Aug 192014
 

Well, it has been a long time since I last logged in on the Atomic MPC forums.  Years in fact.  I was at one time, quite active, particularly in what was the “Unix, Linux and Open Source” forum, back in the days when their forum software was an entirely in-house production.

Lately, my work has been very IT intensive, and while some days things go great, other days it’s a struggle.  And when it’s a struggle, the last thing one wants to look at is a computer.

Now when I was active on the Atomic forums, the threads used to move rather fast.  In their move to VBulletin we gained the ability to subscribe to threads and get notified of replies.  A feature I made quite extensive use of.  It was a useful way to keep track of what was happening.

One day I decided I had enough, rather than draw attention to myself with a leaving thread, I just quietly left.  I continued to watch the threads from a distance, and over time, the replies got less and less frequent as the threads slipped off the front page.  I hadn’t seen an email from Atomic for well over two years, until the other day.  Bam!  I had over 200 emails in one hit!

I thought this was just a one-off glitch, so I ignored it.  Then Bam!  A few days later it happened again.

I suppose it’s happened 4 or 5 times now.  What does it look like?

Atomic MPC spam

Atomic MPC spam

Yes indeedy, that’s my email inbox, and there is more crap from old threads that are old enough to be stored on wooden platter hard drives than legitimate email in my Inbox.

I’ve just recovered my account and hopefully unsubscribed myself from these notifications.  However, to the Atomic MPC mods, be warned, if this continues I will be taking this up with the ACMA as the constant barrage my server is copping is getting beyond a joke.

Aug 082014
 

Well, after my initial post about my experiment, I’ve collected a bit more information and I think I’ve settled on a solution and come up with a hypothesis of what’s going on.

Disposable coveralls

As I suspected, the disposible overalls did have a problem in the longevity department. Not a big one mind you. One pair got ripped when the leg brushed up against the corner of a drawer. Fixable with some tape. A few weekends back I wore them cycling from The Gap to Logan Central and back. This is a ~82km round trip (81.56 to be exact), and represents a fairly rigorous test. They got home intact, but the tape on the seams was starting to come adrift.

I also performed a shower-test on both these and the SMS fabric ones. The MP4 ones passed with flying colours. No seepage other than where I had made ventilation holes: and that could be fixed with a storm flap. My “poor-man’s bikesuit” idea could still work.

So the MP4 ones I have, good for emergencies, I’ll continue to carry a pair just in case.  They roll up to something the size of a drink bottle, and contribute bugger all weight, so for those times I am wearing normal clothes, they’ll be great to toss over when the weather turns foul.

SMS fabric? Good in very light and brief showers only. If it’s prolonged heavy showers for anything more than about 30 seconds you’ll get drenched.

It’d be interesting to have a closer look at the Tyvek ones originally recommended.  I might investigate at some point.

Breathalon Spray Suit

So I went back to the Breathalon spray suit, which, having bought it in 2008, is now starting to look a bit frayed, particularly around the hood.  That, and there’s my attempt at adding pocket access.  I do raise a sweat, but it’s minor, and soon evaporates when I stop. I find I’m a lot more comfortable.

How is this so though? Common sense would suggest I’d sweat like a pig! The material is breathable, and so the vapour can escape. If they’re loose enough, there is also a small wind current to draw vapour out. Crucially though, being non-porous, they do not absorb my sweat, and so I don’t have the wind-chill effect of sweaty clothing.  The key here is to have minimal clothing underneath that might absorb the sweat, as this then relies on your body heat to dry it out, and will take longer.

My nits with these?

  • The zip is one-way.  However you can ignore the zip and just use the velcro storm flap as a fly.
  • No pockets at all.
  • The hood isn’t well shaped, doesn’t track one’s head movement very well, and I found the elastic caused it to obstruct my field of view
  • The yellow colour is great for daytime high visibility, but there are no reflective bands for night use.  (I tried using self-adhesive ones, they didn’t stick very well.)

Otherwise, they’re durable and lightweight.

Castle Clothing Coveralls

I mentioned these in my last post.  Well, I bit the bullet, I bought a pair, something which also necessitated me getting a Visa card for the first time in my life (I can highly recommend these as a payment method).  I tossed up between this and buying another Breathalon spray suit, Mammoth Work Wear had these for £40 plus about £30 shipping, this worked out to be under AU$140.  The Breathalon suits are $150+ without shipping.

A heads up with the Mammoth Work Wear site: ignore the sizing advice they give in the drop-down box, you want to pay attention to the sizing chart table below.  The drop-down box suggested I’d be a size L, whereas the table suggested XL.  I went XL and they’re a perfect fit.

Fedex had estimated they’d arrive on Monday, they actually arrived this afternoon.  So I tried them out on the ride home tonight.

