OK, I'm a new user and I've not been active on ATV up to now.
Emailing BATC officers has produced very quick and useful responses, for which I'm very grateful, but does anyone still monitor these forums?
Is there anybody there?
Forum rules
This forum is run by the BATC (British Amateur Television Club), it is service made freely available to all interested parties, please do not abuse this privilege.
Thank you
This forum is run by the BATC (British Amateur Television Club), it is service made freely available to all interested parties, please do not abuse this privilege.
Thank you
Re: Is there anybody there?
Hello to G0DJA..............yes the formum is checked quit often, where are you located the callsign I think I know from the North of england.
It sound like you are receiving info ok, but dont forget the organisations that run the repeater , they oftwen have their own web site with a great deal of info....try the Bournmouth group and G8AJN. Or the http://www.SCARTCLUB.com.
Best regards PeterB g3pyb
It sound like you are receiving info ok, but dont forget the organisations that run the repeater , they oftwen have their own web site with a great deal of info....try the Bournmouth group and G8AJN. Or the http://www.SCARTCLUB.com.
Best regards PeterB g3pyb
Re: Is there anybody there?
Hi Peter,
Thanks for the reply, I'm glad to see someone else on the forums.
I now live in Bolsover (IO93if) but I used to live in the Wakefield area of IO93 up untill a few years ago.
I would like to connect to other ATV users in my neck of the woods.
de Dave (G0DJA)
Thanks for the reply, I'm glad to see someone else on the forums.
I now live in Bolsover (IO93if) but I used to live in the Wakefield area of IO93 up untill a few years ago.
I would like to connect to other ATV users in my neck of the woods.
de Dave (G0DJA)
Re: Is there anybody there?
Well, I'm a couple of stages on towards transmitting some pictures.
In fact, strickly speaking, I have already transmitted pictures, but only across the bench from the bare-bones Comtech transmitter board to the Wood & Douglas unit that I borrowed from a friend, but it's a start.
The 23cm TX/RX and controller arrived in the post from http://www.13cm.com today (thanks Nigel). I found out the connections for the 12 way output from the controller to the TX and RX boards, and soldered them up using some old PC strip cable that was handy. I then found a site which showed me how to connect the S-Meter line, so I've done that mod. and it's working.
Then I decided to take the plunge and see what I could get from the TX board. I bought a cheap CCTV camera off eBay, and had already tested that into the video input, or AV, channel on the TV, so I knew that worked and I connected the 50mW output of the TX board to a dummy load, put a wire in the aerial socket on the W&D unit, hit 'PTT' and the little LED on the controller board lit up. Then I tuned down to 1280 (which is where I'd set the TX to) and there were my pictures.
A bit of tweaking and I'd got a reasonable picture, but it will need a bit of work to get it right, but next job is to box the TX/RX/Control boards and sort out the relay operation for the 18W PA, and put the PA in a suitable box as well of course.
I think I will put a small fan on the case near the RX board, as the heat sink gets very warm!
In fact, strickly speaking, I have already transmitted pictures, but only across the bench from the bare-bones Comtech transmitter board to the Wood & Douglas unit that I borrowed from a friend, but it's a start.
The 23cm TX/RX and controller arrived in the post from http://www.13cm.com today (thanks Nigel). I found out the connections for the 12 way output from the controller to the TX and RX boards, and soldered them up using some old PC strip cable that was handy. I then found a site which showed me how to connect the S-Meter line, so I've done that mod. and it's working.
Then I decided to take the plunge and see what I could get from the TX board. I bought a cheap CCTV camera off eBay, and had already tested that into the video input, or AV, channel on the TV, so I knew that worked and I connected the 50mW output of the TX board to a dummy load, put a wire in the aerial socket on the W&D unit, hit 'PTT' and the little LED on the controller board lit up. Then I tuned down to 1280 (which is where I'd set the TX to) and there were my pictures.
A bit of tweaking and I'd got a reasonable picture, but it will need a bit of work to get it right, but next job is to box the TX/RX/Control boards and sort out the relay operation for the 18W PA, and put the PA in a suitable box as well of course.
I think I will put a small fan on the case near the RX board, as the heat sink gets very warm!
Re: Is there anybody there?
