Simon Rumble’s blog

I went along to the linux.conf.au open day last night and had a great time. Lots of really cool projects, particularly the OLPC (heavier than I expected), RepRap (homemade fab) and the very cool open source Segway. Really good stuff and I think they've got a good mix of slick corporate-style things and the handmade feel.

Was great to catch up with a bunch of people. Met Kim and Janet from Adelaide at last. Caught up with Dean. Also ran into Raz, who's apparently been living in the UK for the last five years, and Craige.

I really wish I could've been there for the whole conference. Maybe next year.

Last night I got up a ladder to install my shiny new TV aerial that was expected to get us all the digital channels. Problem is, we only ended up getting the ABC and SBS digital channels. This is odd because all of the channels are on the same location so I'd expect that if we can get one, we'd get them all.

I used high quality quad-shielded RG6 coax, an antenna appropriate for the coverage area (UHF) and spent a fair amount of time pointing and checking. Still no joy. Analogue reception is improved over the rabbit ears, though not perfect and still with quite a bit of ghosting.

The only thing I can think is that topography is against us. We're in a bit of a hollow so, while I was up the ladder, I couldn't get direct line-of-sight to either Kings Cross or Gore Hill. There are buildings and trees in the way. I think this is the reason for the problems, though can't explain how we get two channels and not the others.

This has sent me back to the drawing board on my MythTV plans somewhat. I'll have to record the commercial channels from analogue, though I'll use the digital tuner for ABC and SBS. Graeme suggests trying a different tuner, so I might pop into Dick Smith who accept returns.

Any other suggestions? Obviously more height would help. I couldn't reach the top of the mast with the ladder I have, so that might help. A professional installer would be the usual recommendation but I can't justify $200-500 on a rental property!

Internode just upgraded me to ADSL2+ with Annex M. It's very nice!

On the best line profile, I get 10463800 kbps down and 2039400 kbps up. This is using the "MAX24-HS-M" line profile. Internode allows you to change profiles in case you're getting dropouts and the like due to line conditions.

So I now have a broadband connection that can probably max out the wireless hop to my laptop. Excellent!

Today is the first day of linux.conf.au, the biggest free software conference in Australia and generally regarded as one of the better conferences of its type in the world. There's a bunch of people I know in town for the event, including Dean Wilson, Kim and Janet Hawtin and Richard Cohen (who's staying with us for the duration).

Unfortunately due to work I can't make the conference. It's just too costly to take the time off work as a contractor. I'll be going to the Open Day on Thursday afternoon though.

Hopefully will meet up with a bunch of the attendees for a beer or twelve on Thursday.

Plugged in the new server last night and it's a vast improvement on the old one. Fan noise is almost non-existent when it's idling, and no matter how much CPU I used, it didn't seem to power up the fans to maximum even though it was quite a warm evening. Much better than the jet engine roar that the first one had. The only real noise you can hear is a whine from the SCSI disks.

Had some problems installing Ubuntu last night. There seems to be some problem with the CD drive on the Ubuntu server install disk. It can't mount the disk, after booting from it. I noticed last week that Aldi had super-cheap DVD burners on sale, so I might drop in and grab one tonight.

Instead I installed Ubuntu Dapper and attempted to upgrade to Edgy. There's a nasty bug with the current version of initrd-tools that causes upgrades to fail. Worked around it by manually installing a newer version, which seemed to work.

Then there's the problem with the monitor. I'm using a nasty, cheap LCD screen I borrowed from my Mum. The video card in the machine has DVI-out with some kind of adapter attached. Looks like Ubuntu in Edgy does something tricky that causes it to switch back to DVI, as all I get on this (d-sub) monitor is digital-looking noise about halfway through booting. Haven't been able to work out what's going on, but since there's no X installed, I'm a bit stumped.

I need to buy an LCD monitor anyway, so I'll start looking around.

Oh yeah, it also seems to have 900 megs of RAM when it was advertised as only having 500. Very nice. And there's still four slots left, so I can up that even more. It's RDRAM but you can get 256meg sticks reasonably cheaply, so that's at least another gig.