I sweat a little more, but not significantly so.  If anything, the lining means I don’t notice them sticking so much, so in that regard they’re more comfortable.  When I got home, yes there was moisture, but I wasn’t dripping, nor did I suddenly feel cold.

They feature a two-way zip (good), with press-studs on the storm flap (not so good, velcro worked better).  The hood (not a concealed hood, which IMO is a plus) is excellent, tracking my head movement very well, sits forward far enough to keep rain off one’s face, and doesn’t block my vision.  It didn’t pose a problem with the helmet either, keeping out of the way and didn’t impede movement or significantly muffle sound.

There is one pocket on the left at the front.  Too low to be considered a “breast” pocket, but well above the waistline.  They could use an identical one on the other side, and perhaps some side pockets, as I find I’ve got nowhere to put my hands.  That said, it’s a generously sized one.  You could fit a 7″ tablet in there no problems, so can easily fit a wallet, phone and keys.

The test will be longevity, and the summer humidity.  They look well-made so we’ll see.

Aug 062014
 

Unix-to-Unix Copy is a rather old way of sending files between Unix systems.  Before SMTP was invented, it was the de-facto way to shunt email around, and prior to NNTP, was also the backbone of Usenet.

Fast forward to today, we’ve got a lot of options open to us.  So why would I use a crusty old one like UUCP?

UUCP has one big advantage, it doesn’t assume your system is always online.

  • It might be a workstation at your workplace which is behind a corporate firewall.
  • It might be a more powerful desktop computer at home that’s usually in “sleep” mode to save power.

Because the initial connection can be established in either direction, it is ideal for a system that may not be directly reachable, but is able to poll on a regular schedule for instructions.  It’s also useful, since UUCP assumes some steps need to be taken to bring a link up, to perform tasks such as powering on a system using IPMI or Wake-on-LAN, wait for it to come up, perform a task, then have the machine power back down when finished.

UUCP over the Internet

Now, UUCP can and does work directly over the Internet.  in.uucpd runs from inetd, and basically fires up uucico each time someone connects to it. But: it is unencrypted and insecure. It’s not what you want exposed on today’s public Internet.

UUCP does support SSL, and there are ways to make stunnel work with packages like Taylor UUCP. This still requires some significant setup and an additional open port.

There’s another way. Thanks to the OpenBSD community, we have OpenSSH, and it is very trivial to set up a secure UUCP link using public key authentication, to lock down the public key to only be used with uucico, and to effectively secure communications between your hosts.

Generating the SSH key

Since this is going to be used with an automated service, one needs to make it a passwordless key. Go for something secure in terms of the key length and algorithm: I used 4096-bit RSA. To do this, log in as root then:

# su uucp -
$ ssh-keygen -t rsa -b 4096 -N '' -C 'UUCP key'
Generating public/private rsa key pair.
Enter file in which to save the key (/var/spool/uucp/.ssh/id_rsa): 
Your identification has been saved in /var/spool/uucp/.ssh/id_rsa.
Your public key has been saved in /var/spool/uucp/.ssh/id_rsa.
The key fingerprint is:
c3:42:5d:77:a9:c2:3a:da:bd:98:6a:5d:03:62:79:19 UUCP key
The key's randomart image is:
+--[ RSA 4096]----+
|          . . .. |
|       .E. . ..  |
|      ...+   .   |
|     .+.+ o .    |
|     ..oSo .     |
|       .o.o      |
|       + + .     |
|      o oo.      |
|     ...o ..     |
+-----------------+
$

You have a choice. You can either: make a keypair for each host, and set up authorized_keys so the hosts can log into eachother, or you can use the same keypair for all hosts. I went the latter route, as I’m not that paranoid. Whilst still logged in as the UUCP user:

$ echo 'command="/usr/sbin/uucico -l" '$(< .ssh/id_rsa.pub ) > .ssh/authorized_keys

Now, securely transfer the UUCP user’s .ssh directory between your hosts. This will allow uucp to log in.

Populating known_hosts

The easiest way to do this, is to log into each host as the UUCP user, then run a script like this:

$ for h in host1 host2 host3 ; do ssh $host true; done

Check each key carefully, answer yes if you’re satisfied.

