Location: Hull, East Yorkshire
It has been fitted with an ID-Elecktronik duplexer that replaced a low power 1.4GHz unit that was retuned to 23cms. It was prone to flashover at the 15w level and as 10w was needed to achieve the NoV limit it was too close. The 0.5mm wall Teflon tube used to tune the duplexer down to 1275MHz and the same 0.5mm gap in the resonators just wasn't enough. There was also an issue with the lack of a notch at the Rx frequency in the transmitter leg. (However, it will make a good look-through filter!)
The original set top box receivers that were going to give 1 or 2MS/s reception proved to be incapable of changing modes on weak signals. A locked condition was shown on the front panel but there often was no video output unless they were rebooted. They have been replaced by the BATC Ryde receiver in a headless format and set up to give a composite output for the logic and DTX1 modulator.
The receiver is on 1275MHz and will work with DVB-S / DVB-S2, 333 / 500 /1000 kS/s, H262 / H264. FEC selection is automatic. Experimentally, the Tx has been reduced to 1000kS/s, with DVB-S, H262 and FEC 3/4.
The Ryde receiver has been funded by the BATC Bursary which supports repeater groups with upgrades to modern hardware and funds development of new projects for the ATV community such as the Ryde receiver software. The East Yorkshire Repeater Group thanks the BATC for their generous help.
Unfortunately it's a long way down from a decode but there is hope with a little tropo.
Have a look at this sdr plot from a distance while squinting and you will see the 'chunk' of signal ~1MHz wide at 1308.
This is received with the 3m dish and Circular polarity feed with 0.25dB NF LNA.
If you look at this in respect to path loss:
I will be some 10dB above this if I run 100W on Tx
Another 4-5dB if i run 333Ks instead of 1000ks
And some more if I run 1/4 FEC
so maybe 10-15dB over noise going back to the repeater...
I'll try some transmissions and see what happens but I'm sure something will not add up...hi
- GB3EY Trace SDR.png (477.55 KiB) Viewed 991 times
- GB3EY Path.JPG (147.88 KiB) Viewed 991 times
I've run a similar exercise with the online version of RadioMobile and it does suggest that there might be a just detectable signal there. G7AVU gets a similar thumbs down from RadioMobile yet he can see it so it doesn't always follow, but 27dB is a lot to make up! See below.
We're off to a good start; today G8VDP got in @ 68km and its also been seen by G5TV at Kexborough and G4TMZ in Barnsley using a satellite box. G0AZQ, M1ASR and myself have been on too.
Thanks for the report
I didn't know there was a web version of radio mobile.. nice.
EY is about 0.5dB/noise this morning, stronger... but more qsb!
I'll keep a keen eye on this with the high pressure coming.
- GB3EY Trace SDR 241120.jpg (203.08 KiB) Viewed 942 times
You were lucky to catch EY when you did. It's on an IP controlled power switch that is normally set to switch on at 11am and off at midnight to save electricity. Last night I fiddled with the power switch settings and that caused it to be on earlier than as set.
Like most repeater groups our income has dried up because of the pandemic. It shut down our local rally where we would have had a stall to collect subs and sell off surplus kit. Consequently we are having to be very careful.
Last night it came up to 2dB/Noise and i had SR lock but still a few dB short of a decode.
Based on about 4 days monitoring i can say the weakest signals are around 1pm, it then comes back again after 9pm and presumably overnight, Normally quite weak again by 11am.. Quite interesting, always detectable on the 3m dish, not a peep on the 44el Yagi.
The fog is appearing here so maybe interesting later.
Well done the EY team its certainly working well.
We can both see it on SDR's but not enough to lock although I have had SR lock but no decode.
Conditions are very flat and I'm sure with the slightest enhancement we will see it live.
Rob's should be around the 150kW level but it's still a tall order to get over a 1300' hill that's only 6.5 miles away.
I'm now going to plot the path from you to EY. Congratulations on being the best DX to date on GB3EY.