Your house sounds
AWESOME. I've built a small bar in the front room, but all that other crap sounds superb. Unfortunately I know little/nothing about computer programming.
( gareth_alien will be human again at, Tue 4 Nov 2008, 13:41, 1 reply)

I like it
I've just finished making a MythTV box too, put 3 tuner cards in it, so I can record on two channels while watching another, set off recordings from my phone/over the web etc... and stream the live tv and/or recordings all over the house.

It does mean that there are now 4 TV antennas (and the double helicoidal) outside now though - the resteraunt next door are probably not too happy about living next door to what must look like GCHQ to them though!

(especially with all the network cables running around the front of the house - I didn't want to drill up through the floors so just ran them from window to window.)
(dchurch bah, Tue 4 Nov 2008, 13:48, closed)

i love
the idea of intercepting the satellite transmissions...What sort of stuff do you receive from your orbiting metal friends?
(Cancer Joy was short lived, Tue 4 Nov 2008, 14:06, closed)

They're not brilliant (yet)...
...but considering I made the antenna myself out of bits of coax and drainage pipe, they are not so bad.





All the images (regardless of which sat I pick up) seem to have uniform lines across them, so I'm in the middle of writing some software to translate pager signals - these transmit on similar frequencies in the UK (137mhz range) - so that I can work out who/where the interference is coming from.

Mail me if you really want to do it, it's quite easy and not very expensive - I guess you can set this up for less than 80 quid, which to be honest, is less than a decent weekend down the pub.

Here's a few more:








When that storm hit (the swirly bit), I was so fucking smug - I could see it coming and everyone thought I was mad!
(dchurch bah, Tue 4 Nov 2008, 14:13, closed)

that
Is amazing. My geek hairs are on end.

How long did it take to build?

/ wants one.
( rofl harris, Tue 4 Nov 2008, 14:20, closed)

Not long...
Here's a pic of the antenna:



Took an afternoon to build (and that's with my crap soldering).
(dchurch bah, Tue 4 Nov 2008, 14:38, closed)

Hey...
...did anyone notice the lid of the Nescafe jar on the top of the antenna?

No?

Ok, I really am that sad.

(fit perfectly, in case anyone needs to find a cap for a load of bog pipes)
(dchurch bah, Tue 4 Nov 2008, 21:47, closed)

It can be friends
with the upside down nescafe bottle stading in for a light cover on one of my outside lights.

That also happened to fit perfectly.
(misskitty reeks of sex and turpentine; laudanum afternoons, Wed 5 Nov 2008, 5:20, closed)

Looks like
your receiver is as wide as a barn door if it's being desensed by pagers 20Mhz away. You could try building a simple band pass or low pass filter to notch them out. Or you could pull your finger out and build your own receiver dedicated to the band, not simply cobble together a scanner and a PC that's childs play.
( buffet_the_appetite_slayer ٩(●̮̃•)۶ jacked in to the ICE on, Tue 4 Nov 2008, 15:20, closed)

Yeah
you're probably right - I'm only guessing at it being pagers.

I'm squeezing the bandwidth down to 40Mhz as NOAA sats expect, but I'm still getting that interference - I have gone as far as 15 but then it's just too narrow to get anything. I can hear it clearly in the upper side band, but then I get the doppler effect (as you'd expect from something pissing past you at 4km per second) as it's far too narrow.

I have a nuclear power station near by (and the associated army camp next to it as you get with all power stations of that kind), a major port, a coastguard and a major TV broadcaster - all within 20 miles of me, so I'm thinking there just might be too much going on for me to get a decent signal.

Suggestions as to what those big lines are would be very welcomed!

I'm thinking it could be a neighbours wireless router or something - I don't know if there is any spill from those into that range or not, but the noise seems to get a little better if I turn mine off when a sat comes into range.
(dchurch bah, Tue 4 Nov 2008, 16:30, closed)

40Mhz(?)
I thought the NOAA birds on 137Mhz were narrowband slow scan type things?

How long does it take to receive a pic - I'm guessing it takes seconds/minute or so. In which case the bands across the picture look like the duration it takes to send a pager burst and also the amount of bursts and randomness you'd expect.

Near by transmitters on adjacent frequency bands can overload your receiver and cause it to lose the signal from the satellite, hense you get bands of static across the picture as it loses signal then gets it back again as when the pager signal drops all the while your PC/Terminal scrolls out the image.

The antenna certainly looks like it's built for 137MHz band. Pagers are on 157MHz and the transmitters are pretty high power. It's not inconcievable that they are causing de-sensitisation of a 137Mhz receiver but would indicate either it's a pretty shoddy one or a wide band scanner type which is designed to tune to 157Mhz as well.

I don't get any desensing even up on 145Mhz here and the pagers are very very loud round here, but that's on high end amateur receiver(transceiver)

What make/model is your receiver?
( buffet_the_appetite_slayer ٩(●̮̃•)۶ jacked in to the ICE on, Tue 4 Nov 2008, 18:27, closed)

Aha!
I have an ICOM PCR1000 which I am running using QPcr1k under Debian.

The NOAA sats are meant to be WFM at around 50, yet people say (not NOAA) that 40 is the optimum, I have tried all sorts. Oddly, the clearest I can hear them is in the USB, but the doppler effect completely screws the picture.

I must admit, I was in the New Forest with a hand scanner and NOAA15 sounded as clear as a bell (and that was a shite Tandy job too - about 230 Mhz).

The moment I get back here with the antenna and a decent(ish) scanner I get shite pictures once again.

The reason I thought it was a pager is for the exact reasons you describe.

The start of the scan to the end is about 15-20 minutes dependent on the atmosphere. If it's raining I am f*cked.

I am desperate for help with this one!
(dchurch bah, Tue 4 Nov 2008, 20:18, closed)

ICOM PCR1000
Hmmm.

I'd ditch that and go for a dedicated rig for NOAA. I run an Icom on HF which is the bees knees but the PCR1000 is a dirty old goose. OK for general larking about but no good for spot frequencies or serious work. It's a (very) wide band receiver using a PC for demodulation and decoding which is the worst in both worlds.

Have a look at:
www.eham.net/reviews/detail/4743
for recomendations on a dedicated kit you can build yourself
( buffet_the_appetite_slayer ٩(●̮̃•)۶ jacked in to the ICE on, Tue 4 Nov 2008, 23:27, closed)

Oooh
Nice! I think I can feel my next project coming on. So to speak.
(dchurch bah, Wed 5 Nov 2008, 11:40, closed)