UUCP Log-in script

Taylor UUCP, has the ability to define a “port” that runs an arbitrary application. You could put a call to SSH here, but there’s another trick I use. As root:

# cat < /usr/local/bin/uussh
#!/bin/sh
echo -n 'Address: '
read user host wake

if [ -n "${wake}" ]; then
        timeout=60
        until ping6 -c 1 -w 1 -n "${host}" 2>&1 >/dev/null \
                        || ping -c 1 -w 1 -n "${host}" 2>&1 >/dev/null \
                        || [ $timeout -le 0 ]; do
                timeout=$(( ${timeout} - 1 ))
                /usr/bin/wol ${wake} 2>&1 > /dev/null
        done
fi

exec /usr/bin/ssh -x -o StrictHostKeyChecking=no -o batchmode=yes ${user}@${host}
EOF
# chmod 755 /usr/local/bin/uussh

Now we can define one “SSH” port, that will automatically wake a computer if needed, wait for it to become alive, then initiate the SSH link. The chat script will specify the host name.

Taylor UUCP configuration

Now we come to UUCP itself. First, let’s create this special port. Edit /etc/uucp/port and add the following:

port ssh
type pipe
command /usr/local/bin/uussh

Now, we’ll set up login usernames and passwords for each host. The easiest way is to do this from a local shell, then distribute the generated passwords.

$ for src in host1 host2 host3 host4; do
   [ -d $src ] || mkdir $src
   for dest in host1 host2 host3 host4; do
      [ -d $dest ] || mkdir $dest
      if [ $src != $dest ]; then
         passwd=$( dd if=/dev/urandom bs=12 count=1 2>/dev/null | base64 )
         echo "$dest $src $passwd" >> $src/call
         echo "$src $passwd" >> $dest/passwd
      fi
   done
done
$ for h in host1 host2 host3 host4; do scp $h/* root@$h:/etc/uucp/; done

Now we have separate usernames and passwords on each host. We can finish up with the /etc/uucp/sys file:

commands rmail rnews gruntreceive-uucp
chat-timeout 120

These are some initial instructions that apply to all hosts. Here, I give permission to run rnews, rmail and gruntreceive-uucp, and I tell it to wait 2 minutes before giving up.

The following is an example of a host that sleeps and needs to be woken first:

system host1
chat Address: uucp\shost1.local\saa:bb:cc:dd:ee:ff\n\c login: \L Password: \P
port ssh
time any
call-login *
call-password *
protocol t
forward-from ANY
forward-to ANY

The following, is an always-on host.

system host2
chat Address: uucp\shost2.some.domain\n\c login: \L Password: \P
port ssh
time any
call-login *
call-password *
protocol t
forward-from ANY
forward-to ANY

Phoning home and scheduling retries

In the case of satellite systems behind some resticted network, assuming you have a way of tunnelling out of the network, you can “phone home” on a regular basis. You also want to periodically call uucico on all hosts to check if there’s any scheduled work on. This is done via /etc/crontab:

* * * * * uucp /usr/sbin/uucico -r1 -q
0 * * * * uucp /usr/sbin/uucico -r1 -s main_hub -c

The first line is a good idea on all hosts. It checks each minute for work to do, and calls uucico to do it.

The second line is the phone-home bit. In this case, it phones home to a system called main_hub, which in my case, is my public web server. You’ll want this second line on your satellite systems. It basically unconditionally phones home, and checks for instructions.

Great, UUCP works, what now?

Well, now you have a way of sending files between hosts. Two services that run well over UUCP worth investigating:

  • grunt: is a tool for securely running commands on another host. It can work over email or UUCP and uses GnuPG signature verification for authentication.
  • Many MTAs support UUCP as a back-end, such as Postfix. Very handy for sending reminders to yourself in a manner that is guaranteed to be noticed and not get buried in spam.
Aug 032014
 

Well, for a few weeks now I’ve been (metaphorically) tearing my hair out, trying to figure out why I had such bad antenna problems on VHF.  HF, I still have work to do as right now, the RF just induces currents where it pleases, including in my microphone cabling, but that’s a different matter.  VHF until recently had been rock solid.

I tried replacing coax, re-terminating leads, checking solder joints, replacing antennas.  Yesterday, I re-wired the entire antenna system, doing away with the BNC connectors in the top box and hard-wiring the antenna mounts to the coax inside.  Rode up to Ashgrove today thinking I had fixed the problem.

Nope.

Each bump in the road, I watched the S-meter graph move from S9 to S4 and back again.

What could it be?  Why is it that it only occurs when I’m mobile, and not stationary?  There’s a bad link somewhere, but where?  No amount of jiggling cables was locating the problem.  Finally today, I decided to take a peek inside the FT-857D.

Ohh, well that would do it!

Ohh, well that would do it!

I looked closely at the point where the N connector solders to the PCB. I noticed a small line around the wire where it met the solder blob. So I picked at it with pliers, and pulled it away from the blob: it was a dry joint!

Tomorrow, I shall know if this was the final problem.  At least I don’t run full power on FM, my license only affords me 30W continuous, so the only time I do 50W is when I’m doing SSB at which point it’s only on voice peaks.