OK, so now I have at least 15 Watts of 23cm ATV RF output, into a dummy load.
Now I'm starting to think of inter digital filters so that I can see my output going through the repeater, unless someone comes up on 144.750MHz to look at my TX output and let me know if they can see it in the mean time.
Dave (G0DJA)
Now I'm starting to think of inter digital filters so that I can see my output going through the repeater, unless someone comes up on 144.750MHz to look at my TX output and let me know if they can see it in the mean time.
Dave (G0DJA)
Re: Is there anybody there?
Hello again Dave,
Ok on your progress, i thought I recognised the call sign but it is a few years now since i moved south.
Saw your comments re RADAR, the problem varies greatly round the country.
The main issue is not that is directly on your working channels but the peak power can be very high and the selectivity on your receiver and its front end might be easily overloaded.
I have a massive problem here, I live on the side of Portsdown Hill overlooking the harbour and the wider Solent to say nothing of the ships test facilities close by.
Most of the offending Radar signal are well cotained in terms of bandwidth and oabout 20 t0 30 Mhz away from the repeater channel and it is just my front end that overloads. So I use some notch filters specifically set up on the the RADAR to drop the level 20dB or so to try to get the overload down.
We dont see much RADAR on the repeater input, occasional Naval vessel passing the IOW. Shared band are a fact of life across the radio spectrum.
Daves comment about 10Ghz is correct, so we plan to add 10GHz to our local repeater and hopfully link to the Dorset group down the coast.
Some look through filters have added notches to improve the filter edge, if the shape is allready reasonable then you could use the notes on the receive side to sit on the RADAR.
Dont get to dispondent on the subject, in a recent opening we were seeing stations from Lincolshire and up near Newcastle through the IOW repeater with excellent pictures.
Regards Peterb g3pyb
Ok on your progress, i thought I recognised the call sign but it is a few years now since i moved south.
Saw your comments re RADAR, the problem varies greatly round the country.
The main issue is not that is directly on your working channels but the peak power can be very high and the selectivity on your receiver and its front end might be easily overloaded.
I have a massive problem here, I live on the side of Portsdown Hill overlooking the harbour and the wider Solent to say nothing of the ships test facilities close by.
Most of the offending Radar signal are well cotained in terms of bandwidth and oabout 20 t0 30 Mhz away from the repeater channel and it is just my front end that overloads. So I use some notch filters specifically set up on the the RADAR to drop the level 20dB or so to try to get the overload down.
We dont see much RADAR on the repeater input, occasional Naval vessel passing the IOW. Shared band are a fact of life across the radio spectrum.
Daves comment about 10Ghz is correct, so we plan to add 10GHz to our local repeater and hopfully link to the Dorset group down the coast.
Some look through filters have added notches to improve the filter edge, if the shape is allready reasonable then you could use the notes on the receive side to sit on the RADAR.
Dont get to dispondent on the subject, in a recent opening we were seeing stations from Lincolshire and up near Newcastle through the IOW repeater with excellent pictures.
Regards Peterb g3pyb
Re: Is there anybody there?
Thanks Peter,
I guess I was just a bit fed up with the constant 'chirp chirp' when monitoring the GB3VL output frequency. I've seen some designs for interdigital filters, so I may look for a suitable box and hardware at the next rally I go to.
I did transmit a picture through GB3VL the other day and it was seen by one of the regulars, in fact I think he's on the repeater group, Bob, G7AVU. So, that's another step forward...
The TX/RX is off the air for a couple of days whilst I build it into a box. I have had to 'modify' the box because, although the Comtech controller fits just nicely on the front panel, the box behind is smaller than the face plate! Ah well, out with the hacksaw.
I guess I was just a bit fed up with the constant 'chirp chirp' when monitoring the GB3VL output frequency. I've seen some designs for interdigital filters, so I may look for a suitable box and hardware at the next rally I go to.
I did transmit a picture through GB3VL the other day and it was seen by one of the regulars, in fact I think he's on the repeater group, Bob, G7AVU. So, that's another step forward...
The TX/RX is off the air for a couple of days whilst I build it into a box. I have had to 'modify' the box because, although the Comtech controller fits just nicely on the front panel, the box behind is smaller than the face plate! Ah well, out with the hacksaw.