SatSig topic:

X1: replacing a std Ku BUC w/ an extended one...

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Feb 4^th, 2017 at 9:30pm

I must be missing the obvious, but after hours of online search I'm still not clear on how this works.... Never had to deal with that issue before.

As w/ non inverting BUCs the Tx IF will have to be changed with the different BUC LO, how is the whole system, from the NOC to the remote, going to adapt?

Christian

Feb 5^th, 2017 at 9:28pm

Regarding your new "Extended Ku band BUC", use the manufacturer and model number to find the local oscillator frequency and compare with what you have now.

If the new BUC local oscillator frequency is, for example, 250 MHz lower then you need to adjust the transmit IF frequency up 250 MHz.

Note iDirect X1 "TxIF: Type-F, 950 - 1700 MHz"

Talk to the hub and explain what you want to do. Can they change the BUC LO frequency for just one remote site ?

Feb 9^th, 2017 at 9:44am

Quote:

Regarding your new "Extended Ku band BUC", use the manufacturer and model number to find the local oscillator frequency and compare with what you have now.

If the new BUC local oscillator frequency is, for example, 250 MHz lower then you need to adjust the transmit IF frequency up 250 MHz.

Note iDirect X1 "TxIF: Type-F, 950 - 1700 MHz"

Talk to the hub and explain what you want to do. Can they change the BUC LO frequency for just one remote site ?

Yes I happen to have a spare BUC that is the extended variety and would like to know if it is useable, if ever needed:

There sure is not much on all this online! On the simple web access into the X1 there is a short page for "Manual Downstream Config"... but nothing to be found for all the rest including the BUC LO!!! No idea either if I wanted to change a downstream parameter there, would that manual edit be permed and overwrite the config "options" file in use...

Because I just discovered there is such a thing (options file) that I can download and also upload. Fortunately I do have a brand new spare X1, so I'll do some experimentation to see if it is just a plain text file, and if I can make it work just changing the BUC LO, which by the way they seem to call "up_translation". As far as I can tell it is entirely done in the "options" file.

Could there still be an issue that an edited options file would be rejected by the network?

Being in the middle of nowhere I love to have working spare parts sitting on the shelf!

Feb 9^th, 2017 at 11:01am

It is the people at the hub you need to talk to.

For initial installation, the options file has things like:
[FREQ_TRANS]
down_translation = 11300.000000
up_translation = 13050.000000

Once in service it is the hub that tells your modem what frequency to transmit.

If you have an in-service operating system and want to change the BUC for a different type ask the hub what you should do. Starting again with new options file sounds a possibility - in which case get the new options file from the hub rather than amending it yourself - your old version may be out of date in several other respects.