Geminids

[BillW]

Sadly not, 107 clips for the clear spell, too slow tonight one of the cameras/gratings got wet, I don't like that at all!
However 6 spectra which I think are all Geminids, which is good but none particularly bright.
Anyway thats my Geminid long weekend over, I'm off to bed, getting far too old for this!!
'night all.
Bill.

[stewartw]

Hi Bill,

If you think it's worth it (ie spectra are bright enough), please let us know the dates / times and we'll see if any of us caught the same event.

Cheers

William

[allanuk]

Intermittent clouds and clear patches plus a period of rain, but left the cams running all night. Checking the clips today I picked up just over 30 Gems and an assortment of others. I think cloud must screw up the mag estimates because I apparently caught a mag -5.6 meteor just off the Isle of Wight.

    

[BillW]

Hi William,
With the moon coming up the spectro system was to the NW so definitely no mutual volume.
Also they were a bit too faint for any realistic analysis.

A while back you asked about what sort of magnitudes were needed to generate spectra.
Here's an example. The background on the spectrum frame (lower) is "contaminated" with diffracted light scattered from the clouds even though the meteor was in clear sky.
It's not easy!







Only a couple of lines visible. Mg and Na (just like the other one I tweeted)

cheers,
Bill.

[stewartw]

Hi Bill,

Thanks for posting ... I certainly see what you mean.

Up to your NW is the common volume monitored by David Anderson and Denis Buczynski.

That 910 is one hell of a performer ... easily getting down close to 6th magnitude in spite of the moonlight with the east facing view of Ursa Major.

[BillW]

Hi,
Still a bit concerned about the horizontal noise I'm seeing whilst running the camera. Last night I used a 12v battery to ensure there was nothing coming in from the PSU.
It did indeed help but hasn't cured the problem. I also tweaked some of the settings. There is the lowest manual setting on the DNR, AGC MID (can't seem to find a manual adjustment), fixed exposure of 1/50 sec BUT 2x frame integration.
THAT seems to makes a huge difference!

I've ferrites on all the lines and when I get back to work I've got a line isolating transformer for the video coax to try.

When trying it battery powered in a dark room, where there is just a bit more overall sig to noise ratio it does look perfect.
So it might well just be intrinsic to the camera and not a "problem" It does however seem an awful lot of work to go to for an expensive camera compared to the problem free 902's
I don't suppose the WATEC designers were particularly thinking about our area of use.

It is quite impressive though, I may have to put a second one on plastic, just to check of course....
cheers,
Bill.

[stewartw]

Are you using a ground loop isolator?

[allanuk]

Hi Bill, are you using normal coax? You could try a length of twisted pair cat5 cable with baluns. Twisted pair cat5 is supposed to give a cleaner signal and the baluns help to balance it. I sometimes get captures of horizontal bands of fuzzy noise, but not very often.
Manual gain is found by setting AGC to OFF then hit centre button. You can then set gain to a fixed value. I have found about 36dB works ok.
Having 2x sens up will improve the image, having 4x sens up will improve it more. You are just stacking frames internally, and you will be imaging at 1/25sec.( why is that supposed to be a bad thing?) I think you will find that with a crispy clear sky the camera will default to using the sensup unless you set it to OFF. The camera uses the sens up to try and get the best image, much like when the gain is on auto. The only way to get consistent results with varying levels of sky brightness is to have sens up and auto gain OFF so that the camera cannot make any adjustments itself.

I hesitated before laying out a lot of money for a meteor cam. I tried various cheaper cams with some success, and was going to get the 902's because I wanted better results. I was put off by the lack of remote control so decided to get the 910's. Now having seen what this cam is capable off, I'm so pleased that I have got another one. Getting the 910HX was definitely one of my better decisions.

[stewartw]

Hi Bill,

Can't comment on twisted pair Cat 5 for video transmission as I've never tried it but obviosly Allan is getting good results with it.

When I first started out I used to get an intermittant rolling banding interference pattern ... I traced it down to the electrical connectors (not the power supply) ... simply rotating the male / female fit of the connectors would cure the problem, but only temporarily. More robust connectors were a more robust fix but Ian Williams brought my attention to Ground Loop Isolators which proved to be the permanent solution - when they're fitted I can fiddle away with the connections with no ill effects whatsoever.

Here's the ones I use: www.ebay.co.uk/itm/CCTV-Ground-Loop-Isolator-BNC-for-Camera-DVR-Top-Quality-Guaranteed-1000-Sold-/321310156029?pt=UK_CCTV&var=&hash=item4acf93e4fd

Cheers

William

[allanuk]

Thanks for that info William. I'll buy a few for that price and try them out. Every little bit helps.

Edit. Nearly bought 10 thinking it was 99p each. Changed to 5 when I saw they were £6.39 each.

[BillW]

Hi,
Thanks for the info/advice. No I don't thinks its a ground loop problem, that's quite characteristic.
If anything it looks very like impulse ignition noise super imposed on the normal camera noise.
I'll try the baluns/isolator route next clear sky. The kit is all in my workshop.

Once resolved the nice Computar and blue grating will be going on it. Should be a good performer.
Maybe the quadrantids will oblige.

cheers,
Bill.