WXSat proof of concept

[Analoguesat]

Thats pager interference . The bane of the wxsat game in Europe.

 

[Terryl]

I saw on some web site a band pass filter for the WRX band, that could help out greatly, but all that I find now are DIY projects.

 

[Archive-8]

Thats pager interference . The bane of the wxsat game in Europe.

That’s with the uputronics pre-amp.

137.5MHz Filtered Preamp

And the noo-elec txco dongle. About 6 meters of coax. Plus the pi 3.

 

[Analoguesat]

The problem is the wide open front end of the dongle - the adjacent pager transmissions saturate the tuner and blat the weaker wxsat transmission.

 

[Terryl]

That’s with the uputronics pre-amp.

137.5MHz Filtered Preamp

And the noo-elec txco dongle. About 6 meters of coax. Plus the pi 3.

And your using this filtered pre-amp?

And still getting the interference?

Then it could be direct RF radiation into the dongle, there could be a break in the shielding somewhere... OH Is the shielding grounded??? that could make a big difference, a standard TV coax ground block (if you used 75 ohm TV coax) can be used to ground the coax shielding, without a good ground it can act as an antenna and pick up high levels of RF that may be close by.

I would suggest using one and a ground rod driven in right at the antenna.(ground the antenna mast also)

 

[Archive-8]

The gray splat around Portland/Bournemouth is probably the thunder and lightning plus a very heavy rain cloud.

 

[Terryl]

I'm getting interfeance from my other RF equipment, going to build an RF cage for the dongle, it will also have a heat-sink as mine gets warm.

 

[Terryl]

I don't know were that is, but the 137 MHz band is almost weather proof to rain clouds.

 

[Archive-8]

And your using this filtered pre-amp?

And still getting the interference?

Then it could be direct RF radiation into the dongle, there could be a break in the shielding somewhere... OH Is the shielding grounded??? that could make a big difference, a standard TV coax ground block (if you used 75 ohm TV coax) can be used to ground the coax shielding, without a good ground it can act as an antenna and pick up high levels of RF that may be close by.

I would suggest using one and a ground rod driven in right at the antenna.(ground the antenna mast also)

I have a grounding rod to pop in.

 

[Archive-8]

Todays catch so far



I used to struggle with noaa 15.

 

[Analoguesat]

15 has fixed itself for the time being - the scan head has an intermittent issue.

 

[Analoguesat]

Mk 2c antenna now in use - a v-dipole with stiffer rods as the winds here wrecked the flimsy wires of 2b. I shall see how it performs before considering to add the rear radials back in.

 

[Archive-8]

Grabbed this (before earth rod)



Now added an earth rod. Now I have to wait for the next pass.

 

[Terryl]

15's going over you now, but 18's right behind it.

 

[Terryl]

If you knew what direction the paging transmitters are, you could put up a Faraday shield on the side of the antenna facing that direction, it would look funny but it has worked in the past.

 

[Archive-8]

If you knew what direction the paging transmitters are, you could put up a Faraday shield on the side of the antenna facing that direction, it would look funny but it has worked in the past.

I am surrounded by communication masts, from the hospital, police station, sorting office/phone exchange it goes on and on


I don’t know what happened on this pass



The next pass according to predict

 

[Archive-8]

With the earth rod.

 

[Terryl]

Well it looks like it knocked it down some, maybe some quad shielded coax??

But it could be direct to the antenna.

 

[Archive-8]

Well it looks like it knocked it down some, maybe some quad shielded coax??

But it could be direct to the antenna.

I will be adding another aerial in a few days in another spot. I will need a new cable run for both aerials so I will have a look for some better quality shielded coax.

50 or 75 ohm?

 

[Terryl]

75 ohm would probably be better for you to work with, all sorts of connectors are avalible, 50 ohm needs some soldering skills (PL-259 connectors) for good solid connections.

My MK-10 antenna seems to be working good, I will have to work on some drawings and assembly stuff.