Update: It’s been a few days, the difference is like the difference between chalk and cheese.  Prior to the fix my set was deaf as a post, and it’s not hard to see why!

Jul 192014
 

Oi, Microsoft, yes You!

See this?  Now Bugger Off!  Your lack of self-control was pushing my poor server’s CPU through the roof, so I blocked you.  Now I see you’re back and after the 403 you still aren’t taking the hint!

Search just about anywhere else on this site, no problems.  But the git repositories, those are both CPU and I/O intensive.  Had you noticed how long it was taking, and backed off, I might’ve put up with you, but 5-minute CPU load averages in excess of 80 on a dual-core Intel Atom are no fun.

Go bing up someone else’s host!

Jul 192014
 

My only mode of transport these days is a bicycle.  I might get lifts from other people on occasion, but normally I ride everywhere.

It’s a great way to get around, good form of exercise, cheap and whilst I won’t be breaking any speed records, it’s not overly time consuming.  I spend more time waiting for buses and trains than I do getting places on the bike.  The downside is what to wear whilst cycling.  For cycling use, car drivers have a hard enough time seeing a cyclist as it is, so I feel safer if I’m at the very least, light-coloured, ideally day/night high visibility compliant with AS/NZS 4602:1999.  I’ve been cycling as my main mode of transport now for nearly 5 years, and over this time I’ve tried a number of things for clothing.

Regular clothing

“Normal” clothing, was naturally what I started out with.  What I find is that it quickly wears out, particularly trousers, when subjected to this sort of treatment.  The cycling movement puts a lot of stress in the crutch and thus, I find they give out within a year or two.

Cycling is also very physical, so one will sweat a lot.  So at the very least you’ll want a shirt to wear cycling, and another to change into when you get to your destination.  The high-visibility polo shirts work well for this, they’re cheap and lightweight, keep the sun off well without being too hot.

Work clothing

By this I mean industrial work clothing.  After finding that my trousers were wearing out at an alarming rate, I decided I’d go for more industrial type clothing.

I hate wearing belts, so I looked around and bought some overalls.  My preference is for ones that have a front zip.  A bloody pain in the arse to find in this country!  The likes of King Gee, Bisley, Worksense and many others tend to make those sorts for markets like in NZ, but over here they tend to sell only stud-fastening ones which I find are more time consuming to fasten.  A zip: you’re done in about 2 seconds, studs you’ll be clipping them together for about 10.  But I digress…

The ones I found were medium-weight ones, 290gsm or something like that.  In the winter, they’re okay, but once the fabric gets soaked with sweat one’s body temperature then becomes rather uneven.  In summer they’re often too hot to consider.

Lighter-weight ones might fare better in the sweat stakes, not sure about durability.  Given the high cost ($70~$120 a pair) I’ll just have to keep looking.

Ones made out of the same material as the high-visibility polo shirts could work well, no idea where to find them though if they exist.

Seeking the all-weather cycling suit

Some at this point would be screaming at me “why not lycra”?  Well, I’ve never been a fan of lycra and have no intention of becoming a MAMIL.

One evening coming home a few weeks ago, we had some very windy weather. It’s mid-winter right now, and this wind was going right through me. My clothes were wet with sweat, and with the wind, made the cold weather that much worse.

This got me thinking: what have I got or can I get, that will block the wind, without making me sweat ridiculous amounts?  It’s presently winter, and so now’s a good time to go try an experiment, and see how they fare as the weather patterns shift towards the more humid summer weather.  If I’m still wearing this clothing in July 2015, I’ll be onto something.

Breathalon spray coveralls

I had some Breathalon coveralls lying around, previously I had worn these in wet weather, and found they are not bad.

I bought this pair for about $15 off eBay, but they’re rare as hens teeth. One company sells them for about the AU$150 mark. So not the cheapest, amongst my gripes is that they’re not the most comfortable fit and they have a one-way zip which is an annoyance when nature calls. Apart from that though, they’re a bright yellow, and they’re breathable.

The other gripe I have is no pockets: this particular pair I tried cutting access slits in to gain access to the pockets in my trousers. This proved to be unwise, they now leak in wet weather, so I’ll have to look at sealing those slits somehow.

I tried them one week: I found I sweat less than I did wearing other clothing. With just a lycra stinger suit underneath, I got to work mostly dry and comfortable. This was in dry weather. Summer humidity might be another matter, but in bright sunny winter weather, they were fine. However, they’re very hard to get hold of, and are still quite expensive.

That said, they’re probably 60% of the way there.

Disposable clothing

With the above experiment being largely successful, I considered what else would make the grade. The Breathalon coveralls were okay, but they lacked some features. Could I find some material and make my own?

