August 2012 FIT payment

Posted on October 3, 2012 by james

At the end of August our latest FIT payment arrived covering the late Spring/early Summer period. Obviously given the weather this wasn’t as high a figure as we’d been hoping for, but means that 8.6% of the installation cost is now covered. The next payment should take us up to our first full year and we can review how we’re doing at that point.

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Solar PV Generation Update October 2012

Posted on October 3, 2012 by james

And so the abnormal weather continues…

Generation for September this year totalled 333kWh, up 7.5% from the previous September and a somewhat astounding 32% more than would normally be expected for September. That increase completely covers the failure to meet the expected generation figures for April, July and August. It’s also more than was generated in June! Total generation since installation now stands at 3603kWh.

As the FITs year runs from April to March I’m going to work out our figures based on that because it saves having to switch prices halfway through the year. This brings our total generation for April on to 2213kWh worth about £1040 in FITs payments and saving up to £330 in electricity that we haven’t had to purchase from the grid and total income since installation to around £1670 with up to £540 worth of electricity that we haven’t had to purchase from the grid.

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Observation Report 8 September 2012

Posted on October 3, 2012 by james

Another moonlit night washing the less bright objects out, but clear enough to step out with the 10″ dob again…

First up was M39 in Cygnus. I found this one tricky to locate, but eventually got to it starting from ρ Cygni. From there I hopped to g Cygni and noting a straight line of stars ending at that star, moved in the opposite direction. I found M39 to be a small open cluster surrounded by other stars making it hard to pick out. I think it would be possible to overlook it in the surrounding star field very easily.

Next over to the ever popular M31/M32/M110 group in Andromeda. Easy to find and impressively bright despite the moonlight I found I could make out more of the extended area of the galaxy. M32 still appeared some distance from the core of M31 though, so clearly I couldn’t see as much as I know to be there. M32 was still clear and not hard to find even if it was still just a small grey smudge in the prevailing conditions. M110 on the opposite side of the main galaxy was on the other hand much more tricky to find and only just discernable as a faint grey blob.

I moved over to Cassiopeia next for M52 which I found to be quite well-defined though faint. It was very easy to find and filled the field of view of my 9mm BGO nicely with the stars being easy to resolve.

Also in Cassiopeia I found M103, an open cluster which sadly wasn’t too impressive with the Moon now being quite bright in the sky. Another to return to when the viewing conditions are more favourable.

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Observation Report 6 September 2012

Posted on October 3, 2012 by james

Very poor seeing on this particular night. I couldn’t even be sure I could make out the four stars in the “body” of Usra Minor, so the conditions were clearly not at all good. Nonetheless I got out for a while with the 10″ dob to see what was visible.

I first found M2 in Aquarius. A very impressive dense, large cluster. In the conditions it was hard to resolve individual stars, but was well worth finding.

Despite the conditions I also found M15. It appeared a similar size to M2, but perhaps not as dense overall, having a clearer core area with more stars being resolved around the edges especially with averted vision.

These two are clearly well worth another visit on a better night.

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EQ3-2 motor gearbox reduction ratio

Posted on October 2, 2012 by james

I’ve decided there’s nothing more I can do with my EQ3-2 mechanics to improve the backlash that’s painfully obvious in the DEC axis. What backlash there is left (about twelve seconds at the 8x speed when changing direction) appears to be in the motor gearbox. So I’m thinking about replacing the gearbox assuming I can find something to do so at a reasonable price.

The first step was to establish the reduction ratio of the existing gearbox. To that ends I took my spare one apart and photographed all the gears so I could load the images onto the PC and count the teeth. These are the numbers I ended up with:

  • Motor out: 12
  • Gear 1 in: 30, out: 14
  • Gear 2 in: 42, out: 14
  • Gear 3 in: 28, out: 14
  • Gear 4 in: 28, out 10
  • Final drive in: 40

I make that to be reduction ratios of 30/12, 42/14, 28/14, 28/14 and 40/10, or 5/2, 3, 2, 2 and 4, giving a total reduction ratio of 120:1.