In other geek news, it turns out my Internode ADSL is actually connected to one of their DSLAMs. I had been advised I was on a RIM so my only option was a Telstra port, which means more cost and lower speed. Not sure what went wrong, but it means I can get ADSL goodness. For the same price as 8meg/256k ADSL1 I can get (up to) 24meg/2.5meg ADSL2+ with Annex M. Brilliant! Just waiting for the upgrade to happen now.

So Australia really does have broadband, but it's not offered by the biggest player. Yes, broadband requires fast speeds in both directions, in my opinion. It's not television.

My new server, to replace the jet-engine sounding one, just arrived. It's another dual-Xeon system, but this time it's a workstation model so should be quieter and should be a little more accepting of hardware. Quite looking forward to finally getting some horsepower in the house.

My plans for this machine are for it to be a MythTV backend and to be a server for a couple of thin clients I also bought off eBay. I'm planning to play with Xen to get separation between the services.

The TV aerial at home is going up this weekend. I bought one last weekend at Jaycar, along with some quad-shielded RG6 coax. It's UHF-only and I'm hoping I can get the Kings Cross transmitters. Looking around the area, there seem to be a few other people with UHF antennas pointing that way, rather than towards Gore Hill.

The key thing with digital, though, is that the noise floor is a lot lower. You need a much better signal, with a lot less noise, than you do for decent analogue reception. Here's hoping it works!

I'm planning to put up an antenna for digital TV reception this weekend. Being in St Peters, I should be right in the Kings Cross transmitter's footprint. I sure as hell hope so because I'm going to buy a UHF-only antenna.

Now the interesting thing will be working out where to point the thing, and diagnosing that as I move the antenna around. I only have a little USB-stick style DVB receiver for my laptop. So far I've not been overwhelmed by the software-displayed signal strength meter in that. Will be difficult with me up the ladder and Holly down the bottom with the laptop.

I guess I could get an installer in, but since we're only renting I'm loathe to spend big money on the antenna. Yes, the landlord should supply an antenna. He hasn't, though he's put up the mast for me and will let me clip the cable down and drill holes in the floor for the cable.

Any tips?

In response to yesterday's post about acoustic noise measurements, Matt Palmer, Rog and Michael Greb have pointed out that a "bel" is the base unit of "decibel", with a decibel being a tenth of a bel. That much should have been obvious to me, but wasn't.

Michael reckons 37dB isn't loud at all, which means that computer should be a good purchase. Excellent news!

Thanks for the responses guys.

The reason I sold off the server I'd bought on eBay is because of the noise it generated. I already live right under the flight path to Sydney airport, so I don't need my own jet engine noise inside as well. So I'm looking around for a similarly specced machine, in workstation configuration rather than server.

IBM have lots of documentation about their products, and I've found a workstation model I like that's on eBay at a keen price. But I can't understand the noise specifcations they use, and Wikipedia hasn't been all that helpful.

What's specified is this:

Acoustical noise emission: 
Declared (upper limit) sound power levels:
 5.2 bels idle
 5.3 bels operating

Average sound pressure levels:
At bystander position (1 meter):
 37 dBA idle
 39 dBA operating

So what does that mean? Is "bels" another word for decibels? And as it's a ratio, I'm unclear how to read it. Some resources I've found put 30 dB as the sound of a quiet theatre, and 60 dB as a normal household television when switched on. So is 39 noisy or pretty reasonable? Let me know and I'll post the results for posterity.

I'm finding blogging like this quite helpful. I guess the audience is pretty big, what with it being on the SLUG, Linux Australia, GLLUG and Linode planets. Certainly getting lots of helpful responses to questions I pose. All without a commenting system!

Okay the server I I advertised yesterday has sold to a mate of my brother-in-law. Looks like it'll be doing service as a (very capable) file server. Now looking for similar-spec hardware that doesn't sound like a jet engine and will happily take TV tuner cards...