being used to support the recovery efforts and currently not HF.

If you have traffic for someone in Christchurch then one possible route in is via the Auckland D-STAR repeater ZL1VHD.