C-Band LNB test using 2x VMA Simple Spectrum Analyser
Hi,
Inspired by John at www.satellites.co.uk [Click here to go to relevant thread], I tried out a setup to test if a C-Band LNB is working properly.
Being a bit lazy, I just used a Deviser S7200 field meter to power up the LNB (I could have used a regular receiver or even a plain power source for coax, which I do have - I just didn't felt like searching for it, unboxing it, etc.). Connected the LNB is a simple 1-IN, 2-OUT 2-way splitter.
One output connects to the Deviser S7200, the other, USING A DC BLOCKER, connects to the SMA device #1.
The SMA device #2 connects to a basic antenna, pointed to the C-Band LNB.
Starting two sessions of the VMA Simple Spectrum Analyser (side by site on my desktop, thanks to two 22" FullHD monitors), I obtained these results:
The spectrum is inverted (and thus shown mirrored) and the frequencies are displayed, accordingly. For this I set a negative LOF of -5150 MHz, used by my AMERICAN BIRD GCF-D11C LNB. The "-" sign indicates that the spectrum is to be inverted.
Notice that you can set the "Min. Bandwidth" for transponder recognition to values smaller than 1 MHz!
Hope this inspires new ideas!
Regards,
Vitor
Inspired by John at www.satellites.co.uk [Click here to go to relevant thread], I tried out a setup to test if a C-Band LNB is working properly.
Being a bit lazy, I just used a Deviser S7200 field meter to power up the LNB (I could have used a regular receiver or even a plain power source for coax, which I do have - I just didn't felt like searching for it, unboxing it, etc.). Connected the LNB is a simple 1-IN, 2-OUT 2-way splitter.
One output connects to the Deviser S7200, the other, USING A DC BLOCKER, connects to the SMA device #1.
The SMA device #2 connects to a basic antenna, pointed to the C-Band LNB.
Starting two sessions of the VMA Simple Spectrum Analyser (side by site on my desktop, thanks to two 22" FullHD monitors), I obtained these results:
The spectrum is inverted (and thus shown mirrored) and the frequencies are displayed, accordingly. For this I set a negative LOF of -5150 MHz, used by my AMERICAN BIRD GCF-D11C LNB. The "-" sign indicates that the spectrum is to be inverted.
Notice that you can set the "Min. Bandwidth" for transponder recognition to values smaller than 1 MHz!
Hope this inspires new ideas!
Regards,
Vitor
Also can be used to test either a Ku or Ka lnb using a suitable harmonic from the SMA. Very useful indeed, thaks Vitor.
ReplyDeleteJohn.
Satellites.co.uk
Hi John!
DeleteStay tuned as the next version will allow direct frequency input for harmonics signal generation.
Teaser: http://www.mediafire.com/file/tq2jcvew8xhdfp2/VMA%20Simple%20Spectrum%20Analyser%20-%202018-04-26.zip
Regards, Vitor
C-band reception in the Netherlands: I have a VMA and an offset 90cm , a chinese 15K c-band lnb (without dielectric plate) and Dreambox DM800
ReplyDeleteVia Ku-band I try to point out the dish for i.e. SES5 (Ku+C-band) however on C-band I haven't seen even a signal-rise for reception. Can you suggest which sat with c-band to receive (relative strong transponders for 52N, 5E)? And how can a dielectric plate made by you own? Roel
C-band requires correct skew (rotation of the LNB) and the distance to the focal point needs to be tuned. This means you have many parameters that need to be tuned: dish alignment and LNB alignment!
DeleteAlso, note that C-band requires a much bigger dish with 1.5m being normally the smallest recommend size. While it is possible to have reception with 0.9m dish, that is considered DXing and requires extra fine tuning and luck.
Regards,
Vitor