Will Rietveld provided the inspiration for a cheap alternative: Tyvek coveralls. These are about AU$10 a pair, are generally white in colour (okay, not strictly daytime high-vis, but at least not black like motorcycle rainsuits), very lightweight and were apparently not much different to the old Gore Tex for breathability.

Before doing this, I did some research.  I had seen these before but had dismissed the idea thinking, they’re disposable, surely they won’t last!  Looking around, I found Barefoot Jake’s article which gave them the thumbs up, and Ken K’s forum post giving them the thumbs down.  In the forum post, the comment was the failure was in the seams.  The other two articles mention taping the seams to prevent this problem.

For the cost I thought it worth giving a go. There are a few different fabrics used in this sort of clothing. Tyvek being just one.  They’re usually described in therms of protection classes.

Class 6 coveralls tend to be very flimsy, made from single layered polypropylene and are by far the cheapest at ~AU$5 a pair.  You can just about see through them, wind and water will pass right through.  Maybe you can get some in a bright colour, in which case they’re about as good as a high-vis vest.  For keeping wind and water out: useless.

Class 5 coveralls are made from slightly heavier material such as SMS fabric and are more expensive (~AU$8 a pair).  They’re more opaque (although you can still see clothing through these), will repel water and light spray and block a small amount of wind.  If you’re like me, and a bit self-conscious, you could wear these over the top of more conventional cycle clothing.

I found that water will pool on the fabric, and they are a bit more breathable.  However, the slight transparency is a little disconcerting.  They’re worth a look.

Class 4 coveralls are used for things like asbestos removal.  Materials vary, but in amongst these are the Tyvek ones recommended by Wll’s article.  They can be had for about AU$10 a pair.

I decided to start with these, buying 3 pairs of these.  I noted the fact that the seams were taped a bright orange.  The fact they were taped seemed to suggest that someone had noticed this particular failure mode and had taken particular attention to the problem.  These ones I think are the Hazguard MP4 type material, similar to Tyvek, but with a plastic-like coating.

As I’m after a single-piece suit, I dispensed with the scissors.  When I got home, I tried grabbing a pair, turning a tap on and running the water over them to see what the waterproofing was like.  The water pooled, running my hand under the pool did not reveal any leaks.  So from that perspective, they should do exactly what I’m after.

Things were getting draughty outside so I put the pair on, and after wearing them for a few hours basically just pottering around the house, I hadn’t broken out into a ball of sweat, so breathability was there, a PVC suit would have had me sweating like a pig by then.  I wore them on my way into work to try them out.

First experiments with Class 4 coveralls

First thing that became apparent: as I cycled, the back part ballooned out.  Not necessarily a bad thing, as it made me very obvious to drivers by enlarging my apparent size.  Pedalling appeared to act like a pump, pushing air into the suit, and the air appeared to be trapped.  Like in Will’s experiment, I found that I was starting to sweat after about 20 minutes, and when I got to work, I was noticably more sweaty.  However, it was just humidity, I didn’t feel like I was overheating, nor did I feel cold when the wind blew.

So not quite there, but close.  I can buy Tyvek material on a roll cheap enough, so maybe with some work, we can improve on this.

Class 5 coveralls experiment

Since the humidity really did build up quickly, I thought maybe there was something a little more breathable.  I bought a pair of coveralls that were an SMS-type fabric.  The seems are not taped, and so I suspect these will probably have a blow out at some point.  I did the same waterproofness test and found the water pooled there also, however they’re considered splash resistant, so I suspect the water would seep through eventually.

It was at this point I noticed they were slightly more transparent.  So the following Monday I cycled in them, with one of my lycra stinger suits underneath.  I got to work, not quite as sweaty as the previous week, but still with a noticeable amount of moisture.

One hypothesis: with the Breathalon suit, I also had my stinger suit underneath.  Maybe that was helping by soaking up the sweat rather than letting it bead up on my skin, and allowing it to be more efficiently evaporated?

Class 4 + stinger suit

I tried the stinger suit underneath the class 4 coveralls, and found that the amount of sweat hadn’t changed.  In fact, doing this made things worse, the moist air didn’t dissipate fast enough and once I cooled down, the cold sweat kept me a little too cool.  Without the stinger suit, I’d eventually dry out inside the coveralls after about 15 minutes, but with the stinger suit, I was still damp after 30.

Alternative options

So I hit the web again.  Was the answer to buy another pair of spray coveralls like the Breathalon pair?  There aren’t too many options around here in Australia.  Elliots did make some out of their Zetel material, but they’ve stopped making those (pity, they had pockets!).  Castle Clothing over in the UK make something that looks ideal.  Alas, I tried emailing them to see if they had an Australian distributor — I’m yet to hear back.

