I am activ in DATV with german boards.
What sort of equipments are used in GB ?
Is it a specifi G way to do DATV ?
You can see a lot of infos about datv here:
http://www.von-info.ch/hb9afo/DATV/0_DATV_08.htm
But in french only. If it's enough interest, i can translate the most important topics.
It's a serie named "DATV? It's not so complicated!"
73
michel hb9afo
DATV
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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: DATV
To HB9AFO hello Michel,
DATV station in the uk are mostly on 23cm but we have about 5/6 stations on 70cm.
several repeaters have digital input or outputs, more repeater groups have plans for DATV options.
Equipment is quite mixed, early repeaters used ex broadcast encoders from NDS/Tandberg and some similar equipment is used by individual stations.The equipment is quite large and CODEC delays are typical of the broadcast multiplexed services.
SR German and AGAF encoders are in use, one or two low delay encoders from LINK are in use and perform well at low symbol rates on 70cm. Interest in 70cm is growing.
For reception almost all stations use digital L band satelite receivers which are very low cost, some care needs to be made in choice of rx for low symbol rates on 70cm, upconverors for 70cm and LNB to downconvert from 3cm.
You question re G way for DATV..........No special G way..... stations can be quite flexible, receivers only need the frequency and the symbol rate PIDs are found automatically on most receivers, some ex broadcast demoulators need more info FEC etc.
Because of other users we tend to be on 436Mhz with 2 MS/s FEC of 3/4, on 23cm 4MS/s is typical but most stations can be flexible with FEC and frequency.
Near cities interfernce is a problem on 70cm from telemetry and radar can be troublesome on 23cm at times. I assume we will use 1255Mhz for Euro simplx contacts.
Three stations are active on 70cm G8ADM David in London on a high site, G8LES Mike in central southern england also a good site , and myself on a south looking hill near Portsmouth IO90LU.
These stations all have 100W plus and with proven equipment.
144.750 has been used for talback but a lower channel and on SSB is better for the harmonic separation to 70cm. I used 144.17 the same as F stations and will continue to use this frequency. Interest is growing and I expect more stations this year, some repeater are planning or have a 70cm input.
A look at the repeater info on this system will provide more information.
I hope to work into F as my location should make this possible, and I can go portable on 70cm, my best Dx is 110km over a difficult path to G8ADM.
Regards Peter Blakeborough G3pyb
DATV station in the uk are mostly on 23cm but we have about 5/6 stations on 70cm.
several repeaters have digital input or outputs, more repeater groups have plans for DATV options.
Equipment is quite mixed, early repeaters used ex broadcast encoders from NDS/Tandberg and some similar equipment is used by individual stations.The equipment is quite large and CODEC delays are typical of the broadcast multiplexed services.
SR German and AGAF encoders are in use, one or two low delay encoders from LINK are in use and perform well at low symbol rates on 70cm. Interest in 70cm is growing.
For reception almost all stations use digital L band satelite receivers which are very low cost, some care needs to be made in choice of rx for low symbol rates on 70cm, upconverors for 70cm and LNB to downconvert from 3cm.
You question re G way for DATV..........No special G way..... stations can be quite flexible, receivers only need the frequency and the symbol rate PIDs are found automatically on most receivers, some ex broadcast demoulators need more info FEC etc.
Because of other users we tend to be on 436Mhz with 2 MS/s FEC of 3/4, on 23cm 4MS/s is typical but most stations can be flexible with FEC and frequency.
Near cities interfernce is a problem on 70cm from telemetry and radar can be troublesome on 23cm at times. I assume we will use 1255Mhz for Euro simplx contacts.
Three stations are active on 70cm G8ADM David in London on a high site, G8LES Mike in central southern england also a good site , and myself on a south looking hill near Portsmouth IO90LU.
These stations all have 100W plus and with proven equipment.
144.750 has been used for talback but a lower channel and on SSB is better for the harmonic separation to 70cm. I used 144.17 the same as F stations and will continue to use this frequency. Interest is growing and I expect more stations this year, some repeater are planning or have a 70cm input.
A look at the repeater info on this system will provide more information.
I hope to work into F as my location should make this possible, and I can go portable on 70cm, my best Dx is 110km over a difficult path to G8ADM.
Regards Peter Blakeborough G3pyb