So, the search is now on for alternative mechanisms of achieving a 120:1 reduction ratio with the minimum of backlash.

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Observation Report 21 August 2012

Posted on September 28, 2012 by james

This was my first decent length session with the 10″ dob and a good night for it. Checking Ursa Minor suggested a NELM of at least 5.70, so I shan’t be complaining in that respect, although there was a small amount of high cloud about. For much of this session I used either the Revelation 32mm eyepiece giving a magnification of about 40x, or my 9mm BGO for about 130x magnification.

I started with one of everyone’s favourite globular clusters, M13 in Hercules. A 130x I had no problems resolving a huge number of stars in the cluster — more than I could count, but wasn’t convinced I could make out the propeller in the centre. I found myself having to “chase” the cluster with the dob because of the narrow field of view and found that there were a couple of places where the base is a little sticky, so that needs addressing soon. I also caught a meteor zipping across the field of view at one point.

Next was M13’s poor cousin, M92. It appeared much smaller and less dense in the 9mm eyepiece, but was still resolved very nicely with many stars (tens to hundreds, perhaps) being clear with the 9mm eyepiece again.

Over to Lyra next and another favourite, M57, the Ring Nebula. I found this tricky to get a really sharp focus on, perhaps because of the nature of the target, but the ring structure was beautifully clear and obviously slightly off-circular which I’d never seen before with smaller aperture scopes. I couldn’t make out any sign of the central star however. Again I had to work at keeping it in view when I’d got down to the 9mm eyepiece.

Halfway to Albiero from M57 is M56, another globular cluster. Smaller and less well-defined than M92, nonetheless a good number of stars were clear at 130x. Unfortunately a patch of high cloud spoilt the view of this one for some time, though a second meteor passing through the field of view helped improve matters a little.

M27, the Dumbell Nebula could clearly be resolved as an oval patch of nebulosity at 130x with an “apple core” shape in the middle. I couldn’t get much more detail out of it than that though.

M71 in Sagitta I found to be much more faint than either M13 or M56 with only perhaps a couple of dozen stars resolved and an odd sort of triangular shaped patch of starlight in the centre.

Moving up to Sadr for a nice easy finish to the evening, M29 is an easy star-hop down. I stuck to the 32mm eyepiece for this. It struck me as very easy to overlook, but I could resolve at least six major stars which reminded me of the face of a die.

Overall I was very happy with my first night out with the big dob. The base needs a little adjustment which shouldn’t be a major issue.

I do have a couple of eyepiece problems to address though. The first is that whilst the BGOs performed very well, they don’t really have a large enough field of view for a manual scope with that kind of focal length. At times I could probably have pushed the magnification up to 200x with the 6mm, but targets just move across the field of view so fast then that it doesn’t work very well. Some wider field eyepieces will probably become necessary at some point.

Also, whilst I’ve used the Revelation 32mm eyepiece a huge amount, possibly more than any other eyepiece thus far, it’s just not up to coping with an f/4.7 scope. Some new longer focal length eyepieces are clearly therefore a more important required than finding alternatives for the BGOs.

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Arrival of my 27mm Tele Vue Panoptic

Posted on September 28, 2012 by james

Whilst my Baader Genuine Orthos are fine in my 10″ dob the largest focal length I have is 18mm and the longer focal length lenses I have from my Revelation kit just aren’t up to coping with such a fast scope (f/4.7). I’d been dithering over the 82° Explore Scientific eyepieces or the Meade 5000 series UWAs because I just couldn’t justify the price of a Tele Vue when a 27mm Panoptic came up second hand for less than either of the first two would have cost, so it seemed silly not to.