Neither of these options are meant for cycling.  Looking around I saw the BikeSuit.  Clearly Olaf Wit had a similar idea, and actually got his to production.  A few comments:

  • The bikesuit comes in one colour: black.  There are some reflective stripes, so I guess that’s kinda class N (night-time: i.e. reflective) high visibility, but I’d like class D (daytime: i.e. bright colour) too.  In fact, if I had to choose between them, I’ll take class D over class N.
  • The idea of using ventilation to prevent sweat build-up looks like just what the doctor ordered.  That said, wearing this over regular clothes — I sweat in regular clothes without any waterproof gear over the top, surely this will not improve the situation?
  • The suit packs up into a bag about the volume of two soccer balls.
  • Watching the video, it appeared clumbersome to put on.  There are zips everywhere.  The fellow takes it out of its bag at time 0:20.  At 0:50, he’s still adjusting things.  10 seconds later, he’s ready to start cycling.
  • They cost over US$340.  Sure breathable and durable fabric can be expensive, but Ouch!

The class 4 coveralls: I timed myself, and it took me about 50 seconds and I was zipped up.  I had work boots on at the time which I did not remove.  About the only thing BikeSuit has over the dispsable coveralls, is ventilation, durability and built-in shoe covers.  It loses on price, availability and visibility.

Poor man’s “bike suit”?

That got me thinking, could I turn these coveralls into a poor man’s bike suit?  I observed how the back of my coveralls ballooned out, what if I made some ventilation holes?

I tried making 10 small holes just below the line of elastic at the back.  I covered the area over with plastic tape first to give the material some re-enforcing, then punched the holes.  The next day I got to work, not quite sweat free, but certainly much dryer than before.  About on par with my experiment in the Breathalon suit.

I’m thinking if I cut a slit horizontally about 30cm long, then glue (sewing is not good with Tyvek) a triangular patch of mesh fabric maybe 40cm wide and 60cm tall to the inside, that would allow the coveralls to vent.  Fold the material over at the bottom so the bottom of the slit is covered by a layer of material, or use some sheet Tyvek to make a flap, and I think I might be onto a low-cost alternative.  Tier Gear sell sheet Tyvek, so a metre or two of that would suffice for adding the extra flaps needed.

As for day/night high visibility: they exist.  More expensive obviously, but they do exist.

The only real question is one of durability.  Thankfully these things pack up so small and are lightweight enough, I can have a spare pair on the bike for wardrobe malfunction emergencies.  They should be good for WICEN events too: often I’m out on a checkpoint in the wind and rain.  Time will be the ultimate test, we shall see.

Jun 152014
 

This is a simple vertical groundplane antenna intended for mounting atop a 10m Squid Pole. These can be made to nearly any frequency you desire, and can be self-supporting if needed. The main limitation is the stiffness of the wire used.

The antenna gets its name as the original was one I quickly knocked up just prior to a horse endurence ride event that took place at Donnybrook in 2011. I was assisting Brisbane Area WICEN with the emergency communications at this event, and this antenna, worked very well. 10W was more than sufficient to get back to base on 2m FM.

The design is very simple. You’ll need some stiff copper wire, and a panel-mount BNC connector. I used some strands from a thick mains cable: this was being tossed out at a ham radio meeting some years back. The cable had a black plastic coating and inside were 7 strands of solid copper, each about 2mm thick. Perfect for small antennas.

Similar wire can be found in non-stranded house mains cable.

First step is to work out what length to cut the elements. They should all be roughly the same length. This can be calculated by the simple formula:

v=f\lambda

which if you take v as being the velocity of light in a vacuum (~3\times10^8 m/s; radio will travel a little slower through air, but who’s counting?) and f as being 147.050\times10^6 and solve for \lambda you get 2.04m as the wavelength.  We want ¼ of this, so I’ve aimed for 51cm long elements.

Don’t worry about them being perfectly straight when measuring, extra length is good at this point, you’ll want a good 2cm extra.  You can make a wire shorter, you can’t make it longer.

Measuring the elements

Measuring the elements

Measure and cut the 4 elements. 3 will become your groundplane, and the 4th the radiating element. Also cut off about 10cm or so, give or take, which will be the ground wire used to hook the groundplane elements to the BNC connector. Also add to your parts list, some small velcro strips: you’ll find these handy to strap the coax to the squid pole.

Procured parts

Procured parts

Start with the short piece of wire. You’ll want to bend it into a rough triangle shape, with loops of wire at the corners. The groundplane radials will loop through these holes. The excess wire should be coiled up to one side: this is the loop the squid pole will pass through. The BNC connector will be fitted in between the 3 small loops.

Ground wire

donnybrook-03-ground-wire Ground wire

Be sure you can still put the nut back on.

