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Eshailsat



Cluster Activity

Spots per uW band today:
UK spotter or spotted only.

Solar data:
SFI
72
A-Index
12
K-Index
1
Exp.K
2
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0
Activity
qui
GMF
qui
Aurora?
no

My Weather

Date:14/12/17 Time:15:18
Temp:5C
Wind Speed:17.5mph
Wind Dir:202deg
Pressure:979.66mB
Humidity:118%
Dew Point:8.6C
UKHASnet
Eshailsat Tx and Rx ideas

With the approaching launch (currently Q3 2017) of Eshailsat and the new transponder i have been thinking a little about how to get equipment ready for both Narrowband and Wideband use.


Rx:
80cm Dish and Octagon Dual LNB (PLL type).
One port Vertical for Narrow-band segment and the other Horizontal for the Wide-band segment.
External reference for the LNB at 25.6MHz, this allows the IF to be 1200MHz, ideal for DVB Rx.
Narrowband: Still need to convert for Rx unless using rtl-sdr or similar, Base Transceiver is going to be the Red-Pitaya running HPSDR software, IF at 50MHz probably.

Tx:
3M Dish, 30W Spectrian PA or more - see below
Narrow-band: Red-Pitaya with HPSDR software at 50MHz up-converted to 2400MHz.
Wideband: DATV-Express



Based on the specification for the wideband uplink (8MHz DVB-S2 requires 100W into 2.4m dish) here are some approximate numbers to get you started, the bandwidth and dish sizes are in 3dB steps.
Remember DVB-S2 is a couple of dB better than DVB-S!.
To generate the power required you will need an amplifier capable of about four times that below to get a reasonablly clean Tx spectrum.

Power vs Dish vs Bandwidth




More info to follow as things progress...










Last page added:16/08/17 15:45
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