Modern 405 Transmissions - UK Vintage Radio Repair and Restoration Discussion Forum

Mikey405 · 23rd Mar 2007, 9:01 pm

Hi everyone.

Does anyone still transmit 405-lines in an amateur capacity? In the early 90s a few of us down in Devon used to have an ATV net on Thursday evenings and I would sometimes transmit 405 lines on 70CM UHF (430MHz-ish?). Once I transmitted an episode of "The Avengers" to a mate of mine in Woodbury on UHF, with the sound on a "spare"

2M channel around 145MHz. He received it on a Sony 9-90UB and an Icom IC2E.

Although I was licensed to transmit ATV, I don't think it was very legal transmitting episodes of TV programs.

Bye everyone.

From Mike.

brightsparkF5VL · 24th Mar 2007, 2:01 pm

In one of my valve radio searches, I came across an old TV web site(cannot remember where but it should be easy to find) This group have a converter that changes modern broadcasts into 405 line tv. I think it is freely available to enthusiasts.

Good luck

Paul Stenning · 24th Mar 2007, 5:35 pm

There is a whole section discussing standards converters etc right on this forum, immediately below this section......

https://www.vintage-radio.net/forum/...splay.php?f=95

Dave Moll · 24th Mar 2007, 7:52 pm

Returning to the subject of amateur transmissions - if there is anything being transmitted, I would be interested in having a listen, having recently acquired an AR88LF communications receiver. I assume that any video reception would require way too much bandwidth, but might be an interesting experiment whether there would be anything left that could be displayed using a modulator and receiver - once I get my modulator working properly.

ppppenguin · 24th Mar 2007, 7:55 pm

Nothing of any use would be left. Optimistically, a sound receiver might have a maximum bandwidth of 20kHz. To get even vaguely recognisable 405 line pictures you would need more than 10 times this.

Dave Moll · 24th Mar 2007, 8:23 pm

Thanks for confirming that. I thought as much, but thought I would try out a little optimism for a change

Nah! I think I'm happier with pessimism

Kat Manton · 24th Mar 2007, 10:02 pm

Hi,

Amateur television activity (of the "wideband" flavour - 405/525/625-line) was confined to the 70cm band and upwards. If I'm up-to-date, the 70cm band has been eroded somewhat and there's no room for it any more; so it'd be on the 23cm band and up now. Both are a bit beyond an AR88.

There's some slow-scan activity on the HF bands, but that's OT for this thread (though a search for "SSTV Software" may prove fruitful...)

Regards, Kat

Dave Moll · 24th Mar 2007, 10:39 pm

Woops! I realise now that I misread the wavelengths quoted in the original post

23rd Mar 2007, 9:01 pm	#1
Mikey405 Octode Join Date: Jul 2006 Location: Solihull, West Midlands and Beaford, Devon Posts: 1,626	Modern 405 Transmissions Hi everyone. Does anyone still transmit 405-lines in an amateur capacity? In the early 90s a few of us down in Devon used to have an ATV net on Thursday evenings and I would sometimes transmit 405 lines on 70CM UHF (430MHz-ish?). Once I transmitted an episode of "The Avengers" to a mate of mine in Woodbury on UHF, with the sound on a "spare" 2M channel around 145MHz. He received it on a Sony 9-90UB and an Icom IC2E. Although I was licensed to transmit ATV, I don't think it was very legal transmitting episodes of TV programs. Bye everyone. From Mike. __________________ G7TRF

24th Mar 2007, 2:01 pm	#2
brightsparkF5VL Retired Dormant Member Join Date: Mar 2007 Location: Basle France Posts: 1	Re: Modern 405 Transmissions In one of my valve radio searches, I came across an old TV web site(cannot remember where but it should be easy to find) This group have a converter that changes modern broadcasts into 405 line tv. I think it is freely available to enthusiasts. Good luck

24th Mar 2007, 5:35 pm	#3
Paul Stenning Administrator Join Date: Dec 2002 Location: Cardiff Posts: 9,073	Re: Modern 405 Transmissions There is a whole section discussing standards converters etc right on this forum, immediately below this section...... https://www.vintage-radio.net/forum/...splay.php?f=95 __________________ Paul Stenning Forum Admin/Owner and BVWS Webmaster

24th Mar 2007, 7:52 pm	#4
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: Modern 405 Transmissions Returning to the subject of amateur transmissions - if there is anything being transmitted, I would be interested in having a listen, having recently acquired an AR88LF communications receiver. I assume that any video reception would require way too much bandwidth, but might be an interesting experiment whether there would be anything left that could be displayed using a modulator and receiver - once I get my modulator working properly. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

24th Mar 2007, 7:55 pm	#5
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: Modern 405 Transmissions Nothing of any use would be left. Optimistically, a sound receiver might have a maximum bandwidth of 20kHz. To get even vaguely recognisable 405 line pictures you would need more than 10 times this.

24th Mar 2007, 8:23 pm	#6
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: Modern 405 Transmissions Thanks for confirming that. I thought as much, but thought I would try out a little optimism for a change Nah! I think I'm happier with pessimism __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

24th Mar 2007, 10:02 pm	#7
Kat Manton Retired Dormant Member Join Date: Jul 2005 Location: West Yorkshire, UK. Posts: 1,700	Re: Modern 405 Transmissions Hi, Amateur television activity (of the "wideband" flavour - 405/525/625-line) was confined to the 70cm band and upwards. If I'm up-to-date, the 70cm band has been eroded somewhat and there's no room for it any more; so it'd be on the 23cm band and up now. Both are a bit beyond an AR88. There's some slow-scan activity on the HF bands, but that's OT for this thread (though a search for "SSTV Software" may prove fruitful...) Regards, Kat

24th Mar 2007, 10:39 pm	#8
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: Modern 405 Transmissions Woops! I realise now that I misread the wavelengths quoted in the original post __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)