Take 3 of the four elements, and make a hook at one end. Pass this hook through each of the small loops in the triangle. Try to make them sit roughly straight out from the centre of the triangle, then solder each hook into the loop.

Hooking the radials

Soldering the radialsAttaching the radials

Having done this, put the BNC connector in and do the nut up tight. You can do away with the eyelet with the solder tag. To finish off, take your remaining element, make a hook just big enough to go around the centre pin of the BNC connector, then solder into place.

Preparing radiating element

Hooking radiating elementSoldering the radiating element Attaching the radiating element

To finish off, bend this until it is vertical. The antenna is now ready for tuning.

Completed untuned antenna

Completed untuned antenna

Double check the length is about right. It should be around the 51~52cm mark.

Checking length

Checking length (close) Checking length

To check the tuning, use a SWR meter or antenna analyser if you have one. Here, I used the built-in SWR meter on my Yaesu FT-857D. When using a SWR meter, ensure you’re running minimum power. The following are some results from my set.  It is at this point, you do any trimming of your antenna.  The following are without trimming the antenna, you’ll note that in most examples, the SWR is very low, just a point or so showing up on the left side of the screen.

On 2m:

donnybrook-13-test-144500 donnybrook-13-test-145500 donnybrook-13-test-146500 donnybrook-13-test-147500

On 70cm:

donnybrook-13-test-432100 donnybrook-13-test-433100 donnybrook-13-test-434100 donnybrook-13-test-438100 donnybrook-13-test-439100 donnybrook-13-test-440100

To mount the antenna on your squid pole, feed the tip of the squid pole through the remaining loop.  Bend the tip of the antenna around the tip of the squid pole.  Hook your coaxial cable to the BNC connector and use velcro straps at regular points to hold the coax to the side of the squid pole.

Mounted antenna

Mounted antenna

Recommended coax for this purpose is RG-195.  RG-58 will work, but is lossy, RG-213 and LMR400 are too heavy to use on a squid pole and will cause it to bend or collapse.

Update: This antenna performed quite well.  Saturday, we used it for 2m packet, providing a digipeater for the stations in our area in case they couldn’t reach the main node (at “the pineapple farm” just outside Imbil).  We had stable packet communications all day.  Since the stations around us found they could work the main node directly, we swapped antennas around and used it instead for a VHF/UHF cross-band voice repeater.  Signal reports were good through the Imbil state forest.

Jun 012014
 

Just a quick note. I’ve been getting a lot of spambots registering on this site of late. Probably at least 3 an hour.

Thus I have implemented a new policy. Inactive accounts older than a week 3 days old who have posted no comments will be deleted. I will quarantine the account, and can re-instate it should an account be mistakenly deleted.

The comment doesn’t have to be approved, it can be in moderation. If the comment is spam, the account and comment will be deleted upon discovery. So spambots, go ahead, it’ll let me hunt you sooner. Or don’t even bother creating the account, no one will see it so it’s a waste of time anyway.

May 282014
 

Entered into an eBay contact form.

Hi, Just a short note.

I am closing my account: the form that asks why didn’t really capture the true reason why I’m closing.

It’s not quite “identity theft”, but it is security-related.

I haven’t been using my eBay account, so I thought I’d set the password to something nice and *strong*. On the password change form, I noticed a 20-character maximum limit.

This was red flag no. 1.

Then I pasted a randomised password from a generator. The site complained I had forbidden characters.

This was red flag no. 2.

By placing limits on the size of password and its content, it is clear to me that eBay is *not* serious about making its systems truly secure, and that breaches like the one experienced recently will be a recurring event.

By hiding behind “proprietary encryption” it isn’t even serious about reassuring the public: good crypto doesn’t need secret algorithms to work well.

As there’s now very little I buy off eBay, I feel the time has come to say goodbye. If you ever do get your act together, I might consider returning, but until then, farewell.

Apr 142014
 

I just checked my email, and see this:

Return-Path: < …>
X-Original-To: …
Delivered-To: …
Received: by atomos.longlandclan.yi.org (Postfix, from userid 0)
	id 67204200E27C; Sun, 13 Apr 2014 23:05:55 +1000 (EST)
Subject: [Fail2Ban] SSH: banned 138.91.144.167 from atomos
Date: Sun, 13 Apr 2014 13:05:55 +0000
From: Fail2Ban < …>
To: …
Message-Id: <20140413130556.67204200E27C@atomos.longlandclan.yi.org>

Hi,

The IP 138.91.144.167 has just been banned by Fail2Ban after
5 attempts against SSH.