It arrived this week and whilst the weather has been far too poor to actually attempt to use it, I thought I’d post a couple of pictures of it. The first is next to my existing 32mm Revelation eyepiece. It’s a bit of a monster. I might need a counterweight for the dob…

And for a giggle, here’s my biggest eyepiece, and my smallest:

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Cloud Towers

Posted on September 28, 2012 by james

I looked out of the window this evening to see this unusual cloud formation above the northern end of the Quantock Hills. I don’t recall that I’ve seen anything like it before. I can’t imagine that the “pillars” are related to the cloud above, but it frames the ones beneath it rather nicely. A short while later it appeared that the pillars were poking through the flatter layer of cloud above them.

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Why I’m cancelling my Tesco credit card

Posted on September 28, 2012 by james

Taking money out of a cashpoint machine on a credit card is something I would never do, so I tend not to read the terms and conditions that apply to doing so. It’s just something that wouldn’t happen, so I don’t worry about it. Recently however my wife took out some cash against our Tesco credit card unintentionally and as a result I found out quite how unpleasant the situation is if you do. Here’s what happened.

The first bill I received after it happened, there were charges for interest applied. There was no explanation as to how these arose or were calculated, but after spending quite some time on the phone waiting for Tesco’s staff to answer it was explained that one was interest on the cash being taken, and the other was interest on the fee for using the service of taking cash out against the card. I’m not entirely happy about the idea of being charged interest on the latter, but it wasn’t a huge amount and I paid the whole lot off on time thinking that would be the end of it. Lesson learned and all that.

However, the next bill also had charges for interest and no explanation of their origin, so I spent another happy hour on the phone (you know I’m not telling the truth there, don’t you?) waiting for Tesco to answer. It was then explained to me by the woman I eventually spoke to that these were interest charges for the time between the statement being generated and them receiving payment.

Now that confused me. I’d paid the bill on time. Why was I being charged interest? Because there were a number of days between the statement date and me paying, and those days accrue further interest, apparently. I was mildly surprised and inquired as to whether I understood correctly that even if I paid the bill in full on the day I received the bill I would still be charged interest and that there was no way to get out of that situation? Only if I pay on the day the statement is produced (that is, before I even know the statement is actually on its way), apparently, or if I call and find out how much is due at the time I call and pay there and then.

Whilst I accept that those are the rules and will pay to clear the debt owed, I suggested that this absolutely reeks of grubbing every last little penny out of the situation in as underhand a way as possible, but the woman just kept saying “That’s the way everyone does it”. And therein lies my problem. “Everyone does it” is not a reason. It’s an excuse. It’s hiding behind mummy’s skirts because you just don’t have the balls to come out and say “Actually, this isn’t a reasonable way to behave”. It’s a clear attempt to trap people in a never-ending spiral of interest payments and, frankly, it stinks. If I were late paying the bill, or didn’t pay it all off then I could accept further interest charges, but not if I pay by the due date, and especially not when I can’t avoid them even if I pay on the day I receive the bill.

So, Tesco, as soon as I have another credit card sorted out, you’re going to lose our business. And not just our credit card business either. We used to spend an awful lot on food with Tesco. That isn’t be happening any more. I’m sure they won’t care about losing our business. There are plenty more customers where we come from, I’m sure. But there are plenty more banks and supermarkets too, and from now on we shall be taking our money elsewhere.

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Keeping recordings and DVB channels when moving MythTV

Posted on September 28, 2012 by james

Thanks to a server dying I’ve been moving my MythTV installation to a new system. I wanted to install from scratch to clean out a load of old settings and other data that have been hanging around for years (I’ve been using MythTV since somewhere around v0.7), but to keep all my recordings and the tuner settings for my DVB-T cards.

I discovered that having copied the recordings across from the old server, running the following against the old database and importing into the new will extract all the recording data and recording schedules and can be imported into the new copy:

$ mysqldump -u mythtv -p mythconverg record recorded oldrecorded recordedprogram recordedrating recordedmarkup recordedseek > recordings.sql

And for the channel tuning data:

$ mysqldump -u mythtv -p mythconverg dtv_multiplex channel > channels.sql

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