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50MHz activity

Posted: Thu Nov 08, 2018 7:52 pm
by g8gtz
At the request of the RSGB VHF manager to support the WRC19 push for 4MHz at 50MHz, G8GTZ and G8LES conducted some RBTV tests today and achieved what we believe is probably the first 2 way DATV QSO on 6mts - edit, well it wasn't see below!

Using transverters / upconverters we had the first 2 way QSO over 7.5Kms from IO91KD to IO91LC - MER was in excess of 20dB and G8LES transmitted H265 pictures over DVB-S2 16APSK giving some high quality images at 1.1 mbit/sec.

More tests to follow with hopefully greater distances!

73
Noel - G8GTZ

G8LES 50MHz.JPG
G8LES 50MHz.JPG (222.39 KiB) Viewed 1315 times

Re: 50MHz activity

Posted: Thu Nov 08, 2018 10:12 pm
by M0SKM
Ahem..

G4CPE and M0SKM did the two way at least two years back; encouraged at the time by Dave G8ADM. We later adapted the converters and in my case the PA for use at 71MHz.

Good to see a push for it again; I'll have to get the 6M beam out of the shed.

73 Steve

Re: 50MHz activity

Posted: Fri Nov 09, 2018 7:52 am
by g0mjw
TV started out around these frequencies back in the 1930s. I thought that Peter, G3PYB experimented with this back in the early days of Narrow Band DATV.

Here is a thread from 2104 viewtopic.php?t=3952

Mike

Re: 50MHz activity

Posted: Sat Nov 10, 2018 9:29 am
by g8gtz
Hi Steve,

I stand corrected!

I've modified the thread title and my post but would suggest that your QSO was only 4.5Kms and therefore this is a new DX record!

Whilst G8ADM and G8LES did some tests (I don't think Peter ever got on air on 50MHz), these were only ever one way - I've updated the records page on the wiki if you can add a date: https://wiki.batc.org.uk/UK_ATV_DX_Records#50MHz

73
Noel - G8GTZ

Re: 50MHz activity

Posted: Sat Nov 10, 2018 10:50 am
by M0SKM
Noel,

Wiki edited to show the date (10/12/2014) and correct symbol rate of 543Ks; we were using Link Research Encoder boards and that was the lowest rate.

Distance record acknowledged.....for now. :D

73 Steve