Here is more information about 138.91.144.167:


#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/whois_tou.html
#


#
# The following results may also be obtained via:
# http://whois.arin.net/rest/nets;q=138.91.144.167?showDetails=true&showARIN=false&ext=netref2
#

NetRange:       138.91.0.0 - 138.91.255.255
CIDR:           138.91.0.0/16
OriginAS:       
NetName:        MICROSOFT
NetHandle:      NET-138-91-0-0-1
Parent:         NET-138-0-0-0-0
NetType:        Direct Assignment
RegDate:        2011-06-22
Updated:        2013-08-20
Ref:            http://whois.arin.net/rest/net/NET-138-91-0-0-1


OrgName:        Microsoft Corp
OrgId:          MSFT-Z
Address:        One Microsoft Way
City:           Redmond
StateProv:      WA
PostalCode:     98052
Country:        US
RegDate:        2011-06-22
Updated:        2013-10-03
Comment:        To report suspected security issues specific to 
Comment:        traffic emanating from Microsoft online services, 
Comment:        including the distribution of malicious content 
Comment:        or other illicit or illegal material through a 
Comment:        Microsoft online service, please submit reports 
Comment:        to:
Comment:        * https://cert.microsoft.com.  
Comment:        
Comment:        For SPAM and other abuse issues, such as Microsoft 
Comment:        Accounts, please contact:
Comment:        * abuse@microsoft.com.  
Comment:        
Comment:        To report security vulnerabilities in Microsoft 
Comment:        products and services, please contact:
Comment:        * secure@microsoft.com.  
Comment:        
Comment:        For legal and law enforcement-related requests, 
Comment:        please contact:
Comment:        * msndcc@microsoft.com
Comment:        
Comment:        For routing, peering or DNS issues, please 
Comment:        contact:
Comment:        * IOC@microsoft.com
Ref:            http://whois.arin.net/rest/org/MSFT-Z

OrgTechHandle: MRPD-ARIN
OrgTechName:   Microsoft Routing, Peering, and DNS
OrgTechPhone:  +1-425-882-8080 
OrgTechEmail:  IOC@microsoft.com
OrgTechRef:    http://whois.arin.net/rest/poc/MRPD-ARIN

OrgAbuseHandle: MAC74-ARIN
OrgAbuseName:   Microsoft Abuse Contact
OrgAbusePhone:  +1-425-882-8080 
OrgAbuseEmail:  abuse@microsoft.com
OrgAbuseRef:    http://whois.arin.net/rest/poc/MAC74-ARIN


#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/whois_tou.html
#

Regards,

Fail2Ban
atomos ~ # grep 138.91.144.167 /var/log/auth.log ; zgrep 138.91.144.167 /var/log/auth.log-20140*.gz
Apr 13 23:05:40 atomos sshd[3143]: Did not receive identification string from 138.91.144.167
Apr 13 23:05:40 atomos sshd[3144]: SSH: Server;Ltype: Version;Remote: 138.91.144.167-1025;Protocol: 2.0;Client: JSCH-0.1.51
Apr 13 23:05:41 atomos sshd[3144]: SSH: Server;Ltype: Kex;Remote: 138.91.144.167-1025;Enc: aes128-ctr;MAC: hmac-md5;Comp: none [preauth]
Apr 13 23:05:41 atomos sshd[3144]: SSH: Server;Ltype: Authname;Remote: 138.91.144.167-1025;Name: support [preauth]
Apr 13 23:05:48 atomos sshd[3144]: Invalid user support from 138.91.144.167
Apr 13 23:05:48 atomos sshd[3144]: Postponed keyboard-interactive for invalid user support from 138.91.144.167 port 1025 ssh2 [preauth]
Apr 13 23:05:49 atomos sshd[3203]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=138.91.144.167 
Apr 13 23:05:51 atomos sshd[3144]: error: PAM: Authentication failure for illegal user support from 138.91.144.167
Apr 13 23:05:51 atomos sshd[3144]: Failed keyboard-interactive/pam for invalid user support from 138.91.144.16  port 1025 ssh2
Apr 13 23:05:51 atomos sshd[3144]: Postponed keyboard-interactive for invalid user support from 138.91.144.167 port 1025 ssh2 [preauth]
Apr 13 23:05:51 atomos sshd[3236]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=138.91.144.167 
Apr 13 23:05:54 atomos sshd[3144]: error: PAM: Authentication failure for illegal user support from 138.91.144.167
Apr 13 23:05:54 atomos sshd[3144]: Failed keyboard-interactive/pam for invalid user support from 138.91.144.16  port 1025 ssh2
Apr 13 23:05:54 atomos sshd[3144]: Received disconnect from 138.91.144.167: 3: com.jcraft.jsch.JSchException: Auth cancel [preauth]

Seriously, some dodgy ISP in Russia or Asia having a crack, I’ll ignore it. But a big company like you? I expect better behaviour.